Effect of Trimeric Myricetin Rhamnoside (TMR) in Carrageenan-induced Inflammation and Caecal Ligation and Puncture-induced Lung Oxidative Stress in Mice.

The Eugenia jambolana is used in folklore medicine. Leaves of E. jambolana contain flavonoids as their active constituents which possess in vitro antiinflammatory, antioxidant and the antimicrobial activity. The aim of the present study was to investigate the antiinflammatory and antioxidant effects of a flavonoid glucoside, trimeric myricetin rhamnoside (TMR) isolated from leaves of E. jambolana. TMR was studied for antiinflammatory activity in carrageenan-induced hind paw oedema and antioxidant activity in lung by caecal ligation and puncture (CLP)-induced sepsis in mice. Results of the present study indicated that TMR significantly attenuated the oedema, myeloperoxidase (MPO), cytokines and prostaglandin levels in the paw after 5 h of carrageenan injection as compared to vehicle control. It also reduced the lung MPO, lipid peroxides, and serum nitrite plus nitrate levels and increased lung reduced glutathione levels 20 h of CLP as compared to vehicle control. Thus the results of this study concluded that the TMR appears to have potential benefits in diseases that are mediated by both inflammation and oxidative stress and support the pharmacological basis of use of E. jambolana plant as traditional herbal medicine for the treatment of inflammatory diseases.

Protective effect of alcoholic extract of stem of Entada pursaetha in dextran sulphate sodium-induced colitis in mice.

Oxidative stress has been shown to play a critical role in the pathogenesis of ulcerative colitis (UC). Entada pursaetha has been demonstrated to have antioxidant and anti-inflammatory effects. In this study, we investigated the effects of stem of alcoholic extract of E. pursaetha (PSE) in dextran sodium sulfate (DSS)-induced colitis in mice. The protective effect of PSE was determined at three different doses of 30, 100 and 300 mg/kg body weight by oral gavage for 7 days. Morphological (colon length and colon weight/length ratio), clinical (disease activity index) and macroscopic (damage score) features were determined using standard criteria. Lipid peroxides (determined as malonaldehyde; MDA), enzymatic (superoxide dismutase; SOD and catalase; CAT) and non- enzymatic antioxidants (reduced glutathione; GSH), nitrate and nitrite (NOx) levels and myeloperoxidase (PO) activity in colon tissues were determined. The DSS damaged the colonic tissue, increased MPO activity, lipid peroxidation and NOx levels, reduced the antioxidant enzymes and glutathione and lowered the body weight. PSE significantly reduced the inflammation of colon and reversed the increase in MPO activity induced by DSS. It also significantly increased the SOD and catalase activities and did not elicit any effect on depleted levels of GSH in the colonic tissue. In addition, PSE also significantly decreased colonic NOx and MDA levels compared to DSS-treated mice; reduced both infiltration of inflammatory cells and the mucosal damage in colon on histopathological examination. The results suggested the protective potential of PSE in DSS-induced colitis and this might be attributed to its anti-inflammatory and antioxidant activities.

Betulinic acid attenuates renal oxidative stress and inflammation in experimental model of murine polymicrobial sepsis.

Sepsis is a common cause of acute kidney injury (AKI) and is associated with substantial morbidity and mortality. Objective of the study was to evaluate the effect of betulinic acid, a triterpenoid in sepsis-induced AKI using cecal ligation puncture (CLP) mouse model. Mice subjected to CLP developed histologic AKI at 18h after CLP. There was an increase in renal proinflammatory response (nuclear factor-kappa B expression, tumor necrosis factor-alpha, interleukin (IL)-6 and IL-10), matrix metalloproteinase-9, plasma creatinine, renal neutrophil gelatinase-associated lipocalin and oxidant stress response (malondialdehyde, inducible nitric oxide synthase, total nitrite and superoxide); decrease in anti-oxidant levels (superoxide dismutase and catalase) at 18h of CLP. However, BA pretreatment at the doses of 10 and 30mg/kg prevented the CLP-induced kidney damage by restoring the aforementioned inflammatory mediators, oxidant and anti-oxidant imbalance. These evidences suggest that, the protective effects of BA on kidney are associated with defending action against inflammatory and oxidative stress response in CLP mice and BA could be potential therapeutic agent in sepsis-induced AKI.

Betulinic acid attenuates lung injury by modulation of inflammatory cytokine response in experimentally-induced polymicrobial sepsis in mice.

Sepsis commonly progresses to acute lung injury (ALI), an inflammatory lung disease with high morbidity and mortality. Septic ALI is characterized by excessive production of proinflammatory mediators. It remained refractory to present therapies and new therapies need to be developed to improve further clinical outcomes. Betulinic acid (BA), a pentacyclic lupane group triterpenoid has been shown to have anti-inflammatory activities in many studies. However, its therapeutic efficacy in polymicrobial septic ALI is yet unknown. Therefore, we investigated the effects of BA on septic ALI using cecal ligation and puncture (CLP) model in mice. Vehicle or BA (3, 10, and 30mg/kg) was administered intraperitoneally, 3 times (0, 24 and 48h) before CLP and CLP was done on 49(th)h of the study. Survival rate was observed till 120h post CLP. Lung tissues were collected for analysis by sacrificing mice 18h post CLP. BA at 10 and 30mg/kg dose significantly reduced sepsis-induced mortality and lung injury as implied by attenuated lung histopathological changes, decreased protein and neutrophils infiltration. BA also decreased lung NF-κB expression, cytokine, intercellular adhesion molecule-1, monocyte chemoattractant protein-1 and matrix metalloproteinase-9 levels. These evidences suggest that, the protective effects of BA on lungs are associated with defending action against inflammatory response and BA could be a potential modulatory agent of inflammation in sepsis-induced ALI.

Effect of S-methylisothiourea, an inducible nitric oxide synthase inhibitor, in joint pain and pathology in surgically induced model of osteoarthritis.

The aim of the present study was to evaluate in vivo modulatory effect of S-methylisothiourea (SMT), a preferential inhibitor of inducible nitric oxide synthase (iNOS) on pain and pathology in the surgical model of osteoarthritis (OA) in rats. The OA was produced by the anterior cruciate ligament transection (ACLT) and medial meniscectomy (MMx) of right knee. SMT was administered 1 day prior to the production of OA and continued up to day 42 postoperation. Mechanical hyperalgesia, thermal hyperalgesia, tail flick latency after repeated flexion and extension of OA knee and knee diameter of right knee were determined at weekly intervals. Serum levels of IL-1ß, TNF-α and nitrite concentration were determined at the end of the experiment. Glycosaminoglycan (GAG) content, collagen content and histopathological evaluation of articular cartilage were also determined at the end of the experiment. SMT reduced mechanical hyperalgesia and the serum levels of IL-1ß, TNF-α and nitrite. Further, SMT reduced the loss of GAG from articular cartilage. Microscopically, SMT reduced the severity of the cartilage lesion. The results indicate the effectiveness of SMT in attenuating the pain and pathology of experimental OA phase by reducing the production of nitric oxide and interleukin-1ß and tumor necrosis factor-α, which are known to play a major role in the pathophysiology of OA.

Chondroprotective and anti-inflammatory effects of S-methylisothiourea, an inducible nitric oxide synthase inhibitor in cartilage and synovial explants model of osteoarthritis.

OBJECTIVES: To study the chondroprotective and anti-inflammatory potential of inducible nitric oxide synthase (iNOS) inhibitor S-methylisothiourea (SMT) in in-vitro model. METHODS: Rabbit cartilage explants were stimulated with recombinant human interleukin 1ß (rhIL-1ß), and the chondroprotective and anti-inflammatory effects of SMT were investigated. Rat synovial explants were stimulated with LPS, and the anti-inflammatory effect of SMT on synovium was studied. To examine the role of SMT in synovial inflammation mediated cartilage damage, LPS stimulated synovial explants were cultured with dead cartilage with or without SMT for 72 h. The culture medium was analysed for sulfated glycosaminoglycans (GAGs) and hydroxyproline as measure of proteoglycans and collagen degradation, respectively. KEY FINDINGS: SMT significantly reduced GAGs, hydroxyproline, matrix metalloproteinase (MMP)-13, tumour necrosis factor alpha (TNF-α), prostaglindin E2 (PGE2 ) and nitrite release in stimulated rabbit cartilage media indicating chondroprotective and anti-inflammatory effects of SMT in osteoarthritis (OA). Stimulated synovial explants caused release of nitrite, PGE2 , IL-1ß and TNF-α in the medium which were significantly reduced by SMT indicating its anti-inflammatory action. SMT significantly reduced GAGs and hydroxyproline in medium and shown protective effect against synovium-mediated cartilage damage. CONCLUSIONS: SMT inhibited cartilage degradation, synovial inflammation and synovium-mediated cartilage damage, suggesting that SMT may be an agent for pharmacological intervention in OA.