Evaluation of milk yield and some lactogenic hormones in lactating Wistar rats after treatment with ascorbic acid and α-tocopherol

Abstract

Background: Milk synthesis and ejection is essential for breastfeeding and is influenced by nutritional and non-nutritional factors. Vitamin C (L-ascorbic acid) is an essential nutrient for humans and certain animal species. Vitamin E (α-Tocopherol) is a form of vitamin E that is preferentially absorbed. This study was designed to assess milk yield, serum prolactin and oxytocin hormone in lactating Wistar rats following ascorbic acid and α-Tocopherol supplementation.

Methods: At parturition, the animals were randomly divided into five groups thus: Group I: (Normal control) was given commercial feed and distilled water, orally (1 ml/kg), Group II: metoclopramide (5 mg/kg), Group III: 100 mg/kg of Vitamin E. Group IV: 100 mg/kg of Vitamin C and Group V was treated with the co-administration of vitamin C and E 100 mg/kg each. Administration was carried out orally from day 3 to day 13 of lactation at 06:00 hours daily. The animals were euthanized on day 14 using ketamine and diazepam at 75 mg/kg and 25 mg/kg given intraperitoneally and thereafter sacrificed. Milk yield18 hours after gavage as well as serum levels of prolactin and oxytocin were evaluated.

Result: Statistical analysis was carried out using SPSS version 20 with the aid of one-way analysis of variance (ANOVA) and tukey’s post-hoc test. Values of p≤ 0.05 were considered significant. There was a statistically significant (p< 0.05) increase in milk yield in groups IV and V when compared to control: 3.72±0.37, 3.60±0.33 vs 2.28±0.08 respectively, and also a significant decrease (p< 0.05) in group V compared to metoclopramide-treated group; 9.32±0.57 vs 11.48±0.72. Serum oxytocin level was significantly increased (p< 0.05) in group IV compared to the control group 13.32±1.16 vs 9.46±0.81and a significant decrease in group V compared to group IV 8.80±0.95 vs 13.32±1.16 was observed.

Conclusion: This study has shown that Vitamin C possesses more lactogenic activity which increased more milk yield and serum oxytocin level in comparison to vitamin E and metoclopramide.

Keywords: Milk yield, Vitamin C Vitamin E, Prolactin, Oxytocin, Pup and Dams