Preliminary studies on the immunomodulatory and antioxidant properties of Selaginella species

Abstract

OBJECTIVE: To evaluate the immunomodulatory and antioxidant properties, if any, of S elaginella involvens, S. delicatula and S. wightii . MATERIALS AND METHODS: Immunomodulatory activity of the whole plants (water suspension) was studied in mice immunized with sheep RBC. The plant extracts were tested for their effect on lipid peroxidation ( in vitro and in vivo in mice), and for in vitro hydroxyl radical scavenging activity. The most promising extract (water extract of S. involvens ) was evaluated for its short-term toxicity in mice. RESULTS: The dried suspension (500 mg/kg) of the three plants did not influence humoral antibody titre and the number of antibody secreting cells in the mouse spleen. However, the plant suspensions as well as the water extracts (and not the other extracts) of the plants remarkably increased the weight of thymus in adult mice, and not in suckling mice. This effect was very marked in the case of S. involvens compared to the other two species. Although the water extract of all the three plants showed varying degrees of antioxidant activity, the antilipid peroxidation activity of S. involvens (water extract) was remarkable [EC50: 2 µg/ml]. This extract did not exhibit any conspicuous toxicity in mice in general, short-term toxicity evaluation. At high dose, serum cholesterol level was significantly reduced. CONCLUSION: Out of the three Selaginella species studied, the water extract of S. involvens has promising thymus growth stimulatory activity in adult mice and remarkable antilipid peroxidation property; these observations are of interest in view of tribal and folklore belief that this plant prolongs life span.