Chapters authored
Toxicity and Safety Implications of Herbal Medicines Used in Africa
The use of herbal medicines has seen a great upsurge globally. In developing countries, many patronize them largely due to cultural acceptability, availability and cost. In developed countries, they are used because they are natural and therefore assumed to be safer than allopathic medicines. In recent times, however, there has been a growing concern about their safety. This has created a situation of ambivalence in discussions regarding their use. Some medicinal plants are intrinsically toxic by virtue of their constituents and can cause adverse reactions if inappropriately used. Other factors such as herb-drug interactions, lack of adherence to good manufacturing practice (GMP), poor regulatory measures and adulteration may also lead to adverse events in their use. Many in vivo tests on aqueous extracts largely support the safety of herbal medicines, whereas most in vitro tests on isolated single cells mostly with extracts other than aqueous ones show contrary results and thus continue the debate on herbal medicine safety. It is expected that toxicity studies concerning herbal medicine should reflect their traditional use to allow for rational discussions regarding their safety for their beneficial use. While various attempts continue to establish the safety of various herbal medicines in man, their cautious and responsible use is required.
Part of the book: Herbal Medicine
The Ghanaian Flora as a Potential Source of Anthelmintic and Anti-Schistosomal Agents
Parasitic infections including schistosomiasis and soil transmitted helminthiasis are the most commonly encountered Neglected Tropical Diseases (NTDs) in the world. These diseases remain a major public health concern affecting millions of people especially those living in poor regions where access to effective conventional health care is a challenge. Interventions to control these infections in endemic areas have not been successful due to the high cost of drugs, limited availability as well as inequity of access to preventive chemotherapies. Another problem is the development resistance to the limited number of recommended medications due to their intensive use in both human and live-stock. There is an increasing awareness of the potential of natural products as chemotherapeutic agents to combat parasitic infections. Natural products may offer an unlimited source of chemically diverse drug molecules which may be safe, efficient, less toxic, less expensive and readily available for use especially in low-income countries. The Ghanaian flora provides such a ready source for new therapeutic interventions for the local population. Several researches have provided evidence of the anti-parasitic activity of Ghanaian medicinal plants. This chapter provides a review with special focus on medicinal plants collected from Ghana with anthelmintic and anti-schistosomal activity. Evidence of pharmacological activities of crude extracts, fractions and bioactive phytoconstituents as well as possible mechanisms of action where investigated are discussed.
Part of the book: Natural Medicinal Plants