Effect of indomethacin and tenoxicam alone and as adjutants to praziquantel on granulomatous reaction in experimental schistosomiasis: involvement of endogenous histamine

ABSTRACT

Granulomas formed in the liver or lung of man and animals with schistosomal infection are common manifestation of an inflammatory delayed hypersensitivity reaction. Non-steroidal antiinflammatory drugs [NSAIDs], indomethacine and tenoxicam have been used alone and as adjuvants to praziquantel in treating liver granulomas of Schistosoma mansoni infected mice. The size of granulomas, its histamine content and histamine forming capacity [HFC] have been measured at the end of the treatment with the above-mentioned drugs. Both of the antiinflammatory drugs effectively reduced the size of liver granulomas. The granuloma histamine content and HFC of the liver were increased by these drugs. The H2-antagonist [cimetidine] but not the H1-antagonist [diphenhydramine] counteracted the suppressive effect of NSAIDs on granuloma volume indicating that histamine may be involved in the direct immuno-regulatory effect exerted by NSAIDs on the granulomas via its immuno-suppressive properties. The combined therapy of either of the drugs with praziquantel did not result in any significant additional effect