23 - Biochemical Parameters in Toxicological Studies in Africa: Significance, Principle of Methods, Data Interpretation, and Use in Plant Screenings

Abstract

Tropical and subtropical Africa is endowed with approximately 45,000 species of plant with developmental potentials, out of which 5000 species are used medicinally. Although it is widely alleged that medicinal plants are safe because they are natural, many are potentially toxic. There is a growing safety concern, and the toxicity of plants used in traditional medicines is becoming more widely recognized. This chapter is aimed at highlighting the biochemical changes induced by some medicinally used plants in Africa. Emphasis is also put on the importance of the investigated biochemical indices in toxicological studies. We therefore highlight the roles of enzymes such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and creatine phosphokinase (CPK) as well as nonenzymatic parameters such as bilirubin (BIL), creatinine (CRE), blood urea nitrogen (BUN), and malondialdehyde (MDA) in the toxicological survey of African medicinal plants. We report information from literature retrieved from scientific websites such as Pubmed, Scholar Google, Scopus, Sciencedirect, Scirus, and web-of-knowledge on the biochemical values of about seventy African medicinal plants belonging to 43 families. The present work confirms that many plants used in traditional medicine are not completely safe, most of which are potentially toxic especially when used at high doses or in long term. However, a low number of African medicinal plants species including Vernonia amygdalina and Jatropha curcas were found to be potentially nontoxic. Despite the considerable contribution of biochemical parameters in the establishment of African medicinal plants profile, it is worth noting such studies are still at a very preliminary stage throughout the continent, though some advances were noted in some countries such as Cameroon, Ghana, Morocco, Nigeria, and South Africa. Therefore, more work is required to increase the standard of African Traditional Medicine and to render it more attractive worldwide.