So-Hyeon Baek

Resveratrol is a natural polyphenolic compound with antioxidant and anti-melanogenic activities, but it occurs only at low levels in most edible plant tissues, motivating the development of enriched sources. Resveratrol-enriched DJ526 rice provides such a source, and seed germination may further modulate its biological activity. Therefore, this study investigated the effects of 5-day germination on the antioxidant and anti-melanogenic properties of resveratrol-enriched DJ526 rice in Melan-a cells. Seed extracts of ungerminated DJ526 (DJ526_0), germinated DJ526 (DJ526_5), and non-transgenic controls (DJ_0 and DJ_5) were evaluated for antioxidant capacity, cell viability, melanogenic activities, and the expression of MITF and its downstream targets. Five-day germination increased piceid and resveratrol content in DJ526_5 from 4.73 ± 0.06 to 16.90 ± 0.00 µg/g dry weight and from 2.60 ± 0.00 to 3.27 ± 0.06 µg/g dry weight, respectively. DJ526_5 exhibited the strongest antioxidant capacity (ABTS IC₅₀, 16.81 ± 1.26 mg/mL). At 100 µg/mL, DJ526_5 reduced intracellular melanin content and tyrosinase activity to 59.48 ± 2.13% and 45.63 ± 0.24% of the control, respectively, without reducing cell viability. DJ526_5 also reduced the mRNA and protein expression of MITF, tyrosinase, TRP-1, and TRP-2. These findings support the potential of DJ526 as a functional ingredient for hyperpigmentation management.

In the current study, we aimed to evaluate the combined antimelanogenic effects of resveratrol- and protopanaxadiol (PPD)-enriched rice seed extracts (DJ526 and DJ-PPD) in melan-a cells. The treatment antioxidant capacity was evaluated using the ABTS radical scavenging method. TR_3 (70% [wight (w)/w] of DJ526 and 30% [w/w] of DJ-PPD) markedly increased the antioxidant activity at a level similar to that of DJ526 and DJ-PPD alone. The antimelanogenic activities in melan-a cells were evaluated after co-culturing of treatments at the concentration of 100 μg/mL. The in vitro melan-a cell experiment showed that treatment with the DJ526 and DJ-PPD mixture significantly reduced the cellular tyrosinase activity and melanin content; suppressed the expression of melanogenesis-related genes and proteins; decreased the number and size of melanin-containing cells; upregulated phosphorylated extracellular signal-regulated kinase 1/2 and protein kinase B expression levels; and suppressed the expression of p-p38 MAPK. These results show that DJ-PPD does not interfere with the antioxidant and antimelanogeneic activities of DJ526 but enhances the antioxidant and antimelanogeneic activities of DJ526. These findings indicate the potential of resveratrol- and PPD-enriched rice seeds as novel agents for controlling hyperpigmentation.

The overproduction of proinflammatory cytokines triggers a variety of diseases. Protopanaxadiol (PPD) and resveratrol are naturally found in plants such as ginseng and have potential anti-inflammatory properties, and resveratrol- and PPD-enriched rice seeds have been previously successfully generated. Herein, the synergistic anti-inflammatory activities of extracts of these enriched seeds were assessed in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In comparison with treatment using extract prepared from PPD-producing transgenic rice (DJ-PPD) alone, cotreatment with DJ526 and DJ-PPD (TR_3) markedly enhanced the anti-inflammatory activities at a similar (compared to DJ526) or higher (compared to DJ-PPD) level. Cotreatment with DJ526 and DJ-PPD markedly inhibited the activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Thus, DJ526 and DJ-PPD in combination suppressed the expression of phosphorylated (p)-NF-κB p65, p-p38 MAPK, and p-ERK 1/2. Cotreatment with DJ526 and DJ-PPD downregulated the expression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α), LPS receptor (toll-like receptor-4, TLR-4), proinflammatory mediators (nitric oxide and PGE₂), and arachidonic acid pathway critical enzyme (COX-2). These findings demonstrate the synergistic potential anti-inflammatory activities of resveratrol- and PPD-enriched rice seed extract.

Rapeseed (Brassica napus L.) holds significant commercial value as one of the leading oil crops, with its agronomic features and oil quality being crucial determinants. In this investigation, 73,226 single nucleotide polymorphisms (SNPs) across 95 rapeseed mutant lines induced by gamma rays, alongside the original cultivar (‘Tamra’), using genotyping-by-sequencing (GBS) analysis were examined. This study encompassed gene ontology (GO) analysis and a genomewide association study (GWAS), thereby concentrating on agronomic traits (e.g., plant height, ear length, thousand-seed weight, and seed yield) and oil traits (including fatty acid composition and crude fat content). The GO analysis unveiled a multitude of genes with SNP variations associated with cellular processes, intracellular anatomical structures, and organic cyclic compound binding. Through GWAS, we detected 320 significant SNPs linked to both agronomic (104 SNPs) and oil traits (216 SNPs). Notably, two novel candidate genes, Bna.A05p02350D (SFGH) and Bna.C02p22490D (MDN1), are implicated in thousand-seed weight regulation. Additionally, Bna.C03p14350D (EXO70) and Bna.A09p05630D (PI4Kα1) emerged as novel candidate genes associated with erucic acid and crude fat content, respectively. These findings carry implications for identifying superior genotypes for the development of new cultivars. Association studies offer a cost-effective means of screening mutants and selecting elite rapeseed breeding lines, thereby enhancing the commercial viability of this pivotal oil crop.

The excessive production of melanin can cause skin diseases and hyperpigmentation. In this study, resveratrol contained in Dongjin rice seed (DJ526) was increased through callus induction. The antioxidant capacity of resveratrol-enriched rice callus was evaluated using the ABTS radical scavenging method and was equivalent to that of vitamin C. DJ526 rice callus extract significantly increased antioxidant activities in a concentration-dependent manner. The anti-melanogenesis effects of DJ526 rice callus extract were also evaluated in melan-a cells. Resveratrol-enriched rice callus extract significantly (i) decreased the size and number of melanin-containing cells, (ii) suppressed the activity of cellular tyrosinase and melanin content, (iii) downregulated the expression of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein-1, and tyrosinase-related protein-2, (iv) increased the expression of phosphorylated extracellular signal-regulated kinase 1/2 and protein kinase B, and (v) inhibited the activation of phosphorylated p38 in melan-a cells. From the above observations, DJ526 rice callus extract showed strong antioxidant and anti-melanogenesis activity at the concentration test. These findings indicate the potential of resveratrol-enriched rice callus as a novel agent for controlling hyperpigmentation.

Resveratrol and its derivative piceid exhibit a wide spectrum of health-promoting bioactivities. A resveratrol-enriched variety of Dongjin rice (DJ526) has been developed by transfection of a resveratrol biosynthesis gene, and increased resveratrol content has been confirmed in seeds following germination. In the current study, these resveratrol-enriched seeds were induced to produce callus, and callus extracts were evaluated for in vitro anti-inflammatory activity. Callus cultures contained greater amounts of resveratrol and piceid than DJ526 seeds, and treatment with DJ526 callus extract significantly reduced the lipopolysaccharide (LPS)-induced production of proinflammatory mediators nitric oxide and prostaglandin E2 by RAW264.7 macrophages. The inflammation-related nuclear factor kappa B and mitogen-activated protein kinase pathways were also inhibited in DJ526 callus extract-treated RAW264.7 cells, resulting in downregulation of proinflammatory factor genes COX-2, iNOS, IL-1β, IL-6, and TNF-α. Expression of the LPS-binding toll-like receptor-4 was also markedly reduced in DJ526 callus extract-treated cells compared to DJ callus extract-treated cells. These findings demonstrate increased resveratrol and piceid content by callus culture of DJ526 rice seeds and the potent anti-inflammatory activity of resveratrol-enriched callus extract.

Ginseng is a traditional medicine with health benefits for humans. Protopanaxadiol (PPD) is an important bioactive compound found in ginseng. Transgenic rice containing PPD has been generated previously. In the present study, extracts of this transgenic rice were evaluated to assess their antiadipogenic and anti-inflammatory activities. During adipogenesis, cells were treated with transgenic rice seed extracts. The results revealed that the concentrations of the rice seed extracts tested in this study did not affect cell viability at 3 days post-treatment. However, the rice seed extracts significantly reduced the accumulation of lipids in cells and suppressed the activation of CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ), which in turn inhibited the expression of adipogenesis-related mRNAs, such as adiponectin, PPARγ, C/EBPα, sterol regulatory element-binding protein 1, glucose transport member 4, and fatty acid synthase. In adipocytes, the extracts significantly reduced the mRNA expression of inflammation-related factors following LPS treatment. The activation of NF-κB p65 and ERK 1/2 was inhibited in extract-treated adipocytes. Moreover, treatment with extract #8 markedly reduced the cell population of the G2/M phase. Collectively, these results indicate that transgenic rice containing PPD may act as an obesity-reducing and/or -preventing agent.

Obesity is a major risk factor for a variety of diseases and contributes to chronic inflammation. Resveratrol is a naturally occurring antioxidant that can reduce adipogenesis. In this study, the antiadipogenic and anti-inflammatory activities of resveratrol-enriched rice were investigated in 3T3-L1 adipocyte cells. Cotreatment of dexamethasone and isobutylmethylxanthin upregulated adipogenic transcription factors and signaling pathways. Subsequent treatment of adipocytes with rice seed extracts suppressed the differentiation of 3T3-L1 by downregulating adipogenic transcription factors (peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α) and signaling pathways (extracellular signal-regulated kinase 1/2 and protein kinase B Akt), this was especially observed in cells treated with germinated resveratrol-enriched rice seed extract (DJ526_5). DJ526_5 treatment also markedly reduced lipid accumulation in the cells and expression of adipogenic genes. Lipopolysaccharide (LPS)-induced inflammatory cytokines (prostaglandin-endoperoxide synthase 2 (COX-2), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) decreased in cells treated with DJ526_5. Collectively, DJ526_5 exerts antiadipogenic effects by suppressing the expression of adipogenesis transcription factors. Moreover, DJ526_5 ameliorates anti-inflammatory effects in 3T3-L1 adipocytes by inhibiting the activation of phosphorylation NF-κB p65 and ERK ½ (MAPK). These results highlight the potential of resveratrol-enriched rice as an alternative obesity-reducing and anti-inflammatory agent.

Melanin production is an important process that prevents the host skin from harmful ultraviolet radiation; however, an overproduction of melanin results in skin diseases. In the present study, we determined the antioxidative and anti-melanogenic activities of polyphenol- and flavonoid-enriched rice seed extracts in melan-a cells. The polyphenol and flavonoid content of Hopum (HP) and Sebok (SB) rice seed extracts was measured. The antioxidant capacity was determined using the ABTS radical scavenging method. SB contained high amounts of polyphenols and flavonoids, which significantly increased antioxidative activity compared with HP. Various concentrations of these extracts were evaluated in a cytotoxicity using melan-a cells. At 100 µg/mL, there was no significant difference for all treatments compared with untreated cells. Therefore, 100 µg/mL was selected as a concentration for the further experiments. SB significantly suppressed the phosphorylation/activation of p-38 MAPK, increased the expression of phosphorylated ERK 1/2 and Akt, and downregulated the microphthalmia-associated transcription factor (MITF). This resulted in decreased levels of tyrosinase and tyrosinase-related protein-1 and -2. These results indicate the potential of polyphenol- and flavonoid-enriched rice seed as a treatment for hyperpigmentation.

Inflammation is triggered by a variety of danger signals and is now a worldwide concern. Resveratrol, a natural nonflavonoid polyphenol found in naturally consumed plants and foods, has a wide spectrum of bioactive potency. We successfully generated resveratrol-enriched rice by introducing the resveratrol biosynthesis gene into Dongjin rice. In this study, resveratrol- and piceid-enriched rice (DJ526) was investigated for its anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 cells compared to normal rice (DJ). In addition, the 5-day-old germinated DJ526 (DJ526_5) was tested for its anti-inflammatory effects. The piceid and resveratrol amounts increased in DJ526_5 by germination. Treatment of LPS-stimulated RAW264.7 cells with resveratrol-enriched rice seed extracts (DJ526_0 and DJ526_5) significantly decreased the production of nitric oxide (NO) and the inflammatory mediator prostaglandin E2 (PGE₂), downregulated proinflammatory gene expression, and inhibited nuclear factor kappa B (NF-κB) p65, p38 mitogen-activated protein kinase, and extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation. These findings demonstrated the anti-inflammatory mechanisms of resveratrol-enriched rice in LPS-stimulated RAW264.7 cells. Furthermore, resveratrol-enriched rice could be a potential source of anti-inflammatory agents.