Patients with comorbidities of obesity and diabetes are recognized to be at high risk of breast cancer development and face worse breast cancer outcomes. Though several reports showed the reinforced link between obesity, diabetes, and prediabetes with breast cancer, the underlying molecular mechanisms are still unknown. The present study aimed to investigate the underlying molecular link between increased risks of breast cancer due to coincident diabetes or obesity using a spontaneous obese rat model with impaired glucose tolerance (WNIN/GR-Ob rat). A single dose of solubilized DMBA suspension (40 mg/kg body weight) was orally administered to the animals at the age of 60 days to induce breast tumors. The tumor incidence, latency period, tumor frequency, and tumor volume were measured. Histology, immunohistochemistry, and immunoblotting were performed to evaluate the tumor morphology and expression levels of signal molecules. The development of mammary tumors in GR-Ob rats was characterized by early onset and shorter latency periods compared to control lean rats. While 62% of obese rats developed breast tumors, tumor development in lean rats was only 21%. Overexpression of ER, PR, Ki67, and p53 markers was observed in tumor tissues of obese rats in comparison with lean rats. The levels of the hallmarks of cell proliferation and angiogenesis involved in IGF-1/PI3K/Akt/GSK3β/β-catenin signaling pathway molecules were upregulated in obese rat breast tumors compared to lean rats. Furthermore, obesity with prediabetes is associated with changes in IGF-1 signaling and acts on PI3K/Akt/GSK3β/β-catenin signaling, which results in rapid cell proliferation and development of breast tumors in obese rats than the lean rats. These results indicate that tumor onset and development were faster in spontaneous obese rat models with impaired glucose tolerance than in their lean counterparts.

Aging-related muscle atrophy/sarcopenia is the most common type of muscle impairment that affects the quality of life. In the current study, we examined the effect of a functional food mixture of amla, turmeric, black pepper, cinnamon, and ginger on D-galactose-induced muscle alterations in rats. Wistar rats were randomly divided into three groups: Control (C), D-galactose (G), and D-galactose + functional food mixture intervention (G + I). Rats in group-G and -G + I were injected with D-galactose (300 mg/kg/day) for 90 days. After 3 months of the experimental period, the rats were sacrificed to collect gastrocnemius muscle. Group-G rats showed elevated levels of inflammatory cytokines (TNFα and NF-kB), atrogenes (atrogin-1 and MuRF1), decreased insulin/IGF1 signaling (decreased AKT phosphorylation), altered mitochondrial dynamics (increased fission and decreased fusion proteins), increased apoptotic mediators (Bax/Bcl-2, and caspase-3), and decreased muscle cell cross-sectional area when compared with group-C ( p < 0.05). Interestingly, supplementation with the functional food mixture prevented galactose-induced alterations in the muscle. The observed anti-inflammatory, insulin-sensitizing, mitochondria-protective, and antiapoptotic effects of the functional food could be the underlying mechanisms in displaying positive effects against galactose-induced muscle atrophy and, hence, may be useful for the prevention of age-related muscle disorders.

It was found that patients with comorbidities of obesity and diabetes have a high risk of breast cancer occurrence and face worse breast cancer outcomes. Though several reports showed the reinforced link between obesity, diabetes, and prediabetes with breast cancer, the underlying molecular mechanism is still unknown. The present study aimed to investigate the underlying molecular link between increased risks of breast cancer due to coincident diabetes or obesity using a spontaneous obese rat model with impaired glucose tolerance (WNIN/GR-Ob rat). A single dose of solubilized DMBA suspension (40 mg/kg body weight) was orally administered to the animals at the age of 60 days to induce breast tumors. The tumor incidence, latency period, tumor frequency, and tumor volume were measured. Histology, immunohistochemistry, and immunoblotting were performed to evaluate the tumor morphology and expression levels of signal molecules. It was observed that the onset of breast tumor and latency period per tumor development were early in GR-Ob rats compared to respective lean rats. It was found that 62% of obese rats were bearing tumors, and in comparison, only 21% of the lean animals developed breast tumors. Overexpression of ER, PR, Ki67, and p53 markers was observed in tumor tissues of obese rats in comparison with lean rats. The levels of the hallmarks of cell proliferation and angiogenesis involved in IGF-1/PI3K/Akt/GSK3β/β-catenin signaling pathway molecules were upregulated in obese rat breast tumors compared to lean rats. Furthermore, obesity with prediabetes is associated with changes in IGF-1 signaling and acts on PI3K/Akt/GSK3β/β-catenin signaling, which results in quick cell proliferation and development of breast tumors in obese rats than the lean rats. These results indicate that the onset of the tumor and its development was faster in a spontaneous obese rat model with impaired glucose tolerance than their lean counterparts, with a higher percentage of tumor incidence.