Efficacy of aloe vera extracts in attenuating neurological endangerment- induced by dexamethasone in adult male rats

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. 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 and 7], leaves [3 and 8], roots [4 and 9] or stalks extracts [5 and 10], in a dose of 32 mg/kg b.wt./ day. The study was extended to 28 days. 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. Improvement in brain glycogen level may be attributed to -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

Humoral and cellular immune responses induced in mice by purified iridoid mixture that inhibits penetration of schistosoma mansoni cercariae upon topical treatment of mice tails

When tested for possible blocking effect on the cercarial, serine proteinase, elastase [CE] activity, an iridoid mixture extracted from leaves of Citharexylum quadrangular abolished 31% of the enzyme activity at final concentration l5 micro g. When formulated in jojoba oil and applied to mice tails followed by infection with Schistosoma mansoni cercariae, the iridoid mixture blocked cercarial penetration and caused significant reducetion [94%; P < 0.05] in worm burden in treated mice in comparison to controls. Also, immunomodulatory effects of iridoid mixture, iridoid-treated S. mansoni worm homogenate on mice were studied by measuring IgG and IgM levels against E. coil lysates [ECL], solube S. mansoni worm antigenic preparation [SWAP] and cancer bladder homogenates [CBH] as antigens by ELISA. Cellular immune responses were studied by calculating mean percent of CD4+, CD8 +/- T, B-mesenteric lymph node cells [MLNC] and CD4+, CD8 +/- T thymocytes by direct immuno-fluorescence staining in treated mice as compared to untreated homogenate given mice or untreated mice. Injecting mice with serial dilutions of iridoid mixture resulted in fluctuation, peaks and troughs, in both IgG and IgM responses against the above mentioned antigens. lst and 2nd immunizations with iridoid mixture treated homogenate resulted in significantly elevated [P < 0.05]. 1gM and IgG levels against the 3 used antigens in comparison with sera from control mice. Immunized mice with homogenate treated with iridoid mixture showed a significant increase [P < 0.05] in CD4+T thymocytes, a non significant increase in CD8+T thymocytes, a significant increase [P<0.05] in CD4+T lymphocytes [MLNC] and a non significant increase in CD8+T- and B-lymphocytes [MLNC] compared with mice immunized with untreated homogenate or non-injected normal mice