Micronutrient antioxidant status in tropical compared with temperate-zone chronic pancreatitis

Abstract

Micronutrient antioxidants interact with glutathione in tissues to facilitate the disposal of reactive oxygen species and xenobiotic metabolites derived via cytochromes P450. Published evidence linking cytochrome P450I induction with chronic pancreatitis therefore led us to compare antioxidant status in patients at Manchester in the northwest of England and at Madras in the southeast of India. Serum studies in healthy volunteers showed that the biologic availabilities of selenium and a-tocopherol were equally high in the two zones but that the availabilities of β-carotene and ascorbic acid were lower in the tropical area (p< 0.001), where the ratio of ascorbic acid to total vitamin C concentration in serum was substantially reduced (p< 0.001). The serum antioxidant profiles of the chronic pancreatitis groups reflected these indigenous differences: a decrement in selenium and a-tocopherol was evident in both zones, whereas β-carotene and ascorbic acid values were subnormal only in the Manchester group. The concentration of inorganic sulphate in urine-an index of long-term intake of sulphur amino acids for synthesis of glutathione and other detoxifiers-was similar in controls and patients from Manchester, but levels were lower than in their Madras counterparts (p < 0.02, p < 0.01, respectively). The results suggest that culinary practices that erode the biologic availabilities of ascorbic acid and β-carotene may predispose to pancreatic oxidative stress and thereby to the changes leading to chronic pancreatitis at an early age in south India. These findings have implications for treatment and prophylaxis.