Bioprocessing and Functional Characterization of Hibiscus Hamabo Root Culture Bioactives: Antioxidant and Moisturizing Effects with Surfactin-Enhanced Penetration in Artificial Skin Models

Plant tissue culture is a promising platform for producing metabolites with pharmaceutical, nutraceutical, and cosmetic potential. A bioprocess was developed to produce antioxidative and moisturizing bioactive compounds from Hibiscus hamabo (HHSZ) root cultures, and a surfactin-assisted nanoemulsion was optimized to facilitate their effective transdermal delivery. We established a method for culturing HHSZ root in a controlled bioreactor where various conditions such as temperature and pH could be regulated, and subsequently established an extraction process. The 3T3 Neutral Red Uptake (NRU) and a 2’,7’-dichlorofluorescin diacetate (DCFDA) assay confirmed that root extract is non-phototoxic and has a reactive oxygen species (ROS) scavenging effect, respectively. Additionally, the root extract increased hyaluronic acid (HA) synthesis by 70% compared to the untreated sample. Protein expression analysis revealed an upregulation of antioxidant-related factors, including heme oxygenase 1 (HO-1) and phospho-NFκB repressing factor (p-NRF2), as well as hyaluronan synthase 2 (HAS2), a key factor in skin hydration. Similarly, mRNA analysis showed increased expression of HMOX1, the gene of HO-1, in both HaCaT and NHF cells and HAS2 gene in HaCaT cells. These results suggest that HHSZ possesses strong antioxidant and moisturizing properties, evidenced with metabolite profiling. In addition, biosurfactant surfactin-assisted nanodispersion enhanced permeability of the bioactive metabolites through skin layer. This study confirmed potential of HHSZ root extract and its surfactin-assisted nanoemulsion for use in cosmetics and pharmaceutical products.