Recent data from several reports indicate that free radicals are involved in aetiopathogenesis of many human pathologies including neuropsychiatric disorders such as schizophrenia, bipolar disorder etc. In the present study, we aimed at determining and evaluating levels of malondialdehyde (MDA), a product of lipid peroxidation, and antioxidant enzyme superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity levels in patients diagnosed with schizophrenia (n = 25) and bipolar disorder (n = 23). The control group was composed of 20 healthy subjects. There was a significant increase in MDA levels of patients with schizophrenia and bipolar disorder compared with controls. SOD and GSH-Px activity levels were significantly higher in the schizophrenic group compared with controls. SOD activity levels in bipolar the group were significantly higher than controls whereas there were no significant changes in GSH-Px activity levels in the bipolar group and controls. Significant differences between lipid peroxidation product and antioxidant enzyme (SOD and GSH-Px) activity levels in schizophrenic and bipolar disorder patients compared with controls leads us to believe that these differences are related to the heterogenities in aetiologies of these disorders.
There is a clearly documented link between diabetic complications and lipid peroxidation. Hyperglycemia causes a reduction in levels of protective endogenous antioxidants and increases generation of free radicals. The present study was carried out to compare the protective effects of melatonin and vitamin E against streptozocin (STZ)-induced diabetes in rats. Melatonin was administered s.c. (100 microg/kg) whereas vitamin E was given i.p. (100 mg/kg) after induction of diabetes with STZ (60 mg/kg). Plasma total cholesterol, triglyceride and low density lipoprotein (LDL) levels were increased in STZ group while both melatonin and vitamin E injection caused a significant decrease in the levels of all these parameters. The lipid lowering effect of melatonin was greater than that of vitamin E. Melatonin caused a significant decrease in brain, liver and kidney tissue malondialdehyde (MDA) levels which were increased because of STZ-induced diabetes. Vitamin E also reduced elevated MDA concentrations in diabetic rat tissues, but the effect of melatonin was more potent than that of vitamin E. Furthermore, treatment of diabetic rats with melatonin increased brain and kidney glutathione peroxidase (GSH-Px) activity to the levels below that of control rats. Vitamin E was found to be less effective on GSH-Px activity levels in brain and kidney than melatonin whereas it was more potent than melatonin in liver. In summary, melatonin prevents many diabetic complications by reducing oxidative stress and protects organisms from oxidative damage and dyslipidemia. Considering the much lower molar concentration of melatonin compared with vitamin E, melatonin seems to be a more potent antioxidant, especially in the brain and kidney.
It has been well documented that human milk contains several
immunomodulator components which are important during infant
period when the newborn's immune system is still under
development. In this study, we aim at examining levels of
cytokines, zinc (Zn), and copper (Cu) in milk from
mothers of premature and mature infants, and comparing changes
during lactation periods consequently. Milk was collected from
total of 40 mothers (group M: mothers of mature infants, n = 20;
group PM: mothers of premature infants, n = 20) from four
lactation stages: colostrum (0–7 days), transitional (7–14
days), mature milk (21 days), and mature milk (2nd month). Levels
of cytokines (interleukin [IL]-lβ, IL-2, IL-6, IL-8, tumor
necrosis factor-alpha [TNF-α]) were determined by
chemiluminesence method, whereas atomic absorption
spectrophotometer was used for the determination of Zn and
Cu levels. Cytokine levels were determined to be
high in colostrum and transient milk from mothers of full-term
infants, whereas their levels were reduced drastically in the 21st
day and the 2nd month milk (P < .01
, P < .001). Similar
trends were observed in milk from mothers of premature infants,
but cytokine levels were significantly lower in colostrum compared
to colostrum from mothers of mature infants (P < .01). The
differences in cytokine levels were continuous in transient milk
(P < .05) and mature milk (21 days) (P < .05), whereas there was no statistically significant differences between milk from both
groups of mothers in the 2nd month (P > .05). Zn levels in
milk from mothers of premature infants were significantly lower
compared to the ones from mothers of mature infants (P < .01) and
these differences continued through the 2nd month. Although
Cu levels were lower in milk from mothers of premature
infants, there was no statistically significant difference except
colostrum (P > .05). Our results clearly demonstrate that the
level of immunomodulating agents such as cytokines and trace
elements in milk from mothers of premature infants is less than
the level of the same agents in milk from mothers of full-term
infants. Although there are commercially available products for
infant feeding, human milk is still the best natural nutrient for
newborns. Therefore, when premature infants are breastfed,
necessary precautions such as supplemantary diets must be
considered for possible infections and risks related with immune
system deficiency.
Autophagy is a catabolic process for degrading dysfunctional proteins and organelles, and closely associated with cancer cell survival under therapeutic, metabolic stress, hypoxia, starvation and lack of growth factors, contributing to resistance to therapies. However, the role of autophagy in breast cancer cells is not well understood. In the present study, we investigated the role of autophagy in highly aggressive and metastatic triple negative breast cancer (TNBC) and non-metastatic breast cancer cells and demonstrated that the knockdown of autophagy-related genes (LC3 and Beclin-1) inhibited autophagy and significantly suppressed cell proliferation, colony formation, migration/invasion and induced apoptosis in MDA-MB-231 and BT-549 TNBC cells. Knockdown of LC3 and Beclin-1 led to inhibition of multiple proto-oncogenic signaling pathways, including cyclin D1, uPAR/integrin-β1/Src, and PARP1. In conclusion, our study suggests that LC3 and Beclin-1 are required for cell proliferation, survival, migration and invasion, and may contribute to tumor growth and progression of highly aggressive and metastatic TNBC cells and therapeutic targeting of autophagy genes may be a potential therapeutic strategy for TNBC in breast cancer.
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