Evaluation of the wound healing activity of methanol extract of Pedilanthus tithymaloides (L.) Poit leaf and its isolated active constituents in topical formulation

Ethnopharmacological relevance: Pedilanthus tithymaloides leaves are widely used in Indian medicine to heal wounds, burn, mouth ulcers. However, systematic evaluation of these activities is lacking. Thus, the present study aimed to assesses the wound healing activity of Pedilanthus leaves and its isolated constituents in topical ointment formulation. Materials and Methods: Bioassay-guided chromatographic fractionation of the methanol extract of leaves resulted in the isolation of 2-(3,4-dihydroxy-phenyl)-5,7-dihydroxy-chromen-4-one and 1, 2-tetradecanediol, 1-(hydrogen sulfate), sodium salt. The ointment formulation of methanol extract (2.5%, 5% w/w) and isolated compounds (0.25% w/w) was prepared and evaluated on excision, incision and dead space wound models in rats. The effects of formulations on wound healing were assessed by the rate of wound closure, period of epithelialization, tensile strength, granulation tissue weight, hydroxyproline content and histopathology. Results: Significant wound healing activity was observed with methanol extract and isolated constituents. Topical application of isolated compound ointments caused faster epithelialization, significant wound contraction (95.41%), and better tensile strength (565.33 g) on 16 post-wounding day, while 5% extract showed wound epithelialization with 95.55% contraction on 18th post-wounding day, better than the control group (76.39% on 22 day). The tensile strength of incision wound was significantly increased in extract and compound treated animals. Moreover, in dead space model the extract significantly increased granuloma tissue weight, tensile strength and hydroxyproline content. The tissue histology of ointment treated groups showed complete epithelialization with increased collagenation, compared to the povidone-iodine group. Conclusions: The results validated the traditional use of Pedilanthus tithymaloides for cutaneous wound management. (C) 2012 Elsevier Ireland Ltd All rights reserved.