There is a rapidly growing trend in the consumption of herbal remedies in industrialised and developing countries. Users of herbal remedies are at risk of toxicity and adverse interactions of herbal preparations due to their frequent contamination with metals and adulteration with synthetic drugs. The purpose of this study was to assess the quality of herbal remedies present on the market in Saudi Arabia in recent years.
247 herbal remedies and related preparations were examined from 2000-2001 at the Toxicology Laboratory, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. Herbal powder samples were the most common sample type examined (n = 80), followed by complete, packed preparations (n = 59), single undescribed capsules or pills (n = 46), loose plant leaves or seeds (n = 28), creams (n = 18) and liquid or jelly samples (n = 16). All samples were subjected to toxicological screening for organic substances using gas chromatographic-mass spectrometric analysis, screening for heavy metals (arsenic, mercury, and lead) using inductive coupled plasma-mass spectrometry and microbiological examination.
The preparations analysed were used to treat the following indications: leukaemia and other forms of cancer (n = 22); obesity (n = 18); diabetes mellitus (n = 14); rheumatic disorders (n = 14); skin pigmentation problems (n = 11); or to enhance male sexual activity (n = 9). In 123 cases, the indication of use was not known. 39 samples contained high concentrations of heavy metals. This was particularly striking in remedies used to treat leukaemia (arsenic content of 522-161,600 ppm) and in creams for whitening skin (mercury content of 5,700-126,000 ppm). Eight preparations contained synthetic drugs (e.g. benzodiazepines and tricyclic antidepressants in sedative preparations, cyproheptadine in a remedy to gain bodyweight, ibuprofen and dipyrone in herbal capsules used to treat rheumatism). 18 samples were contaminated with micro-organisms. 14 samples contained toxic substances of natural origin. Of the 247 examined preparations, 77 (i.e. over 30%) were disqualified due to high heavy metals content, bacterial contamination or presence of toxic organic substances.
The study shows an urgent need to control the production, importing and selling of herbal preparations.