Herbal plants are very important in traditional community use and enrich our plant biodiversity and conservation. Natural products are vital substances of traditional knowledge systems in complementary and alternative medicine, nutraceutical, food supplements, and pharmaceutical bioactive metabolites of new chemical entities. Bioactive secondary metabolites from herbal plants of different forms are main sources and provide major opportunities for drug active pharmaceuticals due to the diverse flora and fauna biodiversity that produces the necessary available chemical diversity. There has been an increasing popularity in phytochemical research within the high through put (HTS) screening programs in search of lead. Phytochemicals of herbal extracts for traditional uses contain various types of bioactive metabolites of pharmaceutical and pharmacotherapeutic nature, and many phytomedicines for different therapeutic areas have been derived from herbal products. This paper is aimed at giving an insight into the extraction, isolation, and characterization of the rich medicinal plant biodiversity of potential pharmaceutical importance and the major drawbacks and challenges in the extraction, isolation, and characterization of phytochemicals in plant extracts. Phytochemicals in medicinal plants have been studied with more emphasis on the extraction process which is a vital stage in the analysis of bioactive compounds in medicinal plant research. The advantages and disadvantages of the different extraction methods is important to discuss following the regulatory guidelines and different pharmacopoeia. The analysis of bioactive molecules in herbal products involves the applications of various phytochemical screening methods, and the use of chromatographic techniques such as TLC and HPLC, including in some cases the non-chromatographic methods like Fourier Transform Infra-Red (FTIR), immunoassay. This paper has been motivated by the challenges faced by most pharmacy students in data mining of information on phytochemical screening and testing of biological activities in projects related to herbal plants research. This write up is also geared towards providing students with information on the preclinical drug discovery process towards the formulation of an improved traditional medicine/ phytomedicine.

An understanding of the chemistry of the secondary metabolites of neem plant (Azadirachta indica A. Juss) is essential and important due to its medicinal properties. Several studies have been done on the biological and pharmacological activities with a considerable progress made with respect to its biological activity and medicinal uses. The neem safety is known from its long communal ethno-pharmacological uses as a category one herbal product. It is readily available with great access to the local population at low cost and environmentally friendly. This paper attempts to give an insight into the biological activities of some of the compounds isolated, pharmacological actions of the extract, clinical studies and medicinal applications along with their safety evaluations. Issues on the active chemical constituents of various formulations, commercially available neem products, are also mentioned along with their respective application.

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Improved traditional medicine/phytomedicine formulations have gained a global acceptability and popularity as therapeutic agents for many diseases in Sub-Saharan Africa. Herbal products are generally considered as safe, environmentally friendly and increasingly consumed by the community without prescription. There is a lack of systematic data on traditional medicine-associated adverse effects due to complex issues such as products with multiple ingredients, poor standardization, lack of clinical trials, variation in manufacturing processes, contamination, adulteration and misidentification of herbs. The aim of pharmacovigilance is to detect, assess, understand, and prevent the adverse effects or any other possible drug-related problems, related to herbal, traditional and complementary medicines. Pharmacovigilance for herbal medicines is in its infancy, and monitoring the safety of natural products presents unique challenges, and as such, preparations are available from a wide range of sources where limited qualified healthcare professionals are available. The ethico-legal issues and regulatory approval mechanism of herbal medicine vary from country to country. This paper also elucidates the level of challenges associated with herbal pharmacovigilance geared towards improving safety monitoring for herbal medicines in the future.

The drug discovery and development processes are designed to guarantee that drugs are efficacious, nontoxic and of high standards of quality for human consumption. However, patient’s population with access to drugs at approval is only a fraction of the final target population. Therefore, a thorough understanding of the safety of medicines is generally only achieved after the marketing authorization of the drug, followed by pharmacovigilance or post marketing surveillance. Pharmacovigilance (PHV) is defined by WHO as “the science and activities that deals with the detection, assessment, understanding and prevention of the adverse drug reactions or any other possible drug-related interactions”. Health professionals, patients, drug manufacturers and drug regulatory authorities are therefore highly involved in the practice of PHV. Cameroon imports 95 % of drugs and health care products. Therefore, an effective mastery of the knowledge, attitude and practice of PHV will help to elaborate the development of our pharmacovigilance systems. This paper gives an overview of pharmacovigilance in Cameroon for unlocking the drug development process focusing on the past, present and future.