When rats with high cholesterol levels were given either aqueous or methanolic extracts of vine leaves (Vitis vinifera), they showed a reduction in low density lipoprotein cholesterol (LDL-C) together with an increase in high density lipoprotein cholesterol (HDL-C) levels.
Lowered atherogenic index (the ratio of triglycerides to HDL-C - a strong predictor of atherosclerosis and coronary heart disease risk) was also observed by scientists from Maharishi Markandeshwar University, Mullana, India.
Additionally, vine leaf extract consumption induced a reduction in artery wall thickening in the rats.
“Vitis vinifera extracts were found effective in reducing cholesterol level and improved HDL level in experimentally induced atherosclerosis in rats. Also, the administration of extract decreases the disruption of endothelial lining and thickness of blood vessel lining in experimental animals,” wrote lead researcher Professor Randhir Singh.
Although the reductions in LDL-C and atherogenic index in this trial were not as dramatic as those induced by simvastatin, additional research may further demonstrate the lipid reduction capabilities of the plant extract.
The researchers induced hypercholesterolaemia in the rats by feeding them high amounts of cholesterol (2% by weight) and cholic acid (0.5% by weight) in addition to their base diet for 21days.
Rats were also administered with either aqueous or methanolic vine leaf extract (100 milligrams/kilogram (mg/kg), 200 mg/kg or 400mg/kg) or simvastatin (10mg/kg) or neither (cholesterol control group).
The methanolic extract had a higher efficacy than the aqueous extract. The 400mg/kg dose reduced atherogenic index by 72% and LDL-C by 37%. However, they were less effective than simvastatin, which achieved corresponding reductions of 100% and 73%.
Vine leaf benefits
Previous research has identified a wide range of phenolic compounds within vine leaves including resveratrol, quercetin, rutin, gallic acid, catechin and epicatechin. Antioxidant benefits of many of these compounds are widely acknowledged. Vine leaves are also good sources of calcium and magnesium.
In human trials, vine leaves have shown oedema- protective and blood flow improvement in varicose vein treatment. Animal studies have exhibited liver protective, anti-diabetic and antioxidant benefits.
Vine leaves are also cheap, edible and well-tolerated.
Findings from this study, together with the previously demonstrated wider benefits of vine leaves, may warrant further work to determine their possible use as a supplement or functional food.
Source: Food Science and Human Wellness
“Evaluation of antioxidant and anti-hypercholesterolemic potential of Vitis vinifera leaves”
Published online ahead of print. DOI: 10.1016/j.fshw.2017.07.002
Authors: Sushma Devi, Randhir Singh