Evaluation of Immunomodulatory activity of Diosgenin in rats

Background: The immune system is intrinsic to health. Modulation of the immune responses to alleviate the diseases by using herbal plants has been of interest for many years. Diosgenin, a naturally occurring steroid saponin mainly present in the seeds of fenugreek (Trigonella foenum graecum) and in the root tubers of wild yams (Dioscorea villosa). Activation of specific and nonspecific immunity results in stimulation of immune response. Diosgenin has the positive effects on both specific and nonspecific immunity. Aim: To study the immunomodulatory activity of Diosgenin in albino wistar rats. Method: The suspension of Diosgenin was given orally at the dosage level of 50, 100 and 150 mg/kg for 21 days in a rat. The immunomodulatory activity on specific and non-specific immunity was studied by heamagglutination antibody (HA) titer, delayed type hypersensitivity (DTH) response and carbon clearance test. Immunosuppression in a rat was induced by using Cyclophosphamide (100 mg/kg, p.o.). Sheep red blood cells (SRBCs) were used as antigen (0.1ml 20% SRBCs). Result: Diosgenin exhibited significant increase in the production of antibody titer in response to SRBC antigen. A significant increase in both primary and secondary HA titer was observed in immunosuppressed group treated with Diosgenin when compared with negative control. A significant increase in the DTH response was observed in immunosuppressed animals treated with Diosgenin, pre-sensitized with SRBCs antigen. Diosgenin exhibited significant increase in phagocytic index against control group, indicating the stimulation of the reticuloendothelial system. Conclusion: The study indicates that Diosgenin triggers stimulatory effect on specific and nonspecific immune response. The immunostimulant effect of Diosgenin could be attributed due to its saponin glycoside.