Iron modulatory property of a polysaccharide from Indian medicinal plant .

Despite being an essential element for normal functioning of cells and organisms, iron, in excess, can induce oxidative stress by generating reactive oxygen species. A water-soluble, non-toxic iron chelator can reduce the iron-induced oxidative stress in the body as well as help in extricating excess iron. Herein, we report an -derived antioxidant polysaccharide (OSP) that inhibits the deleterious effect of iron.

Molecular events in the activation of B cells and macrophages by a non-microbial TLR4 agonist, G1-4A from Tinospora cordifolia.

G1-4A, a polysaccharide from an Indian medicinal plant Tinospora cordifolia, was recently shown to protect mice against septic shock by modulating the proinflammatory cytokines. G1-4A also activated B cells polyclonally. The present report describes in detail the molecular events associated with G1-4A-induced immunomodulation in vitro and in vivo.

G1-4A, an immunomodulatory polysaccharide from Tinospora cordifolia, modulates macrophage responses and protects mice against lipopolysaccharide induced endotoxic shock.

Pro-inflammatory cytokines are known to be the mediators of endotoxic shock and several immunomodulatory herbs can modulate the expression of these cytokines. Therefore we have investigated the possibility of using an arabinogalactan polysaccharide, G1-4A, from the stem of Tinospora cordifolia, for protection against endotoxin induced sepsis. There was 100% protection against lipopolysaccharide (LPS) induced mortality in mice pretreated with G1-4A.

Antioxidant and radioprotective properties of an Ocimum sanctum polysaccharide.

The antioxidant activity of two polysaccharides isolated from the Indian medicinal plants, Ocimum sanctum and Tinospora malabarica, was studied. Only the O. sanctum polysaccharide (OSP) showed significant activity.

Structural confirmation of decussatin, a Swertia decussata xanthone.

Reinvestigation of the plant, Swertia decussata resulted in the isolation of four antioxidant xanthones, which were characterized as 1-hydroxy-3,7,8-trimethoxy, 1,8-dihydroxy-3,7-dimethoxy, 1,7-dihydroxy-3,8-dimethoxy and 1,7,8-trihydroxy-3-methoxyxanthones. The structural ambiguity of the first compound was settled by ASIS-NMR and 2D NOESY spectroscopy.

Antioxidant activities of Swertia decussata xanthones.

The lipid peroxidation inhibitory activities of four hydroxyxanthones, isolated from the whole plant Swertia decussata, were evaluated for the first time. The most promising antioxidant among the xanthones, 1,7,8-trihydroxy-3-methoxyxanthone (swertianine, 4) was also tested for its scavenging potential against DPPH and superoxide radicals. The data clearly revealed good antioxidant activity of the xanthones, especially 4 which also showed strong protection against y-ray induced pBR322 DNA damage.

Radioprotective property of polysaccharide in Tinospora cordifolia.

Radioprotective activity of a polysaccharide preparation from the Indian medicinal plant. Tinospora cordifolia Miers has been established using Saccharomyces cerevisiae X2180 strain as the in vivo test model. The entire activity could be attributed to the radical scavenging capacity of the preparation, as it did not enhance the expression of the protective enzymes, catalase and superoxide dismutase in the yeast cells.

Antioxidant properties of a Tinospora cordifolia polysaccharide against iron-mediated lipid damage and gamma-ray induced protein damage.

The antioxidant activity of an arabinogalactan polysaccharide (TSP) isolated from Tinospora cordifolia, an Indian medicinal plant, was studied. The polysaccharide showed good protection against iron-mediated lipid peroxidation of rat brain homogenate as revealed by the thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxide (LOOH) assays. TSP also provided significant protection to protein against gamma-ray induced damage.

Protective activities of some phenolic 1,3-diketones against lipid peroxidation: possible involvement of the 1,3-diketone moiety.

The protective activities of four ginger-derived phenolic 1,3-diketones (1-4) and curcumin (5) against lipid peroxidation was studied by using different biologically relevant model systems and pulse radiolysis. The extraordinary activity of 5 vis-à-vis 1-4 against Fe(2+)-mediated peroxidation may be attributed to the additional phenolic hydroxy group in the former, which lends it better iron-chelating and radical-scavenging properties. In iron-independent peroxidation, however, the ginger constituent [6]-dehydrogingerdione (1) showed activity comparable to that of 5; this indicates its higher affinity for the lipid peroxide radical (LOO(.