Wound healing is a natural and spontaneous phenomenon that takes place in three orderly and timely interactive phases: inflammation, proliferation, and remodelling. Normal wound healing cascade begins immediately following injury. Tissue damage and the activation of clotting factors during the vascular phase stimulate the release of inflammatory mediators, such as prostaglandins and histamine, from cells such as mast cells. The transition from the inflammatory to the proliferative phase, the stage characterized by the filling of the wound with new connective tissues, is orchestrated by macrophages. A decrease in wound size is achieved by a combination of the physiological processes of granulation, contraction, and epithelialization. Reepithelialization phase rebuilds the structure while the remodeling phase involves the final form. Surgery in diabetic patients is associated with slow wound healing process and hence requiring longer hospital stay, higher health care resource utilization, and greater perioperative mortality than nondiabetic subjects. The exact pathogenesis of the poor wound healing process in diabetic patients is not clearly understood, but evidence from studies involving both human and animal models reveal increased rate of infections and several abnormalities in the various phases of wound healing process. With the worldwide diabetes incidence now considered to be increasing in an epidemic proportion, there is a growing need to search for novel drugs to combat diabetes and the associated disorders, such as wound complications.
Over 278 natural xanthones belonging to the plant families of Gentianaceae, Guttiferae, Moraceae, Clusiaceae, and Polygalaceae are known to occur. Most xanthones are polyphenols and hence regarded as powerful antioxidants that can offer beneficial health effect either by direct scavenging of reactive oxygen species or by acting as chain-breaking peroxyl radical scavengers. In addition to possessing antioxidant effects, xanthones have also been reported to be hepatoprotective, mutagenic, immunomodulatory, anticomplement, cardioprotective, antitumoral, antidiabetic, anti-inflammatory, antiulcer, and analgesic agents. Smeathxanthone A is a unique xanthone that combines a polyphenolic skeleton with four free hydroxyl groups and a terpenoid geranyl structural moiety. Although the compound has previously been isolated in our laboratories from Garcinia smeathmanii, it has never been investigated for its potential antidiabetic properties. In the present communication, the blood glucose lowering and wound healing effects of smeathxanthone A in diabetic mice are reported
