Evaluation of Athrixia bush tea for cytotoxicity, antioxidant activity, caffeine content and presence of pyrrolizidine alkaloids

• Published in: Journal of ethnopharmacology 2007-03, Vol.110 (1), p.16-22
• Main Authors: McGaw, L.J., Steenkamp, V, Eloff, J.N.
• Format: Article
• Language: English
• Subjects: Animals; Antioxidant; antioxidants; Antioxidants - pharmacology; Artemia; Aspalathus linearis; Asteraceae; Athrixia; Athrixia elata; Athrixia phylicoides; Beverages - standards; Biological and medical sciences; Caffeine; Caffeine - analysis; Cell Line; chemical constituents of plants; Cytotoxicity; Drug-Related Side Effects and Adverse Reactions; ethnobotany; General pharmacology; herbal medicines; herbal tea; Humans; Kidney - cytology; Medical sciences; medicinal plants; medicinal properties; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; plant extracts; Plant Extracts - chemistry; Plant Extracts - pharmacology; Plant Extracts - therapeutic use; Plants, Medicinal - adverse effects; Plants, Medicinal - chemistry; Pyrrolizidine alkaloids; Pyrrolizidine Alkaloids - analysis; quantitative analysis; Solvents; South Africa; traditional medicine
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2006.08.029

In South Africa, Athrixia phylicoides DC. (bush tea) is widely used as a beverage, cough remedy and purgative. The commercialization of this tea in a similar vein to rooibos ( Aspalathus linearis), is being considered. Traditional infusions and decoctions, as well as water and ethanol extracts, were prepared and screened. A related species, Athrixia elata Sond. (daisy tea), was included in many of the assays as a comparison. Extracts of Athrixia phylicoides and Athrixia elata were tested for toxic effects to brine shrimp larvae and the Vero kidney cell line. In both assays, the traditional preparations and aqueous extracts had little effect, but the ethanol extracts were relatively toxic. Antioxidant activity comparable to that found in rooibos was established. No detectable levels of caffeine were present in the Athrixia extracts following analysis using TLC and I/HCl spray reagent. Neither screening using spectrophotometry nor confirmation using gas chromatography–mass spectrometry analyses showed evidence of pyrrolizidine alkaloids in Athrixia phylicoides. Although a wider range of studies needs to be conducted prior to commercialization, these results support the development of bush tea as a healthy alternative to caffeine-containing beverages.