Arecoline is a psychoactive alkaloid containing reduced pyridine nucleus, isolated from Areca catechu L. (Arecaceae) with different biological activities on cardiovascular, digestive, nervous and endocrine systems. Arecoline is the main toxic component of A. catechu responsible for oral carcinoma. It possesses a variety of pharmacological activities; it exhibits anticancer activity. It was reported that arecoline causes cytotoxicity through apoptosis in human endothelial cells. Moreover, death of human leukemia K562 cells was induced by arecoline. Biotransformation is a structural modification of compounds such as amino acids, toxins and drugs by enzymatic chemical reactions within the living organisms. According to enzymatic sources, biotransformation is classified into three major types; microbial, plant cell culture and animal cell culture transformation. It was suggested that microorganisms could be employed as a model of mammalian metabolism. Studying both mammalian and microbial transformation of arecoline is of interest by which we can reduce its toxicity, increase its bioavailability and to produce more active metabolites.