Crowberry (Empetrum nigrum L.) is a wild berry commonly found in the northern hemisphere. Crowberry fruits have been suggested as good resources for functional applications in the cosmetic and pharmaceutical industries, but the high polyphenolic content in crowberry leaves also indicates crowberry aerial parts as potential dietary health supplements. In this study, therefore, the biological activities of the aerial parts of Korean crowberry (E. nigrum var. japonicum) were investigated. Antioxidant activity was measured by three different assays on DPPH free radical scavenging, reducing power, and total antioxidant capacities. Dose-dependent antioxidant activities were exhibited by crude methanol extract and its fractions, suggesting that the crude methanol extract and EtOAc fraction possessed strong antioxidant activities and capacities. In addition, the crude methanol extract and EtOAc strongly inhibited α-glucosidase activity and suppressed the secretion of pro-inflammatory mediator and nitrite oxide from LPS-stimulated RAW 264.7 cells. These findings provide valuable evidence for the potential of such parts as good dietary sources of natural antioxidant, α-glucosidase inhibitory, and anti-inflammatory components, suggesting that using the non-edible parts (e.g., leaves and stems) of crowberry can be a potential natural avenue for improving human health.

The leaves of Sasa quelpaertensis Nakai were extracted with 80% ethanol and further partitioned with n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous fractions to evaluate the biological activity through assessment via various in vitro assays, including total phenol content; 1,1-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazothiazoline-6-sulfornic acid (ABTS) radical scavenging; reducing power; α-glucosidase and tyrosinase inhibitory; and alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity assays. The highest activity was found in the ethyl acetate fraction for all assays and showed stronger DPPH radical scavenging, reducing power, and tyrosinase inhibitory activity than the positive controls (butylated hydroxytoluene, α-tocopherol, and arbutin, respectively). When compared to the ethyl acetate fraction, the n-butanol fraction had lower rates, but it still demonstrated relatively high activity. The activity of the n-hexane fraction was high for DPPH and ABTS radical scavenging activity and contained significant amounts of phenol content, whereas the chloroform fraction possessed the highest reducing power, tyrosinase inhibitory, and ADH and ALDH activity, despite having the lowest phenol content when compared to the other fractions. These findings clearly indicate that S. quelpaertensis Nakai leaves can be a good natural source of antioxidants and tyrosinase inhibitors, as well as ADH and ALDH activity inducers, suggesting that may have potential for treating various diseases and improving human health.

Rumex crispus is a perennial plant that grows in humid environments across Korea. Its roots are used in traditional Korean medicine to treat several diseases, including diseases of the spleen and skin and several inflammatory pathologies. In this study, different solvent fractions (n-hexane, dichloromethane, ethyl acetate, n-butanol, and aqueous fractions) from an ethanol extract of R. crispus roots were evaluated for the presence and composition of anthraquinone compounds and antioxidants by checking for such things as free radical scavenging activity, and electron and proton atom donating ability. In addition, anti-inflammatory activity was measured by NO scavenging activity and inflammatory cytokine production; furthermore, anti-cancer activity was measured by apoptosis-inducing ability. Polyphenolic and flavonoid compounds were shown to be abundant in the dichloromethane and ethyl acetate fractions, which also exhibited strong antioxidant activity, including free radical scavenging and positive results in FRAP, TEAC, and ORAC assays. HPLC analysis revealed that the dichloromethane fractions had higher anthraquinone contents than the other fractions; the major anthraquinone compounds included chrysophanol, emodin, and physcione. In addition, results of the anti-inflammatory assays showed that the ethyl acetate fraction showed appreciable reductions in the levels of nitric oxide and inflammatory cytokines (TNF-α, IL-1β, and IL-6) in Raw 264.7 cells. Furthermore, the anthraquinone-rich dichloromethane fraction displayed the highest anticancer activity when evaluated in a human hepatoma cancer cell line (HepG2), in which it induced increased apoptosis mediated by p53 and caspase activation.