Oral Toxicity Studies, Histopathology, and Anti-Diabetic Activity of Polyherbal Extract in STZ Induced Diabetes in Rats

Abstract

Background: Diabetes mellitus is a disease and endocrine disorder. It is a growing health problem in various countries. The prevalence of diabetes is rising worldwide; around 5.4% rise in patients with diabetes is expected by 2025. The World Health Organization (WHO) has reported that 173 million adults are suffering from diabetes mellitus in developing counties. In this research, estimation of glucose levels was performed in Wistar rats post-induction of diabetes by streptozotocin. Metformin has been used as a standard dose for treatment. This study demonstrated the acute oral toxicity and subacute oral toxicity of ethanolic extract of Saraca asoca leaves and Asparagus racemosus roots and evaluated the antidiabetic activity. Objective: This study aimed to evaluate the acute toxicity and sub-acute toxicity of the polyherbal ethanolic extract on vital organs. The visible changes in the organs of each group of Wistar rats were also determined in this study. Moreover, the hypoglycaemic action of the polyherbal extract of Saraca asoca and Asparagus racemosus was also explored. Methods: Wistar rats were divided into four groups for assessing acute oral toxicity. Groups were administered doses of 5,50, 300, and 2000mg/kg body weight of the polyherbal extract. Subacute oral toxicity studies were performed by administering a polyherbal extract of 250, 500, 1000mg/kg body weight. For evaluating the antidiabetic activity, animals were divided into 5 groups. In group 1 (normal control), saline was administered; in group 2, standard drug Metformin was administered; in group 3, no drug was given to rats with diabetes (Streptozotocin-Induced diabetic with 150mg/kg body weight), thus forming the diseased group. In group 4, ethanolic extract with 100mg/kg group was administered, and in group 5, ethanolic extract of 200mg/kg was administered. On the last day, the blood glucose levels and body weights of rats were examined. Histopathology studies were conducted by sacrificing the animals, isolating the organs, such as tissue pancreas, spleen, heart, lungs, liver, and kidney, and placing them on slides using a microscopic examination. Data were selected by searching the articles in the databases, such as NCBI, Web of Science and ScienceDirect, and PubMed from 1989 to 2020 by using keywords, such as “Antidiabetic,” “Saraca indica,” “Asparagus racemosus,” “ethanolic polyherbal extract,” “oral toxicity study,” “histopathology,” and “Streptozotocin.” Results: The polyherbal ethanolic extract of Saraca asoca and Asparagus racemosus at a dose of 100 mg/kg and 200 mg/kg showed better effects against streptozotocin-induced diabetic rats having 150 mg/kg body weight. Regarding acute toxicity and subacute oral toxicity studies, all the extracts showed significant values (P <0.05) and were found to be safe and non-toxic. The body weight was also improved; no inflammation and erosion were seen on any organs of the Wistar rat in a histopathology analysis. Conclusions: The polyherbal ethanolic extract of Saraca asoca and Asparagus racemosus showed hypoglycaemic activity against STZ-induced diabetes in experimental Wistar rats. The results showed the beneficial effects of these ethanolic extracts, improving the body weight and changes in lipid metabolism and protecting the organs of Wistar rats, such as the liver, kidney, spleen, pancreas, lungs, and heart, against impairment of blood glucose. All organs were weighted, tissues from organs were isolated, then stained using eosin dye, and changes were observed by microscopy photos. No signs of inflammation and erosion were reported at the end of the study, indicating the healing action of the extract.