Microsoft word - 8.doc

JASMR, 2 (1):59 -74 (2007)
http://www.asmr.eg.net
EFFICACY OF ALOE VERA EXTRACTS IN ATTENUATING
NEUROLOGICAL ENDANGERMENT-INDUCED BY
DEXAMETHASONE IN ADULT MALE RATS
Nagat S. Abu-Gabal , Howaida I. Abd Alla *, Hanaa H. Ahmed , Samira M. Al- 1Scientific Department, Girls Faculty, King Abdu-Aziz University, Jeddah, Saudi Arabia Chemistry of Natural Compounds and Hormones Departments, National Research Centre, *Corresponding author: Howaida I. Abd Alla; E-mail:howaida_nrc@yahoo.com ABSTRACT
Objective: The current study aimed at performing phytochemical screening of 24 plant samples belonging to Liliaceae family
and investigating the phytosterols, hydrocarbons, fatty acids and amino acids content of Aloe vera plant parts (flowers, leaves,
roots and stalks) and Aloe hijazensis (leaves and roots) as well as the isolation and identification of certain compounds from
Aloe vera. The study was extended to investigate the possible potential role of methanolic extracts of different Aloe vera plant
parts in attenuating neurological insult-induced by dexamethasone.
Material and Methods: Plants materials were collected from Saudi Arabia from different sources and were phytochemically
screened according to the recorded procedures. The lipoidal matters were investigated by GLC and amino acids by HPLC and
total proteins percentage was carried out. The structures of isolated compounds were established by GC/MS and NMR. Extracts
were prepared for the biological evaluation and eighty adult male Sprague-Dawley rats were divided into ten groups, group (1)
was served as normal control group; groups (6 to10) were intramuscularly injected with dexamethasone in a dose of 8 mg/ kg
b.wt. / day. At the same time animal groups were orally administered with Aloe vera flowers (2&7), leaves (3&8), roots (4 &9)
or stalks extracts (5&10), in a dose of 32 mg/kg b.wt./ day. The study was extended to 28 days.
Results: Two Aloe species were selected from the 24 samples screened. Different plants parts of A. vera and A. hijazensis
showed variation in their lipids and proteins chemical composition. One triterpene (lupeol) and mixture of sterols were isolated
from leaves and roots of A. vera. Co-administration with A. vera extracts and dexamethasone produced remarkable effective role
against hyperglycemia and hyperinsulinemia. Also, A. vera extracts could restore brain glycogen content and serum IGF-1 level.
Moreover, A. vera extracts monitored each of brain ATPase and LDH activity. Interestingly, brain biochemical variables
indicative for oxidative stress showed marked improvement on A. vera extracts supplementation.
Conclusion: Improvement in brain glycogen level may be attributed to β-sitosterol content of A. vera extracts (recorded in major
quantity in all samples except roots in the present study) and the screening of A. vera extracts showed the presence of
anthraquinones and coumarins which are known to have a powerful antioxidant activity. Simultaneous supplementation with
each of A. vera extract and dexamethasone has an officious role in modulating neurological impact-induced by dexamethasone
and this might be accomplished by their antihyperglycemic effects, antioxidative activities and cytoprotective properties.
Key words: Liliaceous plants, Aloe vera, Aloe hijazensis, Protein, Lipid, Antioxidative activity, Dexamethasone, Neurological
endangerment.

Source: http://www.asmr.eg.net/pdf/1-2007/8.pdf