role of oxidative stress and antioxidants in diabetic complications

Diabetes is considered to be one of the most common chronic diseases worldwide. There is a growing scientific and public interest in connecting oxidative stress with a variety of pathological conditions including diabetes mellitus [DM] as well as other human diseases. Previous experimental and clinical studies report that oxidative stress plays a major role in the pathogenesis and development of complications of both types of DM. However, the exact mechanism by which oxidative stress could contribute to and accelerate the development of complications in diabetic mellitus is only partly known and remains to be clarified. On the one hand, hyperglycemia induces free radicals; on the other hand, it impairs the endogenous antioxidant defense system in patients with diabetes. Endogenous antioxidant defense mechanisms include both enzymatic and non-enzymatic pathways. Their functions in human cells are to counterbalance toxic reactive oxygen species [ROS]. Common antioxidants include the vitamins A, C, and E, glutathione [GSH], and the enzymes superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx], and glutathione reductase [GRx]. This review describes the importance of endogenous antioxidant defense systems, their relationship to several pathophysiological processes and their possible therapeutic implications in vivo

Selenium and Hepatocellular Carcinoma / Jurnal Sains Kesihatan Malaysia

While cancer is considered to be one of the leading causes of death worldwide, there is a growing scientific and public interests on selenium as a dietary and antioxidant of many diseases, in particular, cancer. Despite advanced technology and significant improvement of surgical, chemical, hormonal and radio therapies, hepatocellular carcinoma (HCC) is still common in Asia and Africa and is increasing in the developed countries. Prognosis of HCC at an early stage is still challenging. At the moment, combination of Alpha feto protein (AFP) and ultrasonography tests offers more accurate and sensitive results for the diagnosis of HCC. Selenium (also known as the moon element) has been recognized for almost 49 years as an antioxidant and anti cancer agent. The weight of evidence supports the position of selenium as an anti cancer agent for HCC but the molecular mechanism of how selenium inhibits HCC is still unknown. Numerous theories have been proposed and selenium induced apoptosis and cell cycle arrest is the predominant one so far.

Selenium: More than just a micronutrient mineral

Selenium is a micronutrient mineral found mainly in soils. Studies on selenium have increased rapidly worldwide especially after it has been shown to reduce the risk of certain types of cancer in humans and animals. The exact mechanism of action on how selenium inhibits diseases, in particular cancer, is still unknown. To date, the use of selenium in preventing or treating diseases is limited. However, many aspects about the biochemistry of selenium have been identified. This article reviews a number of key clinical, experimental and epidemiological studies on selenium as an anti-carcinogenic agent for some types of cancers. Some nutritional information on selenium and its recommended intake are also included. More clinical and experimental studies are needed to confirm previous findings on the role of selenium as an anticarcinogenic agent.