In this study, tea (Camellia oleifera) seed oil was formulated into self-emulsifying oil formulations (SEOF) to enhance the aqueous dispersibility and intestinal retention to achieve higher bioavailability. Self-emulsifying tea seed oils were developed by using different concentrations of lecithin in combination with surfactant blends (Span^®80 and Tween^®80). The lecithin/surfactant systems were able to provide clear and stable liquid formulations. The SEOF were investigated for physicochemical properties including appearance, emulsion droplets size, PDI and zeta potential. The chemical compositions of tea seed oil and SEOF were compared using GC-MS techniques. In addition, the oil adsorption measurement on artificial membranes was performed using a Franz cell apparatus and colorimetric analysis. The microscopic structure of membranes was observed with scanning electron microscopy (SEM). After aqueous dilution with fed-state simulated gastric fluid (FeSSGF), the droplet size of all SEOF was close to 200 nm with low PDI values and the zeta potential was negative. GC-MS chromatograms revealed that the chemical compositions of SEOF were not significantly different from that of the original tea seed oil. The morphological study showed that only the SEOF could form film layers. The oil droplets were extracted both from membrane treated with tea seed oil and the SEOF in order to evaluate the chemical compositions by GC-MS.

Repeated UV exposure, air pollution, and toxins promote skin oxidative stress. ROS destroy macromolecules, changing cellular mechanisms and signaling cascades. Inflammation and injury to skin cells degrade function and accelerate aging, causing wrinkles, firmness loss, and dermatological disorders. Gymnema inodorum (GI) contains phytochemical antioxidants such polyphenols and triterpenoids that lower ROS and strengthen skin. GI extracts (GIEs) have never been examined for their effects on dermal skin fibroblasts’ oxidative stress and intracellular cytoprotective mechanisms. In this study, GIEs were prepared as a water extract (GIE0) and ethanol extracts with concentrations ranging from 20% to 95% v/v (GIE20, GIE40, GIE60, GIE80, and GIE95). These extracts were assessed for phytochemical content, antioxidant capacity, and free radical scavenging efficacy. The results were compared to a commercially available native Gymnema extract (NGE) obtained from Gymnema sylvestre. During principal component analysis (PCA), the most effective extracts were identified and subsequently evaluated for their ability to mitigate oxidative stress in fibroblasts. Cytoprotective effects of GIE and NGE against H₂O₂-induced human dermal fibroblast injury were investigated by cell viability, intracellular ROS production, and signaling pathways. GIE0, GIE80, GIE95, and NGE were the best antioxidants. By preserving ROS balance and redox homeostasis, GIE and NGE reduce fibroblast inflammation and oxidative stress-induced damage. Decreased ROS levels reduce MAPK/AP-1/NF-κB and PI3K/AKT/NF-κB signaling pathways, diminishing inflammatory cytokines. In conclusion, GIE and NGE have antioxidant and anti-inflammatory capabilities that can reduce H₂O₂-induced fibroblast oxidative stress and damage, thereby preventing skin aging and targeting cancer-associated fibroblasts.