Haider A. Khan

Modulation of the oxidative stress and inflammatory cytokine response by thymoquinone in the collagen induced arthritis in Wistar rats.

Thymoquinone (TQ) is the major active compound derived from Nigella sativa. Our aim of this work was to evaluate the antioxidant and antiarthritic activity of TQ in Wistar rat by collagen induced arthritis (CIA). TQ was administered at a dose of 5mgkg(-1) body weight once daily for 21days. The effects of treatment in the rats were assessed by biochemical (articular elastase, MPO, LPO, GSH, catalase, SOD and NO), inflammatory mediators (IL-1β, IL-6, TNF-α, IL-10, IFN-γ and PGE(2)) and histological studies in joints. TQ was effective in bringing significant changes on all the parameters (articular elastase, MPO, LPO, GSH, catalase, SOD and NO) studied. Oral administration of TQ resulted in significantly reduced the levels of pro-inflammatory mediators (IL-1β, IL-6, TNF-α, IFN-γ and PGE(2)) and increased level of IL-10. The protective effects of TQ against RA were also evident from the decrease in arthritis scoring and bone histology. In conclusion, the fact that TQ abolished a number of factors known to be involved in RA pathogenesis indicates that the administration of thymoquinone may have potential value in the treatment of inflammatory disease.

Piperine ameliorates oxidative stress, inflammation and histological outcome in collagen induced arthritis

OBJECTIVES Piperine, a main component of Piper species, is a plant alkaloid with a long history of medical use in a variety of inflammatory disorders like rheumatoid arthritis. Due to side effects in current treatment modalities of rheumatoid arthritis, the interest in alternative, well tolerated anti-inflammatory remedies has re-emerged. The aim of this work was to evaluate the anti-inflammatory and antiarthritic effects of piperine. METHODS Arthritis was induced in male Wistar rats by collagen induced arthritis (CIA) method. Piperine was administered at a dose of 100mgkg(-1) and indomethacin at 1mgkg(-1) body weight once daily for 21days. The effects of treatment in the rats were assessed by biochemical (articular elastase, MPO, LPO, GSH, Catalase, SOD and NO), inflammatory mediators (IL-1β, TNF-α, IL-10 and PGE2) and histological studies in joints. RESULTS Piperine was effective in bringing significant changes on all the parameters (articular elastase, MPO, LPO, GSH, Catalase, SOD and NO) studied. Oral administration of piperine resulted in significantly reduced the levels of pro-inflammatory mediators (IL-1β, TNF-α and PGE2) and increased level of IL-10. The protective effects of piperine against RA were also evident from the decrease in arthritis scoring and bone histology. CONCLUSIONS In conclusion, the fact that piperine alter a number of factors known to be involved in RA pathogenesis indicates that piperine can be used similar to indomethacin as a safe and effective therapy for CIA and may be useful in the treatment of rheumatoid arthritis.

Boswellia serrata extract attenuates inflammatory mediators and oxidative stress in collagen induced arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory disease which leads to destruction of joints. Current treatment modalities for RA either produce symptomatic relief (NSAIDs) or modify the disease process (DMARDs). Though effective, their use is also limited by their side effects. As a result, the interest in alternative, well tolerated anti-inflammatory remedies has re-emerged. Our aim was to evaluate the antioxidant and antiarthritic activity of Boswellia serrata gum resin extract (BSE) in collagen induced arthritis. Arthritis was induced in male Wistar rats by collagen induced arthritis (CIA) method. BSE was administered at doses of 100 and 200mg/kg body weight once daily for 21 days. The effects of treatment in the rats were assessed by biochemical (articular elastase, MPO, LPO, GSH, catalase, SOD and NO), inflammatory mediators (IL-1β, IL-6, TNF-α, IL-10, IFN-γ and PGE2), and histological studies in joints. BSE was effective in bringing significant changes on all the parameters (articular elastase, MPO, LPO, GSH, catalase, SOD and NO) studied. Oral administration of BSE resulted in significantly reduced levels of inflammatory mediators (IL-1β, IL-6, TNF-α, IFN-γ and PGE2), and increased level of IL-10. The protective effects of BSE against RA were also evident from the decrease in arthritis scoring and bone histology. The abilities to inhibit proinflammatory cytokines and modulation of antioxidant status suggest that the protective effect of Boswellia serrata extract on arthritis in rats might be mediated via the modulation of immune system.

Podophyllum hexandrum Offers Radioprotection by Modulating Free Radical Flux: Role of Aryl-Tetralin Lignans

We have evaluated the effect of variation in aryl-tetralin lignans on the radioprotective properties of Podophyllum hexandrum. Two fractionated fractions of P. hexandrum [methanolic (S1) and chloroform fractions (S2)], with varying aryl-tetralin lignan content were utilized for the present study. The peroxyl ion scavenging potentials of S1 and S2 were found to be comparable [i.e. 45.88% (S1) and 41% (S2)] after a 48 h interval in a time-dependent study, whereas in a 2 h study, S2 exhibited significant (P < 0.05) antioxidant activity in different metal ion + flux states. In the aqueous phase, S2 exhibited non-site-specific reactive oxygen species scavenging activity, i.e. 73.12% inhibition at 500 μg ml−1. S1 exhibited 58.40 ± 0.8% inhibition (at 0.025 μg ml−1) of the formation of reactive nitrite radicals, comparable to S2 (52.45 ± 0.825%), and also showed 45.01% site-specific activity (1000 μg ml−1), along with significant (P < 0.05) electron donation potential (50–2000 μg ml−1) compared to S2. Such activities of S1 could be attributed to the significantly (P < 0.05) higher levels of podophyllotoxin β-d-glucopyranoside (16.5 times) and demethyl podophyllotoxin glucoside (2.9 times) compared with S2. Together, these findings clearly prove that aryl-tetralin lignan content influences the radiation protective potential of the Podophyllum fractions to a great extent.

Scorpion venom (Odontobuthus doriae) induces apoptosis by depolarization of mitochondria and reduces S-phase population in human breast cancer cells (MCF-7)

Venom of some species of scorpions induces apoptosis and arrests proliferation in cancer cells. This is an important property that can be harnessed and can lead to isolation of compounds of therapeutic importance in cancer research. Cytotoxicity was investigated using MTT reduction and confirmed with lactate dehydrogenase release following venom exposure. Apoptosis was evaluated with determination of mitochondrial membrane potential, reactive nitrogen species assay, measurement of Caspase-3 activity and DNA fragmentation analysis. To confirm that venom can inhibit DNA synthesis in proliferating breast cancer cells, immunocytochemical detection of BrdU incorporation was done. Our results demonstrated that venom of Odontobuthus doriae not only induced apoptosis but lead to the inhibition of DNA synthesis in human breast cancer cells (MCF-7). Cell viability decreased with parallel increment of LDH release in dose dependent manner after treatment with varying concentrations of venom. Moreover, venom depleted cellular antioxidants evidenced by depression of GSH and Catalases and concomitantly increased reactive nitrogen intermediates (RNI). These events were related to the depolarization of mitochondria and associated Caspase-3 activation following venom treatment in a concentration dependent manner. Finally, fragmentation of nuclear DNA following venom treatment confirmed the apoptotic property of the said venom. These results suggest that venom of O. doriae can be potential source for the isolation of effective anti-proliferative and apoptotic molecules.

Scorpion (Androctonus crassicauda) venom limits growth of transformed cells (SH-SY5Y and MCF-7) by cytotoxicity and cell cycle arrest

The purpose of study was to examine the cytotoxic and anti-cancer properties along with addressing the plausible pathway followed by scorpion venom to reduce cell viability in SH-SY5Y and MCF-7 cells. Following exposure of cells with scorpion venom, cytotoxicity was estimated using MTT and lactate dehydrogenase assays. Apoptotic effects were measured by assessment of mitochondrial membrane potential, reactive nitrogen species, DNA fragmentation, and caspase-3 activity whereas antiproliferative effect was assayed using BrdU incorporation. Our results indicate that scorpion venom causes suppression of proliferation by arresting S-phase and induction of apoptosis through increased nitric oxide production, caspase-3 activity and depolarization of mitochondrial membrane. Induction of apoptosis and arrest of DNA synthesis are critical determinant factors for development of anti cancer drugs. These properties may lead to isolation of effective molecule(s) with potential anticancer activity from scorpion venom of Androctonus crassicauda.

Effect of cadmium chloride exposure during the induction of collagen induced arthritis.

The precise cause of autoimmune diseases such as rheumatoid arthritis remains uncertain. Collagen induced arthritis (CIA) in animals is the most commonly used model of human rheumatoid arthritis (RA). Exposure of humans and animals to toxic metals is widespread. Cadmium is one of the most prevalent nephrotoxic heavy metal, but it may cause other systemic toxicity as well. Cadmium may cause adverse health effects by impairment of the immune systems and induction of reactive oxygen species. Since rheumatoid arthritis pathogenesis involve immune system disorder and chronic inflammation, the present study has been designed to find out the effect of cadmium chloride exposure on clinical manifestation of development of collagen induced rheumatoid arthritis. Arthritis was induced in rats by intradermal injection of emulsion of type II collagen in Complete Freunds Adjuvant. Rats were treated with cadmium chloride dissolved in drinking water at concentrations of 5ppm and 50ppm for 21 days from day of immunization. The effects of cadmium in the rats were assessed by biochemical parameters (articular elastase, articular nitrite, lipid peroxidation, reduced glutathione, catalase and superoxide dismutase) histopathological analysis and immunohistochemical expression of pro-inflammatory cytokines in rat joint tissue. Histopathological changes further confirmed the biochemical and immunohistochemical results. Our results suggest that exposure to cadmium chloride during the induction phase of collagen induced arthritis abrogate disease development at lower dose whereas exacerbates at higher dose in Wistar rats.

Cytokinetics of adult rat SVZ after EAE

Cytokinetics regulating cell cycle division can be modulated by several endogenous factors. EAE (experimental autoimmune encephalomyelitis) increases proliferation of progenitor cells in the subventricular zone (SVZ). Using cumulative and single S phase labeling with 5-bromo-2-deoxyuridine, we examined cell cycle kinetics of neural progenitor cells in the SVZ after EAE. 20% of the SVZ cell population was proliferating in adjuvant control rats. However, EAE significantly increased them up to 27% and these cells had a cell cycle length (TC) of 15.6h, significantly (P<0.05) shorter than the 19 h TC in non EAE SVZ cells. Few TUNEL (+) cells were detected in the SVZ cells of adjuvant controls. EAE increased (P<0.05) TUNEL (+) nuclei in SVZ suggesting early stage progenitor cell death. Cell cycle phase analysis revealed that EAE substantially shortened the length of the G1 phase (9.6h) compared with the G1 phase of 12.25 h in adjuvant control SVZ cells (P<0.05). This reduction in G1 contributes to EAE-induced reduction of TC because no significant changes were detected on the length of S, G2 and M phases between the two groups. Our results show a surge in proliferating progenitor cells in the SVZ with concomitant increase in apoptotic cell death after EAE. Furthermore, increase in the SVZ proliferation contributes to EAE-induced neurogenesis and this increase is regulated by shortening the G1 phase. Our investigation suggests the activation of quiescent cells in SVZ to generate actively proliferating progenitors. Moreover, the increase in the cell death in proliferating population may contribute towards negative regulation of proliferative cell number and hence diminished regenerative capacity of CNS following EAE.

Quercetin prevents protein nitration and glycolytic block of proliferation in hydrogen peroxide insulted cultured neuronal precursor cells (NPCs): Implications on CNS regeneration

Survival along with optimal proliferation of neuronal precursors determines the outcomes of the endogenous cellular repair in CNS. Cellular-oxidation based cell death has been described in several neurodegenerative disorders. Therefore, this study was aimed at the identification of the potent targets of oxidative damage to the neuronal precursors and its effective prevention by a natural flavonoid, Quercetin. Neuronal precursor cells (NPCs), Nestin+ and GFAP (Glial fibrillary acidic protein)+ were isolated and cultured from adult rat SVZ (subventricular zone). These cells were challenged with a single dose of H2O2 (50μM) and/or pre-treated with different concentrations of Quercetin. H2O2 severely limited the cellular viability and expansion of the neurospheres. Cellular-oxidation studies revealed reduction in glutathione dependent redox buffering along with depletion of enzymatic cellular antioxidants that might potentiate the nitrite (NO2(-)) and superoxide anion (O2(-)) mediated peroxynitrite (ONOO(-)) formation and irreversible protein nitration. We identified depleted PK-M2 (M2 isoform of pyruvate kinase) activity and apoptosis of NPCs revealed by the genomic DNA fragmentation and elevated PARP (poly ADP ribose polymerase) activity along with increased Caspase activity initiated by severely depolarised mitochondrial membranes. However, the pre-treatment of Quercetin in a dose-response manner prevented these changes and restored the expansion of neurospheres preferably by neutralizing the oxidative conditions and thereby reducing peroxynitrite formation, protein nitration and PK-M2 depletion. Our results unravel the potential interactions of oxidative environment and respiration in the survival and activation of precursors and offer a promise shown by a natural flavonoid in the protective strategy for neuronal precursors of adult brain.

Amelioration of oxidative stress in the joint tissue may be the basis for the antiarthritic activity of Terminalia arjuna bark extract

In this study we have evaluated the antioxidant and antiarthritic activity of Terminalia arjuna bark extract (TABE) in collagen‐induced arthritis (CIA) in rats.