Evaluation of synthesized inorganic nanomaterials Plumeria alba against Aedes aegypti and in vivo toxicity

Abstract

Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were fabricated using Plumeria alba leaf extracts to control the mosquito Aedes aegypti. Synthesized AgNPs and AuNPs were characterized by ultraviolet-visible spectroscopy, Fourier-Transform Infrared Radiation (FTIR) spectroscopy, X-ray diffraction (XRD), and transmission electron microscope (TEM) analysis. Susceptibility levels of Ae. aegypti mosquito larvae to the plant extract P. alba and its silver nanoparticles (AgNPs) and gold nanoparticles were determined. The AgNPs and AuNPs spectra displayed their maximum absorption at 300 nm and 500 nm, respectively. The larval mortality of AgNPs and AuNPs were highly effective LC₅₀ were 69.9592 ppm and 88.2635 ppm compared to the aqueous leaf extract of P. alba LC₅₀ was 178.4713 ppm. Furthermore, no significant effects of nanoparticle preparations of P. alba extract 10,000 ppm dose up to one week revealed neither toxic signs nor death within seven days of administration. However, there were no apparent signs of delayed toxicity when the rats were observed for an additional seven days. Current studies revealed that the P. alba leaf extract, AgNPs and AuNPs are biologically safe on animals and eco-friendly for control of Aedes aegypti mosquito.

Keywords

Nanomaterials larvicidal Subacute toxicity

1 Introduction

Aedes aegypti is one identified mosquito species implicated in disease transmission besides Anopheles stephensi and Culex quinquefasciatus [1]. The identification of the role of Ae. aegypti in the transmission cycle of human pathogens since 1906 and reported that Thomas Bancroft demonstrated the ability of Ae. aegypti in transmission dengue viruses [2]. Moreover, the Ae. aegypti is the primary transmitter vector of the other three viruses causing debilitating diseases on humans, including yellow fever, chikungunya, and Zika fever [2]. Scientists proposed the concept of vector control and control of pathogen transmission [2]. Disruption of the life cycle of the vectors is one of the most efficient strategies to control vector-borne diseases.

Ae. aegypti control is being enhanced in many areas, but significant challenges limit the control efficiency. Decreasing the effectiveness of insecticides due to insects resistance and insecticides harmful to the environment is the most challenging. Synthetic and chemical insecticides have been widely used for decades in control Ae. aegypti can cause harm to non-target organisms, the environment, and human health [3]. Therefore, chemical insecticides have increasingly constrained their usage. Plant-based insecticides are a promising alternative for chemical agents for controlling insects as environmental-friendly. The plants and their phytochemicals are mostly considered safe and have been used in wide distribution of vector illnesses such as malaria [4].

Plants contain an untapped reservoir of phytochemicals that can be used directly or as templates for synthetic insecticides. Many studies reported that several plants showed larvicidal effects against Ae. aegypti [5, 6]. On the other hand, the marine algae extracts, seaweed extracts and essential oils obtained from various plants have demonstrated promising larvicidal activities against several vectors [7, 53–55]. Nanotechnology, an emerging research field, offers innovative methods to form active constituents amid nanoscale dimensions. Nanotechnology is fundamentally concerned with synthesizing nanoparticles of changing shapes, sizes, chemical compositions, and controlled disparity and their possible utilization for the benefit of humans. Nanoparticle-based plant insecticides tend to show numerous advantages in comparison to chemical insecticides. Increases its ability to stabilize the formulation, water solubility, and insecticidal activity [8]. The plant-mediated biosynthesis (i.e., green synthesis) of metal nanoparticles is advantageous over chemical and physical methods since it is cheap, single-step, and does not require high pressure, energy, temperature, the use of highly toxic chemicals. In latest years, biological routes for the fabrication of nanoparticles have been suggested as possible eco-friendly alternatives to classic chemical and physical methods [9].

The plant biomass or plant extract could produce nanoparticles eco-friendly better than the chemical and physical methods. Various plants have been successfully used for the effective and fast extracellular composition of silver and gold nanoparticles. Extracts of the geranium leaf (Pelargonium graveolens) [10], Cinnamomum camphora [11], lemongrass (Cymbopogon flexuosus) [12], neem (Azadirachta indica) [13], tamarind (Tamarindus indica) [14] Aloe vera [15], and extract of Emblica officinalis fruit [16] had been shown the potential of reducing Au(III) ions to gold nanoparticles Au(0) and Ag(I) to silver nanoparticles Ag (0). proteins, carbohydrates, and polyphenols are present in plants and might be accountable for the synthesis of nanoparticles. The involvement of these constituents in nanoparticle composition needs experimental evidence to characterize nanoparticle properties.

Nanoparticles of inorganic and many combinations of inorganic with organic or plant materials form a mixture that possesses unique electrical, chemical, physical, and optical properties. They were synthesized inorganic nanoparticles using inorganic oxide materials with plant extracts or other organic compounds. These inorganic nanoparticles are various in size and more useful than large-size materials. The synthesized inorganic nanoparticles showed ease of modification and development, high stability, and apparent substance-loading capacity [17]. The morphological of nanoparticles and other properties be evaluated by using different analytical techniques, including ultraviolet-visible spectroscopy, Fourier-Transform Infrared Radiation (FTIR) spectroscopy, X-ray diffraction (XRD), and transmission electron microscope (TEM). Many research studies showed the ability of these analytical techniques to explain and interpret many morphological properties of nanoparticles [18].

Plumeria alba L. (family: Apocynaceae), commonly called white frangipani, is a tropical and subtropical plant with many traditional uses. This plant could grow up to seven m in height [19], branching with a milky latex inside the elongated green leaves (14 inches long and 1.5 inches wide) [20], barks, and stems [21]. Plumeria alba L. is a flowering plant with a fragrant perfume [22]. The color of the white flower. It showed several pharmacological activities included anticancer [23], antimicrobial against gram-positive and gram-negative bacteria [24], antioxidant [25], antimalarial [26], anti-repellant [27], antiarthritis [28], antihyperlipidemic [29], hypoglycemic activities [30]. The leaves contain plumierin, resinic acid, fulvoplumierin, terpenoids mixture, sterol, and plumeride [31]. A few toxicity studies of Plumeria alba leaves were found in the current literature review. In one recent study, acute toxicity evaluation single oral ethanolic extract 80% of P. alba root (5 g/kg) body weight of female and male Sprague Dawley rats showed no signs of toxicity, behavioral changes, or mortality within 14 days. According to the OECD guidelines, the LD₅₀ was estimated more than 5 g/kg in rats and considered non-toxic or, worst slightly toxic [32]. Moreover, in sub-acute toxicity (28 days treatment), the oral ethanolic extract showed no induction of signs of toxicity and mortality in rats. The other toxicity study of dichloromethane extract of P. alba leaves using brine shrimp lethality test. The fraction of hexane-ethyl acetate extraction of dichloromethane extract showed 54.5 as LC₅₀ in the brine shrimp lethality test [33]. The leaves of P. alba reported that contain plumierin, resinic acid, fulvoplumierin, terpenoid mixture, sterol, and plumeride [31].

To the best of the authors knowledge, no study has been carried out to investigate the larvicidal of P. alba leaves extract and their green-nanomaterials silver NPs (AgNPs) and gold NPs (AuNPs) against Ae. aegypti vector. Therefore, in the present study, the green-synthesized AgNPs and AuNPs using P. alba leaves extract. The AgNPs and AuNPs were characterized by UV–VIS spectroscopy, Fourier-Transform Infrared Radiation (FTIR) spectroscopy, X-ray diffraction (XRD), and transmission electron microscope (TEM). P. alba leaves extract and the green-synthesized AgNPs and AuNPs were evaluated for their larvicidal potential against Ae. aegypti (the dengue vector in Saudi Arabia). Subacute of toxicity of P. alba leaves extract and the green-biosynthesized AgNPs and AuNPs was invisistigated on female rats.

2 Materials and methods

2.1 Preparation of leaf extract

Leaves of the P. alba plant were collected from Jeddah governorate, Saudi Arabia. After identification by a Botanic, the leaves were cleaned with tap water, shade drying, and ground in an electric grinder. Briefly, 50 g of leaf powder was macerated in 250 mL of ethanol (70%). The mixture was filtered after 3 h through Whatman filter paper (no. 1) and then stored in a dark container at 4°C until the time of need [34].

2.2 Synthesis and characterization of NPs

The silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were prepared according to [34]. Silver nitrate (AgNO₃) and gold chloride (AuCl₄) (Sigma Aldrich, UK), and a 1 mM solution were prepared in a 250 ml Erlenmeyer flask in darkness from each. 10 ml of P. alba extract was added to each solution with 90 ml of the 1 mM silver nitrate or gold chloride solution. Two to three drops of 1% NaOH were added to adjust the pH to 8. This mixture from each was kept at 40°C for 1 h under clear sky conditions for irradiation. AgNPs and AuNPs’ formation was indicated by a solution color change [34].

The characterization of synthesized AgNPs and AuNPs was confirmed using UV–VIS spectrometer and Fourier-transform infrared (FTIR) spectroscopy. The mixture was scanned with a UV-3600 UV–VIS spectrometer (Shimadzu, Kyoto, Japan) at a wavelength range of 300–700 nm at the 1 nm resolution to confirm NP formation. NPs were concentrated by centrifugation at 1,500 rpm for 20 min, and then cleansed with distilled water and filtrated through 0.45-μm pore-sized filters. The Fourier-transform infrared (FTIR) spectroscopy was employed to identify functional groups in the extract and the prepared NPs via a Perkin-Elmer Spectrum 2000 (PerkinElmer, USA) within the range of 400–4,000 cm^–1, at a rate of 16 times, and a with clarity of 4 cm^–1.

The shape of the formed nanoparticles of AgNPs and AuNPs were characterized using X-ray diffraction (XRD) microscope (Bruker D8 Discover diffractometer, USA) and transmission electron microscope (TEM) examination was executed using a JEOL GEM-1010 transmission electron microscope (JEOL, Ltd., Akishima, Tokyo, Japan)

X-ray diffraction analysis of silver nanoparticle crystalline growth was performed using a Bruker D8 Discover diffractometer equipped with a Cu microfocus X-ray source (0.15406 nm) and a 2-dimensional Vantec 500 detector. A powder sample of the biosynthesized silver nanoparticles was used. The measurements were taken with a step scan of 0.02 in a 2-theta range of 3° to 70°.

The TEM examination was executed using a JEOL GEM-1010 transmission electron microscope (JEOL, Ltd., Akishima, Tokyo, Japan) with a 70 kV accelerating voltage to determine the size and shape of Pd-NPs. A particle-containing liquid was dropped onto a copper grid and kept at room temperature by allowing water to evaporate.

2.3 Collection, rearing of Ae. aegypti and larvicidal activity

Larvae and pupae of Ae. aegypti were collected from different sites within Jeddah governorate, Saudi Arabia. Larvae were maintained in trays under laboratory conditions of 70% ±5% relative humidity, 27°C±1°C, with a light: dark cycle of 14:10 h. The larval diet was composed of dried bread or fish food combined with milk powder at a 1:1 ratio. Separated water containers in screened cages (60×30×45 cm) were used to collect developed pupae to allow adult emergence. Adults were transferred into separated jars with cotton lids supplied continuously with sucrose (5%) and a few drops of zincovit vitamin solution. Adult females were not provided with sucrose for 12 h on the fourth day after emergence in preparation for blood-feeding on a shaved pigeon previously held in a resting cage overnight. To collect eggs, moistened filter papers were placed at the corners of the cage [34]. Produced larvae were reared using the same protocol to repeat the life cycle and maintain a stock culture.

The Larval susceptibility test was conducted according to the method of [56]. Treatments were carried out by exposing early 4^th instar larvae of Ae. pipiens to various concentrations of the tested extracts in groups of glass beakers containing 100 ml of tap water with minor modifications, as previously reported by [34]. Different concentrations of P. alba extracts, AgNPs, and AuNPs, were prepared in plastic containers containing 100 mL of water. In total, 20 larvae at the fourth instar were exposed to the prepared solutions for 24 h at 27°C±2°C with a 16:8 h light: dark cycle and relative humidity of 80% –90%. During this period, larvae received their regular food. Five replicates of the assay were performed. The live larvae and the mortality were calculated at 24 h post-treatment. The mortality correction was carried out using the Abbott’s formula [35] (Table 1).

Table 1
Lavicidal activity of the P. alba leaf extract and and green synthesized silver and gold nanoparticles against the Ae. aegypti larve 24 h post-treatment

Biolarvicide Conc. Mortality^a LC₅₀ (ppm) LC₉₀ (ppm) χ ² Slope RR

(ppm) (%) (LCL– UCL) (LCL– UCL) d.f (n.s) = 4^b

P. alba 100 18.6 178.4713

150 34.0 (166.3497– 190.7469) 363.656

200 54.6 (322.7048 – 429.2352) 5.4984 4.1459

250 69.1

300 88.7

0 4 2.551

P. alba - AgNPs 30 11.3

60 35.1 69.9592 160.7447 2.0606 3.5473

(63.9542– 75.983) (142.0869– 188.6796)

90 68.0

120 80.4

160 89.7

0 4 2.022

P. alba - AuNPs 30 8.333

60 25

90 56.25 88.2635 228.2207 2.5524 3.1064

(80.5638– 96.784) (192.7081– 288.3328)

120 65.625

160 78.125

0 3

^aFive replicates, 20 larvae each. ^bChi square, degree of freedom. AgNPs = P. alba-silver nanoparticle; AuNPs = P. alba-gold nanoparticle; LC₅₀ = lethal concentration that kills 50 % of the exposed organisms; LC₉₀ = lethal concentration that kills 90 % of the exposed organisms; χ² = chi-square value; d.f. = degrees of freedom; UCL = 95% upper confidence limit; LCL = 95% lower confidence limit; RR = resistance ratio.

2.4 Animals (female rats) and subacute toxicity

Twenty-four female albino rats with body weights of 255.4±26.2 were purchased from the Laboratory Animal Centre of the Qassim University. The rats were housed in polypropylene cages (3 rats/cage) in a ventilated room with a steady light (12 hr): dark (12 hr) cycle and temperature (25±2°C). Food and water were provided ad libitum. The research ethics committee of Qassim University accepted the animal management protocol and the experimental design (Approval number 20-02-03).

After one week of acclimatization, rats were randomly divided into four groups: 6 animals in each group were used for a one-week subacute toxicity study. The rat in group 1 (controls) was administered 1 ml/kg of distilled water by intraperitoneal injection.

The animals in the second, third, and fourth groups were administered P. alba extract, its silver nanoparticle AgNPs, and gold nanoparticle AuNPs, respectively, using intraperitoneal injection at doses of 10.000 ppm extract/kg body weight. Each group of animals was treated daily for seven consecutive days and observed for 14 days. After 14 days of the experiment, the rats were sacrificed, liver, kidneys, and spleen were rapidly excised to calculate relative organ weight [36].

2.5 Statistical analysis

In larvicidal data, descriptive statistics of the data were produced in SAS. ANOVA and Post Hoc Dunnett test were used. The Least Significance Difference test were applied, with P values of 0.05 considered significant. Log concentration-probability regression lines were drawn for the tested compounds and statistical parameters were also calculated using the method of [36].

3 Results and discussion

3.1 Characterization of P. alba-AgNPs and P. alba -AuNPs

3.1.1 Change color

The formation of silver and gold nanoparticles using leaf ethanol extract of P. alba were primarily conformed by the change in color (Fig. 1), and the color could easily be monitored by visual observation of the mixture. The color change is attributed to the surface plasmon resonance caused excitation of electrons with the silver and gold nanoparticles [34 , 37–39].

Fig. 1

(a) Gold nanoparticals (AuNPs), (b) Plumeria alba leaf extract. and (c) silver nanoparticals (AgNPs).

The solutions of nanoparticles formed when studied using UV-VIS spectroscopy showed different absorption bands. For example, the solution of silver nanoparticles formed with the P. alba extract showed an absorption peak at 350 nm, while the solution of gold nanoparticles with the P. alba extract showed an absorption band at 450 nm (Fig. 2). These results were taken after taking into account the reaction time and the concentration of plant extracts.

Fig. 2

UV-VIS spectra of silver and gold nanoparticles synthesized using leaf extract of P. alba. Where (black line) refers to ethanol plant extract without AgNO₃ or AuCl3, (red line) refers to ethanol plant extract-reduced gold nanoparticles (P. alba-AuNPs), and (blue line) refers to ethanol plant extract-reduced silver nanoparticles (P. alba-AgNPs).

The botanical P. alba extract was studied with both AgNPs and AuNPs by UV-VIS Spectrometer to confirm the complete formation of gold and silver ions to gold nanoparticles and silver nanoparticles in the aqueous plant extract. The UV visible spectra were recorded from wavelengths of 250–500 nm. The UV-VIS spectrum showed a clear shift in the absorption curve in the region above 300 nanometers, indicating the formation of gold and silver nanoparticles. Figure (2).

Identification of nanoparticles was made using UV–VIS spectroscopy, which is a suitable method for characterizing the structure of AgNPs [40]. The absorption spectra of AgNPs and AuNPs presented a maximum absorbance peak at 300 nm (Fig. 2). This indicates that the P. alba extract compounds were bound to silver and gold ions [34]. The peaks detected correspond to the functional groups present in different chemical compounds. They are known as potential reducing agents and stabilize the metal ions in the AuNPs and AgNPs synthesis [41].

3.2 Fourier transform infrared spectroscopy (FTIR)

Infrared spectroscopy (FTIR) was used to determine the molecules of P. alba particles or associated with gold and silver nanoparticles. Functional groups in chemical compounds show different patterns of bands under the influence of infrared spectroscopy. The infrared spectrum showed a change in the absorption beam sites in several different regions, and a slight shift occurred in other places, indicating the formation of nanoparticles of gold and silver. The FTIR spectra in Fig. 3 showed that the broad absorption bands in 3500–3000 cm^-1 in the P. alba extract have shifted to 3450–3000 cm^-1 in a composite of AgNPs and AuNPs, and this indicates the formation of nanoparticles for both elements. Likewise, the nanoparticles also showed slight displacement with a change in the shape of the bands in the region 1000 cm^-1 compared with that of the plant extract.

Fig. 3

Fourier transform infrared (FTIR) spectra of silver and gold nanoparticles synthesized using P. alba leaf extract. Where (black line) refers to ethanol plant extract without AgNO3 or AuCl3, (red line) refers to ethanol plant extract-reduced silver nanoparticles (AgNPs), and (blue line) refers to ethanol plant extract-reduced gold nanoparticles (AuNPs) AgNps = silver nanoparticle and AuNps = gold nanoparticles.

The FT-IR spectra of AgNPs and AuNPs prepared by the leaf extract of P. alba (Fig. 3) showed a vibrational band at 3500–3000 cm^–1 that was assigned to O-H arising due to alcohols and phenols) and corresponds to N-H, indicating the presence of primary and secondary amines.

3.3 Morphological characterization of silver and gold nanoparticles using XRD and TEM

3.3.1 Morphological characterization using XRD

Reduced Ag atoms attempted to cluster together, and tiny particles attempted to combine into big particles to reduce total surface energy, resulting in the formation of larger Ag particles [42, 43]. The long organic chains inhibited the aggregation of nanoscale Ag particles, preventing the Ag particles from growing further. This results in the formation of crystalline and amorphous Ag-nanoparticles. XRD analysis of dried Ag-NPs was performed to evaluate particle size and describe the crystalline structure of the produced Ag-NPs. The X-ray diffraction patterns of dried Ag nanoparticles synthesized using Plumeria alba extract are shown in Fig. 4.

Fig. 4

XRD patterns of the biosynthesized nanometal using P. alba leaf extract; (a) silver nanoparticles (AgNps); (b) nanoparticles of gold (AuNps).

According to the XRD results of Ag/ P. alba extract and Au/ P. alba extract, silver and gold nanoparticles have a face-centered cubic (fcc) structure. The peak positions 38.05°, 44.41°, 64.45°, and 77.22° for silver and 39.01°, 43.41°, 62.45°, and 76.30° for gold (as shown in Fig. 3) corresponded to the fcc lattice planes (111), (200), and (220) of Ag-NPs, and (111), (200), (220) and (311) of Au-NPs respectively (standard JCPDS Silver File No. 04–0783) [44]. As well, the X-ray diffraction (Fig. 3) displays the Braggs reflections at 2θ= 27.67°, 32.07 °, 46.09 °, 54.71 °, and 57.41 °, which can be indexed to the (121), (202), (132), (224), and (402) planes of AgO respectively. These peaks were compared to the standard AgO (standard JCPDS Silver Oxide File No: 84-1108). The comparison approves the presence of AgO phases in the present specimen and is found to have a tetragonal structure [45]. It is noted that the organic components of the plant extract caused a broadening of the diffraction peaks.

The silver and gold nanoparticles made with the plant extract were crystalline, as evidenced by the XRD pattern. The Debye–Scherrer method [46] was used to calculate the average nanocrystalline size, D =λk/βcosΘ, where D is the crystal size, k equals unity, λ is the X-ray source wavelength (0.1541 nm), β is the full width at half maximum (FWHM), and Θ is the diffraction angle corresponding to the lattice plane. The average crystallite size at maximum diffraction peak of phase for both Ag-NPs and AgO-NPs is 8.86 nm and 11.76 nm, respectively, according to the Debye–Scherrer equation. This value agrees with TEM measurements. The average crystallite size at maximum diffraction peak of phase for Au-NPs is 23.10 nm, according to the Debye–Scherrer equation. This value agrees with TEM measurements also.

3.4 Morphological characterization using TEM

Modern nanotechnology represents one of the most amazing sciences with the shapes and views of nanoparticles formed. Silver and gold nanoparticles with their distinctive spherical shapes are among the nanotechnology that has attracted many researchers. The aqueous solution of silver or gold precursors at room temperature produces both silver and gold nanoparticles as spherical shapes. A typical TEM image of silver and gold nanoparticles biosynthesized from P. alba extract is shown in Figs. 5a 4b. The silver nanoparticles in the TEM image have a spherical shape and come in a variety of sizes. The average particle size was calculated to be 9.48 nm, which corresponded to the XRD results. The gold nanoparticles in the TEM image also have spherical nanoparticles shape. The remarkable similarity in the shape of gold and silver nanoparticles may be attributed to the ability of biomolecules in plant extracts potential of reductive. Another hand, this study with TEM analysis revealed the possibility of using this plant to stimulate the formation of nanoparticles of gold and silver was catalyzed by metabolites present in the cells plant.

Fig. 5

A TEM image showing the morphological characteristics of silver and gold nanoparticles biosynthesized using the P. alba leaf extract. (a) biosynthesized silver nanoparticles; (b) biosynthesized gold nanoparticles.

3.5 Larvicidal activity of P. alba extract and synthesized NPs

The larvicidal effect of P. alba leaf extract and biosynthesized AgNPs and AuNPs was assessed against the fourth instar larvae Ae aegypti (Table 1 and Figs. 6). Various concentrations of P. alba extract (100–300 ppm), the mortality was calculated at 24 h post-treatment (18.6% –88.7%). The mortality rates were 11.3% –89.7% for AgNPs at 30–160 ppm and 8.3% –78.125% for AuNPs at the same concentration. The LC₅₀ values of AuNPs and AgNPs were significantly lower than that of P. alba extract alone (Fig. 5). The low LC₅₀ and LC₉₀ of AuNPs and AgNPs with high mortality of the fourth instar confirmed the effectiveness of synthesized nanoparticle technique in biological control.

Fig. 6

A relationship between green synthesized silver and gold nanoparticles concentrations using P. alba leaf ethanol extract and the 4^th instar Ae. aegypti larval mortality percentage. Where (line 1) refers to ethanol plant extract-reduced silver nanoparticles (AgNPs), (line 2) refers to ethanol plant extract-reduced gold nanoparticles (AuNPs), and (line 3) refers to ethanol plant extract without AgNO₃ or AuCl₃.

The results of our study showed that synthesized AgNPs and AuNPs of P. alba have significant larvicidal activity against, Ae. aegypti mosquitoes. This result is also comparable to earlier reports of [47] that synthesized AgNPs from P. alba (Apocynaceae) against the first to the fourth instar larvae and pupae of the malaria vector, An. stephensi (Diptera: Culicidae). Another study has tested the larvicidal activity of silver and gold nanoparticles synthesized by using aqueous extracts of bark of C. zeylanicum (C. zyelanicum or C. verumJ. Presl). These nanoparticles were tested as larvicide against An. stephensi and Cx. Quinquefasciatus Soni, [48]. The effectiveness of fungus-mediated silver and gold nanoparticles has been confirmed against the larvae of An. stephensi, Cx., quinquefasciatus and Ae. aegypti. Also, the larvicidal and pupicidal activities of silver and gold nanoparticles synthesized by fungi have been examined against An. stephensi, Cx. quinquefasciatus, and Ae. aegypti [50]. Recently, silver nanoparticles have been synthesized by using the leaf and stem of Piper nigrum for their antibacterial activity against agriculture plant pathogens [51].

3.6 Subacute toxicity

IP administration different nanoparticle preparations of P. alba extract 10,000 ppm dose up to one week revealed neither toxic signs nor death within seven days of administration. However, there were no apparent signs of delayed toxicity when the rats were observed for an additional seven days. Food consumption showed no significant differences for each treated group when compared to the control group (Fig. 7a). However, the relative weight of the right kidney and spleen in all treated animal groups showed no significant difference compared with the control (Fig. 7b,c). However, the relative weight of the liver in both the P. alba extract-treated group and AgNPs treated group (Fig. 7d) and left kidney of AuNPs (Fig. 6b) showed a significant decrease (P < 0.05).

Fig. 7

The toxic effects of IP treatment of P. alba extract and its nanoparticles; (a) Food consumption of rats; (b) the relative weight of rat’s kidneys; (c) the relative weight of rat’s spleen; (d) the relative weight of rat’s liver. Data represent the mean ± SEM. Dunnett test was used, and the significant difference at P < 0.05. *=P < 0.05.

Generally, the P. alba extract leaves and silver and gold nanoparticles (10,000 ppm/kg) showed no significant acute toxicity for seven days of IP administration in adult female albino rats. However, no signs of acute toxicity or mortality for P. alba extract leaves and nanoparticles, but accumulative toxicity may cause liver and kidneys. From result showed a significant reduction in the relative weight of the liver in the treated group with the P. alba extract and its silver nanoparticle. So, they might have accumulative toxicity on the liver. However, the gold nanoparticle of P. alba showed a reduction in relative weights of the right kidney and left kidney but significant in the left kidney. So, the gold nanoparticle of P. alba may have accumulative toxicity on kidneys, but it needs to be confirmed by serum analysis for liver and kidney functions. The toxicity evaluation on P. alba extract leaves studies in the literature review are very limited, so very difficult to elaborate furthermore. One toxicity study on P. alba extract root in rats was found [33]. However, the in vivo toxicity study of nanoparticles did not find, but in vitro cytotoxicity study was reported and is generally triggered by the formation of free radicals such as ROS [52].

4 Conclusion

The records showed that leaf ethanol extract of Plumeria alba L. (family: Apocynaceae) could synthesize AgNPs and AuNPs as a cheap reducing and stabilizing agent. The synthesized AgNPs and AuNPs were confirmed by UV/VIS, FT-IR, XRD, and TEM analyses. This study highlighted that synthesized AgNPs and AuNPs using P. alba L. are easy to produce, are stable over time, and can be employed at low dosages to reduce populations of dengue vectors strongly. In subacute toxicity on female rats, no mortality but showed accumulative toxicity might cause liver and kidneys damage P. alba L. leaves ethanol extract and its preparation in the form of nanoparticles as a promising compound in mosquito control programs to avoid the regular environment unfriendly methods for preparing AgNPs and AuNPs. This study is the first on the promising larvicidal potential of AuNPs and AgNPs synthesized from P. alba L. Generally, carrying out such studies using non-conventional methods (plant extracts and its silver nanoparticles and gold nanoparticles) as alternatives to chemical ones for controlling dengue vectors will undoubtedly be very helpful in mosquito control programmes and rationalization of the application of chemical insecticides that have a negative side effects on humans and the environment at large.

Conflict of interest

The authors state that there are no conflicts of interest of any kind.

Footnotes

Acknowledgments

The authors gratefully acknowledge Qassim university, represented by the Deanship of Scientific Research, on the financial support for this research under the number (10196-cos-2020-1-3-I) during the academic year 1442AH/2020AD.

References

Goodwin

, et al., Mosquito species identification using convolutional neural networks with a multitiered ensemble model for novel species detection, Scientific Reports 11(1) (2021), 13656.

Souza-Neto

J.A.

, Powell

J.R.

and Bonizzoni

, Aedes aegypti vector competence studies: A review, Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 67 (2019), pp. 191–209209, Jan. 2019.

Rani

, et al., An extensive review on the consequences of chemical pesticides on human health and environment, Journal of Cleaner Production 283 (2021), 124657.

Ali

, Chorsiya

, Anjum

, Khasimbi

and Ali

, A systematic review on phytochemicals for the treatment of dengue, Phytotherapy Research 35(4) (2021), pp. 1782–1816, Apr. 2021.

Hari

and Mathew

, Larvicidal activity of selected plant extracts and their combination against the mosquito vectors Culex quinquefasciatus and Aedes aegypti, Environmental Science and Pollution Research 25(9) (2018), 9176–9185.

Komalamisra

, Trongtokit

, Rongsriyam

and Apiwathnasorn

, Screening for larvicidal activity in some Thai plants against four mosquito vector species, Southeast Asian Journal of Tropical Medicine and Public Health 36(6) (2005), 1412.

Huang

H.-T.

, Lin

C.-C.

, Kuo

T.-C.

, Chen

S.-J.

and Huang

R.-N.

, Phytochemical composition and larvicidal activity of essential oils from herbal plants, Planta 250(1) (2019), pp. 59–68.

Ishaaya

, Nauen

and Horowitz

A.R.

, Insecticides design using advanced technologies. Springer, 2007.

Rajan

, Chandran

, Harper

S.L.

, Il Yun

and Kalaichelvan

P.T.

, Plant extract synthesized silver nanoparticles: An ongoing source of novel biocompatible materials, Industrial Crops and Products 70 (2015), 356–373.

10.

Shankar

S.S.

, Ahmad

, Pasricha

and Sastry

, Bioreduction of chloroaurate ions by geranium leaves and its endophytic fungus yields gold nanoparticles of different shapes, Journal of Materials Chemistry 13(7) (2003), 1822–1826.

11.

Huang

, et al., Biosynthesis of silver and gold nanoparticles by novel sundried Cinnamomum camphora leaf, Nanotechnology 18(10) (2007), 105104.

12.

Shankar

S.S.

, Rai

, Ahmad

and Sastry

, Controlling the optical properties of lemongrass extract synthesized gold nanotriangles and potential application in infrared-absorbing optical coatings, Chemistry of Materials 17(3) (2005), pp. 566–572.

13.

Shankar

S.S.

, Rai

, Ahmad

and Sastry

, Rapid synthesis of Au, Ag, and bimetallic Au core–Ag shell nanoparticles using Neem (Azadirachta indica) leaf broth, Journal of Colloid and Interface Science 275(2) (2004), 496–502.

14.

Ankamwar

, Chaudhary

and Sastry

, Gold nanotriangles biologically synthesized using tamarind leaf extract and potential application in vapor sensing, Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry 35(1) (2005), 19–26.

15.

Chandran

S.P.

, Chaudhary

, Pasricha

, Ahmad

and Sastry

, Synthesis of gold nanotriangles and silver nanoparticles using Aloevera plant extract, Biotechnology Progress 22(2) (2006), 577–583.

16.

Ankamwar

, Damle

, Ahmad

and Sastry

, Biosynthesis of gold and silver nanoparticles using Emblica officinalis fruit extract, their phase transfer and transmetallation in an organic solution, Journal of Nanoscience and Nanotechnology 5(10) (2005), 1665–1671.

17.

Kumar

and Yadav

S.K.

, Plant-mediated synthesis of silver and gold nanoparticles and their applications, Journal of Chemical Technology & Biotechnology: International Research in Process, Environmental & Clean Technology 84(2) (2009), 151–157.

18.

Durán

, Marcato

P.D.

, Alves

O.L.

, De Souza

G.I.H.

and Esposito

, Mechanistic aspects of biosynthesis of silver nanoparticles by several Fusarium oxysporum strains, Journal of Nanobiotechnology 3(1) (2005), 1–7.

19.

Sloan

S.A.

, Zimmerman

J.K.

and Sabat

A.M.

, Phenology of Plumeria alba and its herbivores in a tropical dry forest, Biotropica 39(2) (2007), 195–201.

20.

Sura

, Dwivedi

and Dubey

, Pharmacological, phytochemical, and traditional uses of Plumeria alba LINN. an Indian medicinal plant, Journal of Pharmaceutical and BioSciences/Jan-Mar 6(1), 2018.

21.

Murugan

and Inamdar

J.A.

, Organographic distribution, structure and ontogeny of laticifers in Plumeria alba Linn, Proceedings: Plant Sciences 97(1) (1987), 25–31.

22.

Wiart

, Medicinal plants of the Asia-Pacific: drugs for the future? World Scientific, 2006.

23.

Putra

K.C.

, et al., In Silico Study of Thioguanine Derivatives as Hemopexin Matrix Metalloproteinase9 (PEX-9) Inhibitors, Indonesian Journal of Pharmaceutical Science and Technology 1(2) (2019), 17–24.

24.

Syakira

M.H.

and Brenda

, Antibacterial capacity of Plumeria alba petals, World Academy of Science, Engineering and Technology 44 (2010), 68–69.

25.

Dawood

D.H.

and Hassan

R.A.

, Antioxidant activity evaluation of methanolic extract and crude polysaccharides from plumeria alba l. Leaves, Journal of Agricultural Chemistry and Biotechnology 6(11) (2015), 489–507.

26.

Boampong

, Donfack

and Hubert Jean

, in vivo antimalarial activity of stem bark extracts of Plumeria alba against Plasmodium berghei in imprinting control region mice, 2013.

27.

Nurcahyo

and Purgiyanti

, Pemanfaatan bunga kamboja (Plumeria alba) sebagai aromaterapi pengusir nyamuk, Parapemikir: Jurnal Ilmiah Farmasi 6(1) (2017), 121–123.

28.

Choudhary

, Kumar

, Gupta

and Singh

, Investigation of antiarthritic potential of Plumeria alba L. leaves in acute and chronic models of arthritis, BioMed Research International 2014, 2014.

29.

Rahman

, Reddy

V.B.

, Ghosh

, Mistry

S.K.

, Pant

and Sibi

, Antioxidant, cytotoxic and hypolipidemic activities of Plumeria alba L. and Plumeria rubra L, American Journal of Life Sciences 2(6) (2014), 11–15.

30.

Kadébé

Z.T.

, et al., Antidiabetic activity of Plumeria alba Linn (apocynaceae) root extract and fractions in streptozotocin-induced diabetic rats, Tropical Journal of Pharmaceutical Research 15(1) (2016), 87–94.

31.

Anggoro

, Istyastono

and Hariono

, Future molecular medicine from white frangipani (Plumeria alba L.): A review, Journal of Medicinal Plants Research 14(10) (2020), 544–554.

32.

OECD, Guidelines for the testing of chemicals test No 423: Acute oral toxicity-acute toxic class method, OECD guidelines for the testing of chemicals (section 4: health effects) 1 (2002), pp. 14.

33.

Hidajati

and Qodriyah

, Toxicity Test Toward Dichloromethane Fraction from White Frangipani Leaves (Plumeria alba), in Seminar Nasional Kimia-National Seminar on Chemistry (SNK 2018), 2018, pp. 61–62.

34.

Alhag

S.K.

, Al-Mekhlafi

F.A.

, Abutaha

, Abd Al Galil

F.M.

and Wadaan

M.A.

, Larvicidal potential of gold and silver nanoparticles synthesized using Acalypha fruticosa leaf extracts against Culex pipiens (Culicidae: Diptera), Journal of Asia-Pacific Entomology 24(1) (2021), 184–189.

35.

Abbott

W.S.

, and others,A method of computing the effectiveness of an insecticide, J econ Entomol 18(2) (1925), 265–267.

36.

Heywood

, Target organ toxicity, Toxicology Letters 8(6) (1981), 349–358.

37.

Ranganathan

, et al., Nanomedicine: towards development of patient-friendly drug-delivery systems for oncological applications, International Journal of Nanomedicine 7 (2012), 1043.

38.

Azmath

, Baker

, Rakshith

and Satish

, Mycosynthesis of silver nanoparticles bearing antibacterial activity, Saudi Pharmaceutical Journal 24(2) (2016), 140–146.

39.

Syed

, et al., Phyto-biologic bimetallic nanoparticles bearing antibacterial activity against human pathogens, Journal of King Saud University-Science 31(4), 798–803.

40.

Sun

Y.-P.

, Atorngitjawat

and Meziani

M.J.

, Preparation of silver nanoparticles via rapid expansion of water in carbon dioxide microemulsion into reductant solution, Langmuir 17(19) (2001), 5707–5710.

41.

Bhatnagar

, Kobori

, Ganesh

, Ogawa

and Aoyagi

, Biosynthesis of silver nanoparticles mediated by extracellular pigment from Talaromyces purpurogenus and their biomedical applications, Nanomaterials 9(7) (2019), 1042.

42.

Lukman

A.I.

, Gong

, Marjo

C.E.

, Roessner

and Harris

A.T.

, Facile synthesis, stabilization, and anti-bacterial performance of discrete Ag nanoparticles using Medicago sativa seed exudates, Journal of Colloid and Interface Science 353(2) (2011), 433–444.

43.

Xie

, Lee

J.Y.

, Wang

D.I.C.

and Ting

Y.P.

, Silver nanoplates: from biological to biomimetic synthesis, ACS nano 1(5) (2007), 429–439.

44.

Sowmyya

and Lakshmi

G.V.

, Soymida febrifuga aqueous root extract maneuvered silver nanoparticles as mercury nanosensor and potential microbicide, World Scientific News 114 (2018), 84–105.

45.

Varthini

, Carmel Vijila

G.M.

and Jothi

M.R.

, Effect of Medicinal Leaf Extract In Silver Nitrate-Size Reduction To Nanoscale, J Emerg Tech Innov Res 5(6) (2018), 664–666.

46.

Debye

and Scherrer

, Interferenzen an regellos orientierten Teilchen im Röntgenlicht. II., Nachrichten von der Gesellschaft der Wissenschaften zu Göttingen, Mathematisch-Physikalische Klasse 1916 (1916), 16–26.

47.

Roni

, Murugan

, Panneerselvam

, Subramaniam

and Hwang

J.-S.

, Evaluation of leaf aqueous extract and synthesized silver nanoparticles using Nerium oleander against Anopheles stephensi (Diptera: Culicidae), Parasitology Research 112(3) (2013), 981–990.

48.

Soni

and Prakash

, Green nanoparticles for mosquito control, The Scientific World Journal 2014, 2014.

49.

Soni

and Prakash

, Efficacy of fungus mediated silver and gold nanoparticles against Aedes aegypti larvae, Parasitology Research 110(1) (2012), 175–184.

50.

Soni

and Prakash

, Microbial synthesis of spherical nanosilver and nanogold for mosquito control, Annals of Microbiology 64(3) (2014), 1099–1111.

51.

Paulkumar

, et al., Piper nigrum leaf and stem assisted green synthesis of silver nanoparticles and evaluation of its antibacterial activity against agricultural plant pathogens, The Scientific World Journal 2014, 2014.

52.

Siddiqi

K.S.

, Husen

and Rao

R.A.K.

, A review on biosynthesis of silver nanoparticles and their biocidal properties, Journal of Nanobiotechnology 16(1) (2018), 1–28.

53.

Mahyoub Jazem

, Bioactivity of two marine algae extracts and its synthesized silver nanomaterial against housefly, Musca domestica as a safety method for its control. Entomological Research accepted 8 March 2021. doi:10.1111/1748-5967.12512.

54.

Mahyoub Jazem

, Mosquito Larvicidal activity of seaweed extracts against Anopheles d’thali with reference to its side effects on aquatic nontraget organisms, International Journal of Mosquito Research 5(6) (2018), 34–38.

55.

Barnawi Abdul Aziz

B.M.

, Somia Sharawi

, Jazem Mahyoub

and Khalid Al-Ghamdi

, Larvicidal studies of Avicennia marina extracts against the dengue fever mosquito Aedes aegypti (Culicidae: Diptera), International Jornal of Mosquito Research 6(1) (2019), 55–60.

56.

Baeshen Mohammed

, Al-Attas Sanaa

, Ahmed Mohamed

M.M.

, Anwar Yasir2

, Faragalla Abdul-Rahman

, Ramdan Hassan , Ayman

, Jazem Mahyoub

, Alabdali Huda

and Baeshen Nabih

, Genotoxic effect of Rhazya stricta leaf extract against larvae of Aedes aegypti, Research Journal of Biotechnology 14(4) (2019), April (2019).

57.

Mahyoub Jazem

, Biological effects of synthesized silver nanoparticles using Dodonaea viscosa leaf extract against Aedes aegypti (Diptera: Culicidae), Journal of Entomology and Zoology Studies 7(1) (2019), 827–832.

Biolarvicide	Conc.	Mortality^a	LC₅₀ (ppm)	LC₉₀ (ppm)	χ ²	Slope	RR
	(ppm)	(%)	(LCL– UCL)	(LCL– UCL)	d.f (n.s) = 4^b
P. alba	100	18.6	178.4713
	150	34.0	(166.3497– 190.7469)	363.656
	200	54.6		(322.7048 – 429.2352)	5.4984	4.1459
	250	69.1
	300	88.7
	0	4					2.551
P. alba - AgNPs	30	11.3
	60	35.1	69.9592	160.7447	2.0606	3.5473
			(63.9542– 75.983)	(142.0869– 188.6796)
	90	68.0
	120	80.4
	160	89.7
	0	4					2.022
P. alba - AuNPs	30	8.333
	60	25
	90	56.25	88.2635	228.2207	2.5524	3.1064
			(80.5638– 96.784)	(192.7081– 288.3328)
	120	65.625
	160	78.125
	0	3