Antioxidant,Hepatoprotective,and Ameliorative Effects of Methanolic Extract of Leaves of Grewia mollis Juss. on Carbon Tetrachloride

Abstract

The methanolic extract of Grewia mollis leaves was evaluated in vivo for its antioxidant and hepatoprotective properties. Oxidative stress was induced in rats by administering carbon tetrachloride (CCl₄) intraperitoneally at a dose of 0.6 mL/kg, whereas the crude plant extract and standard antioxidant (vitamin E) were administered at a dose of 5 mg/kg and 50 mg/kg, respectively. The effect of G. mollis crude extracts and vitamin E on malondialdehyde (MDA) and liver function parameters such as protein, bilirubin, aspartate aminotransferase, and alanine aminotransferase were measured spectrophotometrically. The methanolic extract of G. mollis leaves and vitamin E showed a significant (P<.05) hepatoprotective potential by lowering the serum levels of bilirubin, aspartate aminotransferase, and alanine aminotransferase and decreasing MDA levels in rats pretreated or post-treated with CCl₄. Based on these results, it is concluded that G. mollis leaves contain potent antioxidant compounds that could offer protection against hepatotoxicity as well as ameliorate preexisting liver damage and oxidative stress conditions.

Introduction

I n the past few decades, there has been growing interest in the application of natural antioxidants to medical treatments as information is constantly gathered linking the development of human diseases to oxidative stress, and even more so as the antioxidant properties of many herbs and spices have been reported to be effective in this respect.¹ Thus, it has been considered important to increase the antioxidant intake in human by enriching foods and drugs with natural antioxidants because some synthetic antioxidants exhibit toxicity and require high manufacturing cost although showing lower efficiency than natural antioxidants. Hence, natural and possibly more economic and effective antioxidants with potential for incorporation in foods and drugs must be identified.^2,3

Grewia mollis, called dargaza in the Hausa language of West Africa, is a plant belonging to the genus Grewia, Family Malvaceae, and Subfamily Tiliaceae. It is a shrub or small tree that grows up to 20 feet high in the savannah and other areas with annual average rainfall of 600–1,400 mm and in forest from sea level in West Africa up to 2,200 m altitude in East Africa. It is gregarious, grows on a range of soil types, and is highly resistant to fire. The leaves are pale greenish and white beneath, flowers are yellow, and fruits are black, when ripe.

The leaf of G. mollis, which grows mainly in the wild, is used as a vegetable, especially during periods of food scarcity in many African countries. The leaf is mucilaginous and commonly used in soups. In the Democratic Republic of Congo, the bark is kneaded with water into a viscous substance that is added to sauces, whereas in Gabon the inner bark is sometimes eaten. In Sudan the young leaves are eaten cooked as a vegetable, whereas in northern Nigeria, this plant is popular as a vegetable among some ethnic groups in the Southern Kaduna and Plateau States in the north central part of the country, where the flowers, buds, and young shoots are added to soups and sauces. The possible contribution of this wild vegetable to the diet and nutrition of pregnant and lactating women in the Plateau State of Nigeria has been reported.⁴

In addition, our mini-survey with local traditional herbal practitioners suggests that different parts of G. mollis, especially the leaves, are also used as an ingredient in many traditional prescriptions. In addition, Gill⁵ reported that G. mollis has been used as an abortificient and antidote agent against unpleasant and unidentified illnesses in South Western Nigeria and elsewhere. However, in general, the medicinal use of G. mollis varies from one ethnic group to the other, although recent findings have indicated that the mucilage obtained from the stem bark may be useful in the pharmaceutical industry as a binder in paracetamol formulations.^6,7

The basis of the importance of G. mollis in medicinal use has not been previously investigated, but it is known that some of the diseases for which it is used as a cure or antidote have oxidative stress as their etiological origin. Hence, the antioxidant and hepatoprotective properties of the crude methanolic extract of G. mollis leaf were studied in vivo using a laboratory animal model. Methanol was selected as the solvent for extraction because it is the solvent of choice when mixed antioxidant phytochemicals are involved,³ and because G. mollis leaves are consumed whole after cooking, it was necessary to exhaustively extract related phytochemicals as much as possible before evaluation of their combined antioxidant and hepatoprotective potential.

Materials and Methods

Chemicals

Thiobarbituric acid was from Sigma Chemical Co. (St. Louis, MO, USA). The other chemicals were acquired from the following sources: α-tocopherol acetate from Teva Pharmaceutical Industries Ltd. (Petach Tikva, Israel); carbon tetrachloride (CCl₄) from Fisher Scientific Co., Chemical Manufacturing Division (Fair Lawn, NJ, USA); and alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase reagent kits from Randox Laboratories Ltd. (Antrim, United Kingdom).

Collection and identification of plant

G. mollis leaves, provided by a traditional herbal practitioner in Zaria, Kaduna State, Nigeria, were identified by the Herbarium Section, Biological Science Department, Ahmadu Bello University, Zaria, and assigned voucher number 1899.

Extract preparation

Exactly 30 g of dried powdered G. mollis leaves was carefully added to the extraction thimble and defatted with 300 mL of petroleum ether for 6 hours in a Soxhlet apparatus. The plant residue left after petroleum ether extraction was air-dried and further extracted with 300 mL of methanol for 3 hours using the same procedure as above to obtain the methanolic extract. The methanol extraction was performed three times following the same procedure. The petroleum ether and methanolic extracts obtained were dried under reduced pressure, kept in a desiccator at room temperature until brittle, then weighed, and stored in the refrigerator at 4°C until required.

Animal and animal husbandry

Male albino rats weighing 150–200 g were obtained from the Department of Pharmacology, Ahmadu Bello University. They were acclimatized for 2 weeks at room temperature and had free access to food and water before the experiment was started. Food, but not water, was withdrawn 18 hours before beginning the experiments. The animal experiment was approved by the Ethical Committee of Biological Sub-Complex of Ahmadu Bello University.

Animal experimentation

Protective effects of G. mollis pretreatment on oxidative stress and liver damage

The experimental animals were divided into six groups composed of six rats each. The intraperitoneal route of administration was used for the experiment following an overnight fast: Group 1, solvent control (3% Tween 80 in corn oil) at a dose of 0.15 mL/kg of body weight; Group 2, G. mollis extract only; Group 3, G. mollis extract + CCl₄; Group 4, vitamin E at a dose of 50 mg/kg before CCl₄ (0.6 mL/kg); Group 5, vitamin E + CCl₄; and Group 6, CCl₄ only. In all cases, CCl₄ was administered as a 33% solution in corn oil, 1 hour after administration of the extract (5 mg/kg) or vitamin E (50 mg/kg) for the second time on the second day. Rats were sacrificed on the third day (24 hours after last treatment), blood was collected, and serum was separated to assay for biochemical parameters. Various organs (liver, heart, and kidney) were collected and immediately stored at −20°C for evaluation of the level of malondialdehyde (MDA) from lipid peroxidation.

Ameliorative effect of G. mollis methanolic extract on existing oxidative stress and liver damage conditions

The experimental animals were divided into six groups composed of six animals each. The intraperitoneal route of administration was also used for the experiment following an overnight fast of all animals: Group 1, solvent control (3% Tween 80 in corn oil) at a dose of 0.15 mL/kg of body weight; Group 2, G. mollis extract only; Group 3, CCl₄ + G. mollis extract; Group 4, vitamin E only; Group 5, CCl₄ (0.6 mL/kg) + vitamin E at a dose of 50 mg/kg; and Group 6, CCl₄ only. In all cases, CCl₄ was administered as a 33% solution in corn oil on the first day and 1 hour before administration of the extract (5 mg/kg) or vitamin E (50 mg/kg) on the second day. Animals were sacrificed on the third day (24 hours after last treatment), blood was collected, and serum was separated to assay for biochemical parameters. Various organs (liver, heart, and kidney) were collected and immediately stored in a deep freezer at −20°C for analysis of the MDA with thiobarbituric acid–reactive substances.

Organ collection and homogenization

The various organs were carefully collected using forceps, immediately washed in physiological saline, and weighed. Homogenization was done using a precooled laboratory pestle and mortar after addition of phosphate buffer (pH 7.2) to obtain 10% homogenate for all the organs.

Evaluation of level of MDA from lipid peroxidation

The degree of lipid peroxidation in the liver, kidney, heart, and serum was assayed by the level of thiobarbituric acid–reactive substances using a spectrophotometric method.^8
–10 The supernatant from tissue homogenization or serum (50 μL) was deproteinized by addition of 14% trichloroacetic acid (1 mL). The reaction was then initiated by addition of 0.6% thiobarbituric acid (1 mL); the mixture was heated in a water bath for 30 minutes to complete the reaction and then cooled on ice for 5 minutes. After centrifugation at 2,000 g for 10 minutes, the absorbance of the colored product, the MDA–thiobarbituric acid complex, was measured at 535 nm with an ultraviolet spectrophotometer. Total protein content of the homogenates and serum was determined with the aid of a refractometer (model 2416, American Optical Corp., Keene, NH, USA). The level of MDA was calculated using the molar extinction coefficient of standard MDA (1.56×10⁵ mol/L/cm) by the following formula: A=ΣCL where A=absorbance, Σ=molar coefficient, C=concentration, and L=path length. All MDA concentrations were expressed in micromoles per gram of protein.

Assay of serum markers of liver damage

Levels of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and total and direct bilirubins were measured spectrophotometrically using Randox kits.

Statistical analysis

The statistical analysis was carried out by one-way analysis of variance and Tukey's test to compare the groups that were statistically significant diferent. Values of P<.05 were considered significant.

Results

Effects of G. mollis pretreatment on MDA levels of liver, heart, kidney, and serum are shown in Table 1. The MDA level increased significantly (P<.05) in the liver of rats in the CCl₄ group compared with that of solvent group organs. However, groups given pretreatment with vitamin E (50 mg/kg) or methanolic extract of G. mollis (5 mg/kg) before CCl₄ treatment showed comparable levels of MDA concentration (Table 1). Similarly, in Table 2, levels of serum total and direct bilirubin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase increased significantly in CCl₄-treated rats, compared with the solvent-only group, but this effect was significantly depressed to an appreciable level (P<.05) only in groups of rats that received either vitamin E or G. mollis extract pretreatment (Table 2). However, no statistical difference was found (P<.05) in the levels of MDA and markers of liver damage between the groups receiving either extract or vitamin E alone and groups pretreated with either vitamin E or G. mollis extract before administration of CCl₄ (Tables 1 and 2). MDA levels in the heart and serum were not significantly affected by the treatments.

Table 1.

Effect of G. mollis Methanolic Extract Pretreatment (5 mg/kg) on Malondialdehyde Levels in Liver, Kidney, Heart, and Serum of CCl₄-Treated Rats

		MDA (μmol/g of protein)
Experimental group	Treatment	Liver	Heart	Kidney	Serum
1	Solvent only	1.42±0.06^a	0.81±0.26^a	1.12±0.25^a	0.80±0.25^b
2	Extract only	1.39±0.27^a	0.66±0.40^a	1.12±0.16^a	0.70±0.01^b
3	Extract + CCl₄	1.60±0.37^a	0.74±0.12^a	1.13±0.14^a	1.08±0.12^a
4	Vitamin E only	1.47±0.80^a	0.92±0.29^a	0.99±0.39^a	0.65±0.24^b
5	Vitamin E + CCl₄	1.74±0.17^a	1.01±0.25^b	1.44±0.26^b	0.76±0.30^b
6	CCl₄ only	3.14±0.95^b	1.38±0.25^b	1.66±0.45^b	1.34±0.26^a

Data are mean±SD values of six rats.

Values with different superscripts vertically are statistically significant at P<.05.

For liver: ^a P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and extract + vitamin E; ^b P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄.

For kidney: ^a P≤.05 compared with solvent only, extract only, and vitamin E only, ^b P≤0.05 compared with extract + CCl₄, vitamin E only, vitamin E + CCl₄, and CCl₄ only.

For heart: ^a P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and extract + vitamin E; ^b P≤.05 compared with solvent only, extract only, vitamin E only, and extract + CCl₄.

For serum: ^a P≤.05 compared with CCl₄ only; ^b P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄.

MDA, malondialdehyde.

Table 2.

Effects of G. mollis Methanolic Extract Pretreatment (5 mg/kg) on Levels of Biochemical Indices of Liver Damage in CCl₄-Treated Rats

		Bilirubin (μmol/L)
Experimental group	Treatment	Total	Direct	ALT (IU/L)	AST (IU/L)	ALP (IU/L)
1	Solvent only	12.49±2.20^a	9.36±0.96^a	46.60±3.29^a	41.40±1.57^a	114.6±19.50^a
2	Extract only	12.14±18.90^a	7.12±1.52^a	41.20±7.09^a	51.20±6.40^a	108.18±29.16^a
3	Extract + CCl₄	18.90±1.71^b	14.45±2.85^b	64.60±12.08^b	69.60±3.65^b	171.60±22.70^c
4	Vitamin E only	12.26±1.01^a	9.74±3.40^a	46.05±1.01^a	44.20±7.78^a	53.00±2.70^b
5	Vitamin E + CCl₄	19.21±2.09^b	13.56±1.80^b	68.60±12.28^b	66.60±8.69^b	175.06±19.05^c
6	CCl₄ only	32.04±2.61^c	18.85±2.27^c	90.40±2.45^c	90.25±2.45^c	204.50±18.28^c

Data are mean±SD values of six rats.

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Values with different superscripts vertically are statistically significant at P<.05.

For total bilirubin: ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with extract + CCl₄ and vitamin E + CCl₄; ^c P≤.05 compared with solvent only, extract only, extract + CCl₄, and vitamin E + CCl₄.

For direct bilirubin: ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with extract + CCl₄ and vitamin E + CCl₄; ^c P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄.

For alanine aminotransferase (ALT): ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with extract + CCl₄ and vitamin E + CCl₄; ^c P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄.

For aspartate aminotransferase (AST): ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with extract + CCl₄ and vitamin E + CCl₄; ^c P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄.

For alkaline phosphatase (ALP): ^a P≤.05 compared with solvent only and extract only; ^b P≤.05 compared with solvent only, extract only, extract + CCl₄, vitamin E + CCl₄, and CCl₄ only; ^c P≤.05 compared with vitamin E + CCl₄, extract + CCl₄, and CCl₄ only.

A statistical difference (P<.05) was observed between the CCl₄-treated group and the control group administered solvent only. A similar observation was made between the CCl₄-treated group and groups administered either vitamin E or G. mollis extract following CCl₄ pretreatment. However, administration of either vitamin E or G. mollis extract following CCl₄ pretreatment brought the levels of MDA and markers of liver damage to where no statistically difference (P<.05) existed between them and the group receiving solvent alone (Tables 3 and 4). Again, only MDA levels in liver and, to some extent, in kidney were drastically affected by the treatments, whereas the levels in serum and heart were barely affected (Table 3).

Table 3.

Effect of G. mollis Methanolic Extract Treatment (5 mg/kg) on Malondialdehyde Levels in Liver, Kidney, Heart, and Serum of CCl₄-Pretreated Rats

		MDA (μmol/g of protein)
Experimental group	Treatment	Liver	Heart	Kidney	Serum
1	Solvent only	1.42±0.06^a	0.81±0.26^a	1.12±0.25^a	0.80±0.25^a
2	Extract only	1.39±0.27^a	0.66±0.40^a	1.12±0.16^a	0.70±0.01^a
3	CCl₄ + extract	2.22±0.35^b	1.08±0.16^b	1.18±0.15^a	0.89±0.20^a
4	Vitamin E only	1.47±0.80^a	0.92±0.29^a	0.99±0.39^a	0.65±0.24^a
5	CCl₄ + vitamin E	2.25±0.32^b	1.11±0.13^b	1.28±0.15^b	1.24±0.06^b
6	CCl₄ only	3.14±0.95^c	1.38±0.25^b	1.66±0.45^b	1.34±0.26^b

Data are mean±SD values of six rats.

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Values with different superscripts vertically are statistically significant at P<.05.

For liver: ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄.

For kidney: ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with CCl₄ + extract and vitamin E only; ^c P≤.05 compared with CCl₄ + vitamin E and CCl₄ only.

For heart: ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with extract + CCl₄, extract + vitamin E, and CCl₄ only.

For serum: ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with CCl₄ + extract and vitamin E only; ^c P≤.05 compared with CCl₄ + vitamin E and CCl₄ only.

Table 4.

Effects of Methanolic Extract of G. mollis Treatment (5 mg/kg) on Levels of Biochemical Indices of Liver Damage in CCl₄-Pretreated Rats

		Bilirubin (μmol/L)
Experimental group	Treatment	Total	Direct	ALT (IU/L)	AST (IU/L)	ALP (IU/L)
1	Solvent only	12.49±2.20^a	9.36±0.96^a	46.60±3.29^a	41.40±1.57^a	114.60±19.50^a
2	Extract	12.14±18.90^a	7.12±1.52^a	41.20±7.09^a	51.20±6.40^b	108.18±29.16^a
3	CCl₄ + extract	18.41±3.33^b	14.45±0.75^b	73.40±11.20^b	70.40±6.35^c	190.90±9.88^b
4	Vitamin E only	12.26±1.01^a	9.74±3.40^a	6.05±1.01^c	44.20±07.78^a	53.04±2.70^c
5	CCl₄ + vitamin E	19.92±2.46^b	15.03±0.65^b	83.80±7.12^b	76.20±07.70^c	197.90±14.88^b
6	CCl₄ only	32.04±2.61^c	18.85±2.27^c	90.40±2.45^d	90.25±2.45^d	204.50±18.28^b

Data are mean±SD values of six rats.

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Values with different superscripts vertically are statistically significant at P<.05.

For total bilirubin: ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with CCl₄ + extract and CCl₄ + vitamin E; ^c P≤.05 compared with solvent only, extract only, extract + CCl₄, and vitamin E + CCl₄.

For direct bilirubin: ^a P≤.05 compared with solvent only, extract only, and vitamin E only; ^b P≤.05 compared with CCl₄ + extract and CCl₄ + vitamin E; ^c P≤.05 compared with solvent only, extract only, extract + CCl₄, and vitamin E + CCl₄.

For ALT: ^a P≤.05 compared with solvent only and extract only; ^b P≤.05 compared with extract + CCl₄ and vitamin E + CCl₄; ^c P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄.

For AST: ^a P≤.05 compared with solvent only and vitamin E only; ^b P≤.05 compared with solvent only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄; ^c P≤.05 compared extract + CCl₄ and vitamin E + CCl₄; ^d P≤.05 compared with solvent only, extract only, vitamin E only, extract + CCl₄, and vitamin E + CCl₄.

For ALP: ^a P≤.05 compared with solvent only and extract only; ^b P≤.05 compared with CCl₄ + extract, CCl₄ + vitamin E, and CCl₄ only; ^c P≤.05 compared with solvent only, extract only, extract + CCl₄, and vitamin E + CCl₄.

Discussion

Among biological molecules, lipids are the most susceptible to oxidative damage. Oxidative deterioration of polyunsaturated fatty acids, which are present in abundance in cell membranes, initiates a self-perpetuating chain reaction that yield a wide range of cytotoxic products such as MDA, and hence lipid peroxidation is quantified by its contents.⁹ Assessment by thiobarbituric acid–reactive substances is often used to measure plasma and tissue concentrations of MDA levels as a decomposition product of oxidized lipids and as an index of plasma/tissue lipid peroxidation,¹¹ and elevation of serum enzyme levels is often used as a marker for liver dysfunction.¹²

CCl₄ is a toxic substance that is metabolized in the liver by cytochrome P450 into toxic intermediate trichloromethyl radicals (CCl₃·) that cause elevation of lipid peroxidation.^13,14 This is evident in the CCl₄-treated rats, and the changes in the marker enzymes reflect the effect on hepatic integrity because the markers are cytoplasmic in origin and are released into circulation only after cellular damage.¹⁵

That groups receiving pretreatment with vitamin E (50 mg/kg) or methanolic extract of G. mollis (5 mg/kg) before CCl₄ treatment showed MDA levels comparable to those of the solvent control group is a strong indication that vitamin E and the plant extract prevented oxidative stress inducible by CCl₄ (Table 1). Similarly, that no statistical difference existed between the levels of markers of liver damage in the group pretreated with G. mollis extract or vitamin E before administration of CCl₄ and the solvent control group as well as the group receiving vitamin E alone further demonstrated that G. mollis extract and the standard antioxidant, vitamin E, prevented liver damage caused by CCl₄ administration (Table 2). It is noteworthy that only 5 mg/kg G. mollis extract produced as much hepatoprotective effect as 50 mg/kg vitamin E, suggesting that even the crude extract of G. mollis leaves was 10 times as effective as vitamin E.

To establish that the plant can cure preexisting liver damage and oxidative stress conditions, the methanolic extract of G. mollis was administered to rats previously intoxicated with CCl₄. The statistical difference observed between the levels of markers of oxidative damage (Table 3) as well as markers of liver damage (Table 4) in the CCl₄ groups treated with either G. mollis extract or vitamin E and in the group treated with CCl₄ alone strongly suggests that G. mollis extract possesses an ameliorative effect on preexisting oxidative stress and hepatocellular damage, although less pronounced than the hepatoprotective effect. However, considering that CCl₄ was administered for two consecutive days before administration of the extract or the vitamin E, this finding may be considered to be particularly significant. The antioxidant, hepatoprotective, and ameliorative effects of extracts of G. mollis are consistent with the growing body of knowledge that strongly suggests that because foods and other plant products contain appreciable levels of antioxidant polyphenols, particularly flavonoids, they might play significant roles in the chemoprevention and management of diseases like diabetes, coronary disorders, and age-related disabilities.^16

–21 It would therefore be interesting to know the effect of higher doses and/or longer durationa of treatment on the ameliorative and even hepatoprotective effects of G. mollis extract.

Nevertheless, the results of this study strongly suggest that G. mollis possesses potent capacity to protect against and cure preexisting oxidative stress as well as hepatocellular injury at a dose that is, at least, 10 times less than the known antioxidant, vitamin E, and thus may warrant further detailed study on the isolation, identification, and evaluation of the pharmaco-toxicological properties of its constituents.

Footnotes

Author Disclosure Statement

No competing financial interests exist.

References

Jukić

, Miloš

. Catalytic oxidation and antioxidant properties of thyme essential oils (Thymus vulgarae L) Croat Chem Acta, 2005; 78:105–110.

Soong

, Barlow

. Antioxidant activity and phenolic content of selected fruit seeds. Food Chem, 2004; 88:411–417.

Atawodi

, Pfundstein

, Haubner

, Spiegelhalder

, Bartsch

, Owen

. Content of polyphenolic compounds in the Nigerian stimulants Cola nitida ssp. alba, Cola nitida ssp. rubra A. Chev, and Cola acuminata Schott & Endl and their antioxidant capacity. J Agric Food Chem, 2007; 55:9824–9828.

Madukorsiri

, Adoga

. Some nutrient composition of some-ready-to-eat foods consumed by pregnant and lactating women in Bassa LGA of Plateau State, Nigeria. Pak J Nutr, 2009; 8:1889–1893.

Gill

. Ethnomedicinal Uses of Plants in Nigeria. University of Benin Press: Benin City, Nigeria, 1992.

Martins

, Christiana

, Olobayo

. Effect of Grewia gum on the mechanical properties of paracetamol tablet formulations. Afr J Pharm Pharmacol, 2008; 2:1–6.

Muazu

, Musa

. Compression, mechanical and release properties of paracetamol tablets containing acid treated Grewia gum. J Pharm Sci Technol, 2009; 1:784–791.

Draper

, Hadley

. Malondialdehyde determination as index of lipid peroxidation. Methods Enzymol, 1990; 186:421–431.

Sivonova

, Tatarkova

, Durackova

, Dobrota

, Lehotsky

, Matakova

, Kaplan

. Relationship between antioxidant potential and oxidative damage to lipids, proteins and DNA in aged rats. Physiol Res, 2007; 56:757–764.

10.

Geetha

, Kedlaya

, Vasdevan

. Inhibition of lipid peroxidation by botanical extract of Ocimium santum in vivo and in vivo studies. Life Sci, 2004; 76:21–28.

11.

Balz

, Higdon

. Antioxidant activity of tea polyphenols in vivo: evidence from animal studies. J Nutr, 2003; 133:32755–32845.

12.

Dahiru

, William

, Nadro

. Protective effect of Ziziphus mauritiana leaf extract on carbon tetrachloride-induced liver. Afr J Biotechnol, 2005; 4:1177–1179.

13.

Paudit

, Surh

, Jana

, Debnata

, Sen

, Bhattacharyga

. Prevention of carbon tetrachloride-induced hepatotoxicity in rats by Adhatoda vasica leaves. Indian J Pharmacol, 2004; 36:312–313.

14.

Gyamfi

, Yonamine

, Aniya

. Free-radical scavenging action of medical herbs from Ghana: Thonningia sanguinea on experimentally-induced liver injuries. Gen Pharmacol, 1999; 32:661–667.

15.

Hanumantha

, Balaji

, Arumugam

, Thiruvengadam

. Hepatoprotective nature of seaweed alcoholic extract on acetaminophen induced hepatic oxidative stress. J Health Sci, 2004; 50:42–46.

16.

Atawodi

. Antioxidant potential of African medicinal plants. Afr J Biotechnol, 2005; 4:128–133.

17.

Halliwell

. Antioxidant and human health and disease. Annu Rev Nutr, 1996; 16:35–50.

18.

Hertog

MGL

, Feskens

EJM

, Hollman

PCH

, Katan

, Kromhout

. Dietary antioxidant, flavonoids and risk of coronary heart diseases: the Zutphen Elderly Study. Lancet, 1993; 342:1007–1011.

19.

Arts

, Hollman

. Polyphenols and disease in epidemiologic studies. Am J Clin Nutr, 2005; 81,1 Suppl:317S–325S.

20.

Valko

, Leibfritz

, Moncol

, Cronin

, Mazur

, Telser

. Free radicals and antioxidants in normal physiological functions and human disease. Int J Biochem Cell Biol, 2007; 39:44–84.

21.

Vaya

, Aviram

. Nutritional antioxidants: mechanisms of action, analyses of activities and medical applications. Curr Med Chem Immunol Endocr Metab Agents, 2001; 1:99–117.

Antioxidant,Hepatoprotective,and Ameliorative Effects of Methanolic Extract of Leaves of Grewia mollis Juss. on Carbon Tetrachloride–Treated Albino Rats

Abstract

Introduction

Materials and Methods

Chemicals

Collection and identification of plant

Extract preparation

Animal and animal husbandry

Animal experimentation

Protective effects of G. mollis pretreatment on oxidative stress and liver damage

Ameliorative effect of G. mollis methanolic extract on existing oxidative stress and liver damage conditions

Organ collection and homogenization

Evaluation of level of MDA from lipid peroxidation

Assay of serum markers of liver damage

Statistical analysis

Results

Discussion

Footnotes

Author Disclosure Statement

References