Background: Endometriosis is the growth of endometrial tissue in ectopic places outside the uterus. Siddha physicians claim that Vitex negundo leaf decoction reduces the symptoms of endometriosis in clinical practice. Objective: To evaluate the effect of Vitex negundo aqueous extract on surgically induced endometriosis in Sprague Dawley rats. Materials and Methods: Endometriosis was surgically induced in nulliparous female Sprague Dawley rats with regular estrus cycle by autografting endometrium tissue on posterior abdominal wall. After 30 days of implantation, rats were allocated into two groups (n=6). Control group did not receive any drug, whereas test group received an oral dose of Vitex negundo aqueous extract (300 mg/kg) for 30 days. After 30 days of treatment, the endometriosis cyst size and adhesion were measured and blood was collected for hematology. Malondialdehyde (MDA, an oxidant) and thiol (antioxidant) levels were estimated in blood as well as in cyst. Endometriosis cyst was studied for histopathological grading. Statistical analysis was done using independent t test by keeping p<0.05. Results: Test drug reduced the adhesion and cyst size compared to control, but the difference was not statistically significant. Histological grade was reduced from 3 to 0 in test group. The test drug significantly increased thiol in blood (p=0.016), and also reduced the blood MDA level (p=0.001) compared to control. Test drug increased the red blood cell distribution width (RDW_CV: p=0.009 and RDW_SD: p=0.003), platelet (p=0.03) and plateletcrit (p=0.026) compared to control group. Conclusion: Our study has created the scientific evidence for the siddha physician’s claim on Vitex negundo by demonstrating reduction in endometriosis cyst size, adhesion, histological grading and oxidant levels as well as elevation in antioxidant level.
Key words: Vitex negundo, Endometriosis , Sprague Dawley Rats, Antioxidants.