ABSTRACT
A synthetic small molecule, 1-[(1H-indol-3-yl)methylene]-2-phenylhydrazine (HMPH) was conveniently synthesised by a one-step reaction, purified and characterised by chromatographic and spectroscopic methods. HMPH scavenged free radicals and inhibited lipopolysaccharide (LPS)-induced ROS generation and NO release in RAW-264.7 cells without signs of any detectable cytotoxicity. HMPH inhibited lipid peroxidation (LPO) with IC50 of 135 ± 9 as against 58 ± 8 µM for α-tocopherol. Further, HMPH (>50 µM) significantly reduced the LPS-induced TNF-α release in mouse peritoneal macrophages and in human peripheral blood mononuclear cells (PBMCs). HMPH did not show any visible signs of toxicity in rats up to 400 mg/kg/intraperitoneal and 2000 mg/kg/oral. HMPH at 25 and 50 mg/kg attenuated neutrophil infiltration in air-pouch lavage and bronchoalveolar lavage (BAL) in rat models. HMPH also reduced myeloperoxidase (MPO), nitrite and TNF-α in air-pouch lavage in addition to MPO in plasma. HMPH reduced acute paw-inflammation in carrageenan-induced paw-edema. HMPH consistently decreased both ipsilateral and contralateral paw inflammation, minimised the clinical scores of arthritis, prevented body weight (B.wt.) loss, attenuated serum C-reactive protein (C-RP) and rheumatoid factors (RF) in rat model of adjuvant-induced arthritis. Histopathology and radio-graphical reports show that HMPH reduced bone erosion in both ipsilateral and contralateral paw joints. Failure to inhibit COX suggests that effectiveness of HMPH in both acute and chronic inflammation is mediated by a multimodal mechanism involving modulation of immunity, attenuating TNF-α, protecting bone attrition and reducing oxidative stress.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Hydrazones/pharmacology , Indoles/pharmacology , Inflammation/drug therapy , Small Molecule Libraries/pharmacology , Animals , Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Carrageenan , Cells, Cultured , Chronic Disease , Disease Models, Animal , Dose-Response Relationship, Drug , Female , Humans , Hydrazones/chemical synthesis , Hydrazones/chemistry , Indoles/chemical synthesis , Indoles/chemistry , Inflammation/chemically induced , Inflammation/metabolism , Leukocytes, Mononuclear/drug effects , Lipid Peroxidation/drug effects , Macrophages/drug effects , Male , Mice , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/chemistry , Structure-Activity Relationship , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/biosynthesisABSTRACT
In the present study, resveratrol, a polyphenolic SIRT1 activator was evaluated for its SIRT1 activation in an in vitro fluorescent based assay (EC(50) : 7 µM). The efficacy of resveratrol was also evaluated in ob/ob mice for its antidiabetic and associated metabolic effects. Mice aged 5-8 weeks were included in four groups; control and resveratrol at 5, 15, 50 mg/kg, b.i.d. and were dosed orally. After 4 weeks of drug treatment, body weights were noted and random blood glucose and insulin was estimated for the antidiabetic effect. Animals were also subjected to the oral glucose tolerance test to observe any improvement in the glucose excursion. Triglycerides, total cholesterol, adiponectin and free fatty acid levels were also estimated. The results showed that resveratrol exhibited significant antihyperglycemic activity with an improvement in the insulin levels compared with the control mice. There was also a significant improvement observed in the glucose excursion in the oral glucose tolerance test performed for 120 min; although an insignificant improvement in the triglycerides, total cholesterol, adiponectin and free fatty acid levels was observed at different doses of resveratrol tested. The present findings suggest that resveratrol is an antihyperglycemic agent and drugs similar to resveratrol can be considered as an effective therapeutic adjuvant for the current treatment of diabetes mellitus.
