Background: Various compounds of plant origin have been widely investigated since ancient times for their possible immunomodulatory properties as well as for the treatment of a wide range of diseases.
Objective: To study the immunomodulatory functions of the aqueous extract of the seeds of Abrus precatorius commonly known as Indian liquorice (Fabaceae), a medicinal plant native to central India.
Methods: Swiss albino mice were intraperitoneally treated with three doses (0.75, 1.25 and 2.5 μg/kg b.w.) of extract for 7 days. Relative organ weight, delayed type hypersensitivity (DTH) response, haemagglutination titre (HT) and Phagocytic index (PI) were studied in various groups of animals.
Results: The results showed no significant difference in relative organ weight of spleen, liver, thymus and kidney in various groups of animals. Treatment of rats with increasing concentrations of the extract decreased the footpad thickness indicating a dose related inhibitory effect of the extract on delayed type hypersensitivity. In the HT test, the plant extract showed a suppressive effect at all doses, and these changes were significant as the dose increased. Phagocytic index was also increased in a dose dependent manner.
Conclusion: The reduction of antibody titre, delayed type hypersensitivity response and the increase in phagocytic index indicates that Abrus precatorius has an inhibitory effect on the immune functions in mice.