Topical application of stem bark ethanol extract of Sonapatha, Oroxylum indicum (L.) Kurz accelerates healing of deep dermal excision wound in Swiss albino mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The Oroxylum indicum is used traditionally to treat fever, colic, stomach ulcers, constipation, indigestion, intestinal worms, strangury, asthma, cough, hiccough, diarrhea, dysentery and wounds by the herbal healers of Mizoram and it is also part of Ayurvedic formulations.

AIMS OF THE STUDY: The wound healing activity of Oroxylum indicum has not been investigated. Therefore, the present study was undertaken to evaluate the ability of different concentrations of ethanol extract of stem bark of Oroxylum indicum in the deep dermal excision wounds of mice.

MATERIALS AND METHODS: The deep dermal excision wound was created on the shaved dorsum of Swiss albino mice. Each excision wound was topically applied with 5%, 10%, 20% or 30% gel of stem bark ethanol extract of Oroxylum indicum (OIE) and wound contraction, mean wound healing time (MHT), collagen and DNA syntheses were studied. The expression of NF-κB and COX-II were evaluated in the regenerating wound granulation tissues of mice.

RESULTS: Topical application of different concentrations of OIE resulted in a concentration dependent rise in wound contraction and MHT and the highest wound contraction was recorded for 10% OIE. Similarly, topical application of different concentrations of OIE increased the DNA and neocollagen syntheses in a dose dependent manner at all post wounding days and the greatest acceleration in DNA and neocollagen formation was observed for 10% OIE. The evaluation of lipid peroxidation (LOO) showed a dose dependent decline in LOO, which was lowest for 10% OIE. The study of molecular mechanisms revealed the suppression of NF-κB and COX-II in a dose dependent manner in the regenerating wound of mice with a maximum inhibition at 10% OIE.

CONCLUSIONS: The present study demonstrates that OIE accelerated the wound contraction and reduced mean wound healing time in mice, which may be due to increased collagen and DNA syntheses, reduced lipid peroxidation coupled by NF-κB and COX-II suppression by OIE in the regenerating wounds of mice.