Pantnagar Journal of Research

Abstract

Organophosphorus pesticides remain widely used in agriculture despite their documented toxic effects in non target species. The present study investigated the modulatory effect of piperine on subacute quinalphos (QNP) toxicity in male Swiss albino mice. Mice were orally administered QNP at 2.5% (0.375 mg/kg) and 5% (0.75 mg/kg) of its maximum tolerated dose (MTD; 15 mg/kg) for 28 days, with or without piperine (10 mg/kg). Parameters evaluated included body weight, relative organ weight, haematological indices, and histopathology of liver, kidney, lung, and bone marrow. QNP exposure resulted in dose-dependent haematological suppression, including significant reductions in total erythrocyte count (TEC), haemoglobin (Hb), and total leukocyte count (TLC). Histopathological examination revealed hepatic congestion, focal necrosis, tubular degeneration in kidneys, and pulmonary inflammatory changes. Co-administration of piperine partially ameliorated hematological alterations and reduced the severity of histopathological lesions. These findings suggest that piperine exhibits protective effects against QNP-induced subacute toxicity, likely through modulation of oxidative and inflammatory pathways. Co-administration of piperine with QNP resulted in a statistically significant improvement in haemoglobin (Hb) and total leukocyte count (TLC) at the higher dose (0.75 mg/kg) compared to QNP II alone (p < 0.05), whereas no significant effect was observed on total erythrocyte count (TEC). No statistically significant changes were observed with piperine co-administration at the lower dose (0.375 mg/kg). Histopathological evaluation showed a reduction in lesion severity in the piperine co-treated group; however, this effect was not statistically quantified. These findings indicated that piperine exerts limited, parameter-specific effects against QNP-induced subacute toxicity rather than a consistent protective effect.