Protective Effect of Alpha-Linolenic Acid on Human Oral Squamous Cell Carcinoma Metastasis and Apoptotic Cell Death.

Oral cancer ranks sixth among Taiwan's top 10 cancers and most patients with poor prognosis acquire metastases. The essential fatty acid alpha-linolenic acid (ALA) has been found to diminish many cancer properties. However, the anti-cancer activity of ALA in oral cancer has yet to be determined. We examined the mechanisms underlying ALA inhibition of metastasis and induction of apoptotic cell death in oral squamous cell carcinoma (OSCC). Migration and invasion assays confirmed the cancer cells' EMT capabilities, whereas flow cytometry and Western blotting identified molecular pathways in OSCC. ALA dramatically reduced cell growth in a concentration-dependent manner according to the findings. Low concentrations of ALA (100 or 200 µM) inhibit colony formation, the expression of Twist and EMT-related proteins, the expression of MMP2/-9 proteins, and enzyme activity, as well as cell migration and invasion. Treatment with high concentrations of ALA (200 or 400 µM) greatly increases JNK phosphorylation and c-jun nuclear accumulation and then upregulates the FasL/caspase8/caspase3 and Bid/cytochrome c/caspase9/caspase3 pathways, leading to cell death. Low concentrations of ALA inhibit SAS and GNM cell migration and invasion by suppressing Twist and downregulating EMT-related proteins or by decreasing the protein expression and enzyme activity of MMP-2/-9, whereas high concentrations of ALA promote apoptosis by activating the JNK/FasL/caspase 8/caspase 3-extrinsic pathway and the Bid/cytochrome c/caspase 9 pathway. ALA demonstrates potential as a treatment for OSCC patients.

Indoxyl sulfate, homocysteine, and antioxidant capacities in patients at different stages of chronic kidney disease.

BACKGROUND/OBJECTIVES: Increased levels of uremic toxins and decreased antioxidant capacity have a significant impact on the progression of chronic kidney disease (CKD). However, it remains unclear whether they interact with each other to mediate the damage of kidney function. The purpose of this study was to investigate whether uremic toxins (i.e., homocysteine and indoxyl sulfate [IS]), as well as glutathione-dependent antioxidant enzyme activities are dependently or independently associated with kidney function during different stages of CKD patients. SUBJECTS/METHODS: One hundred thirty-two patients diagnosed with CKD at stages 1 to 5 participated in this cross-sectional study. RESULTS: Patients who had reached an advanced CKD stage experienced an increase in plasma uremic toxin levels, along with decreased glutathione peroxidase (GSH-Px) activity. Plasma homocysteine, cysteine, and IS concentrations were all positively associated with each other, but negatively correlated to GSH-Px activity levels after adjusting for potential confounders in all CKD patients. Although plasma homocysteine, cysteine, IS, and GSH-Px levels were significantly associated with kidney function, only plasma IS levels still had a significant association with kidney function after these parameters were simultaneously adjusted. In addition, plasma IS could interact with GSH-Px activity to be associated with kidney function. CONCLUSIONS: IS plays a more dominant role than homocysteine and GSH-Px activity in relation to kidney function.

Higher glutathione demand may be necessary for assisting haemodialysis patients to cope with increased oxidative stress.

AIM: The removal of cysteine during a dialysis procedure may affect glutathione (GSH) concentration, allowing haemodialysis (HD) patients to become more susceptible to oxidative damage. This study was performed to determine whether the change of GSH/glutathione disulfide (GSSG) redox state and GSH redox potential were linked with the change of cysteine or oxidative stress in patients receiving HD treatment. METHODS: Sixty-seven HD patients who had received regular HD treatment were recruited. Plasma GSH, GSSG, cysteine and malondialdehyde (MDA) were measured at both pre- and post-HD. RESULTS: Plasma cysteine, GSH and GSSG levels significantly decreased after the completion of HD, compared to the levels at pre-HD. Plasma MDA concentration, GSH/GSSG ratio and GSH redox potential remained constant during the dialysis session. Plasma GSH and GSSG were positively associated with plasma MDA at post-HD, while GSH redox potential was negatively associated with plasma MDA at post-HD. However, plasma GSH, GSSG, GSH/GSSG ratio and GSH redox potential were not associated with plasma cysteine at either pre- or post-HD. CONCLUSION: The GSH and GSSG levels were significantly utilized during a HD session, and their levels were significantly associated with increased oxidative stress. HD patients may require higher GSH demands to cope with increased oxidative stress during an HD session.

Relationship between plasma levels of homocysteine and the related B vitamins in patients with hemodialysis adequacy or inadequacy.

OBJECTIVES: Hemodialysis (HD) with dialysis adequacy could increase the excretion of B vitamins (folate, vitamin B6, and B12) and raise the plasma level of homocysteine. Here we determined the associations of plasma homocysteine with B vitamins in patients with HD adequacy or inadequacy. METHODS: We recruited 68 patients who had received HD treatments (three times a week, 4 h each). Based on the individual's hemogram and quarterly urea reduction rate (Kt/V), patients were pooled into one of the following two groups: the first group with dialysis adequacy (Kt/V > 1.2, n = 48) and the second with dialysis inadequacy (Kt/V ≤ 1.2, n = 20). We also recorded the anthropometric date of each patient and their biochemical data and dietary intakes. Plasma levels of homocysteine, cysteine, folate, pyridoxal 5'-phosphate (PLP), and vitamin B12 were measured twice, once before and once after HD. RESULTS: The plasma levels of homocysteine, cysteine, folate, PLP, and vitamin B12 dropped significantly at the end of HD. The plasma levels of vitamin B12 were negatively correlated with the plasma levels of homocysteine, both pre- and post-HD, and in both groups regardless of dialysis adequacy or inadequacy. In contrast, plasma levels of folate and PLP were not correlated with homocysteine at both pre- or post-HD in both groups. CONCLUSIONS: The plasma level of vitamin B12, but not folate or vitamin B6, was negatively correlated with that of homocysteine both before and after HD treatment, and regardless of dialysis adequacy or inadequacy.

Vitamin B-6, Independent of Homocysteine, Is a Significant Factor in Relation to Inflammatory Responses for Chronic Kidney Disease and Hemodialysis Patients.

The purpose of this study was to investigate whether plasma pyridoxal 5'-phosphate (PLP) and homocysteine were dependent on or independent of each other in order to be associated with inflammatory markers in patients with chronic kidney disease (CKD) or those receiving hemodialysis treatment. This was a cross-sectional study. Sixty-eight stage 2-5 CKD patients and 68 hemodialysis patients had one time fasting blood drawn for measurements of plasma PLP, pyridoxal (PL), homocysteine, and several inflammatory markers. Early CKD stage (stages 2-3) patients showed significantly lower plasma PLP levels and homocysteine concentrations than patients in an advanced CKD stage (stages 4-5) and those undergoing hemodialysis. Plasma PLP significantly correlated with CRP levels (partial rs = -0.21, p < 0.05) and plasma PL significantly correlated with IL-10 levels (partial rs = -0.24, p < 0.01), while plasma PLP plus PL significantly correlated with both CRP levels (partial rs = -0.20, p < 0.05) and interleukin-1ß (partial rs = 0.22, p < 0.05) levels after adjusting for plasma homocysteine and other potential confounders. Plasma homocysteine displayed no significant correlations with any inflammatory markers. Vitamin B-6 status, rather than homocysteine, appeared to be a significant factor in relation to inflammatory responses for CKD and hemodialysis patients.