K.A. Suri

Studies on novel D-ring substituted steroidal pyrazolines as potential anticancer agents.

An efficient and facile synthesis of 17-pyrazolinyl derivatives of pregnenolone and their evaluation as potential anticancer agents against various human cancer cell lines are reported. The scheme involves the transformation of the starting pregnenolone acetate into pregnenolone, conversion of pregnenolone to the corresponding benzylidine derivatives and finally the conversion of this derivative to the stable steroidal 17-pyrazoline. Various compounds 4b, 4c, 4e, 4f, 4h and 4j showed significant cytotoxic activity especially against HT-29, HCT-15, 502713 cell lines.

Immunomodulatory activity of Asparagus racemosus on systemic Th1/Th2 immunity: Implications for immunoadjuvant potential

ETHNOPHARMACOLOGICAL RELEVANCE Roots of Asparagus racemosus Willd (Shatavari in vernacular) are widely used in Ayurveda as Rasayana for immunostimulation, galactogogue as also in treatment of conditions like ulcers and cancer. Various studies have indicated immunomodulatory properties of Shatavari root extracts and formulations. AIM OF THE STUDY To study the effect of standardized Asparagus racemosus root aqueous extract (ARE) on systemic Th1/Th2 immunity of SRBC sensitized animals. MATERIALS AND METHODS We used HPTLC to quantify steroidal saponins (Shatavarin IV, Immunoside) and flow cytometry to study effects of ARE on Th1/Th2 immunity. SRBC specific antibody titres and DTH responses were also monitored as markers of Th2 and Th1 responses, respectively. We also studied lymphocyte proliferation. Cyclosporin, cyclophosphamide and levamisole were used as controls. RESULTS Treatment with ARE (100mg/(kg b.w.p.o.)) resulted in significant increase of CD3(+) and CD4/CD8(+) percentages suggesting its effect on T cell activation. ARE treated animals showed significant up-regulation of Th1 (IL-2, IFN-g) and Th2 (IL-4) cytokines suggesting its mixed Th1/Th2 adjuvant activity. Consistent to this, ARE also showed higher antibody titres and DTH responses. ARE, in combination with LPS, Con A or SRBC, produced a significant proliferation suggesting effect on activated lymphocytes. CONCLUSION The study suggests mixed Th1/Th2 activity of ARE supports its immunoadjuvant potential.

Modulation of P-glycoprotein ATPase activity by some phytoconstituents.

In the present investigation 16 phytoconstituents, which are active moieties found in several medicinal herbs, have been evaluated for their P‐glycoprotein (P‐gp) stimulation/inhibition profiles using a P‐gp‐dependent ATPase assay in rat jejunal membrane (in vitro). Acteoside, agnuside, catechin, chlorogenic acid, picroside ‐II and santonin showed an inhibitory effect. Negundoside, picroside ‐I and oleanolic acid caused a stimulatory effect. Andrographolide, apocyanin, berberine, glycyrrhizin, magniferin and piperine produced a biphasic response (stimulation at low concentration and inhibition at high concentration). The results suggested that a possible interaction of these phytoconstituents at the level of P‐gp, could be an important parameter in determining their role in several key pharmacodynamic events. Copyright

Restoration of stress-induced altered T cell function and corresponding cytokines patterns by Withanolide A

This study was taken up to see the effect of Withanolide A (WS-1), a compound isolated from Withania somnifera root extract on chronic stress-induced alterations on T lymphocyte subset distribution and corresponding cytokine secretion patterns in experimental Swiss albino mice. Stress disturbs the homeostatic state of the organism and brings about behavioral, endocrine and immunological changes. The chronic suppression induced by stress depresses the immune functioning and increases susceptibility to diseases. Oral administration of WS-1 once daily at the graded doses of 0.25, 0.5, 1 and 2 mg/kg p.o. caused significant recovery of stress-induced depleted T cell population causing an increase in the expression of IL-2 and IFN-gamma (a signature cytokine of Th1 helper cells) and a decrease in the concentration of corticosterone in stressed experimental animals. It also reversed the restraint stress-induced increase in plasma alanine aminotransferase (ALT), aspartate aminotransferase(AST) and hepatic lipid peroxidation (LP) levels and improved the restraint stress-induced decrease in hepatic glutathione (GSH), and glycogen levels, thus showing the significant antistress potential of the test drug.

Immunomodulatory activity of biopolymeric fraction BOS 2000 from Boswellia serrata

Oral administration of BOS 2000 (1–10 mg/kg) elicited a dose related increase in the delayed hypersensitivity reaction (early 24 h and delayed 48 h) in mice. It also stimulated the IgM and IgG titre expressed in the form of plaques (PFC) and complement fixing antibody titre. The concentration of cytokines (IL‐4, IFN‐γ and TNF‐α) in serum with respect to T cell interactions, i.e. (CD4/CD8) and the proliferation of lymphocytes were significantly increased at 10 mg/kg compared with the control. The results in these studies demonstrated the immunostimulatory effect of BOS 2000 in a dose‐dependent manner with respect to the macrophage activation possibly expressing the phagocytosis and nitrite production by the enhancement of TNF‐α and IFN‐γ production as a mode of action. Copyright

Anti-inflammatory activity of the hydrosoluble fraction of Euphorbia royleana latex

The hydrosoluble fraction of Euphorbia royleana latex (AER), administered by gavage at doses of 50-200 mg/kg, showed dose-dependent anti-inflammatory and anti-arthritic effects in different acute and chronic test models in rats and mice. It reduced the exudate volume and the migration of leukocytes and showed a poor inhibitory effect on the granuloma formation induced by cotton pellets, while it had a low ulcerogenic score. The oral LD(50) was more than 1500 mg/kg in both rats and mice.

Immunological adjuvant effect of Boswellia serrata (BOS 2000) on specific antibody and cellular response to ovalbumin in mice.

In this study, the biopolymeric fraction BOS 2000 from Boswellia serrata was evaluated for its potential ability as adjuvants on the immune responses to ovalbumin (OVA) in mice. Balb/c mice were immunized subcutaneously with OVA 100 μg alone or with OVA 100 μg dissolved in saline containing alum (200 μg) or BOS 2000 (10, 20, 40 and 80 μg) on Days 1 and 15. Two weeks later, OVA specific antibodies in serum; concanavalin A (Con A), OVA stimulated splenocyte proliferation, CD4/CD8/CD80/CD86 analysis in spleen cells and its estimation of cytokines (IL-2 and IFN gamma) from cell culture supernatant were measured. OVA specific IgG, IgG1 and IgG2a antibody levels in serum were significantly enhanced by BOS 2000 (80 μg) compared with OVA control group. Moreover, the adjuvant effect of BOS 2000 (80 μg) on the OVA-specific IgG, IgG1, and IgG2a antibody responses to OVA in mice were more significant than those of alum. BOS 2000 significantly enhanced the Con A and OVA induced splenocyte proliferation in the OVA immunized mice especially at a dose of 80 μg (p<0.001). However, no significant differences were observed among the OVA group and OVA/alum group. At a dose of 80 μg (p<0.001), there was a significant increase in the CD4/CD8 and CD80/CD86 analysis in spleen cells and cytokine (IL-2 and IFN-gamma) profile in the spleen cell culture supernatant was observed. In conclusion, BOS 2000 seems to be a promising balanced Th1 and Th2 directing immunological adjuvants which can enhance the immunogenicity of vaccine.

Anti-histaminic, anti-inflammatory and bronchorelaxant activities of 2, 7-dimethyl-3-nitro-4H pyrido [1,2-a] pyrimidine-4-one

An immunopharmacological profile of 2, 7-dimethyl-3-nitro-4H pyrido [1,2-a] pyrimidine-4-one (P-I) has been investigated using in vitro and in vivo models representing various features of Type I allergy. P-I prevented compound 48/80-mediated histamine release from rat peritoneal mast cells. A promising anti-inflammatory activity of P-I was evident in active paw anaphylaxis (mice) and carragenan-induced paw edema (rat). P-I inhibited eosonophil accumulation and eosinophil peroxidase activity in bronchoalveolar lavage fluid from ovalbumin challenged balb/c mice: in these animals blood levels of IL-5, and CD4+ T cells also remained attenuated. A promising bronchorelaxant effect of P-I was observed in histamine-contracted guinea pig tracheal chain via its antagonism to H1 receptor. These findings were compared with some known compounds (ketotifen, cetirizine and promethazine). The anti-histaminic, anti-inflammatory and bronchorelaxant activities of P-I has been discussed in context with its potential profile as an anti-allergic and anti-asthmatic agent.

Possible role of macrophages induced by an irridoid glycoside (RLJ-NE-299A) in host defense mechanism

In order to explore the possible role of macrophages and other necessary immune competent (T and B) cells in the modulation of immune responses, an attempt was made to study the immunomodulatory effect of an irridoid glycoside (RLJ-NE-299A) isolated from the roots of Picrorhiza kurroa. Both in vitro and in vivo studies were used to evaluate the effect of RLJ-NE-299A on humoral, cellular, and phagocytic activity of macrophages. The data obtained in the present study showed that RLJ-NE-299A significantly increased sheep red blood cell (SRBC) and induced antibody (IgM and IgG) titer and delayed type hypersensitivity (DTH) reaction in mice. Besides augmenting the humoral and cell-mediated immune response, it induced macrophage phagocytosis and stimulated cytokine-induced macrophage activation and nitric oxide (NO) production, which resulted in a high degree of protection against Candida albicans and Salmonella typhimurium infections. Flow cytometric analysis indicated the enhanced expression of co-stimulatory surface molecules CD80 and CD86. The ability of RLJ-NE-299A to upregulate these cell surface antigens involved in antigen presentation may provide an explanation for the increased T-cell mediated immunity involving macrophages. Taken together this in vitro and in vivo preclinical data suggests that RLJ-NE-299A acts as an effective immunomodulator specifically to improve macrophage function during infections. The effects of this agent on these cells at concentrations relevant to in vivo therapy support its immunopharmacologic application to modify cellular immunity.

Podophyllum hexandrum-Mediated Survival Protection and Restoration of Other Cellular Injuries in Lethally Irradiated Mice

This study aims at the development of a safe and effective formulation to counter the effects of lethal irradiation. The sub-fraction (G-001M), prepared from Podophyllum hexandrum has rendered high degree of survival (>90%) at a dose of 6 mg kg−1 body weight (intramuscular) in lethally irradiated mice. Therapeutic dose of G-001M, at about 20 times lower concentration than its LD100, has revealed a DRF of 1.62. Comet assay studies in peripheral blood leukocytes have reflected that, treatment of G-001M before irradiation has significantly reduced DNA tail length (P < .001) and DNA damage score (P < .001), as compared to radiation-only group. Spleen cell counts in irradiated animals had declined drastically at the very first day of exposure, and the fall continued till the 5th day (P < .001). In the treated irradiated groups, there was a steep reduction in the counts initially, but this phase did not prolong. More than 60% decline in thymocytes of irradiated group animals was registered at 5 h of irradiation when compared with controls, and the fall progressed further downwards with the similar pace till 5th day of exposure (P < .001). At later intervals, thymus was found fully regressed. In G-001M pre-treated irradiated groups also, thymocytes decreased till the 5th day but thereafter rejuvenated and within 30 days of treatment the values were close to normal. Current studies have explicitly indicated that, G-001M in very small doses has not only rendered high survivability in lethally irradiated mice, but also protected their cellular DNA, besides supporting fast replenishment of the immune system.