Anthocyanin oligomers stimulate browning in 3T3-L1 white adipocytes via activation of the β3-adrenergic receptor and ERK signaling pathway

Anthocyanin Oligomers Induce Apoptosis and Autophagy by Inhibiting the mTOR Signaling Pathway in Human Breast Cancer Cells

Anthocyanin oligomers (AOs) are phytochemicals synthesized by fermenting anthocyanins extracted from grape skins and are more biologically active than monomeric anthocyanins. In this study, we evaluate the effects of an AO on triple-negative MDA-MB-231 and HER2-overexpressing SK-BR-3 breast cancer cells. The cell viability of MDA-MB-231 and SK-BR-3 cells was significantly inhibited in a concentration-dependent manner by AO treatment for 24 h, while delphinidin (a monomeric anthocyanin) had no effect on cell viability. In addition, the AO increased H2A.X phosphorylation (a marker of DNA damage), reduced RAD51 (a DNA repair protein) and survivin (a cell survival factor) protein levels, and induced apoptosis by caspase-3-dependent PARP1 cleavage in both cell lines. Surprisingly, the AO induced autophagy by increasing intracellular LC3-II puncta and LC3-II and p62 protein levels. In addition, the AO inhibited the mTOR pathway in MDA-MB-231 and SK-BR-3 cells by suppressing the HER2, EGFR1, and AKT pathways. These results demonstrate that the anti-cancer effect of the AO was due to the induction of apoptosis and autophagy via cleaved caspase-3-mediated PARP1 cleavage and mTOR pathway inhibition, respectively. Furthermore, our results suggest that anthocyanin oligomers could be considered potential candidates for breast cancer treatment.

Transient Receptor Potential (TRP) based polypharmacological combination stimulates energy expending phenotype to reverse HFD-induced obesity in mice

BACKGROUND & AIM

Obesity is a worldwide epidemic leading to decreased quality of life, higher medical expenses and significant morbidity. Enhancing energy expenditure and substrate utilization in adipose tissues through dietary constituents and polypharmacological approaches is gaining importance for the prevention and therapeutics of obesity. An important factor in this regard is Transient Receptor Potential (TRP) channel modulation and resultant activation of "brite" phenotype. Various dietary TRP channel agonists like capsaicin (TRPV1), cinnamaldehyde (TRPA1), and menthol (TRPM8) have shown anti-obesity effects, individually and in combination. We aimed to determine the therapeutic potential of such combination of sub-effective doses of these agents against diet-induced obesity, and explore the involved cellular processes.

KEY FINDINGS

The combination of sub-effective doses of capsaicin, cinnamaldehyde and menthol induced "brite" phenotype in differentiating 3T3-L1 cells and subcutaneous white adipose tissue of HFD-fed obese mice. The intervention prevented adipose tissue hypertrophy and weight gain, enhanced the thermogenic potential, mitochondrial biogenesis and overall activation of brown adipose tissue. These changes observed in vitro as well as in vivo, were linked to increased phosphorylation of kinases, AMPK and ERK. In the liver, the combination treatment enhanced insulin sensitivity, improved gluconeogenic potential and lipolysis, prevented fatty acid accumulation and enhanced glucose utilization.

SIGNIFICANCE

We report on the discovery of therapeutic potential of TRP-based dietary triagonist combination against HFD-induced abnormalities in metabolic tissues. Our findings indicate that a common central mechanism may affect multiple peripheral tissues. This study opens up avenues of development of therapeutic functional foods for obesity.

Inhibition of Lipid Accumulation and Adipokine Levels in Maturing Adipocytes by Bauhinia rufescens (Lam.) Stem Bark Extract Loaded Titanium Oxide Nanoparticles

The present study reports a cost-effective, environmentally friendly method to increase the bioavailability and bio-efficacy of B. rufescens stem bark extract in the biological system via functional modification as B. rufescens stem bark nanoparticles (BR-TO₂-NPs). The biosynthesis of BR- -NPs was confirmed by UV-visible (UV-vis) and Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction analyses. The shifts in FT-IR stretching vibrations of carboxylic and nitro groups (1615 cm^-1), the O-H of phenolics or carboxylic acids (3405 cm^-1), alkanes, and alkyne groups (2925 and 2224 cm^-1) of the plant extract and lattice (455) indicated successful biosynthesis of BR- -NPs. Compared with the stem bark extract, 40 ng/dL dose of BR- -NPs led to a reduction in adipogenesis and an increase in mitochondrial biogenesis-related gene expressions, adiponectin-R1, PPARγC1α, UCP-1, and PRDM16, in maturing-adipocytes. This confirmed the intracellular uptake, bioavailability, and bio-efficiency of BR-TiO₂-NPs. The lipid-lowering capacity of BR-TiO₂-NPs effectively inhibited the metabolic inflammation-related gene markers, IL-6, TNF-α, LTB4-R, and Nf-κb. Further, BR-TiO₂-NPs stimulating mitochondrial thermogenesis capacity was proven by the significantly enhanced CREB-1 and AMPK protein levels in adipocytes. In conclusion, BR-TiO₂-NPs effectively inhibited lipid accumulation and proinflammatory adipokine levels in maturing adipocytes; it may help to overcome obesity-associated comorbidities.