HEALTH NEWS

Study Title:

DHA Stops Cancer Cells, Helps Kidneys

Study Abstract

Background
The fish oil-derived omega-3 fatty acids, like docosahexanoic (DHA), claim a plethora of health benefits. We currently evaluated the antitumor effects of DHA, alone or in combination with cisplatin (CP) in the EAC solid tumor mice model, and monitored concomitant changes in serum levels of C-reactive protein (CRP), lipid peroxidation (measured as malondialdehyde; MDA) and leukocytic count (LC). Further, we verified the capacity of DHA to ameliorate the lethal, CP-induced nephrotoxicity in rats and the possible mechanisms involved therein.

Results
EAC-bearing mice exhibited markedly elevated LC (2-fold), CRP (11-fold) and MDA levels (2.7-fold). DHA (125, 250mg/kg) elicited significant, dose-dependent reductions in tumor size (38%, 79%; respectively), as well as in LC, CRP and MDA levels. These effects for CP were appreciably lower than those of DHA (250mg/kg). Interestingly, DHA (125mg/kg) markedly enhanced the chemopreventive effects of CP and boosted its ability to reduce serum CRP and MDA levels. Correlation studies revealed a high degree of positive association between tumor growth and each of CRP (r= 0.85) and leukocytosis (r=0.89), thus attesting to a diagnostic/prognostic role for CRP. On the other hand, a single CP dose (10mg/kg) induced nephrotoxicity in rats that was evidenced by a disrupted glomerular filtration rate, GFR (2-5-fold rise in serum creatinine/urea levels) after 4days, and globally-induced animal fatalities after 7days. Kidney-homogenates from CP-treated rats displayed significantly-elevated MDA, and -reduced GSH levels. Rats treated with DHA (250mg/kg, but not 125mg/kg) survived the lethal effects of CP, and showed a significant recovery of GFR; while their homogenates had markedly-reduced MDA, and -increased GSH levels. Significant association was detected between creatinine level and each of MDA (r= 0.81) and GSH (r=-0.82), thus indicating causal relationships between these biochemical and functional parameters.

Conclusion
DHA elicited prominent chemopreventive effects on its own, and appreciably augmented those of CP as well. The extent of tumor progression in various mouse groups was highly reflected by CRP levels (thus, implying a diagnostic/prognostic role for CRP). Further, this study is the first to reveal that DHA can obliterate the lethal CP-induced nephrotoxicity and renal tissue injury. At the molecular level, DHA appears to act by reducing inflammation, leukocytosis, oxidative stress, and by replenishing the endogenous antioxidant machinery.

From press release:

Docosahexanoic acid (DHA), an omega-3 fatty acid found in fish oils, has been shown to reduce the size of tumours and enhance the positive effects of the chemotherapy drug cisplatin, while limiting its harmful side effects. The rat experiments provide some support for the plethora of health benefits often ascribed to omega-3 acids.

Professor A. M. El-Mowafy led a team of researchers from Mansoura University, Egypt, who studied DHA's effects on solid tumours growing in mice, as well as investigating how this fatty acid interacts with cisplatin, a chemotherapy drug that is known to cause kidney damage. El-Mowafy said, "DHA elicited prominent chemopreventive effects on its own, and appreciably augmented those of cisplatin as well. Furthermore, this study is the first to reveal that DHA can obliterate lethal cisplatin-induced nephrotoxicity and renal tissue injury."

DHA is an omega-3 fatty acid that is commonly found in cold-water fish oil, and some vegetable oils. It is a major component of brain gray matter and of the retina in most mammalian species and is considered essential for normal neurological and cellular developments. According to the authors, "While DHA has been tentatively linked with protection against cardiovascular, neurological and neoplastic diseases, there exists a paucity of research information, in particular regarding its interactions with existing chemotherapy drugs". The researchers found that, at the molecular level, DHA acts by reducing leukocytosis (white blood cell accumulation), systemic inflammation, and oxidative stress – all processes that have been linked with tumour growth.

El-Mowafy and his colleagues have called for greater deployment of omega-3 in the fight against cancer. They write, "Our results suggest a new, fruitful drug regimen in the management of solid tumors based on combining cisplatin, and possibly other chemotherapeutics, with DHA".

Study Information

M E Elmesery, M M Algayyar, H A Salem, M M Darweish and A M El-Mowafy
Chemopreventive and renal protective effects for docosahexaenoic acid (DHA): implications of CRP and lipid peroxides.
Cell Division
2009 April