Pharmacognostic characterization, wound healing and toxicity assessment of the stem bark of Xylia evansii Hutch (Leguminosae)

Lord Gyimah; Evelyn Asante-Kwatia; Silas Adjei; Frederick Akuffo Owusu; Fanny Darko; Ernest Tabiri; Abraham Yeboah Mensah

doi:10.1016/j.heliyon.2023.e21692

Pharmacognostic characterization, wound healing and toxicity assessment of the stem bark of Xylia evansii Hutch (Leguminosae)

Heliyon. 2023 Oct 26;9(11):e21692. doi: 10.1016/j.heliyon.2023.e21692. eCollection 2023 Nov.

Authors

Lord Gyimah¹, Evelyn Asante-Kwatia¹, Silas Adjei², Frederick Akuffo Owusu³, Fanny Darko¹, Ernest Tabiri¹, Abraham Yeboah Mensah¹

Affiliations

¹ Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
² Department of Herbal Medicine, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
³ Department of Pharmaceutics, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

Abstract

Xylia evansii is widely used in traditional medicine to stop bleeding gums and treat wounds. This study was undertaken to assess the wound healing activity and toxicity profile of the stem bark methanol extract of X. evansii (XES). Wound healing activity was determined by the dermal excision model in rats. The free radical scavenging capacity, antioxidant activity, total phenolic and flavonoid contents were evaluated by the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, total antioxidant capacity (TAC), aluminum chloride colorimetric and Folin Ciocalteu methods respectively. Acute and sub-acute oral toxicity assessment was performed following the Organization for Economic Co-operation and Development guidelines. Signiﬁcant (p < 0.05) dose-dependent wound healing effect, similar to that of 1 % silver sulphadiazine was elicit by the 10, 15 and 20 %^w/_w XES ointments. The highest effect was demonstrated by XES 20 %^w/_w which resulted in 98.3 % wound surface closure by day 9 of treatment (p < 0.0001). The total phenolic and ﬂavonoid contents were determined to be 381.2 ± 12.57 mg/g gallic acid equivalent (GAE) and 460 ± 29.07 mg/g quercetin equivalent respectively. XES exhibited remarkable free radical scavenging effect (IC₅₀ = 68.13 ± 1.87 μg/mL) and had a total antioxidant capacity of 279.2 ± 32.08 mg/g GAE. The LD₅₀ of XES was estimated to be > 5000 mg/kg. In sub-acute toxicity, 28 days treatment with XES (250, 500, 1000 mg/kg body weight) did not result in any significant (p > 0.05) change in the body weight or weight of the heart, lung, spleen, liver and kidneys. The haematological and biochemical profiles of XES-treated rats were not significantly (p > 0.05) affected after 4-weeks treatment with XES, except for platelet count which increased significantly (p < 0.0001) in a non-dose-dependent manner. Histopathological examination did not reveal any toxic effect to liver cells, however at 1000 mg/kg XES, slight abnormalities were identified in the glomeruli. Microscopy of the powdered stem bark displayed calcium oxalate crystals, pitted vessels and lignified fibres. Tannins, flavonoids, coumarins, saponins, triterpenes and alkaloids were identified in the bark. This is the first report on the wound healing potential and safety profile of X. evansii, giving scientific credence to its use in traditional medicine.

Keywords: Histopathology; Microscopy; Safety; Wound; Xylia evansii.