All research on the plant was done with full authorisation granted to Marama II INCO (EU-FP6) research programme. T. esculentum (marama) bean samples were obtained in Botswana in 2005 and 2007, and the T. esculentum tuber sample was obtained in Botswana in 2007. Seeds were stored in plastic bags at room temperature until time for extraction. The T. esculentum tuber (approximately 20 kg wet mass) was dug out from a site in Jwaneng, then ground and air-dried at University of Botswana, and then further ground to fine powder before the extraction was done at University of Maribor, Slovenia. A voucher specimen of T. esculentum plant is kept in the Namibian National Herbarium (collecting number: GM 1063 and herbarium number: 59520). The following water extracts from T. esculentum beans and tuber were obtained: tuber water extract (MTW), cotyledon water extract (MCW), and seed coat water extract (MSCW) ( Table 1 ).