Royal Jelly Supplementation Ameliorated Immune Impairment via Inhibition of Oxidative Stress in Low Micronutrient-induced Immunodeficient Mice

Abstract

The effect of royal jelly (RJ) on the survival and immune dysfunctions of C57BL/6 mice induced by low micronutrient supplementation was investigated. Female C57BL/6 mice were supplemented with 0.2% or 1% royal jelly following induction of immune deficiency by 7.5% low micronutrient intake. The administration was maintained for 16 weeks for mortality assay and 10 weeks for the immunological analysis. Supplementation of 1% RJ was found to extend the median survival time in immune deficient mice. Although dysfunction of T- and B-cell mitogenesis was observed in primary cultured splenocytes during micronutrient deficiency, 1% RJ supplementation significantly increased T- and B-cell response against mitogens. In addition, 1% RJ supplementation partially recovered the abnormal alteration in cytokine secretion, indicated by the decreased secretion of T-helper 1 cytokines and increased secretion of T-helper 2 cytokines resulting from low micronutrient levels. The hepatic vitamin E level was significantly decreased (p<0.05) following micronutrient deficiency, in accordance with the increased hepatic lipid peroxidation level. However, 1% RJ supplementation reduced hepatic lipid peroxidation, which may result from the restoration of the hepatic vitamin E level. Therefore, the present study indicated that 1% RJ supplementation may ameliorate the premature mortality in mice through the restoration of immune dysfunctions, which may result from antioxidative ability of RJ in immune deficient mice caused by low micronutrient intake.