Influence of plant extracts on insulin resistance in experimental diabetes mellitus

Objective. The aim of the study was to evaluate the effect of medicinal plant extracts on insulin sensitivity in the model of diabetes mellitus.Material and Methods. Experiments were carried out using 110 outbred white male rats. Diabetes mellitus was induced by the administration of streptozotocin to animals receiving food with a high fat content for the formation of insulin resistance. The animals were injected with metformin, rosiglitazone, and aqueous extracts of nettle, dandelion, burdock, and Galega officinalis. The rats were divided into two groups during pharmacotherapy: group 1 continued to receive fat-enriched diet; group 2 received a regular diet with 8% fat content. The blood levels of glucose, glycated hemoglobin, triglycerides, and high-density lipoprotein cholesterol were measured. The metabolic index was calculated to assess insulin resistance.Results. The extracts of nettle and burdock reduced the concentration of glucose and glycated hemoglobin in animals with a model of diabetes mellitus treated with fat-enriched food. Dandelion extract did not change the level of fasting glucose in blood whereas it lowered the concentration of glycohemoglobin. The extracts of nettle, Galega officinalis, and dandelion reduced blood concentrations of glucose in animals receiving normal diet. The extracts of all plants reduced the level of glycated hemoglobin. The concentration of triglycerides normalized regardless of the diet when plant extracts were introduced. The concentrations of high-density lipoprotein cholesterol increased in both diets in animals treated with Galega officinalis and dandelion extracts. The metabolic index in rats receiving food with 8%-fat content did not differ from that of intact animals after therapy with nettle and Galega officinalis extracts. Dandelion extract alleviated insulin resistance in animals continuing to receive a diet enriched with fats.Conclusion. The extracts of nettle, Galega officinalis, burdock, and dandelion improved carbohydrate and lipid metabolism in diabetes mellitus caused by the administration of streptozotocin to rats to the same extent as metformin and rosiglitazone. Extracts of nettle and Galega officinalis alleviated insulin resistance in animals receiving a normal diet; dandelion extract alleviated insulin resistance in animals receiving fat-enriched food.