Repeated dose treatment of Tinospora cordifolia polysaccharide rich extract activates splenic antigen presenting cells with no associated organ toxicity

Abstract

Tinospora cordifolia is a medically valuable plant widely used in Ayurveda and has been attributed with immunomodulatory properties. We compared the immunomodulation of repeated doses of the purified polysaccharide G1-4A and polysaccharide-rich extract (PRE) of T. cordifolia in BALB/c mice. Since both had comparable effects, we further compared the repeated dose effects of 50 and 500 mg/kg b.w PRE per dose with particular emphasis on histological changes in different organs, splenic cell death and DNA damage and immunomodulation. In mice treated with both concentrations of PRE, no gross changes were observed in any organ by histopathological analyses along with normal biochemical parameters similar to control. There was no increase in splenic lymphocyte cell death or DNA damage. A significant increase in the number of splenic macrophages with no increase in phagocytosis was observed. Increased expression of phenotypic maturation markers was observed in splenic dendritic cells and not in bone marrow-derived dendritic cells of PRE-treated mice. Increased activation of B cells in response to mitogen with no change in such a response by T cells was also observed. These results from repeated dose experiments indicate that PRE treatment has no associated organ toxicity and activates antigen-presenting cells and thus can be used instead of G1-4A as a promising immunotherapeutic adjuvant.