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.

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.

Analgesic activity of Eugenia jambolana leave constituent: a dikaempferol rhamnopyranoside from ethyl acetate soluble fraction.

CONTEXT: Eugenia jambolana Lam. (Myrtaceae) is a medicinal plant used in folk medicine for the treatment of diabetes, inflammation, and pain. OBJECTIVE: We investigated the antinociceptive effect of kaempferol-7-O-α-l-rhamnopyranoside]- 4'-O-4'-[kaempferol-7-O-α-l-rhamnopyranoside (EJ-01), isolated from the E. jambolana leaves. MATERIALS AND METHODS: EJ-01 (3, 10, and 30 mg kg(-1), orally) was assessed for peripheral (formalin-nociception and acetic acid-writhing) and central (hot plate and tail flick test) analgesic activity in mice and the in vitro anti-inflammatory activity (25, 50, and 100 µg mL(-1)) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. RESULTS AND DISCUSSION: EJ-01 (10 and 30 mg kg(-1)) significantly inhibited mean writhing counts (37.74 and 36.83) in acetic acid writhing and paw licking time (55.16 and 45.66 s) in the late phase of the formalin test as compared with the respective control (60.66 and 104.33 s). EJ-01 did not show analgesic activity in central pain models. Significant reduction in the tumor necrosis factor (TNF)-α (295.48, 51.20, and 49.47 pg mL(-1)) and interleukin (IL)-1ß (59.38, 20.08, and 15.46 pg mL(-1)) levels were observed in EJ-01-treated medium (25, 50, and 100 µg mL(-1)) as compared with vehicle-treated control values (788.67 and 161.77 pg mL(-1)), respectively. Significant reduction in total nitrite plus nitrate (NOx) levels (70.80 nmol) was observed in the EJ-01-treated medium (100 µg mL(-1)) as compared with the vehicle-treated value (110.41 nmol). CONCLUSION: EJ-01 is a valuable analgesic constituent of E. jambolana leaves and this study supports the pharmacological basis for the use of this plant in traditional medicine for curing inflammatory pain.

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.

Protective effect of alcoholic extract of Entada pursaetha DC. against CCl4-induced hepatotoxicity in rats.

The alcoholic extract of stem of E. pursaetha (PSE, 30, 100, 300 mg/kg body weight, po for 7 days) showed hepatoprotective activity against CCl4 (2 mL/kg body weight, ip)-induced hepatotoxicity. The extract exhibited a significant dose-dependent hepatoprotective effect comparable to standard drug silymarin, by preventing increase in serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, and total bilirubin, lactate dehydrogenase; by lowering hepatic levels of malonaldehyde, nitrate-nitrite, myeloperoxidase activity; enhancing activities of antioxidant enzymes, superoxide dismutase, catalase and increasing reduced glutathione levels in liver, which suggests the antioxidant property of PSE. Histopathological studies also supported the above biochemical parameters. The results suggested that alcoholic extract of E. pursaetha possesses significant hepatoprotective activity in CCl4-induced acute hepatotoxicity in rats and this is likely to be mediated through its antioxidant activities.

Atorvastatin prevents vascular hyporeactivity to norepinephrine in sepsis: role of nitric oxide and α1-adrenoceptor mRNA expression.

Hyporeactivity to vasoconstrictors is one of the clinical manifestations of sepsis in man and experimental animals. The objective of the investigation was to examine whether atorvastatin can prevent hyporeactivity to norepinephrine (NE) in mouse aorta in sepsis, and if so, what are the mechanisms involved. Sepsis in mice was induced by cecal ligation and puncture. The aorta was harvested for tension experiment, nitric oxide (NO) and cyclic guanosine monophosphate measurements, and inducible NO synthase (iNOS) and α(1D)-adrenoceptor mRNA expression studies. In comparison with sham-operated controls, sepsis significantly decreased the contractile response to NE in the mouse aorta. Pretreatment with atorvastatin of septic animals completely restored NE-induced contractions to levels similar to those of sham-operated controls and significantly increased survival time and mean arterial pressure. Atorvastatin also attenuated iNOS-induced overproduction of NO, as well as iNOS mRNA expression. Accordingly, hyporeactivity to NE was not evident in tissues pretreated with selective iNOS inhibitor 1400W in sepsis. Although basal cyclic guanosine monophosphate accumulation in the aorta was reduced in sepsis, pretreatment of the tissues with soluble guanylyl cyclase inhibitor 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ) partially restored the reactivity to NE. Interestingly, hyporeactivity to NE in sepsis was associated with a decreased α(1D)-adrenoceptor mRNA expression in the mouse aorta. Atorvastatin pretreatment, however, prevented the decrease in α(1D)-adrenoceptor mRNA expression in septic animals. In conclusion, atorvastatin seems to prevent hyporeactivity to vasoconstrictor NE in the aorta from septic mice through attenuation of overproduction of NO as well as improved α(1D)-adrenoceptor mRNA expression. The findings of the present study may explain the beneficial effects of atorvastatin on improved hemodynamic functions in sepsis.