Accelerated Stability Study and Evaluation of the Wound Healing Activity of the Ointments of Barteria nigritiana (Hook. f.) Stem Bark doi.org/10.26538/tjnpr/v6i8.30

Abstract

In traditional African medicine, herbal medicines are at the centre of various interventions in wound management and are known to achieve this through various mechanisms. This study evaluated the wound healing activity of the extract and fractions of Barteria nigritiana stem bark in excision and incision wound models. The extract and fractions were formulated in the ointment at 10 and 5% (w/w). The stability of the stressed formulations was evaluated by the Arrhenius accelerated stability method. Only the ointments containing the crude extract and ethyl acetate fraction were degraded by first-order kinetics (R2 > 0.9) with shelf-lives of 24 and 33 days when stressed to 70 ºC. In the excision rat model, the extract, n-hexane, ethyl acetate and butanol fractions caused wound contraction of 8.2-96.9%, 2.1-53.1%, 8.0-100% and 2.6- 57.6% respectively compared with blank ointment (2.6-13.9%) and standard control (8.9-100%) from days 4-20 post-wounding. The ointment of the ethyl acetate fraction elicited significantly wound contraction and a decrease in the epithelialization period. The ethyl acetate ointment also caused a significant (p < 0.05) increase in ascorbic acid and hydroxyproline content of the wounded tissues. All the extract and fractions ointments elicited a time-dependent decrease in malondialdehyde levels. In the incision wound model, there was a significant increase (p<0.05) in the tensile strength of the 10-20 day-old wound when treated with the ointment containing extract and fractions. The study identified the wound healing activity of the herbal ointment formulation of B. nigritiana as a validation of its vital role in folk medicine.