Exacerbation of intestinal brush border enzyme activities and oxidative stress in streptozotocin-induced diabetic rats by monocrotophos

The present study was undertaken to investigate the potential of monocrotophos (MCP), one of the
widely used broad spectrum systemic organophosphorus insecticides (OPI) in India, to alter small intestinal
structure and function. Further, its potential to exacerbate diabetes induced alterations in intestinal
structure and function was also studied in experimentally induced diabetic rats. Rats were rendered diabetic
with an acute dose of streptozotocin (60 mg/kg b.w.). MCP was orally administered at a sublethal
dose (1/20 LD50 i.e. 0.9 mg/kg b.w./d) for 15 days to both normal and diabetic rats. MCP significantly
increased unit weight of intestine in diabetic rats. MCP alone increased (up to 57%) the activities of intestinal
brush border disaccharidases in normal rats and further augmented the enzyme activities in diabetic
rats. Similar results were found with intestinal alkaline phosphatase activity. In addition, Na+/K+-ATPase
activity was found to be aggravated in diabetic rats by MCP treatment. Oxidative stress markers showed
similar degree of change in both MCP and diabetic rats while MCP aggravated oxidative stress condition
in diabetic rats. Scanning electron microscopy and histological analysis of the small intestine revealed
increased length of villi, congestion, goblet cell hyperplasia and infiltration of inflammatory cells in
MCP and diabetic rats while MCP also induced necrotic lesions in diabetic rats. Collectively, our findings
provide evidence that multiple doses of MCP has the propensity to augment diabetes associated intestinal
dysfunctions in rats.