Mahmoud M. Said

Bioactive compounds, antioxidant potential, and hepatoprotective activity of sea cucumber (Holothuria atra) against thioacetamide intoxication in rats

OBJECTIVE The identification of the active phenolic compounds in the mixed extract of sea cucumber (Holothuria atra) body wall by high-performance liquid chromatography and an assessment of its hepatoprotective activity against thioacetamide-induced liver fibrosis in rats. METHODS Female Swiss albino rats were divided into four groups: normal controls; oral administration of a sea cucumber mixed extract (14.4 mg/kg of body weight) on days 2, 4, and 6 weekly for 8 consecutive weeks; intoxication with thioacetamide (200 mg/kg of body weight, intraperitoneally) on days 2 and 6 weekly for 8 wk; and oral administration of a sea cucumber extract and then intoxication with thioacetamide 2 h later for 8 wk. RESULTS High-performance liquid chromatographic analysis of the sea cucumber mixed extract revealed the presence of some phenolic components, such as chlorogenic acid, pyrogallol, rutin, coumaric acid, catechin, and ascorbic acid. In vitro studies have shown that the extract has a high scavenging activity for the nitric oxide radical, a moderate iron-chelating activity, and a weak inhibitory effect of lipid peroxidation. The subchronic oral administration of sea cucumber extract to the rats did not show any toxic side effects but increased hepatic superoxide dismutase and glutathione peroxidase activities. The coadministration of sea cucumber extract and thioacetamide (protection modality) normalized serum direct bilirubin, alanine and aspartate aminotransferases, hepatic malondialdehyde, and hydroxyproline concentrations and antioxidant enzyme activities. In addition, the histologic examination of liver sections from the protection group that were stained with hematoxylin and eosin showed substantial attenuation of the degenerative cellular changes and regressions in liver fibrosis and necrosis induced by the thioacetamide intoxication. CONCLUSION Sea cucumber mixed extract contains physiologically active phenolic compounds with antioxidant activity, which afforded a potential hepatoprotective activity against thioacetamide-induced liver injury in a rat model.

Chemoprevention of prostate carcinogenesis by DFMO and/or finasteride treatment in male Wistar rats.

In the present study the chemopreventive activities of DFMO, the irreversible inhibitor of ornithine decarboxylase, and finasteride, the inhibitor of prostatic 5a-reductase, against the development of chemically induced prostate adenocarcinoma by methylnitrosourea/testosterone propionate in male Wistar rats were investigated. According to histological examination, oral administration of DFMO and finasteride, either alone or combined, for two months to MNU/TP-inoculated rats reduced the tumor incidence to 11.11%, 10% and 10%, respectively, compared to tumored controls (64.3%). DFMO and/or finasteride treatment resulted in significant reductions in the wet weight of the prostate gland and seminal vesicles and its ratio relative to the total body weight, as well as the levels of prostate total protein, DNA, RNA and DNA/RNA ratio, compared to tumored controls. However, the effect of the combined treatment was of no statistical significance compared to single DFMO or finasteride treatment, as demonstrated by the non-significant differences between the mean values of most of the studied parameters. The tumor chemopreventive activity and the prostate growth inhibitory effect of DFMO and finasteride were due to suppression of prostate polyamine synthesis. ANOVA test revealed that the relative weight of the prostate as well as blood and tissue polyamine levels could be used as significant endpoint biomarkers for DFMO and finasteride as cancer chemopreventive agents.

Inhibition of prostate carcinogenesis in probasin/SV40 T antigen transgenic rats by leuprorelin, a luteinizing hormone–releasing hormone agonist

The effects of leuprorelin acetate, a luteinizing hormone‐releasing hormone agonist (LHRH‐A), on prostate carcinogenesis in probasin/SV40 Tag transgenic rat was investigated. Fifteen weeks after administration of 0.28 and 2.8 mg/kg leuprorelin, prostate weights and serum testosterone levels were significantly decreased compared to values for transgenic controls. Histopathological findings revealed that the incidence of prostatic adenocarcinomas was significantly reduced in ventral, dorsal and lateral lobes of the prostate, correlating with decreased expression of SV40 Tag oncoprotein as well as inhibition of DNA synthesis and proliferation of epithelial cells in neoplastic lesions of the ventral prostate. Microarray analysis further showed leuprorelin acetate to significantly inhibit testicular steroidogenesis, suppressing the expression of SV40 Tag oncoprotein and altering the expression of a large number of genes which might be involved in the inhibition of prostate cancer progression in this rat model. (Cancer Sci 2006; 97: 459–467)

Aloin: a natural antitumor anthraquinone glycoside with iron chelating and non-atherogenic activities.

Abstract Context: The antitumor activity of aloin, the active anthraquinone of Aloe juice, against different murine and human tumors has been reported. Objective: In the present study, the impact of repeated aloin treatment at its maximum tolerated dose on serum levels of lipid profile, some elements, iron status and kidney function, compared with doxorubicin (a cardiotoxic anthracycline and inhibitor of erythropoiesis), was assessed. Materials and methods: Rats were treated with a single dose of doxorubicin (30 mg/kg body weight, intraperitoneal) or aloin (50 mg/kg body weight, intramuscular) twice weekly over 2 weeks. Results: Acute doxorubicin treatment elevated serum levels of triacylglycerols (59.90%), total cholesterol (42.29%), cholesteryl esters (54.75%), low density lipoprotein–cholesterol (230.16%), very low density lipoprotein–cholesterol (56.42%), urea (287.53%), and creatinine (85.38%), whereas serum high density lipoprotein–cholesterol, sodium, and calcium levels were reduced (44.61, 9.61, and 9.76%, respectively), as compared with controls. In contrast, aloin treatment showed insignificant changes in all the aforementioned parameters. Both doxorubicin and aloin induced erythropoiesis impairment demonstrated by a reduction in blood hemoglobin concentration. While aloin treatment elevated serum iron level (30.28%), doxorubicin treatment reduced serum levels of iron (51.47%) and percent transferrin saturation (55.21%), and in contrast, increased serum total iron binding capacity (34.85%). The chelating affinities of iron-aloin and -doxorubicin complexes, which contain bidentate iron-binding moieties, have been shown in the infrared spectra. Discussion and conclusion: The non-cardiotoxic effect of aloin treatment was due to its non-atherogenic and iron-chelating activities, which might also contribute in part to its anti-proliferative activity.

In Vivo and In Vitro Studies on the Antioxidant Activity of Aloin Compared to Doxorubicin in Rats

Strategy, Management and Health Policy Enabling Technology, Genomics, Proteomics Preclinical Research Preclinical Development Toxicology, Formulation Drug Delivery, Pharmacokinetics Clinical Development Phases I‐III Regulatory, Quality, Manufacturing Postmarketing Phase IV

Neuroprotective effects of eugenol against aluminiuminduced toxicity in the rat brain

Abstract Aluminium (Al) is a neurotoxic metal that contributes to the progression of several neurodegenerative diseases. The aim of the present study was to evaluate the protective effect of dietary eugenol supplementation against aluminium (Al)- induced cerebral damage in rats. Male Wistar rats were divided into four groups: normal controls, rats fed a diet containing 6,000 μg g-1 eugenol, rats intoxicated daily with aluminium chloride (84 mg kg-1 body weight) p. o. and fed either a basal diet or a eugenol-containing diet. Daily oral administration of Al for four consecutive weeks to rats significantly reduced brain total antioxidant status (TAS) (11.42±0.31 μmol g-1 tissue, p<0.001) with a subsequent significant enhancement of lipid peroxidation (MDA) (32.55±1.68 nmol g-1 tissue, p<0.002). In addition, Al enhanced brain acetylcholinesterase activity (AChE) (46.22±4.90 U mg-1 protein, p<0.001), tumour necrosis factor alpha (TNF-α) (118.72±11.32 pg mg-1 protein, p<0.001), and caspase 3 (Casp-3) (8.77±1.26 ng mg-1 protein, p<0.001) levels, and in contrast significantly suppressed brain-derived neurotrophic factor (BDNF) (82.74±14.53 pg mg-1 protein, p<0.002) and serotonin (5-HT) (1.54±0.12 ng mg-1 tissue, p<0.01) levels. Furthermore, decreased glial fibrillary acidic protein (GFAP) immunostaining was noticed in the striatum of Al-intoxicated rats, compared with untreated controls. On the other hand, co-administration of dietary eugenol with Al intoxication restored brain BDNF (108.76±2.64 pg mg-1 protein) and 5-HT (2.13±0.27 ng mg-1 tissue) to normal levels, enhanced brain TAS (13.43±0.24 μmol g-1 tissue, p<0.05), with a concomitant significant reduction in TNF-α (69.98±4.74 pg mg-1 protein) and Casp-3 (3.80±0.37 ng mg-1 protein) levels (p<0.001), as well as AChE activity (24.50±3.25 U mg-1 protein, p<0.001), and increased striatal GFAP immunoreactivity, compared with Al-treated rats. Histological findings of brain tissues verified biochemical data. In conclusion, eugenol holds potential as a neuroprotective agent through its hydrophobic, antioxidant, and anti-apoptotic properties, as well as its neurotrophic ability against Al-induced brain toxicity in rats.

Cyclooxygenase 2 and Prostaglandin E2 are not Involved in N-Nitrosodiethylamine-Initiated Early Rat Hepatocarcinogenesis

The present study was undertaken to investigate the effect of dietary supplementation with nimesulide or eugenol on N-nitrosodiethylamine (DEN)-initiated early hepatocarcinogenesis in F344 male rats. Both compounds did not alter the expression of cytochrome P450 (CYP) 2E1, the enzyme that plays a major role in the activation of DEN to genotoxic products; however, nimesulide induced the expression of CYP1A1. Western blot analysis revealed that COX-1 and COX-2 protein expressions were not modulated by DEN compared with normal controls. Furthermore, post-initiation feeding with nimesulide or eugenol did not modulate COX-2 protein expression in normal or DEN-treated rats, whereas eugenol significantly increased the liver prostaglandin E2 (PGE2) levels of DEN-injected animals compared with the DEN controls. Ultimately, nimesulide or eugenol did not modify DEN-induced hepatocarcinogenesis as evidenced by insignificant changes in the number and size of preneoplastic placental glutathione S-transferase (GST-P) positive liver foci compared with the DEN controls. These results suggest that COX-2, as well as prostaglandin E2, may play no role in the post-initiation development of DEN-induced rat hepatocarcinogenesis at an early stage.

Flaxseed Suppressed Prostatic Epithelial Proliferation in a Rat Model of Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH), a disease occurring frequently among elderly males, is a slow progressive enlargement of the fibromuscular and epithelial structures of the prostate gland. Dietary factors may influence the prostate and exert an influence on prostatic growth and disease. The current study was undertaken to investigate the protective effect of dietary flaxseed supplementation against testosterone-induced prostatic hyperplasia in male rats. Forty male Wistar rats were divided into 5 groups: (1) untreated control; (2) treatment with testosterone propionate (TP) to induce prostate enlargement; (3) TP-treated group fed a diet containing 5% milled flaxseed; (4) TP-treated group fed a diet containing 10% milled flaxseed; and (5) TP-treated group fed a diet containing 20 ppm finasteride. Treatment with TP significantly increased the absolute and relative weights of different prostatic lobes, serum testosterone (T), and testosterone/estradiol ratio, as well as prostatic vascular endothelial growth factor (VEGF) expression, RNA synthesis per cell, and epithelial cell proliferation, detected as Ki67 labeling. Histopathological examination did not reveal marked differences in acinar morphology in ventral prostate, whereas morphometric analysis showed significantly increased epithelial cell height. Co-administration of flaxseed or finasteride with TP significantly reduced prostatic VEFG, epithelial cell proliferation, and RNA/DNA ratio, along with a significant increase in serum T and testosterone/estradiol ratio compared with TP-only-treated rats. Our results indicate that flaxseed, similar to the 5α-reductase inhibitor finasteride, blocked TP-induced prostate enlargement in a rat model of BPH, likely through suppression of prostatic VEFG and cellular proliferation.

The Beneficial Radioprotective Effect of Tomato Seed Oil Against Gamma Radiation–Induced Damage in Male Rats

ABSTRACT Radiation protection research receives intense focus due to its significant impact on human health. The present study was undertaken to investigate the protective effect of pretreatment with tomato seed oil (TSO) against gamma radiation–induced damage in rats. Male Wistar rats were divided into four groups: (1) untreated control; (2) TSO-supplemented; (3) gamma-irradiated; (4) TSO-pretreated and gamma-irradiated. Acute exposure of animals to a single gamma radiation dose (6 Gy) induced oxidative stress in major body organs, altered serum lipid homeostasis, significantly increased serum testosterone and sorbitol dehydrogenase levels, and elicited a systemic inflammation as manifested by the induction of serum vascular cell adhesion molecule-1. Oral pretreatment with TSO (1 ml/kg; 3 times/week for 8 weeks) before exposure to gamma radiation protected rats against ionizing radiation-induced oxidative stress, restored lipid homeostasis, and suppressed systemic inflammation. Histological findings of target tissues verified biochemical data. The radioprotective ability of TSO was attributed to its content of phytosterols, policosanol, and antioxidants, including lycopene, β-carotene, lutein, and tocopherols. TSO is considered a promising radioprotective agent that can be effectively used to protect the body from the damaging effects of harmful radiation.

HepG2 Attenuation Induced by RNase A Modulates Gene Profiling and Immunophenotypic Characterization of Some Immune Cells Operating in Cancer Vaccine

Hepatocellular carcinoma (HCC) ranks as the third leading cause of cancer death. Attempts to induce an effective immune response against cancer by immunotherapeutic intervention, including activation of dendritic cells (DCs), were established. The present study was undertaken to investigate the attenuation of HepG2 cells using ribonuclease enzyme A (RNase A) as a possible biological factor to sensitize allogenic DCs and lymphocytes isolated from Egyptian HCC patients. Attenuation of HepG2 cells resulted in a significant increase in activated DC and T-lymphocyte markers, upregulation of CD44 gene expression and increased lactate dehydrogenase as well as interleukin-12 levels. In contrast, a significant decrease in matureDCs, B-cells, T-helper, cytotoxic T-cells, and NK-cells, as well as LMP-2 gene expression was recorded. In conclusion, the attenuation of HepG2 cells with RNase A and subsequent pulsation to allogenic DCs and lymphocytes caused a differential immune response. Further studies are recommended to explain the role of RNase A in modulating antigen expression on the tumor cell surface.