Exploring Anti-Aging Potential of Dendrobium Species and Novel Microemulsion Delivery of Dendrobium kentrophyllum Extract for Anti-Aging Effect

Abstract

Purpose: The study aimed to investigate in vitro anti-aging activities of 29 Dendrobium spp. and develop and characterize microemulsions (MEs) for topical application. Methods: Antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), H2O2 scavenging, and ferric reducing antioxidant power (FRAP) assays. The anti-collagenase (MMP-1 and MMP-2) and anti-elastase activities were also evaluated. Cytotoxicity and human intracellular reactive oxygen species (ROS) levels were determined using resazurin reduction and 2′,7′-dichlorofluorescin diacetate (DCFDA) assays, respectively. D. kentrophyllum extract-loaded microemulsion (DKME) was then prepared and optimized. The stability of DKME was studied using a heating-cooling cycle. Results: D. kentrophyllum appeared to be the best candidate anti-aging agent because of its antioxidant, anti-collagenase, and anti-elastase activities. The extract was safe for human skin cells at a concentration of 6.25–100 μg/mL. It also decreased the intracellular ROS-induced ultraviolet B (UVB) irradiation compared to that in the control. DKME comprising Tween 80:ethanol (5:1), water, and isononyl isononanoate showed a suitable appearance, droplet size, polydisperse index, zeta potential, pH, and viscosity. This formulation demonstrated desirable physical and chemical stability, with non-cytotoxic effects. Conclusion: DKME is considered a promising anti-aging product. However, an in vivo study of this optimized formulation might be evaluated in further study for anti-aging purposes.