Reactive oxygen species (ROS), commonly known as free radicals, induced by UV radiation can compromise the dermal structure, leading to a loss of skin elasticity and subsequent wrinkle formation. A promising strategy to prevent and mitigate skin aging involves the use of topical formulations with potent antioxidant properties. Secondary metabolites such as astaxanthin and zeaxanthin are known for their robust antioxidant activities, which surpass those of tocopherol, offering significant benefits for skin health and protection against UV-induced damage. These properties suggest their potential application in anti-aging products. This study aims to evaluate the stability, ex vivo penetration, and in vivo efficacy of a radiance serum containing an astaxanthin–zeaxanthin nanoemulsion (AZ-NE) designed as an anti-wrinkle agent for topical application. The research was conducted in four stages: production of the astaxanthin–zeaxanthin nanoemulsion (AZ-NE), formulation of the AZ-NE radiance serum, stability, and efficacy testing. In this study, the formulated radiance serum demonstrated stability over three months under specified storage conditions. Ex vivo penetration studies indicated efficient diffusion of the active ingredients, with astaxanthin showing a penetration rate of 25.95%/cm² and zeaxanthin at 20.80%/cm² after 120 min. In vivo irritation tests conducted on human subjects revealed no adverse effects. Moreover, the serum exhibited substantial anti-wrinkle efficacy, with 15 female participants experiencing a wrinkle reduction of 80% to 93% over a 28-day period.

The rapid rise of antimicrobial resistance underscores the urgent need to identify novel bioactive compounds from underexplored natural resources. This study aimed to isolate, classify, and characterize endophytic fungi associated with Piper crocatum leaves, an ethnomedicinal plant in Indonesia known for its antimicrobial potential, and to evaluate their capacity as alternative sources of oral antimicrobial agents. Endophytic fungi were isolated from P. crocatum leaves collected across 12 locations in Tasikmalaya Regency, Indonesia, yielding 66 pure isolates after repeated subculturing. Morphological characterization was conducted based on 33 phenotypic traits, converted into binary codes, and analyzed using numerical taxonomy with Jaccard similarity coefficients and UPGMA clustering. Representative isolates from 10 major clusters were subjected to antimicrobial screening. Fungal crude extracts were prepared solid-state fermentation on red rice ( Oryza sativa var. andel abang), followed by methanolic maceration. Antimicrobial activity was tested against Streptococcus mutans using the disc diffusion (Kirby–Bauer) method with 2% chlorhexidine as a positive control. Isolates displaying significant activity were further identified via ITS1–4 rDNA sequencing and phylogenetic analysis. Among the 10 representative isolates, four demonstrated notable inhibitory activity against S. mutans . Molecular characterization revealed that Isolate 059 clustered with Colletotrichum truncatum , Isolate 062 with Colletotrichum cliviae , Isolate 064 with Torula canangae , and Isolate 007 with Aspergillus rhizopodus . Phylogenetic analysis confirmed their taxonomic placement with strong bootstrap support. Notably, bioactive derived from Isolate 059 ( C. truncatum ) exhibited the highest antimicrobial potential. This study demonstrates that endophytic fungi from P. crocatum represent a promising reservoir of antimicrobial agents against oral pathogens. The combined application of numerical taxonomy, solid-state fermentation, and molecular identification provides a robust framework for bioprospecting studies. In particular, C. truncatum (Isolate 059) emerges as a compelling candidate for further fractionation, bioactive compound isolation, and development into alternative therapeutics targeting oral infectious diseases.