Raphanus sativus L. var. caudatus Extract Alleviates Impairment of Lipid and Glucose Homeostasis in Liver of High-Fat Diet-Induced Obesity and Insulin Resistance in Mice.

The present study investigated the activities of Raphanus sativus L. var. caudatus extract (RS) on abnormal lipid and glucose homeostasis in a high-fat diet (HFD)-induced obesity and insulin resistance in a mouse model. Institute of Cancer Research mice were rendered obese by 16-week HFD feeding. Obese mice were administered with 100 or 200 mg/kg/d RS orally during the last 8 weeks of diet feeding. Then, the biochemical parameters were determined. The gene and protein expressions regulating lipid and glucose homeostasis in the liver were measured. This study revealed that the state of hyperglycemia, hyperleptinemia, hyperinsulinemia, and hyperlipidemia was reduced after 8 weeks of RS treatment (100 or 200 mg/kg). Administration of RS also improved insulin sensitivity and increased serum adiponectin. The liver total cholesterol and triglyceride concentrations were decreased by both doses of RS. Notably, a decrease in the expression of liver-specific genes, including sterol regulatory element-binding protein 1c, fatty acid synthase, and acetyl-CoA carboxylase, was found in the RS-treated groups. Moreover, administration of RS showed a significant increase in the expression of adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and sirtuin1 (Sirt1) proteins. These findings indicated that RS improved abnormal lipid and glucose homeostasis in the liver of obesity-associated insulin resistance mouse model, possibly through the stimulation of the AMPK/Sirt1 pathway.

Mentha cordifolia Leaf Extract Improves Hepatic Glucose and Lipid Metabolism in Obese Mice Fed with High-Fat Diet.

Mentha cordifolia (MC) is a popular herb used to flavor food in Thailand that exhibits several biological effects. The present study aimed to determine the role of MC in regulating glucose and lipid metabolism in mice fed a high-fat diet (HFD). ICR obese mice were fed an HFD (45 kcal% lard fat) for 12 weeks, with MC (100 and 200 mg/kg/d) treatment from Week 7. After treatment with MC for 6 weeks, mice showed significantly lower rates of hyperglycemia, hyperinsulinemia, hyperleptinemia, and hyperlipidemia, and increased amounts of serum adiponectin. Furthermore, in mice treated with MC, serum interleukin-6 and tumor necrosis factor alpha were significantly inhibited and liver histology results showed decreased lipid accumulation and liver triglyceride content vs. untreated mice. In addition, MC treatment was associated with smaller fat cells and lower gene expression of liver sterol regulatory element binding protein 1c, acetyl-CoA carboxylase, and fatty acid synthase. However, MC treatment was associated with higher carnitine palmitoyltransferase 1a gene expression and significantly higher rates of adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in liver, but lower levels of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. These results indicate MC regulates glucose and lipid metabolism in a HFD-induced obese mouse model, possibly via activation of AMPK signaling pathway.

Molecular and cytogenetic effects of Thai royal jelly: modulation through c-MYC, h-TERT, NRF2, HO-1, BCL2, BAX and cyclins in human lymphocytes in vitro.

Royal jelly (RJ) is widely used as a food supplement for anti-aging and beauty. However, its use has been linked to asthma and hemorrhagic colitis. Since its mechanisms of toxicity have not been fully identified, we conducted an investigation to elucidate its molecular and cytogenetic effects. Using human lymphocytes in vitro, treatments with RJ (0.0005-5 mg/ml) for 3 h did not induce sister chromatid exchanges until 5 mg/ml was used. Treatments for 24 h showed a dose-dependent reduction in BCL2/BAX, c-MYC/BAX and HO-1/BAX ratios. The exception was the NRF2/BAX ratio, showing a dose-dependent reduction at low doses, but a marked increase at the highest dose. The hTERT/BAX ratio was maintained at approximately a 1.2-fold increase but decreased to nearly normal at the highest dose. Our findings indicated that the lowest dose of RJ treatment provided maximum benefits, mainly through hTERT activation relating to prolonged lifespan. The highest dose of RJ inhibited cell survival, cell proliferation and an antioxidative enzyme; nevertheless, it still activated an antioxidative response through NRF2 and maintained telomeres during cell crisis. RJ treatment at 0.05 mg/ml increased cyclin E, BCL2 and BAX to maximum levels indicating that throughout the active cell cycle, both cell survival and cell apoptosis increased. Using the gene expression ratios over BAX, similar to BCL2/BAX, provided more informative data than using individual protein levels alone. With these informative ratios, our results confirm the potential benefits of RJ in enhancing lifespan and activation antioxidative power. Further, in vivo mechanistic studies will be useful in validating these results.

Antigenotoxic activity of Thai Sangyod red rice extracts against a chemotherapeutic agent, doxorubicin, in human lymphocytes by sister chromatid exchange (SCE) assay in vitro.

BACKGROUND: Nowadays, anticarcinogenic potential of pigmented brown rice and rice bran varieties have been increasingly stated. However, their mechanisms of action are still inconclusive. One of which might be their antigenotoxic activity that no study in human cells was reported before. OBJECTIVE: To evaluate the antigenotoxic activities of Thai Sangyod red rice extracts against a chemotherapeutic agent, doxorubicin, by sister chromatid exchange (SCE) assay in human lymphocytes in vitro. MATERIAL AND METHOD: Two fractions of water-soluble of Sangyod rice extracts were used: (i) the washed water extract of brown rice (WWBR) and (ii) the water extract of rice bran (WERB). Human lymphocytes were pretreated with each extracts at concentrations of 6.2, 12.5, 25, 50 and 100 microg/ml for 2 h followed by a genotoxic agent, doxorubicin (DXR) (0.1 microg/ml) for 2 h. SCE level, mitotic index (MI) and proliferation index (PI) were evaluated. Statistical analysis by Dunnett's t-test was performed. RESULTS: The results indicated that the pretreatment of WERB fraction only at concentration of 6.2 microg/ml could significantly decrease SCE level as compared to that of the DXR treated alone (p < 0.05). On the other hand, WERB fraction at other concentrations and all WWBR pretreatments could not. In addition, there was no significant difference in MI and PI levels between all pretreated extracts as compared to the DXR treated alone. CONCLUSION: Our data revealed that WERB pretreatment only at specific low concentration of 6.2 microg/ml possessed the antigenotoxic potential against genotoxic damage but not anticytotoxic induced by DXR. Further work is still needed to clarify more the antigenotoxic and anticytotoxic potentials from other fractions of Sangyod rice extracts.