Analgesic, anti-inflammatory, antipyretic and toxicological evaluation of some newer 3-methyl pyrazolone derivatives.

In this paper, we described the pharmacological and toxicological studies of three pyrazolone derivatives namely PYZ1: 4-[4-N dimethylamino benzylidine]-3-methyl pyrazolin-5(4H)-one, PYZ2: 4-[2-chlorobenzylidine]-3-methylpyrazolin-5(4H)-one and PYZ3: 4-[benzylidine]-3-methylpyrazolin-5(4H)-one derivatives. Analgesic, anti-inflammatory and antipyretic studies of 3-methyl pyrazolone derivatives at 400 mg/kg, p.o. have shown significant activity as compared to control. Amongst three pyrazolone derivatives, PYZ2 was found to be more active. Based on the result of pharmacological studies, PYZ2 was selected for toxicological studies. Acute toxicity studies revealed that methyl pyrazolone derivatives are non-toxic in rats up to 5000 mg/kg, p.o. The subacute toxicity study of PYZ2 showed that decrease in Hb content, RBC and WBC count. In biochemical analysis level of blood glucose and bilirubin reduced where as AST, ALT and alkaline phosphatase level elevated. Histopathological studies revealed that there was mild toxicity on liver and kidney at 1000 mg/kg, p.o.