Assessment of flavonolignans, elemental impurities and pesticide residues in various Silybum marianum L. Gaertn. (milk thistle) products in South Africa

Abstract: Silybum marianum L. Gaertn. (commonly referred to as milk thistle) is a weed that has been used medicinally for over 2000 years. The therapeutic qualities of milk thistle are due to the presence of the flavonolignan silymarin. Herbal medicine is becoming increasingly popular in South Africa and, according to the WHO, an estimated the 80% of the global population rely on these medicines for primary health care. Due to the large number of constituents in herbal medicines, various differences between individual plants occur as a result of their agricultural history. However, few of the herbal medicines available to the consumer have been evaluated by the South African Health Products Regulatory Authority (SAHPRA). As such, some of these herbal medicines may therefore have questionable quality standards. A study conducted in 2019 on the chemical and microbiological quality of 26 milk thistle products sold in America and Czech Republic, noted large differences in the observed silymarin and declared silymarin and high concentrations of several pesticides, as well as the presence of microbiological contamination. No studies have yet been done comparing the quality of milk thistle products in South Africa...M.Tech. (Homoeopathy