Effects of Malvastrum coromandelianum linn. extract on incision wound healing in diabetic and non-diabetic rats

Abstract

The purpose of this study was to investigate the effect of an aqueous extract of Malvastrum coromandelianum on incision wound healing in diabetic and non-diabetic rats. Experiments were carried out in male Spraque-Dawley rats weighing 250-300 g. Rats were divided into 2 groups of 60 animals each for diabetic and non-diabetic rats models. Diabetes was induced by injection of Streptozotocin in the dose of 50 mg/kg B.W. intraveneously into tail vein. The animal in both groups were randomly subdivided into five sub groups as follow: untreated, NSS-treated, 1%, 5% and 10% of Malvastrum coromandelianum treated-group. Tested substances were applied topically once a day. On day 3 and 7 post wounding, the tensile strength, total collagen content, epidermal thickness and histopathological evaluation were assessed. In addition antibacterial activity of Malvastrum coromandelianum (1%, 5% and 10%) was tested using filter paper disk-agar diffusion. It was found that tensile strength and epidermal thickness of incision wound in diabetic group (day 7) and non-diabetic group (day 3) treated with 1% Malvastrum coromandelianum extract was significantly increased in comparison to those of untreated and NSS-treated groups while no significant increase of total collagen content was observed. In histopathological evaluation, the wound treated with Malvastrum coromandelianum extract tended to heal faster than those found in untreated and NSS-treated groups. Granulation as well as re-epithelialization were detected in herbal-treated groups earlier than those of untreated and NSS-treated groups. In addition none of 1%, 5% and 10% of Malvastrum coromandelianum extract was found to exhibit antibacterial activity against Staphylococcus aureus, Streptococcus pyogens, Pseudomonas aeruginosa and Escherichia coli. The present studies have demonstrated the wound healing effect of the aqueous extract of Malvastrum coromandelianum on incision wound in diabetic as well as non-diabetic rats though a slower rate of healing was noted in the diabetic group. An increase in epidermal thickness and positive effects on some other components than collagen of extracellular matrix exerted by 1% Malvastrum coromandelianum but not antibacterial activity seem to underlie an increase in tensile strength observed. Investigations to identify other possible mechanisms as well as active constituents of Malvastrum coromondelianum responsible for the wound healing effects should be further conducted.