Protopanaxadiol-Enriched Rice Exerted Antiadipogenic Activity during 3T3-L1 Differentiation and Anti-Inflammatory Activity in 3T3-L1 Adipocytes.

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.

Inhibitory Effects of Polyphenol- and Flavonoid-Enriched Rice Seed Extract on Melanogenesis in Melan-a Cells via MAPK Signaling-Mediated MITF Downregulation.

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.

Transgenic Rice Seed Extracts Exert Immunomodulatory Effects by Modulating Immune-Related Biomarkers in RAW264.7 Macrophage Cells.

Protopanaxadiol (PPD), a native active triterpenoid present in Panax ginseng, has been reported to exert immune-related effects. We previously created PPD-producing transgenic rice by introducing the P. ginseng protopanaxadiol synthase and dammarenediol-II synthase genes into Dongjin rice. In the present study, the seeds of the T4 generation of this transgenic rice were tested for their immunomodulatory effects in RAW264.7 macrophage cells. Treatment with transgenic rice seed extract in RAW264.7 cells (i) significantly enhanced nitric oxide (NO) production in a dose-dependent manner without any cytotoxicity (up to 100 µg/mL), (ii) upregulated the expression of immune-related genes and increased production of the inflammation mediator prostaglandin E2 (PGE2), and (iii) activated nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) by promoting the phosphorylation of NF-κB p65, p38 MAPK, and c-Jun N-terminal protein kinase (JNK). In lipopolysaccharide (LPS)-treated RAW264.7 cells used to mimic the inflammation condition, treatment with transgenic rice seed extract significantly reduced NO production, proinflammatory cytokine expression, and PGE2 production, all of which are LPS-induced inflammation biomarkers, by inhibiting the phosphorylation of NF-κB p65, p38 MAPK, and JNK. Collectively, these results indicate that PPD-producing transgenic rice has immunomodulatory effects.

Oral toxicity of isotretinoin, misoprostol, methotrexate, mifepristone and levonorgestrel as pregnancy category X medications in female mice.

An oral toxicity study of several pregnancy category X drugs was performed in female ICR mice. The drugs were administered orally once daily for 3 days at doses of 1, 10 and 100 µg/kg for isotretinoin; 6.7, 67 and 670 µg/kg for misoprostol; 83, 830 and 8,300 µg/kg for methotrexate; 3.3, 33 and 330 µg/kg for mifepristone; and 25, 250 and 2,500 µg/kg for levonorgestrel. During the test period, clinical signs, mortality, body weight, hematology, serum biochemistry and necropsy findings were examined. Following administration of methotrexate at 8,300 µg/kg, a number of animals exhibited decreased spontaneous activity, and one animal died. In the hematological analysis, compared with those treated with the control, the animals treated with the drugs exhibited similar significant decreases in the number of granulocytes and granulocyte differentiation, and increases in lymphocyte differentiation. In the serum biochemical analysis, animals receiving high doses of the five drugs demonstrated significant changes in uric acid, glucose, alkaline phosphatase, total bilirubin, lipase, total cholesterol and calcium. At necropsy, intestinal redness was frequently observed in animals that received the high dose of methotrexate. Uterus enlargement and ovary dropsy were also detected in the groups receiving mifepristone and levonorgestrel. Despite the short-term exposure, these drugs exhibited significant side effects, including white blood cell toxicity, in the mouse model. Category X drugs can be traded illegally via the internet for the purpose of early pregnancy termination. Thus, illegal abuse of the drugs should be further discouraged to protect mothers.