Natural products have the potential to be developed into new drugs for the treatment of various diseases. The aim of the present study was to screen the antioxidant activities of some common edible fruits, garden plants and medicinal plants indigenous to Taiwan. This was performed by assessing the activities of lipoxygenase, xanthine oxidase and tyrosinase following incubation with extracts from these plants. A further aim was to use HPLC-DAD and tyrosinase to chromatographically identify the antioxidative constituents obtained from an extract exhibiting strong antioxidative properties. The acetone extracts of 27 cultivated plant species from Taiwan were tested for antioxidant activities towards xanthine oxidase, tyrosinase and lipoxygenase using spectrophotometric assays. Koelreuteria henryi, Prunus campanulata, and Rhodiola rosea showed the highest xanthine oxidase inhibitory activities. Camellia sinensis, Rhodiola rosea, and Koelreuteria henryi exhibited good tyrosinase inhibitory activities and potent anti-lipoxygenase activities. As Koelreuteria henryi had notable significant inhibitory activities towards xanthine oxidase, tyrosinase, and lipoxygenase, it was further tested with tyrosinase and HPLC-DAD. The results from this part of the study revealed that the more powerful the antioxidant capability of the extracted component, the greater the decrease in peak height obtained after reacting with tyrosinase. Additional studies are warranted to further characterize the compounds responsible for the antioxidant properties of the examined extracts.

Different types and ratios of surfactant, co-surfactant, and oil phase, have a greater impact on nanoemulsion preparation. The presence of surfactants in the nanoemulsion can reduce surface tension and characteristic stability. In this study, four groups of oil-in-water (O/W) nanoemulsions (NEs) with different ratios of surfactant and co-surfactant, and two oils were formulated as carriers of Rhodiola rosea. The variable optimization was investigated and then indicated as optimization group A (Opt A) with the formula of 10% of transcutol, 16.63% of tween 80, Opt B with 10% of tween 80, 29.87% of span 80, Opt C with 28.42% of transcutol, 30% of labrasol, and Opt D with 30% of transcutol, 30% of tween 80. Labrafac and soybean oil were used as the oil phase. The optimized formula using the response surface method (RSM) by design expert software showed the ideal conditions with a higher desirability score. Desirability score are 0.72% (Opt A), 0.81% (Opt B), 0.76% (Opt C) and 0.98% (Opt D), the desirability rating close to 1 indicates a high possibility that the projected values would closely match the experimental results for the optimum formula. All of the optimized formulation were also checked for the characteristics of nanoemulsion including particle size, polydispersity index (PDI), zeta potential, viscosity, encapsulation efficiency, transmission electron microscope (TEM), antioxidant activity, skin irritation test and stability studies. Our study provides a promising combination of surfactant-co-surfactant and oil phases to produce a stable nanoemulsion that can be used in pharmaceuticals and cosmetics in the future.

The rapid development of delivery systems for cosmetics has revealed two critical challenges in the field: enhancing the solubility of active ingredients and ensuring the stability of natural materials used in cosmetics. Nanoemulsion technology has emerged as an indispensable solution for addressing these challenges, not only enhancing the stability of cosmetics but also improving the solubility of pharmaceuticals and active ingredients with poor solubility. Nanoemulsion formulations have reinforced stability and amended the bioavailability of hydrophobic drugs. Moreover, nanoemulsion exhibit excellent skin penetration and long-lasting effects, making them particularly appealing to consumers, especially in the cosmetic industry. This article aims to provide an overview of herbal nanoemulsion formulations as cosmetic products, covering formulation, production, and characterization. Herbal nanoemulsions is an effective, stable, and promising option for cosmetic delivery. The nanoemulsions were characterized by their key properties, such as particle size, polydisperse index (PDI), zeta potential, viscosity, stability and others. Techniques like zeta potential measurement, transmission electron microscopy (TEM) and scanning electronmicroscopy (SEM) were used to analyze the surface morphology, whereas stability tests were employed to evaluate nanoemulsion performance. This review also delves into the high-energy and the low-energy methods of manufacturing nanoemulsions. Additionally, we also explore the selection of appropriate surfactants, co-surfactants, and ingredients for creating herbal nanoemulsions with desirable attributes and qualities. Overall, this review consolidates the current knowledge on herbal nanoemulsion formulations for cosmetic preparations, designs, shedding light on their effectiveness, characteristics, and stability. These formulations hold promise in overcoming challenges related to meeting the increasing demand for effective herbal nanoemulsion and high-quality cosmetic products.

Three known flavones and seven known homoisoflavonoids were isolated from the methanolic extract of the leaves of Agave sisalanaPerrine ex Engelm. Their structures were elucidated on the basis of spectroscopic analysis. The isolated compounds were also evaluated for immunopharmacological activity. PBMC were used as target cells, and cell proliferation was determined by ³H-thymidine uptake. (±)-3,9-Dihydroeucomin (4), dihydrobonducellin (5), and 5,7-dihydroxy-3-(4′-hydroxybenzyl)-4-chromanone (7) showed inhibitory effects on PBMC proliferation activated by PHA with IC₅₀ values 19.4, 73.8, and 58.8 µM, respectively. All three compounds significantly inhibited the production of IL-2 and IFN-γ in activated PBMC in a concentration-dependent manner.

The rhizoma of Ligusticum sinense, a Chinese medicinal plant, has long been used as a cosmetic for the whitening and hydrating of the skin in ancient China. In order to investigate the antimelanogenic components of the rhizoma of L. sinense, we performed an antimelanogenesis assay-guided purification using semi-preparative HPLC accompanied with spectroscopic analysis to determine the active components. Based on the bioassay-guided method, 24 compounds were isolated and identified from the ethyl acetate layer of methanolic extracts of L. sinense, and among these, 5-[3-(4-hydroxy-3-methoxyphenyl)allyl]ferulic acid (1) and cis-4-pentylcyclohex-3-ene-1,2-diol (2) were new compounds. All the pure isolates were subjected to antimelanogenesis assay using murine melanoma B16-F10 cells. Compound 1 and (3S,3aR)-neocnidilide (8) exhibited antimelanogenesis activities with IC₅₀ values of 78.9 and 31.1 μM, respectively, without obvious cytotoxicity. Further investigation showed that compound 8 demonstrated significant anti-pigmentation activity on zebrafish embryos (10‒20 μM) compared to arbutin (20 μM), and without any cytotoxicity against normal human epidermal keratinocytes. These findings suggest that (3S,3aR)-neocnidilide (8) is a potent antimelanogenic and non-cytotoxic natural compound and may be developed potentially as a skin-whitening agent for cosmetic uses.