NITROSATION OF NIGERIAN MEDICINAL PLANT PREPARATIONS UNDER CHEMICAL AND SIMULATED GASTRIC CONDITIONS

Preparations of some tropical plants of medicinal importance, collecte d from the savannah vegetational belt of Nigeria, were nitrosated and analysed for volatile N-nitrosamines formed under chemical and simulat ed gastric conditions. N-Nitrosamines were determined on a Thermal Ene rgy Analyser following gas chromatographic separation. Mean concentrat ions of N-nitrosodimethylamine (NDMA) in the range of 7 to 58 ppb acid N-nitrosodiethylamine (NDEA) in the range of 23 to 26 ppb were formed in 31 and 7%, respectively, of the preparations using artificial gast ric juice (simulated gastric condition). Under chemically optimal cond itions, relatively high levels of NDMA (72-2008 ppb), NDEA (23-1528 pp b) and N-nitrosopyrrolidine (20-405 ppb) were formed in 100, 75 and 32 % of the preparations, respectively; N-nitrosomethylethylamine, N-nitr osodibutylamine and N-nitrosomorpholine were formed in fewer preparati ons. These findings suggest that the endogenous formation of N-nitroso compounds from precursors present in medicinal plants might be anothe r source of human exposure to environmental carcinogens in Nigeria and other developing countries.