The purpose of this study was to compare the nutritional components and antioxidant activities of two different cultivars of Brassica juncea (Dolsan, Yeosu, Korea (BJD) and (Jeongseon, Gangwon, Korea (BJJ)). We investigated the proximate composition (moisture, crude ash, crude protein and crude lipid), antioxidant activities (2,2-Diphenyl-2-picrylhydrazil (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP)), total phenol content, total flavonoid content and sinigrin content by high-performance liquid chromatography analysis. Our results show that the proximate compositions of BJD and BJJ were not significantly different. However, both the DPPH radical scavenging and FRAP activities of the BJJ extracts were higher than those of the BJD extracts. The total phenol contents of the BJD and BJJ extracts were 6.56 and 9.80 mg gallic acid equivalent/g, respectively. The total flavonoids content of the BJD and BJJ extracts were 20.92 and 34.81 mg rutin equivalent/g, respectively, whereas the sinigrin contents, one of the major compounds in BJD and BJJ extracts, were 16.16 mg/g and 11.73 mg/g, respectively. In this study, we confirmed that, by comparing BJJ and BJD, the sinigrin content of BJD was higher than that of BJJ, but the antioxidant activity and phenol content of BJD were superior to that of BJJ.

Aster scaber is a wild vegetable cultivated in Korea and is known to contain phytochemicals with various biological activities. The potential antioxidant and anti-obesity effects of A. scaber and their mechanism are yet to be reported. We evaluated the total phenolic, flavonoid, and proanthocyanidin contents and oxygen radical absorbance capacity of A. scaber ethanolic extract (ASE), and analyzed the major phenolic compounds of ASE. Antioxidant activity was measured at the chemical level through 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power assay, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and fluorescence recovery after photobleaching (FRAP) assay. In addition, it was measured in vitro through inhibition of Reactive oxygen species (ROS) production in 3T3-L1 adipocyte, and inhibition of lipid accumulation was also evaluated. ASE reduced the expression of enzymes involved in the production of ROS and increased the expression of antioxidant enzymes that reduce increased ROS levels. They also reduced the expression of adipogenesis transcription factors that regulate adipocyte differentiation in relation to ROS production, inhibited the expression of lipogenesis-related genes related to fat accumulation through AMP-activated protein kinase (AMPK) activity, and increased expression of lipolysis-related genes. Thus, ASE containing CGA (chlorogenic acid) inhibits ROS production in 3T3-L1 adipocytes, owing to its strong antioxidant activity, and inhibits lipid accumulation caused by oxidative stress. The extract can be used as a potential functional food material for reducing oxidative stress and obesity.

Fermentation is a technology that enhances biologically active ingredients, improves the absorption rate and induces the generation of new functional ingredients by the catalytic action of enzyme systems possessed by microorganisms. In this study, changes in the content of five kinds of bioactive compounds (deacetylasperulosidic acid, asperulosidic acid, scopolin, asperuloside and scopoletin) of Morinda citrifolia L. were confirmed by fermentation, and a high-performance liquid chromatography-photodiode array (HPLC-PDA) analysis method for measuring analytes was developed and validated. HPLC method for the determination of five bioactive compounds in Morinda citrifolia L. extracts (MCE) was validated in terms of sensitivity, linearity, selectivity, limit of detection (LOD) and quantification (LOQ), precision and accuracy. The coefficient of determination of the calibration curve for bioactive compounds (1.56–100 μg/mL) showed linearity (R² ≥ 0.9999). LOD and LOQ were in the range 0.04–0.97 and 0.13–2.95 μg/mL, respectively. The range of intra- and intraday accuracies values (recovery) were 97.5–121.9% and 98.8–118.1%, respectively, and precision value (RSDs) of the bioactive compounds were <4%. In addition, changes in the content of five bioactive compounds in MCE by fermentation were confirmed. These results indicate that the developed fermentation and analysis method could be applied in the development of potential functional food ingredients.

The objective of the present study was to develop a concoction of natural products that could dramatically improve immune function with minimal possible side effects. Sasa quelpaertensis Nakai and Ficus erecta var. sieboldii are plants that are native to Jeju Island, Korea and are known to be rich in physiologically active substances. We prepared a mixture of different proportions and extraction conditions using two natural plants and determined their optimum mixing ratio and extraction method by assessing immune function-related biomarkers in RAW264.7 macrophages. Optimal extract (HR02/04(8:2)-W) was selected from in vitro experiments and its immunity-enhancing efficacy was evaluated in mice. After oral administration of extract to BALB/c mice for 2 weeks, nitric oxide production in the peritoneal exudate cells, natural killer cell cytotoxicity, cytokine expression in splenocytes, and total cell number of immune tissues and phenotype analysis were evaluated. Our results demonstrated that HR02/04(8:2)-W significantly enhanced the immune system by increasing natural killer cell activity, cytokine expression, and total number of cells in immune tissues. In conclusion, our study validates the role of HR02/04(8:2)-W in enhancing immunity and its potential development as a functional food.