Antibacterial, antioxidant, and wound healing properties of extract and phytochemicals of Dracontomelon dao (Blanco) Merr. & Rolfe bark

Dracontomelon dao (Blanco) Merr. & Rolfe ( D. dao ), commonly known in Thailand as Phrachao Ha Phra Ong, is recognized for its therapeutic applications and is particularly used in traditional medicine for ulcers and infections. This study aims to determine the antioxidant activity, antibacterial activity, and wound-healing properties of D. dao bark ethanol extract. D. dao bark was extracted using 60% ethanol and then was investigated for phytochemicals and in vitro antioxidant and antibacterial activities along with the wound healing properties. The extract demonstrated high phenolic (474.58 mg GAE/g) and flavonoid contents (48.06 mg QE/g), along with strong antioxidant activity that might be attributed to long-chain fatty acids. Moreover, treatment with D. dao bark extract inhibited hydrogen peroxide-induced ROS production in a dose-dependent manner in NHDF and HEK-293 cells. In addition, treatment of HEK-293 cells with the extract (50 μg/mL) significantly upregulated the mRNA expression of catalase and glutathione peroxidase-1, supporting its role in cellular antioxidant defense. Antibacterial activity by the agar disc diffusion method revealed significant inhibitory effects on Staphylococcus aureus and Methicillin-resistant S. aureus with MIC and MBC values of 0.49 mg/mL and 0.98 mg/mL, respectively. The D. dao bark extract also promoted fibroblast migration determined by wound-healing assays in NHDF cells, indicating potential applications in tissue regeneration without cytotoxic effects. These findings position D. dao bark extract as a promising candidate for developing natural antioxidant, antibacterial, and wound-healing agents, warranting further research into its therapeutic applications. • Dracontomelon dao (Blanco) Merr. & Rolfe ( D. Dao ) bark extract exhibits antibacterial activity against pathogenic bacteria • D. Dao bark extract has strong free radical scavenging activities • D. Dao bark extract inhibits H 2 O 2 -induced ROS levels in HEK-293 and NHDF cells • D. Dao bark extract upregulates catalase and GPx-1 • D. Dao bark extract possesses wound-healing effects in NHDF cells