AIM OF THE STUDY: To investigate the wound healing ability of a concentrated extract of B. orientale in a hydrogel formulation in healing diabetic ulcer wounds.
MATERIALS AND METHODS: The water extract from the leaves of B. orientale was separated from the crude methanolic extract and subjected to flash column chromatography techniques to produce concentrated fractions. These fractions were tested for phytochemical composition, tannin content, antioxidative and antibacterial activity. The bioactive fraction was formulated into a sodium carboxymethylcellulose hydrogel. The extract-loaded hydrogels were then characterized and tested on excision ulcer wounds of streptozotocin-induced diabetic rats. Wound size was measured for 14 days. Histopathological studies were conducted on the healed wound tissues to observe for epithelisation, fibroblast proliferation and angiogenesis. All possible mean values were subjected to statistical analysis using One-way ANOVA and post-hoc with Tukey's T-test (P<0.05).
RESULTS: One fraction exhibited strong antioxidative and antibacterial activity. The fraction was also highly saturated with tannins, particularly condensed tannins. Fraction W5-1 exhibited stronger antioxidant activity compared to three standards (α-Tocopherol, BHT and Trolox-C). Antibacterial activity was also present, and notably bactericidal towards Methicillin-resistant Staphylococcus aureus (MRSA) at 0.25mg/ml. The extract-loaded hydrogels exhibited shear-thinning properties, with high moisture retention ability. The bioactive fraction at 4% w/w was shown to be able to close diabetic wounds by Day 12 on average. Other groups, including controls, only exhibited wound closure by Day 14 (or not at all). Histopathological studies had also shown that extract-treated wounds exhibited re-epithelisation, higher fibroblast proliferation, collagen synthesis, and angiogenesis.
CONCLUSION: The ethnopharmacological effects of using B. orientale as a topical treatment for external wounds was validated and was also significantly effective in treating diabetic ulcer wounds. Thus, B. orientale extract hydrogel may be presented as a potential treatment for diabetic ulcer wounds.
AIM OF THE REVIEW: The present review aims to compile an up-to-date review of the progress made in the continuous pharmacological and phytochemistry investigation of K. africana and the corresponding commercial and pharmaceutical application of these findings with the ultimate objective of providing a guide for future research on this plant.
METHOD: The scholarly information needed for this paper were predominantly sourced from the electronic search engines such as Google, Google scholar; publishing sites such as Elsevier, scienceDirect, BMC, PubMed; other scientific database sites for chemicals such as ChemSpider, PubChem, and also from online books.
RESULTS: Pharmacological investigations conducted confirm the anti-inflammatory, analgesic, antioxidant and anticancer activity of the extract of different parts of the plant. Bioactive constituents are found to be present in all parts of the plant. So far, approximately 150 compounds have been characterized from different part of the plant. Iridoids, naphthoquinones, flavonoids, terpenes and phenylethanoglycosides are the major class of compounds isolated. Novel compounds with potent antioxidant, antimicrobial and anticancer effect such as verbascoside, verminoside and pinnatal among others, have been identified. Commercial trade of K. africana has boosted in the las few decades. Its effect in the maintenance of skin has been recognized resulting in a handful of skin formulations in the market.
CONCLUSIONS: The pharmaceutical potentials of K. africana has been recognized and have witness a surge in research interest. However, till date, many of its traditional medicinal uses has not been investigated scientifically. Further probing of the existential researches on its pharmacological activity is recommended with the end-goal of unravelling the pharmacodynamics, pharmacokinetics, clinical relevance and possible toxicity and side effects of both the extract and the active ingredients isolated.