Plant immunomodulators for termination of unwanted pregnancy and for contraception and reproductive health

Abstract

Neem (Azadirachta indica) seed and leaf extracts have spermicidal, anti-microbial, anti-fungal and anti-viral properties. They are also immunomodulators that induce primarily a TH, type response. These properties are being exploited to develop two different useful methods of fertility control. Neem extracts given orally at early post-implantation stage terminate pregnancy in rodents and primates. Treatment has no residual permanent effect and fertility is regained in subsequent cycles. The mechanism by which the action occurs is not fully clear. A transient increase in CD₄ and more significantly in CD₈ cells is noticed in mesenteric lymph nodes and spleen. A rise in immunoreactive and bioactive TNF- and IFN- in draining lymph nodes, serum and foetal-placental tissue is observed. A polyherbal cream and pessary have been developed containing three active ingredients of plant origin. These have synergistic spermicidal properties on human sperm as determined by the Sander Cramer test. Their use before mating has high contraceptive efficacy in rabbits and baboons. Another interesting property is their inhibitory action on a wide spectrum of micro-organisms, including Candida albicans. C. tropicalis, Neisseria gonorrhoeae, the multidrug-resistant Slaphylococcus aureus and urinary tract Escherichia coli. Herpes simplex-2 and HIV-1, Phase I clinical trials have been completed in India, Egypt and the Dominican Republic, and indicate the safety of the formulation, its acceptability and beneficial action invaginosis due to infections.