Medicinal plants of the genus Anthocleista--A review of their ethnobotany, phytochemistry and pharmacology

Abstract

Ethnopharmacological relevance: The genus Anthocleista of the Gentianaceae family contains 14 species of trees and shrub-like plants distributed in tropical Africa, in Madagascar and on the Comoros. Traditionally, they are commonly used in the treatment of diabetes, hypertension, malaria, typhoid fever, obesity, diarrhea, dysentery, hyperprolactinemia, abdominal pain, ulcer, jaundice, asthma, hemorrhoids, hernia, cancer, wounds, chest pains, inflammations, rheumatism, STDs, infertility and skin diseases. They serve as an anthelmintic, laxative, diuretic and contraceptive. This review aims to provide for the first time a repository of ethnopharmacological information while critically evaluating the relation between the traditional medicinal uses, chemical constituents and pharmacological activities of the Anthocleista species so as to unveil opportunities for future research.

Materials and methods: A search for relevant information on Anthocleista species was performed on scientific databases (Pubmed, Google Scholar, SciFinder, Web of Science, Scopus, PubChem and other web sources such as The Plant List, Kew Botanical Garden and PROTA) and books, PhD and MSc dissertations for un-published resources.

Results: Out of the 14 species of Anthocleista, 6 have been reported in literature to be widely used in traditional medicine for the treatment of various ailments. The six species include: A. djalonensis, A. vogelii, A. nobilis, A. grandiflora, A. schweinfurthii, and A. liebrechtsiana. The chemical compounds isolated from Anthocleista species fall into the class of phytochemicals such as secoiridoids, nor-secoiridoids, xanthones, phytosterols, triterpenes, alkaloids, and others of which majority of the compounds were isolated from A. djalonensis and A. vogelii. The in vitro and in vivo pharmacological studies on the crude extracts, fractions and few isolated compounds of Anthocleista species showed antidiabetic, antiplasmodial, antimicrobial, hypotensive, spasmogenic, anti-obesity, antiulcerogenic, analgesic, anti-inflammatory, antioxidant, antitrypanosomal, anthelmintic, fertility, diuretic and laxative activities which supports most of their uses in traditional medicine. However, the bulk of the studies where centered on the antidiabetic, antiplasmodial and antimicrobial activities of Anthocleista species, although the evidence of its antiplasmodial effect was not convincing enough due to the discrepancies between the in vitro and in vivo results.

Conclusion: A. djalonensis and A. vogelii are potential antidiabetic and antibacterial agents. The antibacterial potency relates to infections or diseases caused by E. coli, S. typhi and S. aureus such as urinary tract infections, typhoid, diarrhea, skin diseases, and food poisoning. Pharmacological research on this genus is quite elementary and limited, thus, more advanced research is necessary to isolate and determine the activities of bioactive compounds in vitro and in vivo, establish their mechanisms of action and commence the process of clinical research.

Keywords: 1-hydroxy-3,7-dimethoxyxanthone (PubChem CID: 5488808); 3-oxo-Δ4′5-sitosterone (PubChem CID: 9801811); 6-ketobauerenone (not found); 7α-hydroxysitosterol (PubChem CID: 161816); Anthocleista; Antidiabetic; Antiobesity; Antiplasmodial; D-(+)-bornesitol (PubChem CID: 440078); Gentianaceae; Traditional uses; anthocleistenolide (not found); anthocleistin (not found); anthocleistol (not found); bauerenol (PubChem CID: 111220); bauerenone (not found); caryophyllene oxide (PubChem CID: 6604672); de-O-methyllasiodiplodin (PubChem CID: 14562693); decussatin (PubChem CID: 5378284); djalonenol (not found); djalonenoside (not found); djalonensin (PubChem CID: 5360741); djalonensone (PubChem CID:5359485); fagaramide (PubChem CID: 5281772); gentianine (PubChem CID: 354616); grandiflorol (not found); grandifloroside (not found); hexadecanoic acid (PubChem CID: 985); humulene epoxide II (PubChem CID: 10704181); irlbacholine (PubChem CID: 177983); lichexanthone (PubChem CID: 5358904); lupenone (PubChem CID: 92158); methyl grandifloroside (not found); schweinfurthin (PubChem CID: 643463); scopoletin (PubChem CID: 5280460); secologanin (PubChem CID: 161276); sitosterol (PubChem CID:222284); sitosterol 3-O-β-D-glucopyranoside (PubChem CID: 70699351); stigmasterol (PubChem CID: 5280794); sweroside (PubChem CID:161036); swertiamarin (PubChem CID: 442435); swertiaperennin (PubChem CID: 5281653); ursolic acid (PubChem CID: 64945); vogeloside (not found); α-humulene (PubChem CID: 5281520); β-caryophyllene (PubChem CID: 5281515).