Developmental retardation in neonates of aldehyde reductase (AKR1A)-deficient mice is associated with low ascorbic acid and high corticosterone levels.

Aldehyde reductase encoded by the Akr1a gene catalyzes the NADPH-dependent reduction of a variety of aldehyde compounds, and it plays a role in the biosynthesis of ascorbic acid (AsA) by converting D-glucuronate to L-gulonate. Although supplementing drinking water with AsA (1.5 mg/mL) ameliorates the fertility of Akr1a-/- (KO) female mice, litter sizes in the KO mice are typically smaller than those for Akr1a+/+ (WT) mice, and about one-third of the neonates have a reduced stature. Half of the neonates in the smallest, developmentally retarded group died before weaning, and the remaining half (less than 6 g in weight) also barely grew to adulthood. While no difference was found in the number of fetuses between the KO and WT mice at 14.5-embryonic days, the sizes of the KO fetuses had already diverged. Among the organs of these retarded KO neonates at 30 d, the spleen and thymus were characteristically small. While an examination of spleen cells showed the normal proportion of immune cells, apoptotic cell death was increased in the thymus, which would lead to thymic atrophy in the retarded KO neonates. Plasma AsA levels were lower in the small neonates despite the fact that their mothers had received sufficient AsA supplementation, and the corticosterone levels were inversely higher compared to wild-type mice. Thus, insufficient AsA contents together with a defect in corticosterone metabolism might be the cause of the retarded growth of the AKR1A-deficient mice embryos and neonates.

Ascorbic acid prevents N-nitrosodiethylamine-induced hepatic injury and hepatocarcinogenesis in Akr1a-knockout mice.

To gain insights into the benefits of ascorbic acid (AsA) in hepatoprotection, we examined the status of Akr1a-/- (KO) mice, which biosynthesize AsA at about 10% the rate as Akr1a+/+ (WT) mice, in terms of their response to an N-nitrosodiethylamine (NDEA)-induced hepatic injury. The intraperitoneal injection of NDEA (35 mg/kg) started at 4 weeks of age and was performed at weekly intervals thereafter. While the fatality rate was substantial in the KO mice, AsA supplementation (1.5 mg/ml in the drinking water) greatly extended their life-spans. Only two out of 54 KO mice survived to 28 weeks, and both contained approximately an order of magnitude greater number of tumor nodules compared to WT mice or KO mice with AsA supplementation. Histological and biochemical examinations at 20 weeks indicated that AsA potently protected against the hepatotoxic action of NDEA. Interestingly, the AsA levels in the liver were higher in the AsA-supplemented KO mouse groups that had received the NDEA treatment compared to the corresponding control group. While the protein levels of Cyp2e1, an enzyme that plays a major role in the bioactivation of NDEA, had declined to a similar extent among the experimental groups, p-nitrophenol-oxidizing activity was sustained at high levels in the KO mouse livers but AsA supplementation suppressed this activity. These findings confirm that AsA is a potent micronutrient that copes with hepatic injury and cancer development caused by exposure to NDEA in the livers of Akr1a-knockout mice.

Ascorbic acid and CoQ10 ameliorate the reproductive ability of superoxide dismutase 1-deficient female mice†.

Superoxide dismutase 1 suppresses oxidative stress within cells by decreasing the levels of superoxide anions. A dysfunction of the ovary and/or an aberrant production of sex hormones are suspected causes for infertility in superoxide dismutase 1-knockout mice. We report on attempts to rescue the infertility in female knockout mice by providing two antioxidants, ascorbic acid and/or coenzyme Q10, as supplements in the drinking water of the knockout mice after weaning and on an investigation of their reproductive ability. On the first parturition, 80% of the untreated knockout mice produced smaller litter sizes compared with wild-type mice (average 2.8 vs 7.3 pups/mouse), and supplementing with these antioxidants failed to improve these litter sizes. However, in the second parturition of the knockout mice, the parturition rate was increased from 18% to 44-75% as the result of the administration of antioxidants. While plasma levels of progesterone at 7.5 days of pregnancy were essentially the same between the wild-type and knockout mice and were not changed by the supplementation of these antioxidants, sizes of corpus luteum cells, which were smaller in the knockout mouse ovaries after the first parturition, were significantly ameliorated in the knockout mouse with the administration of the antioxidants. Moreover, the impaired vasculogenesis in uterus/placenta was also improved by ascorbic acid supplementation. We thus conclude that ascorbic acid and/or coenzyme Q10 are involved in maintaining ovarian and uterus/placenta homeostasis against insults that are augmented during pregnancy and that their use might have positive effects in terms of improving female fertility.

Hepatocellular injuries observed in patients with an eating disorder prior to nutritional treatment.

BACKGROUND/AIMS: Although hepatocellular injuries are occasionally observed in patients with an eating disorder, such as anorexia nervosa (AN), it remains unclear how malnutrition in patients with AN causes hepatocellular damage. In this retrospective study, we aimed to reveal the characteristics of hepatocellular injuries in patients with an eating disorder without any nutritional treatment, to eliminate the possible hepatotoxic effects of nutritional support. SUBJECTS AND METHODS: Twenty-five patients with an eating disorder who visited St. Luke's International Hospital were enrolled. No nutritional treatment had been performed for these patients. The diagnosis of eating disorder as well as typing (anorexia nervosa or bulimia nervosa) was made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-4). We reviewed the charts of these patients and examined the clinical parameters. RESULTS: Elevation of serum alanine aminotransferase (ALT) was found in 13 out of 25 (52%), all of whom were categorized as AN. In 13 AN patients with elevated ALT, the median of serum ALT values was 92 [39-438] IU/L. The body mass index (BMI) was significantly lower (13.5 vs. 17.3, p=0.011), and the duration since the onset of AN was shorter (4.2 years vs. 8.9 years, p=0.037) in patients with elevated ALT. The age was younger in patients with elevated ALT, even though not significant (24.5 vs. 29.8, p=0.139). Logistic regression analysis revealed that only BMI was a significant determinant for the development of hepatocellular injuries (OR=3.46; 95% CI 1.06-11.34, p=0.041). Imaging studies failed to demonstrate any abnormalities, including fatty liver. CONCLUSION: The current study indicated that lower BMI might significantly contribute to the development of hepatocellular injuries in AN patients prior to any nutritional treatments.