Naresh Kumar Satti

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.

A rational approach for the design and synthesis of 1-acetyl-3,5-diaryl-4,5-dihydro(1H)pyrazoles as a new class of potential non-purine xanthine oxidase inhibitors.

Xanthine oxidase is a complex molybdoflavoprotein that catalyses the hydroxylation of xanthine to uric acid. Fifty three analogues of 1-acetyl-3,5-diaryl-4,5-dihydro(1H)pyrazoles were rationally designed and synthesized and evaluated for in vitro xanthine oxidase inhibitory activity for the first time. Some notions about structure activity relationships are presented. Six compounds 41, 42, 44, 46, 55 and 59 were found to be most active against XO with IC(50) ranging from 5.3 μM to 15.2 μM. The compound 59 emerged as the most potent XO inhibitor (IC(50)=5.3 μM). Some of the important interactions of 59 with the amino acid residues of active site of XO have been figured out by molecular modeling.

Terminalia chebula (fruit) prevents liver toxicity caused by sub-chronic administration of rifampicin, isoniazid and pyrazinamide in combination.

Terminalia chebula Gertn. (Combetraceae) is an important herbal drug in Ayurvedic pharmacopea. In the present study, a 95% ethanolic extract of T. chebula (fruit) (TC extract), which was chemically characterized on the basis of chebuloside II as a marker, was investigated for hepatoprotective activity against anti-tuberculosis (anti-TB) drug-induced toxicity. TC extract was found to prevent the hepatotoxicity caused by the administration of rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA) (in combination) in a sub-chronic mode (12 weeks). The hepatoprotective effect of TC extract could be attributed to its prominent anti-oxidative and membrane stabilizing activities. The changes in biochemical observations were supported by histological profile.

Effect of Emblica officinalis (fruit) against UVB-induced photo-aging in human skin fibroblasts.

ETHNOPHARMACOLOGICAL RELEVANCE Emblica officinalis fruit (EO), commonly known as Amla is a reputed traditional medicine and functional food used in Indian subcontinent. It has long been used in Indian folk medicine to treat liver diseases, stomach ulcers, inflammatory diseases, metabolic disorders, geriatric complaints, skin disorders and beauty care. AIM OF THE STUDY Recently, it has been shown to promote pro-collagen content and inhibit matrix metalloproteinase levels in skin fibroblast. The aim of the present study was to investigate the efficacy of EO to inhibit UVB-induced photo-aging in human skin fibroblasts. MATERIALS AND METHODS Mitochondrial activity of human skin fibroblasts was measured by MTT-assay. Quantifications of pro-collagen 1 and matrix metalloproteinase 1 (MMP-1) release were performed by immunoassay techniques. Hyaluronidase inhibition assay was studied in vitro using bovine testicular hyaluronidase and human umbilical cord hyaluronic acid. Cell cycle analysis was performed by flowcytometry using propidium iodide. RESULTS EO stimulated, the otherwise UVB inhibited cellular proliferation and protected pro-collagen 1 against UVB-induced depletion via inhibition of UVB-induced MMP-1 in skin fibroblasts (10-40 μg/mL, p>0.001). EO exhibited inhibitory activity of hyaluronidase (10-40 μg/mL, p>0.001). Treatment with EO also prevented UVB disturbed cell cycle to normal phase. CONCLUSION The results of the present study suggests that EO effectively inhibits UVB-induced photo-aging in human skin fibroblast via its strong ROS scavenging ability and its therapeutic and cosmetic applications remain to be explored.

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

Evaluation of the Antimicrobial, Antioxidant, and Anti-Inflammatory Activities of Hydroxychavicol for Its Potential Use as an Oral Care Agent

ABSTRACT Hydroxychavicol isolated from the chloroform extraction of aqueous extract of Piper betle leaves showed inhibitory activity against oral cavity pathogens. It exhibited an inhibitory effect on all of the oral cavity pathogens tested (MICs of 62.5 to 500 μg/ml) with a minimal bactericidal concentration that was twofold greater than the inhibitory concentration. Hydroxychavicol exhibited concentration-dependent killing of Streptococcus mutans ATCC 25175 up to 4× MIC and also prevented the formation of water-insoluble glucan. Interestingly, hydroxychavicol exhibited an extended postantibiotic effect of 6 to 7 h and prevented the emergence of mutants of S. mutans ATCC 25175 and Actinomyces viscosus ATCC 15987 at 2× MIC. Furthermore, it also inhibited the growth of biofilms generated by S. mutans and A. viscosus and reduced the preformed biofilms by these bacteria. Increased uptake of propidium iodide by hydroxychavicol-treated cells of S. mutans and A. viscosus indicated that hydroxychavicol probably works through the disruption of the permeability barrier of microbial membrane structures. Hydroxychavicol also exhibited potent antioxidant and anti-inflammatory activities. This was evident from its concentration-dependent inhibition of lipid peroxidation and significant suppression of tumor necrosis factor alpha expression in human neutrophils. Its efficacy against adherent cells of S. mutans in water-insoluble glucan in the presence of sucrose suggests that hydroxychavicol would be a useful compound for the development of antibacterial agents against oral pathogens and that it has great potential for use in mouthwash for preventing and treating oral infections.

N-(1,3-Diaryl-3-oxopropyl)amides as a new template for xanthine oxidase inhibitors.

A series of forty two N-(1,3-diaryl-3-oxopropyl)amides were synthesized via an efficient, modified Dakin-West reaction and were evaluated for in vitro xanthine oxidase inhibitory activity for the first time. Structure-activity relationship analyses have been presented. Selected active xanthine oxidase inhibitors (3r, 3s, and 3zh) were assessed in vivo to study their anti-hyperuricemic effect in potassium oxonate induced hyperuricemic mice model. Compound 3s emerged as the most potent xanthine oxidase inhibitor (IC(50)=2.45 μM) as well as the most potent anti-hyperuricemic agent. The basis of significant inhibition of xanthine oxidase by 3s was rationalized by its molecular docking into catalytic site of xanthine oxidase.

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.

Stimulatory effects of Cuminum cyminum and flavonoid glycoside on Cyclosporine-A and restraint stress induced immune-suppression in Swiss albino mice

Many herbs and spices are known to modulate the immune system and have been shown to restore the immunity in immuno-compromised individuals. Spices generally used to increase the taste and flavor of food also has the history of usage as an ayurvedic medicine. Therefore to explore the health modulating effects of Cuminum cyminum and to identify the active compound, immunomodulatory properties were evaluated using flowcytometry and ELISA in normal and immune-suppressed animals. C. cyminum and compound 1 stimulated the T cells and Th1 cytokines expression in normal animals. Swiss albino mice subjected to Cyclosporine-A induced immune-suppression were dosed orally with C. cyminum (25, 50, 100 and 200 mg/kg) on consecutive days. The results showed that administration significantly increased T cells (CD4 and CD8) count and Th1 predominant immune response in a dose dependent manner thereby suggesting immunomodulatory activity through modulation of T lymphocytes expression. In restraint stress induced immune-suppressed animals, compound 1 countered the depleted T lymphocytes, decreased the elevated corticosterone levels and size of adrenal glands and increased the weight of thymus and spleen. Based on the data we may conclude that C. cyminum is a potent immunomodulator and may develop as a lead to recover the immunity of immuno-compromised individuals.

Differential Effects of Chlorogenic Acid on Various Immunological Parameters Relevant to Rheumatoid Arthritis

Despite chlorogenic acid (CGA) being widely present in nature, particularly in the human diet, there is very little information regarding its pharmacological activities. The present investigation was carried out to investigate the antiarthritic activities of this compound in adjuvant induced‐arthritis in male Wistar rats, and to explore the underlying mechanisms of actions in view of immunological responses. We observed that CGA effectively controlled the total (CD3) and differentiated (CD4 and CD8) T cells count at the dose of 40 mg/kg. We also assessed the effect on co‐stimulatory molecules (CD28, CD80/86) and found that CGA efficiently suppressed CD80/86 but failed to bring any changes in the CD28 count, whereas ibuprofen (standard drug) resulted in highly significant inhibition of both. We next examined the effect on CD4+ T cells specific Th1/Th2 cytokines by flow cytometry and observed that CGA suppressed the Th1 cytokines in a highly significant manner but elevated Th2 cytokines with dose dependence. Results of the present investigation suggest that CGA is a potent antiarthritic agent. Copyright