The effect of crude aqueous and alcohol extracts of Aloe vera on the gastrointestinal tract and accessory organs of suckling rats.
For centuries Aloe vera has been exploited for several verified and unverified medicinal uses such as wound healing, treatment of gastrointestinal ulcers and for its many biological effects including anti-microbial, laxative, anti-inflammatory and immunostimulatory activities. Studies have generally focused on its effects in vitro and in adults. When nursing mothers use Aloe vera extracts, their suckling infants are at risk of indirect exposure to Aloe vera via breast feeding or directly as dietary/health supplements. The gastrointestinal tract (GIT) of the neonate is sensitive to dietary manipulations during the suckling period with long lasting effects that can be irreversible. Thus babies may be at risk if administered Aloe vera extracts directly as dietary supplements or indirectly via breast milk. The main objectives of this study were to evaluate the effects of orally administered aqueous and alcohol extracts of Aloe vera on growth performance, the morphometry and morphology of the gastrointestinal tract and accessory organs, and liver function of suckling rats. Suckling Sprague-Dawley rats (77), males (n=38) and females (n=39) of 6 days old were randomly assigned to one of five treatment groups and given once daily by oral gavage a suspension of lyophilized crude alcohol or aqueous extracts of Aloe vera suspended in distilled water. Group I (control) was gavaged with distilled water (vehicle). Group II received a low dose of the aqueous extract (AqL) at 50mg. kg-1; Group III received a high dose of the aqueous extract (AqH) at 500mg. kg-1; Group IV received a low dose of the alcohol extract (AlcL) at 50mg. kg-1 whilst Group V received a high dose of the alcohol extract (AlcH) at 500mg. kg-1. The extracts and distilled water were 2 administered at a volume of 10ml.kg-1. The pups remained with their dams for the duration of the study and after 8 days on the treatments, the pups were humanely killed to harvest their tissues for measurements and physiological analysis. All data were expressed as mean ± SD and analyzed by one way ANOVA, the values were considered statistically significant when p < 0.05 and then a Bonferroni Post hoc test was applied. The suckling rats fed respectively with high doses of AlcH and AqH had a significantly higher body mass gain than the other groups (p < 0.05, one way ANOVA). Linear growth as measured by tibial length was significantly increased in the AqH group compared to the other groups. There was no significant difference in the mass and relative density of the tibia bones of the rats from the different treatment groups. The differences in growth could not be attributed to circulating concentrations of the somatotrophic hormone, Insulin-like growth factor-1 (IGF-1) which was not significantly different between the groups. The treatments did not result in any significant differences in lengths, and mass of the small and large intestine, however the caecum was significantly enlarged (hypertrophy of muscularis, submucosa and mucosa) in the rats that received the Aloe vera extracts. Although, there was no significant difference in the mass of the rats’ livers, the lipid and glycogen content were significantly higher (p < 0.001) for the AqH group compared to the other groups. Histologically, the hepatocytes showed enlarged nuclei, granular cytoplasm and dilated sinusoids for AqH and AlcH as compared to the control group. An indirect assessment of liver function by measurement of blood concentrations of alkaline phosphatase (ALP) and alanine amino transaminase (ALT) did not reveal a significant difference between the groups. The non fasting concentration of metabolic substrates (glucose and triglycerides) was also not significantly different between the groups. The pups given high doses of the extracts had a significantly greater (p < 0.05) thymus mass (hyperplastic) than the other groups. The short term administration of Aloe vera extracts has shown a growth promoting effect, enhanced hepatic storage of metabolic substrates and hypertrophy of the caecum and thymus of neonatal rats. These effects need to be explored further to enhance animal production and health.
Aloe vera, effects on suckling rats, gastrointestinal tract, medicinal plants