Anjali Pandey

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.

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.

Saponins as novel TNF-α inhibitors: isolation of saponins and a nor-pseudoguaianolide from Parthenium hysterophorus

Two novel saponins and a 13-nor-pseudoguaianolide designated as hysterolactone were isolated from Parthenium hysterophorus. The two saponins were found to be potent inhibitors of TNF-alpha. Their mode of inhibition was studied through molecular modeling. The wet lab results were in concordance with the data obtained from docking experiments.

Semi-synthetic analogs of pinitol as potential inhibitors of TNF-α cytokine expression in human neutrophils

Semi-synthetic analogs of pinitol were subjected to screening by determining TNF-alpha expression in human neutrophils using flowcytometry. Among the tested compounds, three derivatives displayed more than 50% inhibition of TNF-alpha cytokine secretion in LPS induced stimulated neutrophils and can be considered as potent anti-inflammatory moieties.

Hydroxychavicol inhibits immune responses to mitigate cognitive dysfunction in rats.

This study was carried out to investigate the protective effect of Hydroxychavicol (HC), a phenolic compound derived from Piper betel on experimentally induced Alzheimers disease (AD) in rat. HC at graded doses administered orally once daily for a duration of 21 days significantly improved the cognitive impairment and attenuated the elevated levels of pro-inflammatory cytokines like IL-1 beta, TNF alpha, IL-6, nitric oxide, lipid peroxidation and both β- and γ-secretase enzymatic activities. Chronic oral administration of HC also significantly reversed the decline in acetyl cholinesterase and glutathione (GSH) activity induced by streptozotocin (STZ) injection. The results also suggest the inhibition of elevated levels of CD3+ T cells and CD19+ B cells as well as CD3+ T cell specific IFN-γ in blood of the experimental animals. There was however no change in blood glucose levels in the animals treated with HC. The result of the present study demonstrates the effectiveness of HC in preventing the cognitive deficit.

Amelioration of adjuvant induced arthritis by apocynin

The premise of the study was to investigate the antiarthritic potential of apocynin (APO) in Balb/c mice (in vivo). The experiment showed a dose‐dependent decrease in oedema and showed a suppression of proinflammatory cytokines such as TNF‐α and IL‐1β and mediators such as prostaglandin E2 (PGE2) and LTB4. At oral doses of 0.5, 1.0, 2.0 and 4.0 mg/kg once daily during the course of the experiment, APO induced an inhibition of T cell mediated immune response causing suppression of CD4+ and CD8+ T cells and of intracellular interferon‐gamma (IFN‐γ) by flow cytometry in arthritic mice. In parallel there was a dose‐dependent inhibition in vascular permeability causing an inhibition in the migration of leucocytes and exudate volume at the site of the inflammatory reaction. These observations validate the immunoregulatory potential of apocynin. Copyright

Downregulation of pro‐inflammatory cytokines by lupeol measured using cytometric bead array immunoassay

The objective of the study was to investigate the activity of Lupeol (LUP) on proinflammatory and anti‐inflammatory cytokines in the pleural exudate from male swiss albino mice. We applied Cytometric bead array technology for simultaneously measurement of these cytokines in pleurisy induced mice treated with lupeol in graded oral doses. Cytometric bead array uses the sensitivity of amplified fluorescence detection by flowcytometer to measure soluble analytes in a particle based immune assay. This assay can accurately quantitate 5 cytokines in a 50 microlitre sample volume. Oral administration of LUP at doses of 25, 50, 100 and 200 mg/kg p.o. produced dose related inhibition of IL‐2, IFN‐gamma and TNF‐α in the pleural exudate with the most significant effect at 100 mg/kg oral dose. LUP had a non significant inhibitory effect on the levels of IL‐4 and IL‐5. Copyright

Modulation of Th1/Th2 cytokines and inflammatory mediators by hydroxychavicol in adjuvant induced arthritic tissues

The present study was undertaken to investigate the anti-arthritic activity of hydroxychavicol (HC) a major phenolic compound isolated from the aqueous extract leaves of plant Piper betle (Piperaceae). The compound showed significant lowering of pro-inflammatory (Th1) cytokine levels in arthritic paw tissue homogenate supernatant viz. IL-2, IFN-gamma, and TNF-alpha with maximum inhibition at higher dose levels of 2 and 4 mg/kg p.o. and enhanced the production of anti-inflammatory (Th2) cytokines IL-4 and IL-5 estimated by cytometric bead array immunoassay. Cytometric bead array uses the sensitivity of amplified fluorescence detection by flowcytometer to measure soluble analytes in a particle based immune assay. This assay can accurately quantitate five cytokines in a 50-microl sample volume. The T-helper (Th1) deviated cells produce detectable level of tumor necrosis factor (TNF-alpha), interleukin-2 (IL-2), and interferon-gamma (IFN-gamma), while the Th2 deviated cells produce significant amount of interleukin-4 (IL-4) and interleukin-5 (IL-5). HC at graded doses also significantly decreased the expression of IL-1beta, PGE(2), LTB(4), and nitric oxide levels showing significant inhibition of these parameters. Elevated levels of CD4(+) T cell specific interferon-gamma (IFN-gamma) in splenocytes of arthritic animals was also inhibited in treated animals. The oral LD(0) in both mice and rats was more than 1000 mg/kg.

Anti-inflammatory terpenoids from Boswellia ovalifoliolata

Ten compounds, including three new compounds (1–3, one sesquiterpenoid and two triterpenoids), were isolated and characterized from the ethanolic extract of oleo-gum-resin from Boswellia ovalifoliolata. It is noteworthy that, for the first time, compound 4 has been reported from any of Boswellia species, and 5–9 from B. ovalifoliolata. These isolated compounds were screened for TNF-α inhibition and the results showed that 2 and 5 significantly inhibited the expression of TNF-α at 1 μM, whereas inhibition by rolipram (a standard TNF-α inhibitor) occurred at 100 μM. Furthermore, 2 and 5 were found to considerably reduce levels of interleukin (IL-6 and IL-8) and nitric oxide (NO) production, which suggests they have anti-inflammatory potential and possible therapeutic uses.

Anti-arthritogenic effect of Saponin-1 by alteration of Th1/Th2 cytokine paradigm in arthritic mice.

OBJECTIVE & DESIGN Investigation was carried out on Saponin 1 (SAP-1), a novel molecule isolated from Parthenium hysterophorus, on proinflammatory (Th1) & anti-inflammatory (Th2) cytokines in blood of arthritic balb/c mice. METHODS Adjuvant induced developing inflammatory arthritis was induced in mice which were treated with SAP-1 in graded oral doses. The molecular markers were determined using Flow Cytometry which uses sensitivity of amplified fluorescence detection to measure soluble analytes in particle based immune assay. The T-helper (Th1) deviated cells produce detectable level of Tumor necrosis factor (TNF-alpha), interleukin-2 (IL-2) & interferon-gamma (IFN-gamma), while the Th2 deviated cells produce significant amount of interleukin-4 (IL-4) and interleukin-5 (IL-5). RESULTS SAP-1 at graded oral doses inhibited expression of IFN-gamma & TNF-alpha in serum & correspondingly increased expression of IL-4 significantly. SAP-1 also inhibited IL-17 and CD4(+)CD25(+) cell population showing to have suppressive effect on Th-17 pathway as well as T-regulatory cells. It also suppressed the increased levels of pro-inflammatory mediators like IL-1β and NO. Inhibitors of Cox-2 and MCP-1 provide effective improvements in signs and symptoms of Rheumatoid Arthritis. SAP-1 decreased the elevated concentration of both COX-2 and MCP-1 in arthritic animals. CONCLUSIONS SAP-1 diminishes Th1 immunity activation, a primary cause of arthritis, in favour of Th2 dominance, which reduces arthritic condition in mice displaying immune-modulatory potential.