Oil-in-water (O/W) nanoemulsions play an important key role in transporting bioactive compounds into a range of cosmeceutical products to the skin. Small droplet sizes have an inherent stability against creaming, sedimentation, flocculation, and coalescence. O/W emulsions varying in manufacturing process were prepared. The preparation and characterization of O/W nanoemulsions with average diameters of as low as 62.99 nm from palm oil esters were carried out. This was achieved using rotor-stator homogenizer and ultrasonic cavitation. Ultrasonic cell was utilized for the emulsification of palm oil esters and water in the presence of mixed surfactants, Tween 80 and Span 80 emulsions with a mean droplet size of 62.99 nm and zeta potential value at -37.8 mV. Results were comparable with emulsions prepared with rotor-stator homogenizer operated at 6000 rpm for 5 min. The stability of the emulsions was evaluated through rheology measurement properties. This included non-Newtonian viscosity, elastic modulus G', and loss modulus G″. A highly stable emulsion was prepared using ultrasonic cavitation comprising a very small particle size with higher zeta potential value and G' > G″ demonstrating gel-like behavior.
Crinum asiaticum Linne var. japonicum has long been used as a rheumatic remedy, as an anti-pyretic and as an anti-ulcer treatment, and for the alleviation of local pain and fever in Korea and Malaysia. In order to investigate the possibility of Crinum asiaticum Linne var. japonicum extract as a cosmetic ingredient, we measured its anti-inflammatory effect by its inhibition of iNOS (inducible nitric oxide synthase) and the release of PGE2, IL-6, and IL-8. We also measured its anti-allergic effect by its inhibition of beta-hexosamidase release. An HPLC experiment after extraction with 95% EtOH at pH 3.5 showed that Crinum asiaticum Linne var. japonicum was mainly composed of lycorine (up to 1%), a well-known immunosuppressor. The content of lycorine varied, depending on the type of plant tissue analyzed and the extraction method. In an anti-inflammatory assay for inhibition of nitric oxide formation on lipopolysaccharide (LPS)-activated mouse macrophage RAW 264.7 cells, the ethanol extract of Crinum asiaticum showed an inhibitory activity of NO production in a dose-dependent manner (IC50 = 58.5 microg/ml). Additional study by RT-PCR demonstrated that the extract of Crinum asiaticum significantly suppressed the expression of the iNOS gene. Moreover, the extract of Crinum asiaticum did not show any cytotoxicity, but did show a cell proliferation effect against LPS (a 10 approximately 60% increase in cell viability). In an assay to determine inhibition of the H2O2-activated release of PGE2, IL-6, and IL-8 in human normal fibroblast cell lines, the release of PGE2 and IL-6 was almost completely inhibited above concentrations of 0.05% and 1%, respectively. Moreover, the release of IL-8 was completely inhibited over the entire range of concentration (>0.0025%). In order to investigate the skin-sensitizing potentials of the extract of Crinum asiaticum, a human clinical test was performed after repeated epicutaneous 48-h applications under an occlusive patch (RIPT). The repeated and single cutaneous applications of Crinum asiaticum Linne var. japonicum extract under the occlusive patch did not provoke any cumulative irritation and sensitization reactions. The result showed that the extract of Crinum asiaticum Linne var. japonicum has a sufficient anti-inflammatory effect. Therefore, Crinum asiaticum Linne var. japonicum extract may be useful for development as an ingredient in cosmetic products.