Oral Toxicity Studies, Histopathology, and Anti-Diabetic Activity of Polyherbal
Extract in STZ Induced Diabetes in Rats
Authors: Wal Pranay , Saraswat Nikita , Wal Ankita , Pal Rashmi Saxena , Maurya Deepa 
Published: December 2021

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.