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

Abstract

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.

Red Rice Bran Extract Attenuates Adipogenesis and Inflammation on White Adipose Tissues in High-Fat Diet-Induced Obese Mice

“…In agreement with previous studies [36,37], HFD feeding resulted in adipose tissue inflammation, as evidenced by increased CLS formation and expressions of macrophage marker gene F4/80, along with increased inflammatory gene expressions, including NF-κB p65, MCP-1, TNF-α, and iNOS, in the HFD group compared to the LFD group (Figure 2D,E and Figure 4A-D). The ELISA results confirmed an increase in the serum levels of TNF-α in mice fed an HFD (Figure 4F), which is one of the main biomarkers of systemic inflammation; this finding is consistent with a previous study [38]. Nevertheless, our result shows that the 12-week HFD feeding duration is not sufficient to increase serum MCP-1 levels (Figure 4E), indicating that this duration is not long enough to induce increased production of this chemokine.…”

Red Rice Bran Extract Alleviates High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease and Dyslipidemia in Mice

“…The abnormal lipid metabolism in the liver and adipose tissue results in hepatic steatosis, typically promoting the secretion of lipids, and hence, contributing to high circulating FFA levels, hypertriglyceridemia, and hypercholesterolemia [ 4 , 6 ]. Consistent with previous reports [ 20 , 21 , 26 , 27 , 28 ], our findings showed that HFD-fed animals presented the typical features of hepatic steatosis and hyperlipidemia, including high serum FFA, hypertriglyceridemia, and hypercholesterolemia, associated with the elevated expression of ATGL in adipose tissue, CD36, LXRα, SREBP-1c, SREBP-2, and HMGCR, as well as decreased CPT1A expression in the liver, which were overall reversed by RRBE treatments, especially at the middle and high doses. Interestingly, although a high-dose RRBE treatment did not reduce serum total-C in HFD-fed mice, it significantly attenuated LDL-C and enhanced HDL-C in the serum, as discussed in more detail below.…”

“…This study indicates that dyslipidemia, NAFLD, and obesity were successfully induced in our model by feeding the mice with HFD, which may be due to the significant increase in their energy intake. Our results are in accordance with those reported by previous studies [ 20 , 21 , 26 , 27 , 28 , 29 , 30 , 31 ]. Thus, this model is appropriate for examining the precise mechanisms underlying the anti-dyslipidemic and anti-NAFLD activities of RRBE.…”

“…The animals were housed under standard laboratory conditions (temperature: 22–25 °C; 60% humidity; 12/12 h light/dark cycle) and allowed access to food and water ad libitum. Obesity and NAFLD were induced in 4-week-old male Institute of Cancer Research (ICR) mice (weighing 20 g, Nomura Siam International Co., Ltd., Bangkok, Thailand) by the administration of high-fat diet (HFD; 45% kcal from fat, Research Diets, New Brunswick, NJ, USA) for 12 weeks, and the control mice were kept on a low-fat control diet (LFD; 10% kcal from fat, Research Diets) [ 20 , 21 ]. After 1 week of acclimation, 36 mice were randomly divided into two different diet groups: LFD ( n = 12) and HFD ( n = 24) groups for 6 weeks to induce obesity.…”

The Potential of Lamiaceae Herbs for Mitigation of Overweight, Obesity, and Fatty Liver: Studies and Perspectives

“…Mentha villosa Huds (the synonym of Mentha cordifolia ) is another popular herb typically used both as flavour in Thai food and as herbal tea. It has been shown to improve lipid metabolism and glycemia in obese mice treated with M. villosa leaf extract for six weeks, leading to a reduction in GLU, insulin, leptin, TG levels, and in the inflammatory cytokines IL-6 and TNFα, and an increase in adiponectin level, accompanied with the activation of the AMPK signaling pathway [ 69 ] ( Table 2 ).…”