Assessment of phenolic and flavonoid contents, tannins, and antifungal potential of heat-assisted aqueous Piper betle leaf extract

Tóm tắt

Piper betle leaf (betel leaf) has been traditionally used in Southeast Asian medicine to treat ailments such as sore throat, skin abscesses, and digestive disorders. Modern research has demonstrated that the leaf contains a wide range of bioactive compounds, including phenolic acids and essential oils such as eugenol, chavicol, and chavibetol, which possess notable antibacterial, antifungal, anti-inflammatory, antioxidant, and potential anticancer properties. This study evaluated the total phenolic content, flavonoid content, the tannin presence of the aqueous extract obtained from fresh young P. betle leaf using a heat-assisted extraction method as well as the antifungal efficacy of that extract. The antifungal activity was evaluated against two opportunistic yeast strains: Candida albicans, a representative of spoilage yeasts in food and dairy products, and Candida auris, a multidrug-resistant species. Antifungal activity was assessed in-vitro using the agar well diffusion method, and the extract exhibited inhibition zones diameter ranging from 1.37 ± 0.06 cm to 2.23 ± 0.06 cm, indicating clear growth suppression. The minimum inhibitory concentration (MIC) of the extract was determined to be 32 mg dry weight equivalent per mL of extract for C. albicans and 64 mg/mL for C. auris. The total phenolics and flavonoid content were 131.06 ± 2.92 µg GAE/mg and 8.48 ± 0.19 µg QUE/mg dry weight basis, respectively. Tannin was also found in betle leaves extract, indicated by the presence of a brownish green color when reacted with FeCl₃ . These findings suggested that aqueous extracts of P. betle leaves offered promising antifungal properties against both foodborne and clinically relevant yeasts. The use of water as a solvent not only ensured safety and compatibility with food systems but also supported the development of sustainable, plant-based antifungal agents. Overall, this study contributes to the growing body of evidence supporting the application of traditional medicinal plants in modern food preservation, with P. betle offering a viable natural alternative to synthetic antifungal compounds.