Effects of Hibiscus rosa sinensis L (Malvaceae) on wound healing activity: a preclinical study in a Sprague Dawley rat.

Hibiscus rosa sinensis (H rosa sinensis), a plant product, has been used for the treatment of a variety of diseases as well as to promote wound healing. The wound-healing activity of the ethanol extract of H rosa sinensis flower was determined in rats, using excision, incision, and dead space wound models and is presented in this report. The animals were randomly divided into 2 groups of 6 each in all the models. Test group animals in each model were treated with the ethanol extract of H rosa sinensis orally by mixing in drinking water (120 mg kg(-1) day(-1)), and the control group animals were maintained with plain drinking water. Healing was assessed by the rate of wound contraction, period of epithelialization, tensile strength (skin breaking strength), granulation tissue weight, and hydroxyproline content. The antimicrobial activity of the flower extract against selected microorganisms that infect the wounds was also assessed. Animals treated with the extract exhibited an 86% reduction in the wound area compared with controls, who exhibited a 75 per cent reduction. The extract-treated animals were found to epithelize their wounds significantly faster than controls (P < .002) and have shown significantly higher skin-breaking strength than controls (P < .002). The dry and wet weight of granulation tissue and hydroxyproline content were also increased significantly when compared with controls. The reported observations suggest H rosa sinensis aids wound healing in the rat model.

Genotoxic and cytotoxic effects in the bone marrow of rats exposed to a low dose of paraquat via the dermal route.

The genotoxic effect of the herbicide paraquat was studied in rat bone-marrow by means of the micronucleus assay. Paraquat at dose levels of 6, 15 and 30 mg/kg body weight was given to rats in a single application via the dermal route. Marrow was collected at 24, 48 and 72 h after the application. The micronucleus assay was done as recommended by standard procedures. Paraquat gave rise to an increase in the number of micronuclei in a dose-dependent manner. The number of micronucleated polychromatic erythrocytes showed a maximum at 48 h and the toxicity was further prolonged, as there was no complete recovery at 72 h. These findings suggest a genotoxic effect of paraquat even after exposure via dermal application.