A toxicological assessment of Athrixia phylicoides aqueous extract following sub-chronic ingestion in a rat model.

Athrixia phylicoides is an aromatic, indigenous shrub used to brew "bush tea." Surveys have shown that the consumption of bush tea is widespread and commercialization of the extract holds economic and developmental potential. Aqueous extracts of A. phylicoides are non-toxic to brine shrimp and renal cell lines; however, verification in a mammalian model is needed. In this study, daily ingestion of high doses of aqueous A. phylicoides extract by mature Wistar rats was tested for potential toxicity over a 3-month period. Three-month-old Wistar rats were randomized into a control group (receiving no extract) and three experimental groups receiving 30, 90, or 180 mg dried aqueous A. phylicoides extract/kg body mass/day. After 90 days of daily extract ingestion, blood and tissue were harvested. There was no morbidity or mortality during the study. Food and water intake, as well as body mass and stool production, were unaffected by the consumption of the extract. Urine production was increased in the 90 and 180 mg/kg groups suggesting that A. phylicoides is mildly diuretic. Serum alkaline phosphatase, creatinine, and urea levels were normal for all groups. Histopathology showed no signs of any extract induced toxicity in the liver, kidneys, gastrointestinal tract, and other tissues studied.