Ahmed Olatunde’s scientific contributions

Citation: Asong, J.A.; Ndhlovu, P.T.; Olatunde, A.; Aremu, A.O. Uses of African Plants and Associated Indigenous Knowledge for the Management of Diabetes Mellitus. Diabetology 2024, 5, 476-490. https:// Abstract: Diabetes mellitus (DM) is a common non-communicable and chronic metabolic disorder regarded as a global epidemic with high morbidity and mortality. Although, conventional medicines are available for the management of DM, Indigenous knowledge, including the use of botanicals, has contributed to the management of this life-threatening disease in Africa. This is due to the perceived effectiveness and minimal side effects associated with plants and plant-derived compounds as an affordable remedy against DM. This review focuses on the contribution of Indigenous African plants to the management of DM. Relevant literatures were reviewed from online scientific databases, such as PubMed, ScienceDirect, and Google Scholar, using keywords singly and in combination. The review revealed that Indigenous health practitioners use several medicinal plants in the management of DM, with a range of 14-255 botanicals recorded. Approximately 80 compounds with antidiabetic potency have been isolated from different parts of African medicinal plants, with the majority belonging to flavonoids and terpenoids. Particularly, compounds such as apigenin, combretin B, convallatoxin, kaempferol, and quercetin remain the most promising antidiabetic compounds isolated from African medicinal plants. Limited clinical trials have been conducted on these compounds despite these milestones. There is, therefore, the need for further investigations to explain their antidiabetic effects, particularly under clinical conditions. Plants from which these compounds were isolated were selected based on ethnopharmacological knowledge. With these developments, medicinal plants and Indigenous knowledge remain an integral part of the global strategy to combat DM.

Lycopene is an extensively studied phytochemical that belongs to the hydrocarbon class of the carotenoid family. In 1876, a red-colored pigment in tomato was discovered by Millardet. Later on, this red-colored pigment became known as “lycopene,” a name that was given by Schunck. Lycopene is also known as carotene present in fruits and vegetables of red color (grapefruit, papaya, tomato, grapefruit, and watermelon). It is one of the most potent naturally and abundantly occurring antioxidants of the dietary carotenoids. Its peculiar structural and chemical features are responsible for its various pharmacological and biological activities. The antioxidant activity of lycopene is attributed to be responsible for its associated health benefits in the management of chronic diseases such as cancer, diabetes, and cardiovascular disorders. Specifically, it is an acyclic isomer of β-carotene with 11 conjugated and two unconjugated double bonds that makes it susceptible to cis-trans isomerization and thermal or photodegradation. The biological activity is due to the presence of double bonds in its structure. It differs from other carotenoids because it lacks pro Vitamin A activity due to the absence of a terminal beta-ionone ring. The chemical formula for lycopene is C40H56. Lycopene is a potent lipophilic pigmented antioxidant that is naturally synthesized by various plants, microorganisms, and certain algae and fungi but not by animals and humans. Over 80% of dietary sources of lycopene in the United States are obtained from cooked or processed tomato products such as ketchup, tomato juice, spaghetti sauce, and pizza sauce.

Lycopene is a phytochemical that is present at high concentration in fruits and vegetables such as tomato, guava, watermelon, spinach, carrot, beetroot, and red grapefruit. Lycopene, just like some members of the carotenoids family, has proven to be of high medicinal, scientific, pharmaceutical, and commercial value. These features of lycopene can be attributed to its chemical structure that has been proved to be responsible for its antioxidant properties. The conjugated polyene chains are responsible for its unstable and electrophilic attacks against free radicals because this double π electron system reduces the energy requirement for the oxidation of electrons in each double bond. This reactivity contributes to the efficacy of lycopene as the basis of its antioxidant activity in biological systems and its efficacy as a chemopreventive. This chapter presents this in details while emphasizing more on the therapeutic importance of lycopene.

Preparation of Phytopharmaceuticals for the Management of Disorders: The Development of Nutraceuticals and Traditional Medicine presents comprehensive coverage and recent advances surrounding phytopharmaceuticals, nutraceuticals and traditional and alternative systems of medicines. Sections cover the concepts of phytopharmaceuticals, their history, and current highlights in phytomedicine. Also included are classifications of crude drugs, herbal remedies and toxicity, traditional and alternative systems of medicine, nanotechnology applications, and herbal cosmeticology. Final sections cover applications of microbiology and biotechnology in drug discovery.