Immunomodulatory and cellular anti-oxidant activities of an aqueous extract of Limoniastrum guyonianum gall

Ethnopharmacological relevance: Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses to disease/infection/etc. or to ameliorate immune based pathologies (i.e., inflammation, autoimmune associated diseases, etc.). In this particular study, the immunomodulatory potential of gall aqueous extract from Limoniastrum guyonianum Boiss. (Zita) was assessed in vitro.

Materials and methods: The effect of G extract on splenocytes proliferation and NK activity were assessed by MTT test. The induction of NO production and the phagocytic activity of macrophages were evaluated in vitro. Activation of the cellular anti-oxidant activity in splenocytes was determined by measuring the fluorescence of the DCF product.

Results: The studies first demonstrated that the extract could enhance lysosomal enzyme activity and nitrite oxide production in murine peritoneal macrophages, suggesting a potential role in activation of these cells. In studies to assess potential effects on humoral immunity, the results indicated that the extract could significantly promote LPS-stimulated splenocyte proliferation implying a potential activation of B-cells and enhanced humoral immune responses in hosts given this natural product. In studies to assess any effects of extract on cellular immunity, the results showed that the extract significantly enhanced the killing activity of isolated NK cells but had negligible effects on mitogen-induced proliferation of splenic T-cells. Considerable effects were also observed on the cellular anti-oxidant activity.

Conclusion: We conclude from these studies that aqueous extract from L. guyonianum gall exhibited an immunomodulator effect which could be ascribed, in part, to its cytoprotective effect via its anti-oxidant capacity. Furthermore, these results suggest that L. guyonianum gall extract contains potent components such as flavonoids which should be potentially used to modulate immune cell functions in physiological and pathological conditions.