The relationship between nutritional antioxidants and serum lipid peroxides in cancer patients.

A new parameter, the ratio of lipid peroxide and vitamins E and C [LPO/(VE + VC)], has been proposed and used to reflect the balance between lipid peroxidation and antioxidation capability of cancer patients and of healthy human controls. The effects of vitamins E, C, and selenium on the serum LPO level in mice bearing Ascites Hepatomas (H22) have also been examined. The results showed that the average of LPO/(VE + VC) ratios in cancer patients (135 cases) was significantly higher than that of the normal controls (222 cases). The authors suggest that this ratio might be used as one of the parameters for early diagnosis and prognosis of diseases (including cancers) caused by free radicals and lipid peroxides. The results also showed that antioxidants - Se(Na2SeO3, 1mg/kg) or vitamin E (5mg/kg) could markedly decrease the level of serum LPO in the tumor-bearing animals. A smaller dose of VE (1mg/kg) and doses of Vc up to 300mg/kg showed no effect on the serum LPO levels when given separately. However, synergistic effects were observed when any 2 out of 3 or three nutrients were given together. Those with three nutrients significantly lowered the serum LPO level. These antioxidants also inhibited the proliferation of tumour cells.