Evaluation of hemostatic, anti-inflammatory, wound healing, skin irritation and allergy, and antimicrobial properties of active fraction from the ethanol extract of Chromolaena odorata (L.) R.M. King & H. Rob.

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE Chromolaenaodorata (L.) R.M. King & H. Rob, a perennial herb, has been traditionally utilized as a herbal remedy for treating leech bites, soft tissue wounds, burn wounds, skin infections, and dento-alveolitis in tropical and subtropical regions. AIM OF THE STUDY The present study was to analyze the active fraction of C. odorata ethanol extract and investigate its hemostatic, anti-inflammatory, wound healing, and antimicrobial properties. Additionally, the safety of the active fraction as an external preparation was assessed through skin irritation and allergy tests. MATERIALS AND METHODS: The leaves and stems of C. odorata were initially extracted with ethanol, followed by purification through AB-8 macroporous adsorption resin column chromatography to yield different fractions. These fractions were then screened for hemostatic activity in mice and rabbits to identify the active fraction. Subsequently, the hemostatic effect of the active fraction was assessed through the bleeding time of the rabbit ear artery in vivo and the coagulant time of rabbit blood in vitro. The anti-inflammatory activity of the active fraction was tested on mice ear edema induced by xylene and rat paw edema induced by carrageenin. Furthermore, the active fraction's promotion effect on wound healing was evaluated using a rat skin injury model, and skin safety tests were conducted on rabbits and guinea pigs. Lastly, antimicrobial activities against two Gram-positive bacteria (G+, Staphylococcus aureus and S. epidermidis) and three Gram-negative bacteria (G-, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa) were determined using the plate dilution method. RESULTS: The ethanol extract of C. odorata leaves and stems was fractionated into 30%, 60%, and 90% ethanol eluate fractions. These fractions demonstrated hemostatic activity, with the 30% ethanol eluate fraction (30% EEF) showing the strongest effect, significantly reducing bleeding time (P < 0.05). A concentration of 1.0 g/mL of the 30% EEF accelerated cutaneous wound healing in rats on the 3rd, 6th, and 9th day post-operation, with the healing effect increasing over time. No irritation or allergy reactions were observed in rabbits and guinea pigs exposed to the 30% EEF. Additionally, the 30% EEF exhibited mild inhibitory effect on mice ear and rat paw edema, as well as antimicrobial activity against tested bacteria, with varying minimal inhibitory concentration (MIC) values. CONCLUSIONS: The 30% EEF demonstrated a clear hemostatic effect on rabbit bleeding time, a slight inhibitory effect on mice ear edema and rat paw edema, significant wound healing activity in rats, and no observed irritation or allergic reactions. Antibacterial activity was observed against certain clinically isolated bacteria, particularly the G- bacteria. This study lays the groundwork for the potential development and application of C. odorata in wound treatment.