1. Oxidative stress and antioxidant status in cancer patients and healthy subjects.

Article Summary: Since raised free-radical-induced oxidative stress (OS) or weak antioxidant defence or both are considered to be important players in multimechanistic pathogenesis of cancer, the study was undertaken to evaluate their possible involvement in the pathogenesis of this disease in the local (Nepalese) population. Levels of plasma vitamin C, vitamin E, total antioxidant activity (TAA) and thiobarbituric acid reacting substances (TBARS) as a marker of oxidative stress were measured in 20 cancer patients (Mean age 63.1 + 9.3 yr.) and 20 age, sex and socioeconomically matched healthy subjects (Mean age 63.7+7.8 yr.). Significantly low level of vitamin C (p <0.001), vitamin E (p <0.001) and total antioxidant activity (p <0.003) were observed in cancer patients, whereas oxidative stress was significantly increased in patients as compared to control (p <0.003). Smokers had significantly lowered TAA and significantly raised oxidative stress than non-smokers, in both case and control groups. Tobacco chewer patients had raised oxidative stress as compared to control. This study supports the thesis that oxidative stress is a risk factor in carcinogenesis and that smoking, an established risk factor in cancer, at least partly appears through it.

Article Authors: Adhikari D, Baxi J, Risal S, Singh PP. Nepal Medical College Journal. 2005 Dec;7(2):112-5. PMID: 16519076.

2. Prostate cancer prevention through pomegranate fruit.

Article Summary: Prostate cancer (CaP) is the second leading cause of cancer-related deaths among U.S. males with a similar trend in many Western countries. Prostate cancer is an ideal candidate disease for chemoprevention because it is typically diagnosed in men over 50 years of age, and thus even a modest delay in disease progression achieved through pharmacological or nutritional intervention could significantly impact the quality of life of these patients. In this regard we and others have proposed the use of dietary antioxidants as candidate prostate cancer chemopreventive agents. The fruit pomegranate derived from the tree Punica granatum has been shown to possess strong antioxidant and anti-inflammatory properties. In a recent study, we showed that pomegranate fruit extract (PFE), through modulations in the cyclin kinase inhibitor-cyclin-dependent kinase machinery, resulted in inhibition of cell growth followed by apoptosis of highly aggressive human prostate carcinoma PC3 cells. These events were associated with alterations in the levels of Bax and Bcl-2 shifting the Bax:Bcl-2 ratio in favor of apoptosis. Further, we showed that oral administration of a human acceptable dose of pomegranate fruit extract to athymic nude mice implanted with CWR22Rnu1 cells resulted in significant inhibition of tumor growth with concomitant reduction in secretion of prostate-specific antigen (PSA) in the serum. The outcome of this study could have a direct practical implication and translational relevance to prostate cancer patients, because it suggests that pomegranate consumption may retard prostate cancer progression, which may prolong the survival and quality of life of the patients.
Article Authors: Malik A, and Mukhtar H. Cell Cycle. 2006 Feb;5(4):371-3. PMID: 16479165.