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
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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.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/10540 |
| Date | 12 October 2011 |
| Creators | Wabeya, Beya |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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