Korean red pine () is one of the major species in Korea. Red pine bark is removed prior to the chipping process in the wood industry and discarded as waste. However, red pine bark contains a considerable amount of naturally occurring phenolics, including flavonoids, and therefore may have a variety of biological effects. In this study, we investigated if Korean red pine bark extract (KRPBE) could protect neuronal PC-12 cells from oxidative stress and inhibit cholinesterase activity. Analysis of reversed-phase high-performance liquid chromatography results revealed four phenolics in KRPBE: vanillin, protocatechuic acid, catechin, and taxifolin. The total phenolic and flavonoid contents of KRPBE were 397.9 mg gallic acid equivalents/g dry weight (DW) and 248.7 mg catechin equivalents/g DW, respectively. The antioxidant capacities of KRPBE measured using ABTS, DPPH, and ORAC assays were 697.3, 521.8, and 2,627.7 mg vitamin C equivalents/g DW, respectively. KRPBE and its identified phenolics protected against H₂O₂-induced oxidative cell death in a dose-dependent manner. Acetylcholinesterase and butyrylcholinesterase, which degrade the neurotransmitter acetylcholine to terminate neurotransmission in synaptic clefts, were inhibited by treatment with KRPBE and its identified phenolics. Taken together, these results suggest that KRPBE and its constituent antioxidative phenolics are potent neuroprotective agents that can maintain cell viability under oxidative stress and inhibit cholinesterase activity.

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The aim of this study was to investigate the skin anti‐inflammatory activity of rose petal extract (RPE) and the mechanisms underlying this phenomenon. Recently, flowers have been considered as dietary resources owing to their biological activities, such as inhibition of nephritis and hemorrhoids. The Rosa plant exerts various biological functions, including antioxidant and anti‐microbiological activities. Herein, we confirmed the skin anti‐inflammatory activity of RPE upon solar UV (sUV) exposure. RPE reduced sUV‐induced COX‐2 expression as well as expressions of several cytokines. Activation of MKK4‐JNK, MEK‐ERK, and MKK3‐p38 signaling pathways, which are associated with cytokine production, was also attenuated by RPE treatment. We hypothesized these RPE‐induced changes are because of its antioxidant activity, because RPE displayed drastic radical scavenging and oxygen radical absorbance capacity (ORAC). Furthermore, high anthocyanins, polyphenols, and flavonoids contents were found in RPE. Hence, these results indicated the skin anti‐inflammatory activity of RPE is because of antioxidant activity.

Cholecalciferol, also known as vitamin D3, is a recognized therapeutic agent for treatment of bone diseases and cancer. However, instability and poor bioavailability have been major challenges for delivering Vitamin D3. The objective of this study was to formulate improved nanostructured lipid carrier (NLC) vitamin D3 emulsions. We tested the effect of different carrier oils and the use of a solid lipid nanoparticle emulsifier, polyglycerol polyricinoleate (PGPR) on the stability of the vitamin D3 emulsions. In contrast to the control that used glyceryl monostearate (GMS) the PGPR substitution resulted in relatively small particle sizes (0.30 to 0.43 μm), with high absolute value of zeta potentials (39.5 to 67.8 mV) and high encapsulation efficiency (85.2% to 90.4%). The stability of the NLC emulsions against environmental stresses was evaluated under varying conditions of ionic strength, pH, freeze–thaw cycles, and storage at different temperatures. Although NLC emulsions were stable at high ionic strengths, they were found to be unstable at low pH (<3), which led to aggregation and coalescence of emulsion droplets. In case of freeze–thaw stress, although relatively stable compared to control NLC, the PGPR substituted groups exhibited a slight increase in particle size and a decrease in zeta potential when the cycle was repeated five times. Additionally, we found that PGPR‐substituted emulsions showed higher liquid dispersion stability than controls at 25 and 65 °C. Thus, we have formulated a modified NLC vitamin D3 emulsion that can be widely used in the food industry. Practical Application Vitamin D3, an essential micronutrient, is often added as supplements in food products and beverages for added health benefits. However, the stability of vitamin D3 emulsions that are used in the preparation of such products has been a major concern. We have developed a modified emulsion that has improved stability against environmental stresses. We believe, in future, this formulation can be efficiently used in the food industry.

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