Bauhinia forficata link extract attenuates insulin resistance by preserving glucose uptake in gastrocnemius muscle.

Bioactive metabolites from Bauhinia forficata Link (Bf extract) hold therapeutic potential for type 2 diabetes mellitus (T2DM) but the mechanism remains poorly understood. This study aimed to test the extract from Bf leaves obtained by decoction on the prevention of T2DM in vivo. The Bf extract was tested on a streptozotocin-induced T2DM mouse model fed on a high-fat diet. The insulin resistance was attenuated in T2DM animals supplemented with Bf extract, which indicates glucose intolerance reduction and p-AKT/AKT ratio preservation in the gastrocnemius muscle. These observations suggested that Bf extract enhanced glucose uptake. Nevertheless, there was no preservation in ß-cell insulin secretion in Bf extract-treated T2DM mice. Interestingly, the Bf extract reduced body weight gain without affecting total energy intake. Hence, Bf extract has a hypoglycemic effect which could attenuate the development of insulin resistance.

Phosphorylated Akt1 expression is associated with poor prognosis in cutaneous, oral and sinonasal melanomas.

Melanomas are highly aggressive tumours derived from melanocytes, which occur most commonly in the skin. Occasionally, these tumours may appear in oral and sinonasal mucous membranes. In this study, we performed a comparative analysis of the Phosphorylated Akt1 (p-Akt1) expression in 144 patients affected by cutaneous (CM), 34 oral cavity (OM), and 31 sinonasal melanomas (SNM). Similar to the metastatic cutaneous melanomas, p-Akt1 was overexpressed in 17/34 of the oral cavity and 20/31 of the sinonasal melanomas. In addition, the p-Akt1-nuclear expression was associated with poorer cancer-specific survival in cutaneous (P < .0001), oral (P < .0001), and sinonasal (P = .001) melanomas. Multivariate analysis showed p-Akt1 to be an independent prognostic marker in oral (P = .041) and sinonasal (P < .0001) melanomas patients. In conclusion, p-Akt1 overexpression is an independent prognostic marker in mucosal melanomas and is significantly up-regulated in sinonasal melanomas. As both mucosal and metastatic cutaneous melanomas showed high frequency of p-Akt1 expression, these findings suggest that mucosal melanomas have a biological behaviour, similar to the aggressive cutaneous melanomas.

Evaluation of the p-AKT, p-JNK and FoxO3a function in oral epithelial dysplasia.

OBJECTIVES: To evaluate the expression of p-AKT, p-JNK, FoxO3a, and Ki-67 in samples of oral squamous cell carcinoma (OSCC) and oral epithelial dysplasias (OEDs) to understand their possible involvement in the malignant transformation process of oral lesions. MATERIALS AND METHODS: Tissue samples of 20 cases of OSCCs, 20 OEDs, and normal oral mucosa were subjected to immunohistochemistry reactions for anti-p-AKT, anti-p-JNK, anti-FoxO3a, and anti-Ki-67 antibodies. It was analyzed using quantitative (number of immunostained cells) and qualitative (immunostaining intensity) parameters in different cell immunostaining sublocations. RESULTS: Nuclear p-AKT was observed significantly greater immunostaining in OSCC (21.2 ± 19.0) than in dysplasias (7.9 ± 8.1) and controls (1.8 ± 4.7) (P = 0.002). Immunostaining of strong nuclear p-JNK was greater in controls (48.3 ± 13.7) than in OEDs (11.0 ± 10.3) and OSCCs (1.1 ± 1.3) (P < 0.001). Strong nuclear immunostaining of FoxO3a proved to be absent in OSCCs (0.0 ± 0.1) with little staining on dysplasias (3.2 ± 5.4) and increased expression in controls (13.5 ± 4.8) (P < 0.001). Immunostaining of strong nuclear Ki-67 was grater in OSCCs (48.1 ± 49.6) than in OED (11.8 ± 10.6) and controls (1.9 ± 2.0) (P < 0.001). CONCLUSIONS: Malignant process of OEDs in this research may involve the same mechanisms of established malignant lesions.

p-Akt and its relationship with clinicopathological features and survival in oral squamous cell carcinoma: an immunohistochemical study.

BACKGROUND: The aim of this study was to evaluate, through immunohistochemical reaction in samples of oral squamous cell carcinoma, the correlation between the expression status of protein kinase B (p-Akt) and patient survival as well as histological grade and some clinicopathological features. METHODS: Samples were collected from 46 patients with oral squamous cell carcinoma. The immunohistochemical expression of p-Akt was analysed, as were clinicopathological features including the use of tobacco, tumour stage, size and infiltration of metastatic lymph nodes. The association of immunostaining with histological grade was analysed in 40 patients. The associations were examined for statistical significance using a chi-square test. Overall survival rates were estimated by the Kaplan-Meier method and compared using a log rank test (P > 0.05). RESULTS: The results indicated a statistically significant association with p-Akt immunostaining for the variables lymph node metastasis (P = 0.006), tumour size (P = 0.044) and survival rate (P = 0.0298). CONCLUSION: From these results, the present study suggests that high p-Akt expression found in oral squamous cell carcinoma patients may contribute to tumour growth, metastasis to regional lymph nodes and shorter survival time.

DHEA supplementation in ovariectomized rats reduces impaired glucose-stimulated insulin secretion induced by a high-fat diet.

Dehydroepiandrosterone (DHEA) and the dehydroepiandrosterone sulfate (DHEA-S) are steroids produced mainly by the adrenal cortex. There is evidence from both human and animal models suggesting beneficial effects of these steroids for obesity, diabetes mellitus, hypertension, and osteoporosis, conditions associated with the post-menopausal period. Accordingly, we hypothesized that DHEA supplementation in ovariectomized (OVX) female rats fed a high-fat diet would maintain glucose-induced insulin secretion (GSIS) and pancreatic islet function. OVX resulted in a 30% enlargement of the pancreatic islets area compared to the control rats, which was accompanied by a 50% reduction in the phosphorylation of AKT protein in the pancreatic islets. However, a short-term high-fat diet induced insulin resistance, accompanied by impaired GSIS in isolated pancreatic islets. These effects were reversed by DHEA treatment, with improved insulin sensitivity to levels similar to the control group, and with increased serine phosphorylation of the AKT protein. These data confirm the protective effect of DHEA on the endocrine pancreas in a situation of diet-induced overweight and low estrogen concentrations, a phenotype similar to that of the post-menopausal period.