The use of plants in the traditional management of diabetes in Nigeria: Pharmacological and toxicological considerations

Ethnopharmacological relevance: The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system. Materials and methods: Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. ‘Diabetes’ and ‘Nigeria’ were used as keywords for the primary searches; and then ‘Plant name – accepted or synonyms’, ‘Constituents’, ‘Drug interaction’ and/or ‘Toxicity’ for the secondary searches. Results: The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants. Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs. Conclusion: This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb–drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided

Acute toxicity profile of the methanolic stem bark extract of Omphalocarpum procerum (p. beauv) sapotaceae in mouse models

This study investigates the acute toxicity profile of the stem bark extract of Omphalocarpum procerum. O. procerum is traditionally used to treat infertility and other health conditions in Africa. A 24 h and 14 day single dose administration was performed. The animals were placed in two groups  (control and treatment) of 5 mice each for both 24 h and 14 days. O. procerum was orally administered at a dose of 5 g/kg to adult female mice in the treatment group while the control group received water only. The body weights and body temperatures of the animals were  determined, blood samples were collected at the end of the study for haematological analyses, while organs (lungs, heart, uteri, liver and kidneys) were collected, weighed and examined for histopathological changes. In both treatment periods, no mortalities and altered behaviour were observed; there were also no changes to body weights. No differences in haematological parameters were observed except for a significant increase (P < 0.01) in platelet count in the 14 day study on treatment with the extract. There were also no significant changes in organ weights. Mild inflammation was however observed in the lung and kidney tissues in both the 24 h and 14 day studies. The stem bark extract of O. procerum is  relatively safe for consumption at a high dose on a short term, however caution should be observed as mild inflammation may occur on the lungs and kidneys. Keywords: Acute toxicity, stem bark, inflammation, histopathology, treatment