Amber (Succinite) Extract Enhances Glucose Uptake through the Up-Regulation of ATP and Down-Regulation of ROS in Mouse C2C12 Cells.

Traditionally, amber (Succinite) has been used to alleviate all types of pain, skin allergies, and headaches. However, no studies have been conducted on its antidiabetic and antioxidant effects. In this study, differentiated skeletal muscle C2C12 cells were used to demonstrate the protective effects of amber (AMB) against H2O2-induced cell death. In addition, the effects of AMB on glucose uptake and ATP production were investigated. Our results showed that AMB at 10, 25, and 50 µg/mL suppressed the elevation of ROS production induced by H2O2 in a dose-dependent manner. Moreover, AMB enhanced glucose utilization in C2C12 cells through the improvement of ATP production and an increase in PGC-1α gene expression resulting in an amelioration of mitochondrial activity. On the other hand, AMB significantly increased the gene expression of glucose transporters GLUT4 and GLUT1. Our finding suggests that AMB can be used as a natural supplement for diabetes treatment and for the promotion of skeletal muscle function.

Kaempferol ameliorates symptoms of metabolic syndrome by improving blood lipid profile and glucose tolerance.

Kaempferol (KPF) is a dietary polyphenol reported to have various beneficial effects on human health. However, its molecular mechanisms in regulating lipid and glucose metabolism are not fully understood. This study examined the effects of KPF on obesity, dyslipidemia, and diabetes in Tsumura, Suzuki, Obese Diabetes mice. The 6-week administration of KPF decreased fat weight, serum total cholesterol, and low-density lipoproteins (LDLs); increased high-density lipoproteins (HDLs); and improved glucose tolerance. Additionally, KPF increased LDL receptor (LDLR) and apolipoprotein A1 (ApoA1) gene expression and decreased serum resistin levels. These findings suggest that the decrease in LDL and the increase in HDL caused by KPF may be due to increases in hepatic LDLR and ApoA1 expression, respectively. Furthermore, it is possible that the improvement in glucose tolerance by KPF may occur via resistin reduction. These mechanisms may be parts of complex mechanism by which KPF improves metabolic syndrome.

Modulation of the neurotransmitter systems through the anti-inflammatory and antidepressant-like effects of squalene from Aurantiochytrium sp.

Although algae have been the focal point of biofuel research, studies on their biological activities have been limited. In recent years, however, the importance of algae as sources of functional ingredients has been recognized due to their health beneficial effects. In this study, we evaluated the antidepressant-like activities of ethanol extract of Aurantiochytrium sp. (EEA) in the forced swimming test (FST)-induced depression in ICR mice. Imipramine, a commercially available tricyclic antidepressant drug, was used as positive control. Animals were administered EEA orally for 14 consecutive days and were subjected to the locomotor activity testing. Additionally, changes in gene expression in mice brain were assessed by real-time PCR and microarray assays to understand the molecular mechanisms underlying the effect of EEA. We found that the immobility time in FST was significantly reduced in the EEA-treated mice compared to that of in the control mice. Microarray and real-time PCR results revealed that EEA treatment induced changes in several genes in mice brain associated with pro-inflammation and dopaminergic, cholinergic, glutamatergic, and serotonergic synapses. It has previously been reported that several cytokines, such as IL-6 and TNF-α, which mediate neuroinflammation, are also responsible for indirectly altering brain neurotransmitter levels in neuropsychiatric disorders. Therefore, the regulation of the expression of pro-inflammatory genes in EEA-administered mice brain is considered to contribute to the enhancement of neurotransmitter systems-related gene expression in our study. Moreover, our in vitro study suggested that squalene, a component produced by Aurantiochytrium, was one of the active substances in EEA. In conclusion, our study provides the first evidence that Aurantiochytrium sp. can reduce neuroinflammation that may contribute to the modulation of the neurotransmitter systems, which could underlie its antistress and antidepressant effects.