Samy Mohamed

Nonalcoholic fatty liver disease (NAFLD) is a metabolic-related disorder ranging from steatosis to steatohepatitis, which may progress to cirrhosis and hepatocellular carcinoma (HCC). This study aimed at assessing the regulatory and protective role of miR-26a on lipid metabolism and progression of NAFLD in human HepG2 cells loaded with free fatty acids (FFA). Lentivirus expressing miR-26a or negative control miR was used to transduce HepG2 cells and to establish stable cell lines. Gain or loss of function using an miR-26a inhibitor was used to compare triglyceride content (TG), total cholesterol level (CL), total antioxidant capacity (TAC), malondialdehyde (MDA) and the level of apoptosis. In addition, quantitative reverse transcription polymerase chain reaction (qPCR) was used to assess the mRNA levels of lipogenesis, TG synthesis, storage genes, inflammatory and fibrogenic markers, and autophagic besides endoplasmic reticulum (ER) stress markers after gaining or losing the function of miR-26a. miR-26a levels decreased in response to FFA in human HepG2 cells. After the establishment of a stable cell line, the upregulation of miR-26a resulted in the downregulation of TG, CL, and MDA levels, through regulating mRNA levels of genes involved in lipid homeostasis, ER stress marker, inflammatory and fibrogenic markers. Nevertheless, there was a marked increment in the mRNA expression of autophagic marker genes. Moreover, miR-26a overexpression protects the cells from apoptosis, whereas inhibition of miR-26a, using an anti-miR-26a oligonucleotide, decreased the expression of miR-26a which potentially contributes to altered lipid metabolism in HepG2 cells loaded with FFA. In conclusion, these findings suggested that miR-26a has a crucial role in regulating fatty acid and cholesterol homeostasis in HepG2 cells, along with the offered protection against the progression of NAFLD in vitro. Hence, miRNAs could receive growing attention as useful noninvasive diagnostic markers to follow the progression of NAFLD and to identify novel therapeutic targets.

Despite tamoxifen (TAM) is beneficial in treating a significant proportion of patients with breast cancer, many women still relapse after long-term therapy. Caffeic acid phenethyl ester (CAPE) is a component of honeybee propolis, with a plethora of important biological actions including anticancer activity. This study aimed to explore the cytotoxicity, the type of drugs interaction as well as the apoptotic and autophagic pathways of the combined treatment of TAM and CAPE in MCF-7 cells. Their antitumor activity and effect on survival of mice bearing Ehrlich tumor were also analyzed. The results showed synergistic cytotoxic effects, manifested by significant activation of apoptotic machinery, along with downregulation of protein levels of Bcl-2 and beclin-1, upon using the combination regimen. However, the ratio between microtubule-associated protein light chain 3-II and -I was not altered. Moreover, a decrease in vascular endothelial growth factor level was detected. Similarly, TAM + CAPE increased the life span of tumor-bearing animals and caused a marked regression in their tumor size and weight compared with those treated with either TAM or CAPE alone. In conclusion, CAPE relatively improved the anticancer activity of TAM in both in vitro and in vivo models via its apoptotic and angiostatic potentials.

Although Tamoxifen (TAM) is one of the most widely used drugs in managing breast cancer, many women still relapse after long-term therapy. Caffeic acid phenethyl ester (CAPE) is a polyphenolic compound present in many medicinal plants and in propolis. The present study examined the effect of CAPE on TAM cytotoxicity in MCF-7 cells. MCF-7 cells were treated with different concentrations of TAM and/or CAPE for 48 h. This novel combination exerted synergistic cytotoxic effects against MCF-7 cells via induction of apoptotic machinery with activation of caspases and DNA fragmentation, along with downregulation of Bcl-2 and Beclin 1 expression levels. However, the mammalian microtubule-associated protein light chain LC 3-II level was unchanged. Vascular endothelial growth factor level was also decreased, whereas levels of glutathione and nitric oxide were increased. In conclusion, CAPE augmented TAM cytotoxicity via multiple mechanisms, providing a novel therapeutic approach for breast cancer treatment that can overcome resistance and lower toxicity. This effect provides a rationale for further investigation of this combination.

This study investigates the efficacy of idebenone, carnosine and vitamin E in ameliorating some of the biochemical indices induced in the liver of titanium dioxide nanoparticles (TiO2 NPs) intoxicated mice. Nano-anatase TiO2 (21 nm) was administered (150 mg/kg/day) for 2 weeks followed by the aforementioned antioxidants either alone or in combination for 1 month. TiO2 NPs significantly increased serum liver function enzyme activities, liver coefficient and malondialdehyde levels in hepatic tissue. They also suppressed hepatic glutathione level and triggered an inflammatory response via the activation of macrophages and the enhancement of tumor necrosis factor-α and interleukin-6 levels. Moreover, the mRNA expression of nuclear factor-erythroid-2-related factor 2, nuclear factor kappa B and Bax was up-regulated whereas that of Bcl-2 was down-regulated following TiO2 NPs. Additionally, these NPs effectively activated caspase-3 and caused liver DNA damage. Oral administration of idebenone (200mg/kg), carnosine (200mg/kg) and vitamin E (100mg/kg) alleviated the hazards of TiO2 NPs with the combination regimen showing a relatively higher effect. The histopathological examination reinforced these findings. In conclusion, oxidative stress could be regarded as a key player in TiO2 NPs-induced liver injury. The study also highlights the anti-inflammatory and the anti-apoptotic potentials of these antioxidants against the detrimental effects of TiO2 NPs.

BACKGROUND/AIM: The present study investigated the in vitro and in vivo effects of individual and combined doses of idebenone, carnosine and vitamin E on ameliorating some of the biochemical indices of nano-sized titanium dioxide (n-TiO2) in mice liver.

METHODS: The in vitro cytotoxic effect of nano-sized anatase TiO2 (21 nm) on hepatic cell lines (HepG 2) was investigated. Additionally, n-TiO2 was orally administered (150 mg/kg/day) for 2 weeks, followed by a daily intragastric gavage of the aforementioned antioxidants for 1 month.

RESULTS: n-TiO2 induced significant cytotoxicity in hepatic cell lines and elevated the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic total antioxidant capacity (TAC) and nitrite/nitrate (NOx) levels. Meanwhile, glutathione-S-transferase (GST) activity was significantly reduced. Moreover, RT-PCR and western blot analysis showed that n-TiO2 significantly altered the mRNA and protein expressions of transforming growth factor-beta (TGF-β1) and Smad-2, as well as vascular endothelium growth factor (VEGF). Histopathological examination of hepatic tissue reinforced these results.

CONCLUSION: Idebenone, carnosine and vitamin E ameliorated the deviated parameters with the combination regimen demonstrating the most pronounced effect. Oxidative stress, liver fibrosis and angiogenesis may be implicated in n-TiO2-induced liver toxicity.

The objective of this study was undertaken to evaluate the protective effect
of Ginger extract either alone or in combination with Rosiglitazone and
Glimepiride on serum Glucose, Triglycerides, Cholesterol ,AST, ALT, γ-GT,
as well as liver Malondialdehyde, Catalase (CAT), Superoxide Dismutase
(SOD), reduced Glutathione (GSH) and lysosomal enzymes ;Acid
phospahtase (ACP), β-D-galactosidase (β-GAL) and N-acetyl-β-Dglucosaminidase

(β-NAG), in streptozotocin-induced diabetic rats. The
animals were divided into seven groups: control normal animals (CN),
control untreated diabetic animals (CD) in which experimental
hyperglycemia were induced by single intraperitoneal injection of
streptozotocin (40mg/kg body mass). The other 5 diabetic groups were
treated orally for 30 days with Rosiglitazone (D/Rosi) (0.8 mg/kg b.w),
Glimepiride (D/Glim) (0.8 mg/kg of b.w), Ginger extract (D/G)(500 mg/kg
of body mass), combination of Glimepiride and Ginger extract (D/Glim+G)
and combination of Rosiglitazone and Ginger (D/Rosi+G) starting 24 hours
after streptozotocin injection. The antioxidant effect of the Ginger extract
was compared with Rosiglitazone and Glimepiride, well-known
hypoglycaemic drugs. The diabetic rats exhibited lowered hepatic GSH
content and CAT, SOD activities associated with elevated levels of hepatic
MDA, liver functions enzymes and lysosomal enzymes as compared with
normal rats. In contrast ginger treatment exerts a therapeutic protective effect
in diabetes by decreasing oxidative stress, liver functions enzymes,
lysosomal enzymes and hepatic damage. Ginger extracts showed an
encouraging hypoglycemic, hypolipaemic, as well as antioxidant properties

and could be considered as a valuable candidate in the reversal of the
complication of diabetes.