Effects of Bauhinia forficata Link Tea on Lipid Profile in Diabetic Patients

Type 2 diabetes mellitus is a chronic metabolic disease, for which the therapeutic objective is to reduce the risk of cardiovascular diseases and chronic complications. ¹ The use of medicinal plants to treat the disease has for years played a fundamental role in popular medicine in different countries. ² In Chile, Bauhinia forficata Link, popularly known as “pata de vaca” (cow foot), is used as a complementary therapy for the treatment of diabetes. ^3,4 This plant belongs to the Fabaceae family (Leguminosae) and is characterized by its hypoglycemic effects, including decreased levels of glycemia and glucose in urine, as evidenced in studies, and even a beneficial effect on lipid profile. ^{5 –7} These therapeutic effects are attributed to the presence of phytochemical compounds present in the aerial plant, such as phytosterols, flavonoids, alcohols, polyalcohols, and alkaloids. ⁸ Among them, rutin and trigonelline are highlighted. ^{9 –11}

There are studies that have demonstrated the hypoglycemic effects of B. forficata ^7,12 but there have been no previous reports regarding its effects on lipid profile. This study evaluates the effects of B. forficata tea on lipid profile when used as complementary therapy in type 2 diabetic patients. The study included 25 type 2 diabetic patients (mean age 62 years).

The criteria for inclusion were as follows: type 2 diabetic patients who received outpatient care at the Family Health Community Center in Concepción, Chile, and who volunteered to participate. Participants were recruited using brochures and flyers. Patients with acute or chronic hepatic or renal failure, backgrounds of acute myocardial infarction and patients with oral anticoagulants were excluded.

Patients who participated in the study experienced no changes in their chronic pharmacological therapy or lifestyle and were instructed not to take natural supplements or change their diets during the study period. The study protocol was approved by the ethics committee of the Family Health Community Center in Concepción, and participants provided informed consent before the beginning of the study.

The subjects participated in a 3-month quasi-experimental pilot study without a control group to study the effects of B. forficata tea on lipid profile, specifically on total cholesterol and triglycerides, parameters that frequently elevated in diabetes patients.

Dried and ground leaves of B. forficata Link collected in central and southern Chile were used. The plant was identified and entered into the CONC Herbarium with the number 179895. The standardization of the tea of dry leaves of B. forficata was performed through two phytochemical compounds, rutin and trigonelline, using the analytical techniques described for Toloza et al. ¹² The tea used consisted of 0.4% B. forficata leaves, with a concentration of 4.30 mg/dose of trigonelline and 1.02 mg/dose of rutin, in 200 mL of water. Participants drank the tea twice a day for a period of 3 months. Instructions on how to prepare the tea were given to each patient. Patients needed to register daily tea consumption. This register (diary) was reviewed by the researcher in each control session.

Clinical parameters were measured at the beginning and end of the study period and were obtained through capillary blood extracted by fingertip puncture. These parameters included total cholesterol, triglycerides (Cardiocheck^® equipment), and other parameters such as %HbA_1c (glycosylated hemoglobin; Quo-lab^® equipment), postprandial glycemia (One Touch^® equipment), and patient weight (Medisana^® digital scale), which can affect final results. Postprandial glycemia was measured 2 h after participants consumed food.

All of the values were analyzed by applying a Student's t-test for statistical analyses, with a probability value of P < .05 considered significant. Statistical software Stata^® version 13 was used for data analysis.

Table 1 demonstrates the changes in clinical parameters for the 3-month study period. The results showed statistically significant differences in triglycerides, total cholesterol, and HbA_1C, with reductions of 48 mg/dL, 17 mg/dL, and 0.25%, respectively. No significant changes in postprandial glycemia and weight were observed.

With respect to cholesterol levels, a 9% decrease from baseline was observed and levels of triglycerides decreased 26% from baseline. These lipid-lowering effects can be attributed to both the standardized compounds trigonelline ^2,13 and rutin ¹⁴ as well as to other quercetin derivatives and flavonoids present in the leaves. It has been described that quercetin derivatives would stimulate the metabolism of hepatic lipids, reducing the levels of plasmatic lipids, suppressing the accumulation of fat in the liver and adipose tissue. It is also known that quercetin derivatives directly improve the metabolism of lipids in the liver ¹⁵ and are inhibitory on pancreatic lipase. ¹⁶ It has also been reported that the administration of trigonelline inhibits key enzymes of lipid metabolism and absorption, such as lipase activity, in the small intestine, which leads to a decrease in triglyceride and total cholesterol in animals. ¹⁷

It is important to highlight the effects observed on lipid profile, emphasizing the 26% decrease in triglyceride levels, which, despite not achieving the figures recommended for diabetic patients (<150 mg/dL), ¹ is quite significant. It would be important to study the effect on the level of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, as it has been noted that a reduction in triglycerides alone is not enough to evaluate the decrease in the cardiovascular risk of patients. ^18,19

Despite the significant difference between HbA_1C before and after the study, this difference is not comparable with the decrease of this parameter observed in other studies. ¹²

The use of B. forficata tea as complementary therapy in type 2 diabetic patients could help to reduce the levels of triglycerides and total cholesterol. However, this decrease is not clinically significant. Additional studies are suggested to further evaluate the clinical effect of the tea, including on other lipid profile parameters, such as LDL and HDL cholesterol, with prolonged times and a larger sample size.