Hossam M.M. Arafa

Prophylactic role of curcumin in dextran sulfate sodium (DSS)-induced ulcerative colitis murine model.

We have addressed in this study the possible protective role of the main principle of turmeric pigment; curcumin on a murine model of ulcerative colitis (UC). Colitis was induced by administration of dextran sulfate sodium (DSS) (3% W/V) in drinking water to male Swiss albino rats for 5 consecutive days. DSS challenge induced UC model that was well characterized morphologically and biochemically. DSS produced shrinkage of colon length and increased the relative colon weight/length ratio accompanied by mucosal edema and bloody stool. Histologically, DSS produced submucosal erosions, ulceration, inflammatory cell infiltration and crypt abscess as well as epithelioglandular hyperplasia. The model was confirmed biochemically, and the test battery entailed elevated serum tumor necrosis factor (TNF-alpha) and colonic activity of myleoperoxidase (MPO). Colonic glutathione-S-transferase (GST) activity and its substrate concentration; GSH, were notably reduced, while lipid peroxidation, expressed as malondialdehyde (MDA) level, and total nitric oxide (NO) were significantly increased. Prior administration of curcumin (100mg/kg, IP) for 7 consecutive days ahead of DSS challenge mitigated the injurious effects of DSS and ameliorated all the altered biochemical parameters. These results suggest that curcumin could possibly have a protective role in ulcerative colitis probably via regulation of oxidant/anti-oxidant balance and modulation of the release of some inflammatory endocoids, namely TNF-alpha and NO.

Neuroprotective effect of taurine in 3-nitropropionic acid-induced experimental animal model of Huntington's disease phenotype

An experimental animal model of Huntingtons disease (HD) phenotype was induced using the mycotoxin 3-nitropropionic acid (3-NP) and was well characterized behaviorally, neurochemically, morphometrically and histologically. Administration of 3-NP caused a reduction in prepulse inhibition (PPI) of acoustic startle response, locomotor hyper- and/or hypoactivity, bilateral striatal lesions, brain oxidative stress, and decreased striatal gamma-aminobutyric acid (GABA) levels. Taurine is a semi-essential beta-amino acid that was demonstrated to have both antioxidant and GABA-A agonistic activity. In this study, treatment with taurine (200 mg/kg daily for 3 days) prior to 3-NP administration reversed both reduced PPI response and locomotor hypoactivity caused by 3-NP injection. Taurine pretreatment also caused about 2-fold increase in GABA concentration compared to 3-NP-treated animals. In addition, taurine demonstrated antioxidant activity against oxidative stress induced by 3-NP administration as evidenced by the reduced striatal malondialdehyde (MDA) and elevated striatal glutathione (GSH) levels. Histochemical examination of striatal tissue showed that prior administration of taurine ahead of 3-NP challenge significantly increased succinate dehydrogenase (SDH) activity compared to 3-NP-treated animals. Histopathological examination further affirmed the neuroprotective effect of taurine in 3-NP-induced HD in rats. Taken together, one may conclude that taurine has neuroprotective role in the current HD paradigm due, at least partly, to its indirect antioxidant effect and GABA agonistic action.

Protective role of carnitine esters against alcohol-induced gastric lesions in rats.

We have investigated in the current study the possible protective effects of two carnitine esters known to have powerful anti-oxidant potential namely, propionyl L-carnitine (PLC) and acetyl L-carnitine (AC) against alcohol-induced gastric lesions in rats. Both drugs were administered as a single oral dose of 200 mg kg(-1) body weight 1h before alcohol intake. Both carnitine esters could protect the gastric mucosa against the injurious effect of absolute alcohol and promote ulcer healing as evidenced from the ulcer index (UI) values. Propionyl L-carnitine prevented alcohol-induced increase in thiobarbituric acid-reactive substances (TBARS), an index of lipid peroxidation. The propionyl carnitine ester also increased the gastric content of reduced glutathione (GSH), besides it increased the enzymatic activities of gastric superoxide dismutase (SOD) and glutathione-S-transferase (GST). Likewise, AC did protect against the ulcerating effect of alcohol and mitigate most of the biochemical adverse effects induced by alcohol in gastric mucosa, but to a lesser extent than PLC. Neither PLC nor AC did affect catalase activity in gastric tissue. Based on these observations, one could conclude that carnitine esters, particularly PLC could partly protect gastric mucosa from alcohol-induced acute mucosal injury, and these gastroprotective effects might be probably induced, at least partly, through anti-oxidant mechanisms.

Immunomodulatory effects of L-carnitine and q10 in mouse spleen exposed to low-frequency high-intensity magnetic field.

In the current study, we have investigated the bioeffects of repeated exposure to low-frequency (50 Hz) high-intensity (20 mT; 200 G) electromagnetic field (EMF) on some immune parameters in mice. The animals were exposed to EMF daily for 30 min three times per week for 2 weeks. We also studied the possible immunomodulatory effects of two anti-radical substances known to have non-specific immunostimulant effects namely, L-carnitine (200 mg/kg body weight i.p.) and Q10 (200 mg/kg body weight, p.o.). Both drugs were given 1 h prior to each EMF exposure. Immune endpoints included total body weight, spleen/body weight ratio, splenocytes viability, total and differential white blood cell (WBCs; lymphocytes, monocytes, neutrophils) counts, as well as the lymphocyte proliferation induced by the mitogens; phytohaemagglutinin (PHA), concanavalin-A (Con-A) and lipoploysaccharide (LPS). Magnetic field decreased splenocyte viability, WBCs count, as well as mitogens-induced lymphocyte proliferation. L-carnitine, but not Q10 could ameliorate the adverse effects of EMF on the vast majority of the immune parameters tested, suggesting a possible immunoprotective role of L-carnitine under the current experimental conditions.

Memy I: a novel murine model for uterine leiomyoma using adenovirus-enhanced human fibroid explants in severe combined immune deficiency mice

OBJECTIVE This study was undertaken to develop a representative murine model for human leiomyoma. STUDY DESIGN Human fibroid tumor tissues were cut into small pieces and treated with medium alone, adenoviral-beta-galactosidase, adenoviral-vascular endothelial growth factor-A, adenoviral-cyclooxygenase-2, or both adenoviral-vascular endothelial growth factor-A and adenoviral- cyclooxygenase-2. Tissue pieces were inserted subcutaneously in the flank of each severe combined immunodeficient mouse. The developed lesion was measured twice per week. Xenograft tissues were harvested after 30 days and analyzed. RESULTS Tissue pieces transfected with both adenoviral-cyclooxygenase-2 and adenoviral-vascular endothelial growth factor-A continued to grow up to 30 days postimplantation. The number of proliferating and apoptotic cells, as well as the expression of smooth muscle actin, desmin, vimentin, estrogen receptors, and progesterone receptors was similar between retrieved grafts from that group and the original patient tissue. Furthermore, hematoxylin and eosin and Massons Trichrome stains confirmed this similarity. CONCLUSION Human uterine leiomyoma xenografts, pretreated with both adenoviral- cyclooxygenase-2 and adenoviral-vascular endothelial growth factor-A and implanted subcutaneously in severe combined immunodeficient mice, represent a novel model for human uterine leiomyoma.

Uroprotective Effects of Curcumin in Cyclophosphamide-Induced Haemorrhagic Cystitis Paradigm

The possible uroprotective effects of curcumin have been addressed in the current study. Haemorrhagic cystitis was induced by challenging male Swiss albino rats with a single dose of cyclophosphamide (150 mg/kg, i.p.). Curcumin (200 mg/kg, i.p.) was administered for 10 consecutive days followed by a single dose of cyclophosphamide. Haemorrhagic cystitis was well characterized morphologically and biochemically. The hallmark of this toxicity was marked congestion, oedema and extravasation in rat urinary bladder, as well as a marked desquamative damage to the urothelium and severe inflammation in the lamina propria. Leucocytic infiltration was also observed and determined by histopathological examination. Serum level of tumour necrosis factor-alpha was notably elevated associated with apparent hypokalaemia and hyponatraemia. Bladder contents of adenosine triphosphate, reduced glutathione and glutathione-S-transferase activity were markedly reduced. Malondialdehyde level, myeloperoxidase activity and urinary nitrite-nitrate levels, expressed as nitric oxide, were dramatically increased. Prior administration of curcumin ahead of cyclophosphamide challenge improved all the biochemical and histologic alterations induced by the cytotoxic drug. Based on these broad findings, it could be concluded that curcumin has proven uroprotective efficacy in this cyclophosphamide haemorrhagic cystitis model, possibly through modulating the release of inflammatory endocoids, namely tumour necrosis factor-alpha and nitric oxide, improving the energy status and restoring the oxidant/antioxidant balance.

Carnitine deficiency aggravates carboplatin nephropathy through deterioration of energy status, oxidant/anti-oxidant balance, and inflammatory endocoids

We have recently shown that carnitine deficiency could represent a risk factor in paracetamol hepatotoxicity. By the same token, d-carnitine-induced carnitine deficiency aggravated carboplatin nephropathy following challenge with a single dose (35mg/kg, IP) of the platinum drug in male Swiss albino rats. The combination modality induced marked degenerative changes and severe inflammation in kidney tissues that surpassed either carboplatin or d-carnitine given alone. The combined regimen synergistically increased the serum levels of creatinine, blood urea nitrogen (BUN), tumor necrosis factor alpha (TNF-alpha), palmitate, and kidney malondialdehyde (MDA), adenosine triphosphate (ATP), nitric oxide (NO) contents as well as kidney myeloperoxidase (MPO) activity. The only parameter that has been notably decreased was the kidney reduced glutathione (GSH) level. Exaggeration by carnitine deficit of the deleterious effects of carboplatin is most probably ascribed to energy starvation. The reduction in kidney content of ATP parcels was associated with elevation of serum palmitate level that reflected debilitated fatty acid oxidation, and this further deteriorated energy resources in kidney tissues. Compromising the oxidant/anti-oxidant balance and modulating the release of some inflammatory endocoids namely, TNF-alpha and NO could also possibly account for such combinatorial detrimental toxicity. The current study was further extended to elucidate any possible nephroprotective effects of l-carnitine. Interestingly, carnitine supplementation ahead of carboplatin challenge ameliorated and almost normalized all the biochemical parameters and also mitigated the injurious effects of the cytotoxic drug. Thus, one could conclude that carnitine deficiency, whether being a causative clue or a sequela, might represent a risk factor in carboplatin nephropathy.

Towards Fibroid Gene Therapy: Adenovirus-Mediated Delivery of Herpes Simplex Virus 1 Thymidine Kinase Gene/Ganciclovir Shrinks Uterine Leiomyoma in the Eker Rat Model

Background/Aims: The objective of this study was to assess in vivo gene therapy of uterine leiomyomas in the Eker rat model using adenovirus (Ad)-mediated delivery of herpes simplex virus 1 thymidine kinase gene (HSV1TK) followed by ganciclovir (GCV) treatment. Methods: We randomized 27 female Eker rats with MRI-confirmed uterine leiomyomas to a single treatment with direct intra-tumor injection of Ad-HSV1TK/GCV, Ad-LacZ/GCV, or medium alone. Samples were collected from tumors, other body organs, and blood at 10, 20, and 30 days after treatment to assess the safety and efficacy of the treatment. Results: Ad-HSV1TK/GCV treatment significantly decreased uterine fibroid volume by 75 ± 16, 58.7 ± 6.3, and 67.5 ± 27.5%, of the pretreatment volume at days 10, 20, and 30, respectively. Ad-HSV1TK/GCV increased caspase-3 activity, Bax expression, and TUNEL apoptosis marker, and it decreased cyclin D1, PCNA, Bcl2, and PARP protein expressions. Ad transfection induced local CD4+ and CD8+ infiltration and serum anti-Ad antibodies. Additionally, Ad transfection was tumor-localized and safe to non-target tissues. Conclusion: These studies demonstrate a marked efficiency and high safety for the Ad-HSV1TK/GCV therapeutic approach in the context of Eker rat uterine leiomyomas and provide essential preclinical data for the development of Ad-HSV1TK/GCV gene therapy for uterine fibroids.

Acetyl-L-Carnitine Ameliorates Caerulein-induced Acute Pancreatitis in Rats

In the present study, we have addressed the possible protective role of acetyl-L-carnitine in caerulein-induced acute pancreatitis in male Swiss albino rats. Acute pancreatitis paradigm was developed by challenging animals with a supramaximal dose of caerulein (20 microg/kg, SC) four times at hourly intervals. Caerulein induced acute pancreatitis that was well-characterized morphologically and biochemically. Severe oedema with marked increased relative pancreatic weight, marked atrophy of acini with increased interacinar spaces, vacuolization, and extensive leucocytic infiltration were diagnostic fingerprints of the pancreatitis phenotype. A biochemical test battery that confirmed the model comprised increased plasma amylase and lipase activities, calcium levels as well as increased pancreatic enzymatic myeloperoxidase and glutathione-S-transferase activities, beside increased pancreatic contents of nitric oxide and malondialdehyde and reduced pancreatic glutathione level. Prior administration of acetyl-L-carnitine (200 mg/kg, IP) for seven consecutive days ahead of caerulein challenge alleviated all the histological and biochemical manifestations of acute pancreatitis. These results suggest a possible protective role of the carnitine ester in such a murine acute pancreatitis model probably via regulation of the oxidant/antioxidant balance, beside modulation of the myeloperoxidase and nitric oxide systems, which are involved in the inflammatory cascade that most often associate the disease.

Possible contribution of β-glucosidase and caspases in the cytotoxicity of glufosfamide in colon cancer cells

Glycoconjugates represent a recent trend in cancer chemotherapy that adopts the concept of selective prodrug/drug targeting of tumor cells by binding to specific transmembrane glucose transporters. Following preferential uptake of sugar conjugates into cancer cells, they are presumably subject to enzymatic cleavage by specific beta-glycosidases to liberate the free active cytotoxic aglycones that act selectively on cancer cells and spare other noncancerous ones. In this sense, the role of beta-glucosidase and caspases in the bioactivation and cytotoxicity of glufosfamide has been addressed in the current study. The cytotoxicity of glufosfamide has been investigated over 24-96 h in a panel of human colon cancer cells namely, Caco-2, HT29 and T84 using a tetrazole dye; 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; MTT assay technique. Apoptosis was assessed by fluorometric assay of caspase-3 and caspase-9 activities. Enzymatic cleavage of glufosfamide was accomplished using a host of hydrolytic enzymes and cleavage kinetics was determined using HPLC. Glufosfamide has proven cytotoxic efficacy in a concentration- and time-dependent manner. The sensitivity rank order of tumor cells towards the glycoconjugate was Caco-2>HT29>T84. This sensitivity ranking was well correlated with the enzymatic activity of beta-glucosidase assessed in these cell lines. Initiation and activation of apoptosis were increased in all colon cancer cells following exposure to glufosfamide and were well correlated with the cytotoxicity rank order of the glycoconjugate. Glufosfamide was cleaved by cytosolic and lysosomal beta-glucosidases but not by other hydrolytic enzymes such as cytosolic beta-galactosidase, pancreatic lipase or hepatic esterase. In conclusion, the current data could possibly unravel the mechanistic role of beta-glucosidase and apoptotic caspases in the bioactivation and cytotoxicity of glufosfamide within colon cancer cells.