Hypoglycemic and hypolipidemic effects of Garcinia cambogia extracts in streptozotocin-nicotinamide induced diabetic rat model.

BACKGROUND AND OBJECTIVES: Diabetes mellitus, a global health problem, is associated with metabolic complications such as hyperglycemia, hyperlipidemia, hypertension, cardiovascular diseases, and loss of vision. The present study evaluated the antidiabetic and antihyperlipidemic effects of ethanol extract of Garcinia cambogia (L.) N. Robson (G. cambogia) fruit rind in a streptozotocin-nicotinamide induced diabetic Wistar Rat model. MATERIALS AND METHODS: Streptozotocin-nicotinamide was injected intraperitoneally to induce diabetes in Wistar rats. Five groups of rats (n=6) - normal control, diabetic, diabetic treated with G. cambogia at 400 mg/kg and 800 mg/kg body weight, and diabetic treated with metformin at 500 mg/kg body weight, were studied. Blood samples were collected after three weeks of treatment. Random blood glucose (RBG), Serum total cholesterol levels (TCL), serum total triglyceride levels (TGL), high-density lipoprotein levels, and body weight were measured. RESULTS: Although G. cambogia treatment did not have any antidiabetic activity (p>0.05) rind in the streptozotocin-nicotinamide induced diabetic Wistar Rat model, it decreased the serum TCL, and body weight significantly (P<0.05). CONCLUSIONS: Ethanolic extract of G. cambogia fruit rind possesses anti-obesity activity and significantly reduces total cholesterol but does not have antidiabetic activity.

Relation of Serum and Salivary Total Sialic Acid and Total Sialic Acid/Total Protein Ratio with Clinical Parameters of Disease Progression in Preeclampsia.

Sialic acid is a terminal component of carbohydrate chains of glycoproteins and glycolipids. The present study estimated total sialic acid (TSA) and its ratio with total proteins (TP), in serum and saliva of preeclampsia. The study further investigated the association of these parameters with clinical variables of disease progression. 50 preeclampsia patients (32 mild preclampsia and 18 severe preeclampsia cases) and 50 pregnant controls were included in the study. Serum and salivary free sialic acid, protein bound sialic acid and TP were measured spectrophotometrically. Serum and salivary TSA and its ratio with TP were calculated. There was a significant increase in serum TSA and its ratio with TP in preeclampsia compared to the controls. The increase reflected with the severity of the disease. Serum TSA and TSA/TP showed a significant positive correlation with blood pressure, proteinuria and a significant negative correlation with infant birth weight. In saliva, there was no statistical difference between TSA in preeclampsia and controls. Salivary TSA/TP increased significantly in preeclampsia. However the increase was not in accordance to the disease severity. Salivary TSA and TSA/TP were not significantly associated with any of the clinical parameters of disease progression. Significant increase in seum TSA reflects the disturbance in sialyation of serum proteins in preeclampsia, that could not be depicted in the saliva of these patients. Disturbance in serum protein sialyation is further exaggerated with the severity of the disease. Serum TSA and TSA/TP and not the respective salivary parameters, could serve as useful indicators in assessment of clinical progression of the disease.

Inhibition of bone morphogenetic proteins signaling suppresses metastasis melanoma: a proteomics approach.

BACKGROUND: Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-ß superfamily, known to promote the tumor invasion and metastasis. There are continual progresses in understanding the role of BMP signaling pathways in carcinogenesis. However, the biological significance of BMPs in human melanoma has received very little attention. The study aimed to explore the effect of BMP inhibition on melanoma treated with LDN193189 (BMP inhibitor) using a quantitative proteomics approach in a melanoma xenograft model. MATERIALS AND METHODS: Melanoma tumor was induced in C57BL6 mice and treated intraperitoneally with LDN193189 for ten consecutive days. Post-treatment, tumors were collected, and comparative proteomics was performed using a high-resolution Orbitrap Fusion Tribrid mass spectrometer. RESULTS: Treatment of melanoma with LDN193189 at 3 mg/kg body weight twice daily showed a significant decrease in the growth rate of the tumor compared to the other doses tested. Quantitative proteomic profiling identified 3231 proteins. Bioinformatics analysis of the 131 differentially expressed proteins selected by their relative abundance revealed that LDN193189 induces alterations in the cellular and metabolic process and the proteins that are involved in protein binding and catalytic activity in melanoma. CONCLUSIONS: Down-regulation of metallothionein (MT) 1 and MT2, emerging proteins for their role in tumor formation, progression, and drug resistance and transcription factor EB that plays a crucial role in the regulation of basic cellular processes, such as lysosomal biogenesis and autophagy, were identified upon inhibition of the BMP pathway in melanoma, suggesting their roles in melanoma growth. Understanding the role of these proteins will provide new directions for treating cancer.

Hyperphosphorylation of HDAC2 promotes drug resistance in a novel dual drug resistant mouse melanoma cell line model: an in vitro study.

Drug-resistant melanoma is very difficult to treat, and a novel approach is needed to overcome resistance. The present study aims at identifying the alternate pathways utilized in the dual drug-resistant mouse melanoma cells (B16F10R) for their survival and proliferation. The dual drug-resistant mouse melanoma, B16F10R, was established by treating the cells with a combination of U0126 (MEK1/2 inhibitor) and LY294002 (PI3K-AKT kinase inhibitor) in a dose-escalating manner till they attained a resistance fold factor of ≥2. The altered phosphoproteome in the B16F10R, as compared to the parental B16F10C, was analyzed using a high-resolution Orbitrap Fusion Tribrid mass spectrometer. Histone deacetylases 2 (HDAC2) was validated for its role in drug resistance by using its inhibitor, valproic acid (VPA). In the B16F10R cells, 363 altered phosphoproteins were identified, among which 126 were hyperphosphorylated, and 137 were hypophosphorylated (1.5-fold change). Pathway analysis shows the altered phosphoproteins are from RNA metabolism and cell cycle proteins. Inhibition of HDAC2 by VPA induces apoptosis in B16F10C and B16F10R. The present study highlights the role of HDAC2, a cell cycle regulator, in the development of resistance to dual drugs in murine melanoma. Therefore, designing leads for targeting HDAC2 along with key signaling pathways may be explored in treatment strategies.

Salivary L-fucose as a biomarker for oral potentially malignant disorders and oral cancer.

BACKGROUND: The objective of this study was to evaluate the serum and salivary L-fucose in oral potentially malignant disorders (OPMDs) and oral cancer (OC) in order to investigate the possibility of using this as biomarker for early diagnosis. MATERIALS AND METHODS: The study included 85 participants, who were grouped as control (30), OPMDs patients (25), and OC patients (30). Serum and unstimulated whole saliva were collected from participants of all groups and fucose estimation was done using spectrophotometry. The results were tabulated and analyzed statistically. RESULTS: The mean serum L-fucose levels in normal, OPMDs, and OC group were 3.49, 19.18, and 35.75 mg/dl, respectively, while the levels of salivary L-fucose were 3.18, 7.02, and 11.66 mg/dl, respectively. A highly significant rise (P < 0.001) in serum and salivary L-fucose was observed in the study participants compared to control. CONCLUSIONS: The present study showed a significant and gradual increase in serum and salivary L-fucose from control to OPMDs to OC. From this study, we suggest that L-fucose can be used as a reliable biomarker and saliva can be used as a diagnostic fluid for screening and early detection of OC.

HDAC2 Inhibitor Valproic Acid Increases Radiation Sensitivity of Drug-Resistant Melanoma Cells.

Resistance to anticancer drugs limits the effectiveness of chemotherapy in cancers. Melanoma cell lines B16F10C and A375C (parental) and B16F10R and A375R (drug-resistant sublines) were used to test radiation sensitization potential of valproic acid (VPA), an inhibitor of Histone deacetylase2 (HDAC2) and LDN193189 (BMP inhibitor). Inhibitors of other signaling pathways were tested for cross-resistance with the resistant cell lines. Cells were pretreated with low concentrations of VPA/ LDN193189 and exposed to 2 Gy radiation for radiation sensitization experiments. Assays-3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), live/dead, clonogenic, and melanin estimation were performed to test the effects of radiation sensitization. Interactions of VPA and HDAC2 were studied in silico. Dose-dependent growth inhibition was observed with all tested drugs. Radiation sensitization of melanoma cells with low dose of VPA induced synergistic cell death, decreased clonogenicity, and decreased melanin content. In silico docking showed two stable interactions between Arg39 of HDAC2 and VPA. In conclusion, pretreatment with low doses of VPA has a potential for sensitizing melanoma cells to low doses of radiation. The binding of VPA to HDAC2 reverses the drug resistance in melanoma and induces the cell death. Sensitization effects of VPA can be used for targeting drug-resistant cancers.

Cytotoxic, DNA Cleavage and Pharmacokinetic Parameter Study of Substituted Novel Furan C-2 Quinoline Coupled 1, 2, 4-Triazole and Its Analogs.

BACKGROUND: Furan, quinoline and triazoles are known for their wide spectrum biologically active molecules. A series of novel furan C-2 quinoline and 1, 2, 4-triazole (FQT) coupled hybrids were designed and synthesized to evaluate for their DNA cleavage and cytotoxic studies. OBJECTIVES: In this work we describe the synthesis and biological evaluation of furan C-2 quinoline coupled triazoles exposed for cytotoxic and DNA cleavage study. METHODS: The electrophoretic DNA cleavage studies on λ-DNA (Eco-RI/Hinda-III double digest) using agarose gelelectrophoresis and the cytotoxic activity were carried out by MTT assay method. RESULTS: The results revealed that, the molecules 7(a-o) did cleave the DNA completely with no trace of fragments at 100 µg concentration, on the other hand, cytotoxic assay was achieved by two different human cancer cell lines (melanoma cell line-A375 and breast cancer cell line MDA-MB 231). Among the synthesized compounds 7a, 7b, 7c and 7k exhibited potent cytotoxic activity with IC50 values ranging from 2.9, 4.0, 7.8 and 5.1 µg/ml against A375 and 6.2, 9.5, 11.3 and 7.3 µg/ml against, MDA-MB 231, respectively. CONCLUSION: In synthesized compounds 7(a-o) exhibited complete DNA cleavage at 100 µg/ml and the compounds 7a, 7b, 7c and 7k showed very less cytotoxic in nature. The structure activity relationship revealed that, the presence of halogen group/atoms at para position of phenyl ring remarkably enhanced the DNA cleavage and cytotoxic activities among the synthesized compounds.

Synthesis and evaluation of thiazolidinone-pyrazole conjugates as anticancer and antimicrobial agents.

AIM: To synthesize a series of new thiazolidinone-pyrazole hybrids (5a-o) and assess their anticancer (in vitro and in vivo) and antimicrobial activities. RESULTS: The compounds 5h (against Ehrlich ascites carcinoma cells), 5e and 5i (against the human breast cancer [MDA-MB231] cell line) exhibited potent anticancer activity. All the compounds except 5g and 5e found to be less toxic for the human dermal fibroblast cells. The effective interactions of the compounds in silico with MDM2 exemplified their inhibitory potency. The derivatives also showed moderate antimicrobial activity. CONCLUSION: The halogen atoms on various positions of the N-arylamino ring played an advantageous role in elevating the potency of the molecules. Thus, these conjugates could be used as a lead for further optimization to achieve promising therapeutics.

Inhibition of ERK1/2 or AKT Activity Equally Enhances Radiation Sensitization in B16F10 Cells.

BACKGROUND: The aim of the study was to evaluate the radiation sensitizing ability of ERK1/2, PI3K-AKT and JNK inhibitors in highly radiation resistant and metastatic B16F10 cells which carry wild-type Ras and Braf. METHODS: Mouse melanoma cell line B16F10 was exposed to 1.0, 2.0 and 3.0 Gy of electron beam radiation. Phosphorylated ERK1/2, AKT and JNK levels were estimated by ELISA. Cells were exposed to 2.0 and 3.0 Gy of radiation with or without prior pharmacological inhibition of ERK1/2, AKT as well as JNK pathways. Cell death induced by radiation as well as upon inhibition of these pathways was measured by TUNEL assay using flow cytometry. RESULTS: Exposure of B16F10 cells to 1.0, 2.0 and 3.0 Gy of electron beam irradiation triggered an increase in all the three phosphorylated proteins compared to sham-treated and control groups. B16F10 cells pre-treated with either ERK1/2 or AKT inhibitors equally enhanced radiation-induced cell death at 2.0 as well as 3.0 Gy (P < 0.001), while inhibition of JNK pathway increased radiation-induced cell death to a lesser extent. Interestingly combined inhibition of ERK1/2 or AKT pathways did not show additional cell death compared to individual ERK1/2 or AKT inhibition. This indicates that ERK1/2 or AKT mediates radiation resistance through common downstream molecules in B16F10 cells. CONCLUSIONS: Even without activating mutations in Ras or Braf genes, ERK1/2 and AKT play a critical role in B16F10 cell survival upon radiation exposure and possibly act through common downstream effector/s.

Increased Oxidatively Modified Forms of Albumin in Association with Decreased Total Antioxidant Activity in Different Types of Hypertensive Disorders of Pregnancy.

Protein oxidation has been demonstrated in preeclampsia, but this finding has not been established in other hypertensive disorders in pregnancy (HDP). The present study comparatively evaluated ischemia modified albumin (IMA) and advanced oxidation protein products (AOPP) in different HDP and investigated their association with total antioxidant activity (AOA) and total thiols. There was a significant increase in AOPP and IMA, a significant decrease in AOA, total thiols and albumin in every HDP compared to controls. Among HDP groups, eclampsia patients showed more significant change in each of the parameter. IMA and AOPP were negatively associated with AOA in every HDP and with total thiols only in eclampsia. The present study supports the hypothesis of oxidative stress, as evidenced by increased protein oxidation, decreased antioxidant status and significant negative association between protein oxidation and AOA in every HDP. The imbalance of prooxidants and antioxidants was further augmented in eclampsia.

Chemotherapy Resistance Mechanisms in Advanced Skin Cancer.

Melanoma is a most dangerous and deadly type of skin cancer, and considered intrinsically resistant to both radiotherapy and chemotherapy. It has become a major public health concern as the incidence of melanoma has been rising steadily over recent decades with a 5-year survival remaining less than 5%. Detection of the disease in early stage may be curable, but late stage metastatic disease that has spread to other organs has an extremely poor prognosis with a median survival of less than 10 months. Since metastatic melanoma is unresponsive to therapy that is currently available, research is now focused on different treatment strategies such as combinations of surgery, chemotherapy and radiotherapy. The molecular basis of resistance to chemotherapy seen in melanoma is multifactorial; defective drug transport system, altered apoptotic pathway, deregulation of apoptosis and/or changes in enzymatic systems that mediate cellular metabolic machinery. Understanding of alterations in molecular processes involved in drug resistance may help in developing new therapeutic approaches to treatment of malignant melanoma.

High predictive ability of glycated hemoglobin on comparison with oxidative stress markers in assessment of chronic vascular complications in type 2 diabetes mellitus.

OBJECTIVE: To validate the diagnostic utility of oxidative stress markers along with glycated hemoglobin (HbA1c ) in the assessment of chronic vascular complications in type 2 diabetes mellitus (DM). METHODS: Ischemia modified albumin (IMA), advanced oxidation protein products (AOPP) and malondialdehyde (MDA) were measured in 100 type 2 DM (without complications n = 50, with complications n = 50) and healthy controls (n = 50). Diagnostic potential was evaluated by receiver operating characteristic analysis and their relationships to risk variables were analyzed. RESULTS: MDA, IMA and AOPP were significantly increased in diabetics, both with and without complications. Oxidative stress parameters correlated with fasting blood glucose and HbA1c (independent predictors). Duration of diabetes was an independent predictor for AOPP and MDA. The association of IMA with diabetes duration was lost on multiple regression analysis. Area under the curve, sensitivity and specificity for MDA were 0.795, 84%, 66%; for AOPP, they were 0.762, 82%, 56%; for IMA, they were 0.611, 60%, 52%; and for HbA1c, they were 0.848, 90%, 70%, respectively. CONCLUSION: MDA and AOPP could be considered better than IMA in the evaluation of diabetes progression, but MDA is more useful as a diagnostic indicator to detect vascular complications. HbA1c measurement is of greater value than the oxidative stress markers in the prediction of vascular complications.

IMA and IMAR in serum and saliva of preeclampsia--a preliminary study.

INTRODUCTION: Oxidative stress could play a role in the development of preeclampsia. Ischemia modified albumin (IMA) is a oxidatively modified form of albumin. OBJECTIVE: To evaluate the levels of salivary and serum IMA and IMA: albumin ratio (IMAR) in preeclampsia and with its severity and investigate their correlation with the fetal birth weight. METHODS: This case control study was conducted on 50 preeclamptic (32 mild and 18 severe cases) and 50 normal pregnant controls. Blood and saliva were obtained to measure albumin, IMA and IMAR was calculated. RESULTS: serum and salivary IMA and IMAR were significantly increased in preeclampsia. Although the increase in serum was in accordance with the severity, it was not so in the saliva. Yet, salivary IMAR showed significant difference between controls and mild preeclampsia. There was a negative correlation between IMA and albumin in both serum and saliva. A weak negative correlation was seen between the serum IMAR and fetal birth weight (r = -0.293; p < 0.05), but not with salivary IMAR. CONCLUSION: This study is an evidence for involvement of oxidative stress in the pathogenesis of preeclampsia, which is reflected in serum and saliva. Salivary IMAR could be a better marker for early prediction of preeclampsia.