Melanin is a brown or black pigment that protects skin from ultraviolet radiation and reactive oxygen species (ROS). However, overproduction of melanin is associated with lentigines, melasma, freckles and skin cancer. Licorice has shown antioxidant, anti-tumor, anti-platelet, anti-inflammatory and immunomodulatory activities and is used as a natural treatment for skin whitening. We aimed to confirm the potential of Wongam, a new cultivar of licorice developed by the Rural Development Administration (RDA), as a whitening agent in cosmetics. In addition, we verified the effect of heat treatment on the bioactivity of licorice by comparing antioxidant and anti-melanogenic activities of licorice extract before and after heating (130 °C). The heat-treated licorice extract (WH-130) showed higher radical-scavenging activities in the ABTS⁺ (2,2′-azino-bis-(3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays. In addition, WH-130 inhibited melanogenesis more effectively due to downregulation of tyrosinase in B16F10 melanoma cells than non-heated licorice extract. Moreover, heat treatment increased total phenolic content. In particular, isoliquiritigenin, an antioxidant and anti-melanogenic compound of licorice, was produced by heat treatment. In conclusion, WH-130, with increased levels of bioactive phenolics such as isoliquiritigenin, has potential for development into a novel skin whitening material with applications in cosmetics.

(1) Background: Astragalus membranaceus (AM) has antioxidant and anti-inflammatory effects, but its specific mechanism of action in the brain is still unclear. In this study, we developed a roasting process to maximize the cognitive improvement impact of AM. We focused on enhancing physiological activity to enhance the brain neuron protection effect and alleviate neuronal damage caused by neurodegenerative diseases. (2) Methods: AM was roasted at 260 °C for 20, 30, or 40 min, and the hot water extracts were tested on HT22 cells for ROS levels, apoptosis, and antioxidant protein expression. The effect on the BDNF-AKT-CREB pathway under stress was also analyzed. (3) Results: Roasted AM decreased ROS production and the expression of apoptosis-related factors while activating the expression of antioxidant proteins in HT22 cells treated with Aβ25–35. In particular, 30 min roasting (R-AM2) significantly reduced ROS production, inhibited cell death, and increased antioxidant protein expression. The Nrf2 pathway was activated Bax, and cleaved caspase-3 levels were reduced. BDNF and p-CREB expression were increased by 20% and 50–70%, respectively. In the MAPK pathway, p-ERK levels were increased by 30%, and p-P38 levels were increased by approximately 20%. (4) Conclusions: These findings suggest that roasted AM upregulates brain-derived neurotrophic factor (BDNF) in HT22 cells, providing neuroprotective effects by activating the AKT/CREB/BDNF pathway and inhibiting neuronal apoptosis. Therefore, roasted AM shows potential as a neuroprotective agent for preventing or treating neurodegenerative diseases, such as Alzheimer’s, linked to BDNF deficiency.

Coreopsis lanceolata L. is a perennial plant of the family Asteraceae, and its flower is known to contain flavonoids with various bioactivities. We evaluated the effect of Coreopsis lanceolata L. flower (CLF) extracts on H₂O₂-induced oxidative stress (OS) in neuronal cells and mouse neurons. The flowering part of CL was used as CLF1 (70% ethanol extract) and CLF2 (water extract), and 10 types of phenolic compounds were quantified using high-performance liquid chromatography. To evaluate the neuroprotective effects of CLF, the antioxidant activities of the extracts were measured, and the expression levels of antioxidant enzymes and proteins related to OS-induced apoptosis in neuronal cells and mouse neurons treated with the extracts were investigated. In the in vitro study, CLF ameliorated H₂O₂-induced oxidative stress and induced the expression of antioxidant enzymes in PC12 cells. Furthermore, CLF1 enhanced the expression of the Bcl-xL protein but reduced the expression of Bax and the cleavage of caspase-3. In the same manner, CLF1 showed neuroprotective effects against OS in vivo. Pretreatment with CLF1 (200 mg/kg) increased the Bcl-2 protein and decreased Bax compared with the 1-methyl-4-phenylpyridinium ion (MPP+)-treated C57BL/6 mice model group. Our results suggest that the protective effects of CLF1 on MPP+-induced apoptosis may be due to its anti-apoptotic activity, through regulating the expression of the Bcl-2 family. CLF1 exerts neuroprotective effects against OS-induced apoptosis in PC12 cells in a Parkinson’s disease model mouse. This effect may be attributable to the upregulation of Bcl-2 protein expression, downregulation of Bax expression, and inhibition of caspase-3 activation. These data indicate that CLF may provide therapeutic value for the treatment of progressive neurodegenerative diseases.

Four Korea-native wild vegetables belonging to the Allium genus (Allium tuberosum Rottl., Allium senescens L., Allium thunbergii G. Don., and Allium sacculiferum Maxim.) were investigated for their antioxidant and anti-obesity potential, in order to promote the utilization of wild edible plants for the development of potential new crops. In this study, we compared the antioxidant activity of the plant extracts by ABTS+ and DPPH scavenging method. We then compared the anti-adipogenic effects of the extracts in adipocytes. We quantified the phenolics in the extracts using high-performance liquid chromatography (HPLC) to identify the bioactive compounds. A. tuberosum and A. sacculiferum had a higher total phenolic content (19.0 ± 0.3 and 19.6 ± 0.7 mg GA/g extract, respectively) than A. senescens and A. thunbergii (16.0 ± 0.2 and 14.5 ± 0.7 mg GA/g extract). Caffeic acid, an antioxidant and anti-adipogenic compound, was detected in A. tuberosum and A. sacculiferum, but not in A. senescens and A. thunbergii. A. tuberosum, and A. sacculiferum showed superior antioxidative and anti-adipogenic activities compared to A. senescens and A. thunbergii. Therefore, A. tuberosum and A. sacculiferum, both of which contain antioxidant and anti-adipogenic phenolics, such as caffeic acid, present a therapeutic potential against obesity. Various phenolic compounds, which have been found to differ among Allium spp., may partially account for differences among the Allium spp. with respect to their antioxidant and anti-obesity effects.

External stimulation of the skin by ultraviolet B (UVB) radiation induces oxidative stress or inflammation, causing skin aging and skin cancer. Glycyrrhiza uralensis (licorice) has been used as a medicinal plant for its antioxidant, anti-inflammatory, antiviral, antimicrobial, anticarcinogenic, and hepatoprotective properties. The present study analyzed the effects of thermal processing on the bioactivities of licorice. Heat-treated licorice (HL) extracts had better antioxidant and anti-inflammatory activities than non-treated licorice (NL) extract. HL extracts also had higher total phenol contents than NL extract. In particular, contents of isoliquiritigenin, an antioxidant and anti-inflammatory substance of licorice, increased in proportion to the skin-protection effects of HL extracts. Heat treatment increased the contents of phenolic compounds such as isoliquiritigenin in licorice extract, which improved the UV photoprotective effect of licorice in human dermal fibroblasts.

The overproduction of reactive oxygen species (ROS) can cause oxidative stress to biomolecules such as nucleic acids, proteins, and lipids, leading to neurodegenerative disorders. Sasa borealis (SB) has antioxidant, anti-inflammatory, antidiabetic, and anti-obesity effects. We evaluated the neuroprotective activity of SB on hydrogen peroxide (H₂O₂)-induced oxidative stress. We investigated the antioxidant and neuroprotective effects of SB water extract (SBW) and SB ethanol extract (SBE) by measuring the radical scavenging activities and intracellular ROS production. SBE, which had a high level of isoorientin, had higher antioxidative activities than SBW in 2,2′-azino-bis-(3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt (ABTS⁺) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. It also reduced ROS generation in pheochromocytoma 12 (PC12) cells more significantly than SBW. It increased the translation of heme oxygenase-1 (HO-1), superoxide dismutase 2 (SOD2), catalase (CAT), and glutathione peroxidase (GPx) with a corresponding increase in the translation of NF-E2-related factor-2 (Nrf-2). In conclusion, SBE with high levels of phenolic compounds such as isoorientin shows promise for preventing neurodegenerative diseases.