Evaluation of nitric oxide scavenging activity, in vitro and ex vivo, of selected medicinal plants traditionally used in inflammatory diseases.
Steroidal and non-steroidal antiinflammatory drugs, despite their various side effects, are in great demand worldwide. Alternatively, herbal formulations provide relief to a large percentage of the population suffering from inflammatory diseases. Therefore, such practices need to be rationalized through a mechanistic approach. Thus, four traditional medicinal plants, namely Ventilago madraspatana Gaertn., Rubia cordifolia Linn., Lantana camara Linn. and Morinda citrifolia Linn. were selected for a study on the inhibition of nitric oxide (NO*), a key mediator in the phenomenon of inflammation, signifying the presence of effective antiinflammatory constituents therein. Plant samples were extracted with different solvents for evaluation of their inhibitory activity on NO* produced in vitro from sodium nitroprusside, and in LPS-activated murine peritoneal macrophages, ex vivo. Further, the inhibition of NO* synthesis was correlated with the reduction of iNOS protein expression through Western blot. Notable NO* scavenging activity was exhibited in vitro by some extracts of V. madraspatana, R. cordifolia and L. camara (IC(50) < 0.2 mg/mL). Most of them showed marked inhibition (60%-80%), ex vivo, at a dose of 80 microg/mL without appreciable cytotoxic effect on the cultured macrophages. Immunoblot analysis confirmed that the modulatory effect of the samples had occurred through suppression of iNOS protein.
Basu
Subhalakshmi
S
Department of Pharmaceutical Technology, Jadavpur University, Calcutta 700032, India.
Hazra
Banasri
B
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000302:isolation & purification / Q000494:pharmacology*; D002478:Cells, Cultured; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology*; D032410:Lantana / Q000737:chemistry; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D032066:Morinda / Q000737:chemistry; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors; D009589:Nitrogen Oxides / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*; D027823:Rhamnaceae / Q000737:chemistry; D045470:Rubia / Q000737:chemistry
D000894:Anti-Inflammatory Agents, Non-Steroidal; D016166:Free Radical Scavengers; D009589:Nitrogen Oxides; D010936:Plant Extracts; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C039900:nitroxyl