Influence of Piper longum (Linn) on the anti-inflamatory and anti-nociceptive effect of diclofenac in rats

Abstract

The present study was undertaken to assess the influence of P. longum on the anti-inflammatory and anti-nociceptive effects of diclofenac in rats. The experiment was conducted in two stages. In the first stage the anti-inflammatory effect was assessed by carrageenin induced paw oedema method. Four groups of eight albino rats each were used for the study. First group was kept as control which received tween 80 only. Group II served as the positive control which received diclofenac at the dose of 3 mg/kg on the seventh day. Groups III and IV were given 100 mg/kg and 200 mg/kg P. longum extract respectively for seven days, and 3 mg/kg diclofenac on the seventh day. The percentage inhibition of paw oedema was 64.26 and 62.32 for groups III and IV, while it was 67.38 for the diclofenac treated group II. No significant change was noticed in the weight of adrenal gland in groups II, III and IV as compared with that of control. The adrenal ascorbic acid and adrenal cholesterol levels were reduced in all the treatment groups (Group II, III and IV), compared with the control group (Group I). The maximum reduction was observed in the diclofenac alone treated group. In the groups treated with P. longum extract and diclofenac, the reduction in the level of adrenal ascorbic acid and adrenal cholesterol was more for the 100 mg/kg P. longum treated group. The serum AST levels were significantly higher in Group II compared with the control group. The serum ALT and cholesterol levels showed no significant variation between groups. Variation in the haematological parameters between groups was not significant. For evaluating the influence of P. longum extract on the anti-nociceptive effect of diclofenac, four groups of eight rats each were used.The results of the anti-nociceptive study also revealed a reduction in the anti-nociceptive activity of diclofenac in the groups treated with P. longum extract and diclofenac combinations compared with the diclofenac alone treated group. The change in weight of the adrenals was not significant in the groups II, III and IV compared with that of the control. The adrenal ascorbic acid and adrenal cholesterol levels were found to be depleted in all the three treatment groups (Group II, III and IV) compared with the control group (group I). The depletion was maximum in the diclofenac treated group. In the groups treated with P. longum extract and diclofenac, the reduction in the level of adrenal ascorbic acid and adrenal cholesterol was more for the 100 mg/kg P. longum treated group. Variations in serum parameters like AST and cholesterol were not significant between groups. The serum ALT levels for groups given diclofenac alone and those given the P. longum extract and diclofenac combinations were significantly increased compared with that of the control group. The ALT level was maximum in the diclofenac treated group. The haematological parameters showed no significant variation between the groups. Phytochemical study on the alcoholic extract of P. longum revealed the presence of alkaloids. The results of the study indicate that the rats given diclofenac alone showed a greater anti-inflammatory and anti-nociceptive effect than those administered P. longum extract in combination with diclofenac. This may be due to the microsomal enzyme induction which enhances the metabolism of diclofenac. Thus the experimental findings indicate that co-administration of P. longum extract decreases the anti-inflammatory and anti-noceptive effect of diclofenac.