Tanyawan Suantawee

Plasma and synovial fluid connective tissue growth factor levels are correlated with disease severity in patients with knee osteoarthritis

Background: Connective tissue growth factor (CTGF) has been implicated in development of osteoarthritis (OA). Objective: To determine the correlation between plasma and synovial fluid CTGF levels and the severity in knee osteoarthritis patients. Methods: A total of 100 subjects were recruited into this study (75 OA patients and 25 controls). CTGF concentrations in plasma and synovial fluid were analyzed by enzyme-linked immunosorbent assay. Results: Plasma and synovial fluid CTGF concentrations were correlated with radiographic severity. There was a positive correlation between plasma and synovial fluid CTGF levels. Conclusion: CTGF could be useful for monitoring the severity and progression of OA.

Oxidative Stress, Vitamin E, and Antioxidant Capacity in Knee Osteoarthritis

BACKGROUND Osteoarthritis (OA) is a chronic progressive degenerative joint disorder which is characterised by strongly age-related regressive changes in articular cartilage. The objective of this study was to evaluate oxidative stress and antioxidant parameters in plasma and synovial fluid of patients with primary knee osteoarthritis. MATERIAL AND METHODS Thirty-five OA patients and 35 healthy controls were recruited for this study. Nitrite, malondialdehyde (MDA), vitamin E, Trolox Equivalent Antioxidant Capacity (TEAC), and Ferric Reducing Antioxidant Power (FRAP) levels in plasma and synovial fluid were determined. RESULTS Plasma nitrite levels in OA patients were significantly higher than those in healthy controls (p = 0.037). Furthermore, plasma MDA levels were significantly higher in OA patients than those in healthy controls (p < 0.001). Moreover, plasma vitamin E levels in OA patients were significantly lower than those in healthy controls (p < 0.001). Synovial fluid vitamin E levels of OA patients were significantly lower than paired plasma samples (p < 0.001). The total antioxidant capacities, as were measured by TEAC and FRAP assays in plasma of OA patients, were significantly lower than those in healthy controls (p < 0.01). MDA concentrations were positively correlated with nitrite concentrations but they were negatively associated with vitamin E and TEAC levels in synovial fluid of OA patients. CONCLUSION The increased plasma levels of nitrite and MDA and the decreased plasma levels of vitamin E, TEAC, and FRAP indicated that oxidative stress was present in OA patients. These findings suggest that oxidative stress plays a potential role in pathophysiology of knee osteoarthritis.

Protective effect of cyanidin against glucose- and methylglyoxal-induced protein glycation and oxidative DNA damage.

Cyanidin, a natural anthocyanin abundant in fruits and vegetables, has shown the health benefits due to its pharmacological properties. However, there was no evidence regarding anti-glycation activity of cyanidin. The aim of the study was to investigate the inhibitory effect of cyanidin on methylglyoxal (MG)- and glucose-induced protein glycation in bovine serum albumin (BSA) as well as oxidative DNA damage. Free radical scavenging activity and the MG-trapping ability of cyanidin were also investigated. The results demonstrated that cyanidin (0.125-1mM) significantly inhibited the formation of fluorescent and non-fluorescent AGEs in BSA/MG and BSA/glucose systems. There was a significantly improved protein thiol in BSA/MG and BSA/glucose when incubated with cyanidin. Correspondingly, cyanidin decreased the level of protein carbonyl content in BSA/glucose system. Moreover, cyanidin (0.5-1mM) prevented lysine/MG-mediated oxidative DNA damage in the absence or presence of copper ion. The results demonstrated that cyanidin showed the MG-trapping ability in a concentration-dependent manner. Cyanidin also reduced superoxide anion and hydroxyl radical generation in lysine/MG system. The mechanism by which cyanidin inhibited protein glycation was the MG-trapping ability and the free radical scavenging activity. The present study suggests that cyanidin might be a promising antiglycation agent for preventing or ameliorating AGEs-mediated diabetic complications.

Cyanidin Stimulates Insulin Secretion and Pancreatic β-Cell Gene Expression through Activation of l-type Voltage-Dependent Ca2+ Channels

Cyanidin is a natural anthocyanidin present in fruits and vegetables with anti-diabetic properties including stimulation of insulin secretion. However, its mechanism of action remains unknown. In this study, we elucidated the mechanisms of cyanidin for stimulatory insulin secretion from pancreatic β-cells. Rat pancreatic β-cells INS-1 were used to investigate the effects of cyanidin on insulin secretion, intracellular Ca2+ signaling, and gene expression. We detected the presence of cyanidin in the intracellular space of β-cells. Cyanidin stimulated insulin secretion and increased intracellular Ca2+ signals in a concentration-dependent manner. The Ca2+ signals were abolished by nimodipine, an l-type voltage-dependent Ca2+ channel (VDCC) blocker or under extracellular Ca2+ free conditions. Stimulation of cells with cyanidin activated currents typical for VDCCs and up-regulated the expression of glucose transporter 2 (GLUT2), Kir6.2, and Cav1.2 genes. Our findings indicate that cyanidin diffuses across the plasma membrane, leading to activation of l-type VDCCs. The increase in intracellular Ca2+ stimulated insulin secretion and the expression of genes involved in this process. These findings suggest that cyanidin could be used as a promising agent to stimulate insulin secretion.

Transient receptor potential melastatin 4 channel is required for rat dental pulp stem cell proliferation and survival

Investigate the role of the transient receptor potential melastatin 4 (TRPM4) channel in rat dental pulp stem cell (DPSC) proliferation and survival.