Helicobacter pylori cagA gene polymorphism affects the total antioxidant capacity of human saliva

Helicobacter pylori-induced premature senescence of extragastric cells may contribute to chronic skin diseases

Helicobacter pylori, one of the most frequently observed bacterium in the human intestinal flora, has been widely studied since Marshall and Warren documented a link between the presence of H. pylori in the gastrointestinal tract and gastritis and gastric ulcers. Interestingly, H. pylori has also been found in several other epithelial tissues, including the eyes, ears, nose and skin that may have direct or indirect effects on host physiology and may contribute to extragastric diseases, e.g. chronic skin diseases. More recently, it has been shown that H. pylori cytotoxin CagA expression induces cellular senescence of human gastric nonpolarized epithelial cells that may lead to gastrointestinal disorders and systemic inflammation. Here, we hypothesize that also chronic skin diseases may be promoted by stress-induced premature senescence (SIPS) of skin cells, namely fibroblasts and keratinocytes, stimulated with H. pylori cytotoxins. Future studies involving cell culture models and clinical specimens are needed to verify the involvement of H. pylori in SIPS-based chronic skin diseases.

Assessment of salivary total antioxidant capacity in patients with primary untreated head and neck squamous cell carcinoma with ORAC

BACKGROUND

Oxidative DNA damage leads to abnormalities in endogenous cellular processes and constitutes a direct link between free radicals, antioxidants and squamous cell carcinoma (SCC). Oxygen radical absorbance capacity (ORAC) method is used to measure antioxidant capacity versus oxygen free radicals. There is no report on the application of ORAC to evaluate salivary antioxidant capacity in patients with head and neck SCC. This study investigated the relation between total antioxidant capacity of saliva, measured with ORAC method, and the incidence, location, size and histopathological grading of SCC.

METHODS

Salivary antioxidant capacity was assessed in 30 male and female patients with histopathologically confirmed oral and laryngeal SCC. Histopathological grading of SCC was based on WHO classification.

RESULTS

Mean ORAC in patients with SCC was higher than the mean value in the control group. Statistically significant difference was observed in the study group versus the control group. No significant differences were observed for ORAC values in relation to histopathological grading, tumour size and spread to lymph nodes.

CONCLUSIONS

The obtained results can advocate local compensatory mechanism in saliva in response to increased oxidative stress associated with primary tumour. ORAC can become an additional factor in head and neck SCC prognosis, but further investigation is required.

Salivary and Urinary Total Antioxidant Capacity as Biomarkers of Oxidative Stress in Humans

Total Antioxidant Capacity (TAC) is a biomarker often used in order to investigate oxidative stress in many pathological conditions. Saliva and urine can be collected noninvasively and represent attractive diagnostic fluids for detecting biomarkers of various pathological conditions. The reviewed case-control and intervention studies that measured salivary or urinary TAC revealed that diseases, antioxidant foods, or supplements and age, gender, and lifestyle factors influenced salivary or urinary TAC. Salivary and urinary TAC were particularly affected by oral or renal status, respectively, as well as by infection; therefore these factors must be taken into account in both case-control and intervention studies. Furthermore, some considerations on sample collection and normalization strategies could be made. In particular, unstimulated saliva could be the better approach to measure salivary TAC, whereas 24 h or spontaneous urine collection should be chosen on the basis of the study outcome and of the creatinine clearance. Finally, the uric acid-independent TAC could be the better approach to evaluate red-ox status of body, in particular after nutritional interventions and in diseases associated with hyperuricaemia.