Garcinia Cambogia Improves High‐Fat Diet‐Induced Glucose Imbalance by Enhancing Calcium/CaMKII/AMPK/GLUT4‐Mediated Glucose Uptake in Skeletal Muscle

Abstract

Scope: Garcinia cambogia (G. cambogia) is known to have antiobesity effects. In this study, the therapeutic effects of G. cambogia on glucose homeostasis in obesity-induced diabetes are explored and the underlying mechanisms are investigated. Methods and results: C2C12 myotubes are treated with G. cambogia; glucose uptake, intracellular Ca 2+ levels, and related alterations in signaling pathways are examined. High-fat diet (HFD)-fed mice are administered G. cambogia for 8 weeks; oral glucose tolerance is evaluated, and the regulation of identified targets of signaling pathways in quadriceps skeletal muscle are examined in vivo. G. cambogia increases glucose uptake in C2C12 myotubes and induces the upregulation of AMPK, ACC, and p38 MAPK phosphorylation. Notably, G. cambogia markedly elevates both intracellular Ca 2+ levels, activating CaMKII, a Ca 2+ -sensing protein, and TBC1D4-mediated GLUT4 translocation, to facilitate glucose uptake. Furthermore, high-glucose-induced inhibition of glucose uptake and signal transduction is reverted by G. cambogia. In an HFD-induced diabetes mouse model, G. cambogia administration results in significant blood glucose-lowering effects, which are attributed to the regulation of targets that have been identified in vitro, in quadricep skeletal muscle. Conclusion: These findings provide new insights into the mechanism by which G. cambogia regulates glucose homeostasis in obesity-induced diabetes.

Assessment of Novel Oligopeptides from Rapeseed Napin (Brassica napus) in Protecting HepG2 Cells from Insulin Resistance and Oxidative Stress

“…In this study, a 2 mM dose of napin-derived oligopeptides was used primarily to elucidate the possible mechanisms of their protective effects against IR and oxidative stress in the IR-HepG2 cells. Recent studies reported that glucose consumption has been tightly related to GLUT4 on the plasma membrane, and glucose fails to freely enter cells through the lipid bilayer structure of the plasma membrane without GLUT4. , Therefore, it is necessary to investigate whether oligopeptides significantly increase GLUT4 expression and translocation in vitro or in vivo.…”

Douchi Peptides VY and SFLLR Improve Glucose Homeostasis and Gut Dysbacteriosis in High‐Fat Diet‐Induced Insulin Resistant Mice

“…Previous studies have shown that insulin resistance is the central feature of pathogenesis of metabolic syndrome, obesity, and T2DM. [30,31] Insulin resistant mice often show abnormal glucose homeostasis. [32] Thus, a model of HFD-induced insulin resistant mice was applied to evaluate the effects of peptides VY and SFLLR on insulin resistance.…”

“…[32] Thus, a model of HFD-induced insulin resistant mice was applied to evaluate the effects of peptides VY and SFLLR on insulin resistance. As shown in Figure S1, Supporting Information, the body weight at week 7 and 8, and glucose level at different test time points (15,30,60,90, and 120 min) as well as areas under the curve (AUC) based on oral glucose tolerance test (OGTT) were significantly increased in HFD-fed mice compared with the normal chow diet-fed mice, suggesting that HFD-fed induced obesity, impaired glucose tolerance, and insulin resistance. After 8 weeks of peptide VY or SFLLR supplementation, the fasting blood glucose (FBG) was gradually improved (Figure 2A); in particular, the VY-H and SFLLR-H groups reduced FBG by 35.38% (p < 0.001) and 38.31% (p < 0.001), respectively, in comparison to the HFD group.…”

Recent Advances in Garcinia cambogia Nutraceuticals in Relation to Its Hydroxy Citric Acid Level. A Comprehensive Review of Its Bioactive Production, Formulation, and Analysis with Future Perspectives

“…Morover, G . cambogia administration resulted in significant blood glucose-lowering effects . HCA has attracted attention in Garcinia among its many other bioactives owing to its antiobesity effect and various action mechanisms in obesity management.…”

“…24 Morover, G. cambogia administration resulted in significant blood glucose-lowering effects. 25 HCA has attracted attention in Garcinia among its many other bioactives owing to its antiobesity effect and various action mechanisms in obesity management. Chiefly, HCA is a competitive inhibitor of the ATP-citrate lyase enzyme that converts mitochondria-derived citrate into acetyl CoA, a precursor for both fatty acid and mevalonate synthesis pathways.…”