**1. Introduction**

A medicinal plant contains either in all or some of its parts or organs substances that can be used for therapeutic purposes or as starting material for the synthesis of pharmaceutically active drugs [1]. In Africa, medicinal plants are the main ingredients used for the preparation of medicaments by the traditional healer. Therefore, due to the frequent utilization of medicinal plants, African Traditional Medicine has played a key role in socio-economic and socio-cultural heritage that services more than 80% of the African populations [2]. Several Africans especially the rural dweller earn their living from the medicinal plant trade [3]. Medicinal plants have formed the basis for the treatment of various diseases in ancient medical practice especially from the recorded history of the Sumerians and Akkadians; and also in Egypt, China, India and Greece [4, 5].

The first recorded history that depicted the importance of the cultivation and conservation of plants is found in the Bible. God created the garden of Eden and carefully put selected plants for specific purposes (Genesis 2:8-9). This story demonstrates the importance of the cultivation of plants; God himself placed our ancestor (Adam) to take care of the garden and there his needs for medicine, food and shelter can be met (Genesis 1:29; 2:8-9).

The cultivation of medicinal plants for pharmaceutical research and development is an area that has received little or no attention from African countries. Medicinal plants are endowed with chemicals substances that have been used and are still in use today for the development of new drugs. Nature has provided mankind with the reservoir of millions of complex/simple bioactive compounds from plants; mainly the secondary metabolites that can be used for therapeutic purposes [6–8]. Therefore, it is evident that cures yet to be discovered (e.g., COVID-19) lie largely in the medicinal plants [9].

Medicinal plants are mainly sourced from the wild. This is no longer sustainable and reliable due to over-harvesting and over-exploitation by the plant collectors and herb sellers [10]. Today, many medicinal plants have gone extinct or are very scarce to find. Therefore, speedy investment in the cultivation of medicinal plants for pharmaceutical research and development beyond the COVID-19 is needed. Cultivation of medicinal plants also provides numerous advantages over wild sources in many ways. The export of cultivated medicinal plants may add to the economy of many African countries [11].

The African continent is enriched with biodiverse varieties of plants which are reservoirs of chemical diversities for the development of new drugs. The African medicinal plants are mainly found in the wild and it has been estimated that there exist about 40,000 to 45,000 plant species on the African continent and out of this; 5000 plant species are thought to have some therapeutic benefits [12]. In Nigeria, there are over 4600 plant species identified, ranking it 11th in Africa for diversity [13]. Therefore, medicinal plants may serve as a huge raw material reservoir, which if harnessed will serve as the driving force towards the revolution of pharmaceutical research and development of the African pharmaceutical industries.
