Anti-Inflammatory Potential of Phenolic Compounds Isolated From Entada africana Guill. & Perr. Used in the Republic of Benin

In West African medicine, Entada africana Guill. & Perr. from the family of Fabaceae is used to treat inflammatory conditions in the management of fractures, wounds, and sprains in the northern region of the Republic of Benin. The aim of the present study was to isolate and elucidate phenolic compounds from a hydroalcoholic leaf extract from E. africana and to identify compounds with anti-inflammatory activity in vitro. Eleven compounds were purified from three fractions, which have shown strong to medium anti-inflammatory activity. The isolated compounds were characterized by HRESI-MS and NMR methods as gallic acid (1), ethyl gallate (2), 5,7-dihydroxychromen-4-one (3), 3′,4′,7-trihydroxyflavone (4), dihydrokaempferol-7-O-glucoside (5), catechin (6), quercetin-3-O-[β-apiosyl- (1‴→2″)-β-glucoside] (7), quercetin-3-O-glucoside (8), naringenin-7-O-glucoside (9), aromadendrin (10), and myricetin-3-O-glucoside (11). Nine of the major phenolic compounds were tested using TNF-α stimulated human keratinocytes (HaCaT) as skin inflammation model to identify molecules, which may explain the use of the plant leaves as an anti-inflammatory remedy by assessing the release of proinflammatory cytokines IL-8 and IL-6. The hydroacoholic leaf extract of E. africana exerted a medium inhibitory effect on the release of IL-8. 3′,4′,7-trihydroxyflavone, aromadendrin, dihydrokaempferol-7- O-glucoside and ethyl gallate demonstrated a strong to medium effect on the release of IL-6. For the release of IL-8, 3′,4′,7-trihydroxyflavone demonstrated a medium activity. This study provides for the first time a detailed screening of phenolic compounds occurring in the hydroethanolic leaf extract of E. africana. Additionally, it is shown that E. africana contains active compounds which may justify its traditional medicinal use as an antiinflammatory remedy to treat inflammatory and pain-related skin conditions in the Republic of Benin

Ethnomedicinal Information on Plants Used for the Treatment of Bone Fractures, Wounds, and Sprains in the Northern Region of the Republic of Benin

Medicinal plants are frequently used in African countries due to their importance in the treatment of various conditions. In the northern Republic of Benin, traditional healers are recognized as specialists in the treatment of fractures, wounds, and sprains. The present study was conducted to document the practices (diagnosis and materials) and traditional knowledge accumulated by healers in this region on their area of specialty. In addition, literature-based research was performed to support the usage of the most cited plants. Sixty traditional healers identified as “reference persons” from Atakora and Donga departments in the northern Republic of Benin, who specialized in the treatment of fractures, wounds, and sprains, were interviewed in their communities through a semi-structured questionnaire. Information about the practice, age of the healers, medicinal plants used in this treatment, methods of preparation, and administration were collected. Samples of the plant species were also collected, identified, and stored in the national herbarium at the University of Abomey-Calavi, the Republic of Benin. The study enabled the identification of thirty-four (34) species belonging to twenty-three (23) families. Ochna rhizomatosa and Ochna schweinfurthiana (21%) were the most quoted plants among the species, followed by Chasmanthera dependens (12.1%), Piliostigma thonningii (11.3%), and Combretum sericeum (8.1%). These plants were reported to strengthen bones, reduce inflammation, relieve pain, and promote healing in the northern part of the Republic of Benin. Besides their ability to treat fractures, wounds, and sprains, they are also used for multiple purposes in the West African subregions. According to the available literature, some of the plants will need to be investigated for their phytoconstituents and pharmacological activity to validate their ethnobotanical uses. These results confirm the need for documenting traditional knowledge since it represents an opportunity for exploring plant species with potentially good pharmacological effects, which have been barely investigated. Plants identified may constitute a significant source of bioactive compounds in the treatment of various ailments such as skin inflammation and musculoskeletal disorders. They can be further explored to justify their use in traditional Beninese medicine