Screening and characterization of antioxidant, anti-aging, and anti-microbial activity of herbal extracts in Northern Thailand

Background: Aging is a process caused by oxidants and aging-related enzymes. Therefore, the inhibition of these processes can exacerbate anti-aging agents. This study aimed to evaluate the antioxidant and anti-aging activities of leaf extracts from seven herbs used in traditional Thai herbal remedies. Methods: Researchers assessed the total levels of phenolic content (TPC), antioxidant, anti-collagenase, and anti-tyrosinase activity using colorimetric methods. Cytotoxicity effects were determined using MTT assays, and matrix metalloproteinases(MMPs) secretion was assessed through gelatin zymography. In addition, inhibitory effects on the growth of microorganisms were examined using the disc diffusion and broth microdilution method.Results: TPC ranged between 48.68–440.91 mg GAE/g of ethanolic leaf extracts. High antioxidant activities against ABTS radicals were detected in P. granatum, P. emblica, P. guajava, T. bellirica, and T. chebula, while high DPPH neutralization appeared in M. coreia, P. guajava, and P. granatum. FRAP assays significantly reduced the power of T. chebula and P. granatum. T. chebula and P. guajava exhibited the highest inhibitory effect on H2O2induced ROS production. P. emblica, P. guajava, T. bellirica, and E. hygrophilus reduced tyrosinase and collagenase activities.  P. gaujava, T. chebula, and T. bellirica were shown to inhibit the secretion of MMP-2 from fibroblast cells. All concentrations of leaf extracts were non-toxic to fibroblast cells. P.granatum and T. bellirica could inhibit the growth of P. acnes, E. coli, and S. aureus. Conclusion: Preliminary studies showed that P.granatum and T. bellirica leaf extracts have antioxidants, anti-aging, and anti-bacterial activities, as well as active ingredients suitable for cosmetic products.Keywords: antioxidants, anti-aging, leaf extracts