Biochemical study of the effect of mesenchymal stem cells-derived exosome versus L-Dopa in experimentally induced Parkinson's disease in rats

Parkinson's disease (PD) is a chronic and ongoing neurological condition. Unfortunately, as the dopaminergic terminals continue to deteriorate, the effectiveness of anti-Parkinson therapy decreases. This study aimed to examine the effects of BM-MSCs-derived exosomes in rats induced with Parkinson's disease. The goal was to determine their potential for neurogenic repair and functional restoration. Forty male albino rats were divided into four groups: control (group I), PD (group II), PD-L-Dopa (group III), and PD-exosome (group IV). Motor tests, histopathological examinations, and immunohistochemistry for tyrosine hydroxylase were performed on brain tissue. The levels of α-synuclein, DJ-1, PARKIN, circRNA.2837, and microRNA-34b were measured in brain homogenates. Rotenone induced motor deficits and neuronal alterations. Groups (III) and (IV) showed improvement in motor function, histopathology, α-synuclein, PARKIN, and DJ-1 compared to group (II). Group (IV) showed improvement in microRNA-34b and circRNA.2837 compared to groups (III) and (II). MSC-derived exosomes showed a greater suppression of neurodegenerative disease (ND) compared to L-Dopa in Parkinson's patients.

Soya bean rich diet is associated with adult male rat aggressive behavior: relation to RF amide-related peptide 3-aromatase-neuroestrogen pathway in the brain

Relation between soya bean (SB) consumption and aggressive behavior has not been elucidated yet. Thus, this study was conducted to investigate the effect of large amount of SB consumption on adult male rats' aggressive behavior through investigating changes in the expression of gonadotropin-inhibitory hormone/ RF amide-related peptide 3 (GnIH/RFRP3), neuropeptide FF receptor, cytochrome P450, family 19, subfamily A, polypeptide 1 (Cyp19A1), estrogen receptors α and β and the levels of neuroestrogen, dopamine, glutamate and testosterone as well as aromatase activity in the brain. Adult male rats were divided into three equal groups: group I, control group, received standard diet; group II and group III received 25% and 50% SB of their standard diet contents, respectively, for 12 weeks. The obtained results showed that feeding male rats with large amount of SB could induce aggressive behavior in a dose dependant manner possibly through inhibition of brain GnIH/RFRP-aromatase-neuroestrogen pathway. These effects may be through decreasing aromatase activity, neuroestrogen concentration, Cyp19A1 and ER β mRNA levels and increasing ER α mRNA levels and immunostaining as well as testosterone, dopamine and glutamate levels in the brain. These findings also provide further support for the inhibitory role of RFRP3 on aggressive behavior of male rats. These data may open new avenues for the potential harmful effects of consumption large amounts of SB rich food on humans.

Melatonin maximizes the therapeutic potential of non-preconditioned MSCs in a DEN-induced rat model of HCC

Pretreatment of mesenchymal stem cells (MSCs) with melatonin (Mel) improves their potential therapeutic effect on chronic diseases and cancers. However, this preconditioning strategy may direct the effect of Mel toward MSCs alone and deprive cancer cells of the oncostatic effect of Mel. Herein, we hypothesized that Mel given before transplantation of non-preconditioned MSCs may maximize the therapeutic outcome via the oncostatic effect of Mel by preparing a suitable tumor microenvironment for MSCs. Female rats (n = 60) were equally divided into 6 groups; normal control, diethylnitrosamine (DEN), DEN + Mel, DEN + MSCs, DEN + MSCs preconditioned with Mel, and DEN + MSCs + Mel. The obtained data revealed that administration of Mel before MSCs treatment without preconditioning yielded a better ameliorative effect against DEN-induced hepatocellular carcinoma (HCC) as evidenced by: 1) reduced serum levels of alpha fetoprotein and gamma-glutamyl transferase; 2) decreased number and area of glutathione S-transferase placental positive foci; 3) induced apoptosis (as indicated by increased cleaved caspase-3 activity, upregulated expression of proapoptotic genes Bax and caspase 3 and downregulated expression of anti-apoptotic genes Bcl2, survivin); 4) decreased malondialdehyde level and increased activities of superoxide dismutase, catalase, and glutathione peroxidase enzymes; and 5) reduced inflammation, angiogenesis and metastasis as indicated by downregulated expression of interleukin 1 beta, nuclear factor kappa B, vascular endothelial growth factor, and matrix metallopeptidase 9 genes and upregulated expression of metalloproteinase inhibitor 1 gene. Thus, administration of Mel before MSCs (without preconditioning) fostered the survival and therapeutic potential of MSCs in HCC, possibly through induction of apoptosis and inhibition of inflammation and oxidative stress. This new strategy showed better therapeutic outcomes and may improve MSC-based therapies for HCC.

Obestatin protects and reverses nonalcoholic fatty liver disease and its associated insulin resistance in rats via inhibition of food intake, enhancing hepatic adiponectin signaling, and blocking ghrelin acylation

This study investigated the ameliorative and protective effects of long-term obestatin administration (80 nmol/kg/ intraperitoneal injection (i.p.)) on the pathogenesis of high-fat diet (HFD) induced nonalcoholic fatty liver disease (NAFLD) in rats. Rats (n = 8/group) were divided as control, NAFLD, NAFLD + Simvastatin, NAFLD + obestatin, NAFLD then obestatin, and obestatin then NAFLD. Obestatin co -or post-therapy significantly reduced hepatomegaly and reversed hyperlipidemia, hepatic lipid accumulation, and insulin resistance (IR). Mechanistically obestatin treatments in these rats significantly prevented the increases in final body weights and food intake. Concomitantly, it enhanced circulatory adiponectin levels and hepatic signaling as evident by elevated hepatic protein levels of adiponectin receptors (adipoRII), carnitine palmitoyltransferase-1 (CPT-1), peroxisome proliferator-activated receptor- α (PPAR-α), and phosphor-AMPK (p-AMPK). In addition, obestatin enhanced total circulatory ghrelin levels and significantly increased deacylated ghrelin to acylated ghrelin (DAG/AG) ratio. These data suggest that obestatin reverses and protects against development or progression of NAFLD directly by modulating ghrelin and adiponectin signaling or indirectly by lowering food intake.

Rutin hydrate ameliorates cadmium chloride-induced spatial memory loss and neural apoptosis in rats by enhancing levels of acetylcholine, inhibiting JNK and ERK1/2 activation and activating mTOR signalling

This study aimed at studying the potential neuroprotective effect of Rutin hydrate (RH) alone or in conjugation with α-tocopherol against cadmium chloride (CdCl₂)-induced neurotoxicity and cognitive impairment in rats and to investigate the mechanisms of action. Rats intoxicated with CdCl₂ were treated with the vehicle, RH, α-tocopherol or combined treatment were examined, and compared to control rats received vehicle or individual doses of either drug. Data confirmed that RH improves spatial memory function by increasing acetylcholine availability, boosting endogenous antioxidant potential, activating cell survival and inhibiting apoptotic pathways, an effect that is more effective when RH was conjugated with α-tocopherol. Mechanism of RH action includes activation of PP2A mediated inhibiting of ERK1/2 and JNK apoptotic pathways and inhibition of PTEN mediated activation of mTOR survival pathway. In conclusion, RH affords a potent neuroprotection against CdCl₂-induced brain damage and memory dysfunction and co-administration of α-tocopherol enhances its activity.

Resveratrol improves high-fat diet induced fatty liver and insulin resistance by concomitantly inhibiting proteolytic cleavage of sterol regulatory element-binding proteins, free fatty acid oxidation, and intestinal triglyceride absorption

Resveratrol (RES) has the ability to ameliorate nonalcoholic fatty liver disease (NAFLD) and the mechanism remains unclear. Hence, using high-fat diet (HFD) obese rat model, we investigated the effect of a low dose of RES (20 mg/kg) on the hepatic sterol regulatory element-binding protein (SREBPs) – lipogenesis pathway, enzymes involved in β-oxidation and activity of pancreatic lipase. Four groups of rats (n = 8) of control (12% of calories as fat) and HFD (40% of calories as fat) were administered orally with either normal saline as a vehicle or RES as a concomitant treatment for 8 weeks on a daily basis. Then, various biochemical, histological, and molecular experiments were carried out. RES prevented the development and progression of NAFLD and significantly improved insulin sensitivity through (1) inhibiting the proteolytic cleavage of SREBPs-1 and SREBPs-2 without affecting their precursor mRNA or protein levels, (2) inhibiting free fatty acid β-oxidation and generation of reactive oxygen species through significant inhibition of CPT-1 and UCP-2, and (3) decreasing activity of pancreatic lipase in vivo and in vitro. In conclusion, our findings are the first in the literature to show new mechanisms of the hepatoprotective effect of RES against HFD induced NAFLD in rats.

Neuroprotective effect of resveratrol against brain ischemia reperfusion injury in rats entails reduction of DJ-1 protein expression and activation of PI3K/Akt/GSK3b survival pathway

In the current study, we aimed to investigate the mechanistic role of DJ-1/PI3K/Akt survival pathway in ischemia/reperfusion (I/R) induced cerebral damage and to investigate if the resveratrol (RES) mediates its ischemic neuroptotection through this pathway. RES administration to Sham rats boosted glutathione level and superoxide dismutase activity and downregulated inducible nitric oxide synthase expression without affecting redox levels of DJ-1 forms or components of PI3K/Akt pathway including PTEN, p-Akt or p/p-GSK3b. However, RES pre-administration to I/R rats reduced infarction area, oxidative stress, inflammation and apoptosis. Concomitantly, RES ameliorated the decreased levels of oxidized forms of DJ-1 and enhancing its reduction, increased the nuclear protein expression of Nfr-2 and led to activation of PI3K/Akt survival pathway. In conclusion, overoxidation of DJ-1 is a major factor that contributes to post-I/R cerebral damage and its reduction by RES could explain the neuroprotection offered by RES.

Experimental schistosomal hepatitis: protective effect of coenzyme-Q10 against the state of oxidative stress

Schistosoma mansoni (S. mansoni) eggs trapped in the host liver elicit a chain of oxidative processes that may be, at least in part, responsible for the pathology and progression of fibrosis associated with schistosomal hepatitis. This study was designed to assess the protective effect of the antioxidant coenzyme-Q10 (Co-Q10) against experimental S. mansoni-induced oxidative stress in the liver, and its potential role as an adjuvant to praziquantel (PZQ) therapy. The oxidative stress and overall liver function were improved under Co-Q10 therapy as evidenced by significant reduction in oxidative stress markers and preservation of antioxidant factors. Liver fibrosis was also reduced with a positive impact on liver function. Moreover, addition of Co-Q10 to PZQ therapy caused: significant reduction of liver egg load, significant improvement of the redox status, and lastly decreased liver fibrosis.