Sleep is one of the most essential factors required to maintain good health. However, the global prevalence of insomnia is increasing, and caffeine intake is a major trigger. The objective of this study was to investigate the inhibitory effect of black pepper, Piper nigrum extract (PE), on caffeine-induced sleep disruption and excitation in mice. Caffeine significantly decreased sleep duration in the pentobarbital-induced sleep test. It also resulted in a significant increase in sleep onset and a decrease in non-rapid eye movement sleep. Moreover, in an open-field test, caffeine-treated mice exhibited a significantly increased time in the center zone and total distance traveled. However, the co-administration of caffeine and PE did not result in similar arousal activities. Thus, our results suggest that PE can be used as a potential therapeutic agent to treat sleep problems and excitatory status associated with caffeine intake.

In age-related macular degeneration, N-retinylidene-N-retinylethanolamine (A2E) accumulates in retinal pigment epithelium (RPE) cells and generates oxidative stress, which further induces cell death. Polyphenols are well known for their antioxidant and beneficial effects on vision. Chrysanthemum boreale Makino (CB) flowers, which contain flavonoids, have antioxidant activity. We hypothesized that polyphenols in ethanolic extracts of CB (CBE) and its fractions suppressed A2E-mediated ARPE-19 cell damage, a human RPE cell line. CBE is rich in polyphenols, shows antioxidant activity, and suppresses intracellular accumulation of A2E and cell death induced by A2E. Among the five fractions, the polyphenol content and antioxidant effect were in the order of the ethyl acetate fraction (EtOAc) > butanol fraction (BuOH) > hexane fraction (Hex) > dichloromethane fraction (CH2Cl2) > water fraction (H2O). In contrast, the inhibitory ability of A2E accumulation and A2E-induced cell death was highest in H2O, followed by BuOH. In the correlation analysis, polyphenols in the H2O and BuOH fractions had a significant positive correlation with antioxidant effects, but no significant correlation with cell damage caused by A2E. Our findings suggest that substances other than polyphenols present in CBE can suppress the effects of A2E, and further research is needed.

Recently, cultured meat has been considered as an alternative food source. However, the commercialization of cultured meat essentially requires the development of serum-free or low-serum media that reduces production costs. This study aimed to discover a food-derived plant extract that can maintain cell proliferation in Hanwoo satellite cells (HWSC) subsequent to reducing the amount of fetal bovine serum (FBS) by half. Totally, 115 plants were extracted by ethanol and hot water. In the primary screening, compared with the control containing 20% FBS, the proliferation rate of HWSC was screened for 230 extracts treated in a medium containing 10% FBS for 6 days. Of the 230 extracts, four ethanol extracts and four hot water extracts showed proliferation rates similar to the control. In the secondary screening, these eight extracts were subjected to surface plasmon resonance to select the extracts that directly bind to MyoD and Pax7 proteins, which are involved in the proliferation of muscle satellite cells. Of these, Pyrus pyrifolia and Hordeum vulgare, were determined to bind directly to the MyoD and Pax7 proteins. The two extracts promoted HWSC proliferation in a dose-dependent manner (25∼200 μg/mL) and exerted no negative effects on differentiation. Finally, the proliferation efficacy results were classified according to the extracted plant parts and the extraction methods. Three plant parts (the fruiting body, root, and stem) and the ethanol extraction method showed good proliferative efficacy. The results of this study can be used as basic data for research on the production of culture media for cultured meat.