Mohamed A. Morsy

Fucoidan ameliorates steatohepatitis and insulin resistance by suppressing oxidative stress and inflammatory cytokines in experimental non-alcoholic fatty liver disease.

Fucoidan, a sulfated polysaccharide derived from brown seaweeds, possesses a wide range of pharmacological properties. In the present study, we investigated the therapeutic effect of fucoidan on non-alcoholic fatty liver disease (NAFLD) in rats. Rats were fed a high-fat diet (HFD) for 12 weeks to induce NAFLD. Oral administrations of fucoidan (100mg/kg, orally), metformin (200mg/kg, orally) or the vehicle were started in the last four weeks. Results showed that administration of fucoidan for 4 weeks attenuated the development of NAFLD as evidenced by the significant decrease in liver index, serum liver enzymes activities, serum total cholesterol and triglycerides, fasting serum glucose, insulin, insulin resistance, and body composition index. Further, fucoidan decreased hepatic malondialdehyde as well as nitric oxide concentrations, and concomitantly increased hepatic reduced glutathione level. In addition, the effect of fucoidan was accompanied with significant decrease in hepatic mRNA expressions of tumor necrosis factor-α, interleukins-1β and matrix metalloproteinase-2. Furthermore, histopathological examination confirmed the effect of fucoidan. In conclusion, fucoidan ameliorated the development of HFD-induced NAFLD in rats that may be, at least partly, related to its hypolipidemic, insulin sensitizing, antioxidant and anti-inflammatory mechanisms.

Protective effects of captopril in diabetic rats exposed to ischemia/reperfusion renal injury

To investigate the potential protective effects of captopril, the angiotensin‐converting enzyme inhibitor, in diabetic rats exposed to ischaemia/reperfusion (I/R) renal injury.

Protective mechanisms of thymoquinone on methotrexate-induced intestinal toxicity in rats

Background: Intestinal toxicity is a serious side effect in methotrexate (MTX) chemotherapy. Objective: To investigate the mechanisms by which the anticancer drug MTX-induced intestinal damage could be prevented by thymoquinone (TQ), an active ingredient of Nigella sativa. Materials and Methods: TQ was given orally for 10 days, and MTX toxicity was induced at the end of day 3 of the experiment, with or without TQ pretreatment. Results: MTX caused intestinal damage, represented by distortion in normal intestinal histological structure, with significant oxidative stress, exhibited as decrease in reduced glutathione concentration and catalase activity, along with significant increase in malondialdehyde level compared to control group. MTX also caused nitrosative stress evident by increased intestinal nitric oxide (NO) level, with up-regulation of inducible NO synthase expression shown in immunohistochemical staining. Furthermore, MTX caused inflammatory effects as evident by up-regulation of intestinal necrosis factor-kappa beta and cyclooxygenase-2 expressions, which were confirmed by increased intestinal tumor necrosis factor-alpha level via enzyme-linked immunosorbent assay. Moreover, MTX caused apoptotic effect, as it up-regulated intestinal caspase 3 expression. Concomitant TQ significantly reversed the MTX-induced intestinal toxic effects by reversing intestinal microscopic damage, as well as significantly improving oxidative/nitrosative stress, inflammatory and apoptotic markers tested compared to MTX alone. Conclusion: TQ may possess beneficial intestinal protective effects as an adjuvant co-drug against MTX intestinal toxicity during cancer chemotherapy. TQ protection is conferred via antioxidant, anti-nitrosative, anti-inflammatory, and anti-apoptotic mechanisms.

Nebivolol Ameliorates Cisplatin‐Induced Nephrotoxicity in Rats

Treatment with cisplatin is associated with dose‐limiting side effects, mainly nephrotoxicity. On the other hand, nebivolol, a β1‐adrenoceptor antagonist, exhibits vasodilatory and antioxidative properties. This study aimed to determine whether nebivolol possesses a protective effect against cisplatin nephrotoxicity and explore many mechanisms underlying this potential effect. Nephrotoxicity was induced in Wistar rats by a single intraperitoneal injection of cisplatin (6 mg/kg) on day 2. Nebivolol (10 mg/kg) was administered orally for 7 consecutive days. Nebivolol showed a nephroprotective effect as demonstrated by the significant reduction in the elevated levels of serum creatinine and urea as well as renal levels of malondialdehyde, nitric oxide products (nitrite/nitrate), inducible nitric oxide synthase, tumour necrosis factor‐alpha, caspase‐3, angiotensin II and endothelin‐1 with a concurrent increase in renal levels of reduced glutathione and endothelial nitric oxide synthase compared to untreated rats. Histopathological examination confirmed the nephroprotective effect of nebivolol. Pre‐treatment with Nω‐nitro‐L‐arginine methyl ester, the non‐specific nitric oxide synthase inhibitor, partially altered the protection afforded by nebivolol. In conclusion, nebivolol protects rats against cisplatin‐induced nephrotoxicity that is most likely through its antioxidant, anti‐inflammatory and antiapoptotic effects as well as by abrogation of the augmented angiotensin II and endothelin‐1 levels.

Multi-drug resistance protein (Mrp) 3 may be involved in resveratrol protection against methotrexate-induced testicular damage

AIMSnTo investigate the effect of resveratrol (RES) on methotrexate (MTX)-induced testicular damage.nnnMAIN METHODSnRES (10mg/kg/day) was given for 8 days orally and MTX (20mg/kg i.p.) was given at day 4 of the experiment, with or without RES in rat.nnnKEY FINDINGSnMTX decreased serum testosterone, induced histopathological testicular damage, and increased testicular tumor necrosis factor-α level and expression of nuclear factor-κB and cyclooxygenase-2. In MTX/RES group, significant reversal of these parameters was noticed, compared to MTX group. Testicular expression of multidrug resistance protein (Mrp) 3 was three- and five-folds higher in RES- and MTX/RES-treated groups, respectively. In vitro, using prostate cancer cells, each of MTX and RES alone induced cytotoxicity with IC50 0.18 ± 0.08 and 20.5 ± 3.6 μM, respectively. RES also significantly enhanced cytotoxicity of MTX.nnnSIGNIFICANCEnThus, RES has dual beneficial effects, as it promotes MTX tumor cytotoxicity, while protecting the testes, probably via up-regulation of testicular Mrp3 as a novel mechanism.

Protective mechanisms of resveratrol against methotrexate‐induced renal damage may involve BCRP/ABCG2

Resveratrol (RES) is a well‐known polyphenol antioxidant. We have previously shown that testicular protective effect of RES against the anticancer drug methotrexate (MTX)‐induced toxicity involves transporter‐mediated mechanisms. Here, we investigated the effect of RES on MTX‐induced nephrotoxicity. Rats were administered RES (10 mg/kg/day) for 8 days, with or without a single MTX dose (20 mg/kg i.p.) at day 4 of the experiment. MTX induced nephrotoxicity, as evidenced by a significant increase in serum blood urea nitrogen and creatinine compared to the control, as well as distortion of kidney microscopic structure. MTX also significantly increased renal nitric oxide level along with inducible nitric oxide synthase, fas ligand, and caspase 3 expressions. Administering RES prior to MTX significantly improved kidney function and microscopic picture and also significantly decreased nitrosative and apoptotic markers compared to MTX alone. RES, but not MTX, caused a significant increase in expression of breast cancer resistance protein (BCRP), an apical efflux renal transporter that participates in urinary elimination of both MTX and RES. Interestingly, concomitant MTX and RES caused further upregulation of renal BCRP compared to RES alone. Using Human BCRP ATPase assay, both RES and MTX exhibited a dose‐dependent increase in ATPase activity, with Km values of 0.52 ± 0.03 and 30.9 ± 4.2 μm, respectively. Furthermore, combined RES and MTX caused ATPase activity which was significantly less than maximum ATPase activity attained by the positive control, sulfasalazine (12.5 μm). In conclusion, RES exerted nephroprotection against MTX‐induced toxicity through antinitrosative and anti‐apoptotic effects, as well as via upregulation of renal BCRP.

Inhibition of NF-κB/TNF-α pathway may be involved in the protective effect of resveratrol against cyclophosphamide-induced multi-organ toxicity

Abstract Context: Cyclophosphamide (CyP), an efficient anticancer drug, may damage normal human cells. Resveratrol (RES), a natural polyphenol, has a diverse pharmacological properties. Objective: To test possible protective effect of RES on multi-organ damage caused by CyP. Materials and methods: RES (10u2009mg/kg/day) was administered orally for 8u2009days. In independent rat groups, CyP toxicity was induced via a single dose of 150u2009mg/kg i.p. 3u2009days before the end of experiment, with or without RES treatment. Results: Compared to control, CyP caused significant increase in organ-to-body weight ratios of heart, kidney and liver, with deterioration in their functional parameters; namely serum creatine kinase, blood urea nitrogen, creatinine, alanine aminotransferase and aspartate aminotransferase. CyP also caused distortion in these organs histology, with significant tissue oxidative stress, manifested by decrease in reduced glutathione and catalase, as well as increase in malondialdehyde and nitric oxide levels. Furthermore, CyP caused multi-organ inflammatory effects as shown by increased tumor necrosis factor-α levels, as well as up-regulation of nuclear factor-κB expressions. Using RES concurrently with CyP restored heart, kidney and liver functional parameters, as well as their normal histology. RES also reversed oxidative stress, as well as inflammatory signs caused by CyP alone. Conclusions: RES may be beneficial adjuvant that confers multi-organ protection against CyP toxicity via antioxidant and anti-inflammatory mechanisms.

The effect of adjuvant therapy with TNF-α on animal model of triple-negative breast cancer

AIMnThis study tested the effect of TNF-α, a cytokine associated with inflammation, and tumor progression, on enhancing doxorubicin (Dox) tumor accumulation, and improving its therapeutic effect.nnnMATERIALS & METHODSn4T1 murine breast cancer cells were injected into the flanks of Balb/c female mice and treated with TNF-α, Dox and a combination of both.nnnRESULTS & CONCLUSIONnThe addition of TNF-α to Dox did not improve anticancer activity against 4T1 breast cancer cells in vitro. In 4T1 tumor-bearing mice, the pretreatment with TNF-α increased tumor Dox concentration. The accumulation of Dox was even higher when systemically injected with a micellar formulation of Dox. This work provides a rationale for testing the combination on breast cancer patients.

In silico comparisons between natural inhibitors of ABCB1/P-glycoprotein to overcome doxorubicin-resistance in the NCI/ADR-RES cell line

ABSTRACT To investigate compound‐protein binding mode and molecular dynamic simulation of P‐glycoprotein (P‐gp), in silico studies were performed to compare 12 naturally occurring compounds using two softwares. The net results showed that piperine (PIP) had the best binding affinity. In vitro studies on doxorubicin (DOX)‐resistant NCI/ADR‐RES cells, known to express P‐gp, showed that, dose‐dependently, PIP significantly increased intracellular accumulation of rhodamine‐123 and had cytotoxic effects accessed by MTT assay. In addition, PIP at 25 and 50 &mgr;M significantly potentiated DOX‐induced cytotoxicity on the same cell line. P‐gp ATPase assay showed that both DOX and PIP had dose‐dependent inhibition of orthovandate‐sensitive ATPase activity, indicating they are both P‐gp inhibitors, with IC50 of 84 ± 1 and 37 ± 2 &mgr;M, respectively. PIP did not show any activation of ATPase activity, while DOX did, indicating that P‐gp does not accept PIP as a substrate. Using DOX at concentration 33.33 &mgr;M together with PIP (100 &mgr;M), DOX‐mediated P‐gp ATPase activity was decreased to levels 4‐folds lower than DOX alone. In conclusion, both in silico and in vitro studies confirm that PIP is an inhibitor of P‐gp mediated DOX efflux, suggesting PIP as a promising adjuvant to DOX cancer chemotherapy. Graphical abstract Figure. No Caption available.

Synthesis and Structural Elucidation of Novel Benzothiazole Derivatives as Anti-tubercular Agents: In-silico Screening for Possible Target Identification

BACKGROUNDnBenzothiazole derivatives are known for anti-TB properties. Based on the known anti-TB benzothiazole pharmacophore, in the present study, we described the synthesis, structural elucidation, and anti-tubercular screening of a series of novel benzothiazole (BNTZ) derivatives (BNTZ 1-7 and BNTZ 8-13).nnnOBJECTIVEnThe study aims to carry out the development of benzothiazole based anti-TB compounds.nnnMETHODSnTitle compounds are synthesized by microwave method and purified by column chromatography. Characterization of the compounds is achieved by FT-IR, NMR (1H and 13C), LCMS and elemental analysis. Screening of test compounds for anti-TB activity is achieved by Resazurin Microplate Assay (REMA) Plate method.nnnRESULTSnIt was noted that the BNTZ compound with an isoquinoline nucleus (BNTZ 9) exhibited remarkable anti-tubercular activity at 8 µg/mL against both the susceptible strain H37Rv and the multi-drug resistant tuberculosis strains of Mycobacterium tuberculosis. On the other hand, the BNTZ compound with a naphthalene nucleus (BNTZ 2) revealed anti-tubercular activity at 6 µg/mL and 11 µg/mL against both the susceptible strain H37Rv and the multi-drug resistant tuberculosis strains of M. tuberculosis, respectively. One of the selected BNTZ derivatives BNTZ 13 was used for single crystal X-ray studies.nnnCONCLUSIONnTo identify the appropriate target for potent BNTZ compounds from the series, molecular modeling studies revealed the multiple strong binding of several BNTZs with mycobacterium lysine-ɛ-aminotransferase and decaprenyl-phosphoryl-β-D-ribose 2-oxidase. The interaction is derived by forming favorable hydrogen bonds and stacking interactions. This new class of BNTZ compounds gave promising anti-tubercular actions in the low micromolar range, and can be further optimized on a structural basis to develop promising, novel, BNTZ pharmacophore-based anti-tubercular drugs.