Toxicological evaluations of aqueous extracts of two Nigerian ethnobotanicals (Tetrapleura tetraptera and Quassia undulata) of neurological importance in rats

An Ethnobotanical Survey and Pharmacological and Toxicity Review of Medicinal Plants Used in the Management of Obesity in the North Central Zone of Nigeria

Introduction: Obesity is increasing worldwide. Due to the unavailability of affordable obesity drugs in most parts of Nigeria, many overweight and obese people rely on medicinal plants to manage obesity. Thus, the aim of this study is to document medicinal plants traditionally used in the treatment and management of obesity in the North Central Zone of Nigeria, determine the plants to which pharmacological assessment of their use in obesity management has not been reported, and assess their toxicity based on the literature. Methods: Semistructured questionnaires and interviews were used to assess sociodemographic information of the 700 herb sellers/practitioners (100 for each state) who consented to participate in the study. Information gathered on plants that are traditionally used in the management of obesity included administration/dosage, method of preparation, plant part used, method of growth, and plant type. The field study was conducted over a one-year period, from March 2018 to March 2019. Reports of pharmacological activity pertaining to obesity as well as toxicity of the plants were obtained from the literature via scientific databases (Scopus, Web of Science, PubMed, Google Scholar, SciFinder, AJOL, PubChem, and other web sources) after the field survey. Results: A total of 39 families and 70 plant species were used to treat or manage obesity. The majority of plant species used resulted in the family Leguminosae. The relative frequency of citation (RFC) and percentage values for the five most frequently used plants were as follows: Citrus aurantifolia (0.0500; 3.56%), Citrus limon (0.0457; 3.26%), Garcinia kola (0.0429; 3.05%), Zingiber officinale (0.0429; 3.05%), and Allium sativum (0.0414; 2.95%). The majority of the medications were prepared as decoctions (50.5%), and cultivated plants (62.86%) were in the majority of plants used. Results showed that 23 plants have no pharmacological report for antiobesity activities while among the five frequently used plants, only Garcinia kola was reported toxic in preclinical models. Conclusions: This paper provides a valuable compilation of the plants used in obesity treatment in the study area by indigenous healers, highlights plants with no reported pharmacological activity pertaining to obesity, and indicates the toxicity profile of used plants. However, further studies on the mechanism of action are warranted, especially where no reports were obtained.

Phytochemical composition, bioactive properties, and toxicological profile of Tetrapleura tetraptera

The use of medicinal plants has gained renewed wide popularity in Africa, Asia, and most parts of the world because of the decreasing efficacy of synthetic drugs. Thus, natural products serve as a potent source of alternative remedy. Tetrapleura tetraptera is a medicinal plant with cultural and traditional significance in West Africa. In addition to the plant being commonly used as a spice in the preparation of traditional spicy food for postpartum care it is also widely used to constitute herbal concoctions and decoctions for treatment of diseases. This review aimed to provide an up-to-date information on the ethnomedicinal uses, pharmacological activities and phytoconstituents of T. tetraptera. Preclinical studies regarding the plant's toxicity profile were also reviewed. For this updated review, literature search was done on PubMed, Science Direct, Wiley, and Google Scholar databases using the relevant keywords. The review used a total of 106 papers that met the inclusion criteria from January 1989 - February 2022 and summarised the bioactivities that have been reported for the rich phytoconstituents of T. tetraptera studied using various chemical methods. Considering the huge report, the review focused on the antimicrobial and antiinflammatory activities of the plant extracts and isolated compounds. Aridan, aridanin and several bioactive compounds of T. tetraptera have shown pharmacological activities though their mechanisms of action are yet to be fully understood. This study also highlighted the influence of plant parts and extraction solvents on its biological activities. It also presented data on the toxicological profile of the plant extracts using different models. From cultural uses to modern pharmacological research the bioactive compounds of T. tetraptera have proved effective in infectious disease management. We hope that this paper provided a robust summary of the biological activities and toxicological profile of T. tetraptera, thus calling for more research into the pharmacological and pharmacokinetic activities of natural products to help combat the growing threat of drug resistance and provide guidelines for their ethnomedicinal uses.

Medicinal Plants for Anti-neurodegenerative diseases in West Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Neurodegenerative diseases are neuronal diseases that affect the brain components by degenerating the structure and function of the central or peripheral nervous system progressively. It is a leading cause of death and affects huge amount of people worldwide. Plant-based medicines have been utilised in the therapies for many illnesses that have defied western treatments, including neurodegenerative diseases.

AIM OF THIS REVIEW

This review presents an overview of the major neurodegenerative diseases and reported prominent medicinal plants used in managing those diseases in West Africa.

METHODS

Scientific articles regarding medicinal plants and their usefulness in managing neurodegenerative diseases in West Africa were pooled from different scientific databases. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses to filter articles based on their relevance. Pharmacological activity, plant parts used, experimental models, and some isolated chemical compounds of those plants were summarised.

RESULTS

In the West Africa region, Fabaceae (19%) and Solanaceae (13%) have the highest representation of plant families used to treat neurological diseases, while Apocynaceae, Asteraceae, Euphorbiaceae have also been utilised. Flavonoids, alkaloids, phenolic compounds, terpenoids, coumarins present in those plants and their derivatives are reported to possess neuro-protective effects. Biochemical enzymes correlating to antioxidants, anti-inflammatory effects are the potential targets against neurodegenerative diseases.

CONCLUSION

Medicinal plants for anti-neurodegenerative diseases in West Africa have been documented with their neuropharmacological activities. Plant families such as Fabaceae, Solanaceae, Apocynaceae, Asteraceae, and Euphorbiaceae could be a major natural source for discovery of anti-neurodegenerative drugs, thus the metabolites from them should be given priority for neurological research. This review will provide clues for further investigations on the screening and development of anti-neurodegenerative natural products from West African medicinal plants.