Implication of endoplasmic reticulum stress and mitochondrial perturbations in remote liver injury after renal ischemia/reperfusion in rats: potential protective role of azilsartan.

Objectives: Distant liver injury is a complication of renal ischemia-reperfusion (I/R) injury, which imposes mortality and economic burden. This study aimed to elucidate the cross-talk of endoplasmic reticulum (ER) stress and mitochondrial perturbations in renal I/R-induced liver injury, and the potential hepatoprotective effect of azilsartan (AZL).Methods: Male albino Wister rats were pre-treated with AZL (3 mg/kg/day, PO) for 7 days then a bilateral renal I/R or sham procedure was performed. Activities of liver enzymes were assessed in plasma. The structure and ultra-structure of hepatocytes were assessed by light and electron microscopy. Markers of ER stress, mitochondrial biogenesis and apoptosis were analyzed in livers of rats.Results: Renal ischemic rats showed higher plasma levels of liver enzymes than sham-operated rats, coupled with histological and ultra-structural alterations in hepatocytes. Mechanistically, there was up-regulation of ER stress markers and suppression of mitochondrial biogenesis-related proteins and enhanced apoptosis in livers of renal ischemic rats. These abnormalities were almost abrogated by AZL pretreatment.Discussion: Our findings uncovered the involvement of mitochondrial perturbations, ER stress and apoptosis in liver injury following renal I/R, and suggested AZL as a preconditioning strategy to ameliorate remote liver injury in patients susceptible to renal I/R after adequate clinical testing.

Impact of vitamin D in children with chronic tonsillitis (immunohistochemical study of CD68 polarisation and proinflammatory cytokines estimation).

Inflammatory processes are increasingly attributed to macrophage polarization. Proinflammatory macrophages promote T helper (Th) 1 response, tissue repair, and Th2 responses. Detection of macrophages in tissue sections is facilitated by CD68. Our study is focused on the expression of CD68 and the estimation of proinflammatory cytokines in children's patients with chronic tonsillitis secondary to vitamin D supplementation. This hospital-based Randomized prospective case-control study was conducted on 80 children with chronic tonsillitis associated with vitamin D deficiency where (40 received vitamin D 50,000 IU weekly for 3-6 months and 40 received 5 ml distilled water as placebo). The serum 25-hydroxyvitamin D [25(OH)D] was measured using an Enzyme-linked immunosorbent assay on all included children. Different histological and immunohistochemical studies for the detection of CD68 were done. There was a significantly lower serum level of 25(OH)D in the placebo group versus the vitamin D group (P < 0.001). The levels of pro-inflammatory cytokines, TNFα, and IL-2 significantly increased in the placebo group as compared to the vitamin D group (P < 0.001). The increased level of IL-4 and IL-10 in the placebo group as compared to the vitamin D group was insignificant (P = 0.32, 0.82) respectively. Vitamin D supplementation alleviated the deleterious effect of chronic tonsillitis on the histological structure of the tonsil. Tonsillar tissues of the children in the control and vitamin D groups demonstrated a highly statistically significantly lower number of CD68 immunoexpressing cells compared with those in the placebo group (P < 0.001). Low vitamin D may play a role in chronic tonsillitis. Vitamin D supplementation could help reduce the occurrence of chronic tonsillitis in susceptible children.

Salix babylonica L. mitigates pancreatic damage by regulating the Beclin-P62/SQSTM1 autophagy pathway in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Salix babylonica L. belongs to the genus Salix, family Salicaceae. It is traditionally used as an antipyretic, antirheumatic, antidiabetic and for the treatment of ulcers and parasite skin diseases. It also has a range of pharmacological effects, such as anti-inflammatory, anti-tumor, antioxidant, and antibacterial effects. However, there are no reports on the phytochemical profile and efficacy of its leaves extract to modulate dexamethasone induced pancreatic damage. AIM OF THE STUDY: The present study was performed to annotate the phytoconstituents of Salix babylonica leaf extract and explore whether and how it could modulate dexamethasone-induced pancreatic damage and the role of oxidative stress and autophagy in mediating its protective effects. MATERIALS AND METHODS: Wistar rats were used for this study. Salix babylonica in two dose levels (100 and 200 mg/kg) or metformin (50 mg/kg) was given by oral gavage concurrently with dexamethasone which was injected SC in a dose of 10 mg/kg for 4 consecutive days. RESULTS: LC-MS analysis furnished 84 secondary metabolites belonging to phenolic acids, salicinoids, proanthocyanidins, flavonoids, cyclohexanediol glycosides, and hydroxy fatty acids. S. babylonica at both dose levels and metformin decreased the elevated pancreatic beclin while elevated the decreased pancreatic P62/SQSTM1 content compared to dexamethasone. These effects were associated with improved histopathological changes, glycemic and lipid parameters indicating that there might be a connection between autophagy and dexamethasone-induced pancreatic damage. Given that the level of GSH was negatively correlated with the levels of beclin and positively correlated with P62/SQSTM1, while both MDA and NO levels were positively correlated with beclin and negatively correlated with P62/SQSTM1, it seems that dexamethasone induced autophagy may be attributed to dexamethasone induced pancreatic oxidative stress. CONCLUSION: Our results indicate that S. babylonica protects pancreatic tissues against dexamethasone-induced damage by decreasing oxidative stress and its associated autophagy. Our study reveals a new mechanism for dexamethasone effects on pancreas and shows the potential therapeutic role of S. babylonica in mitigating dexamethasone adverse effects on pancreas and establishes the groundwork for future clinical applications.

Coriander Oil Reverses Dexamethasone-Induced Insulin Resistance in Rats.

In the present study, we aimed to investigate the effect of coriander oil on dexamethasone-induced insulin resistance in rats and characterize its chemical composition using gas chromatography-mass spectrometry (GC-MS). Rats were divided into five groups (n = 6): Normal control, insulin resistance (IR) control, IR + metformin (50 mg/kg/day, PO, Per Oral), IR + coriander oil low dose (0.5 mL/kg, PO), and IR + coriander oil high dose (1 mL/kg, PO). IR groups were injected with a dose of 10 mg/kg dexamethasone subcutaneously for four consecutive days. All groups received either vehicle or drugs daily for four days. Animal weights and pancreatic weights were measured, and oral glucose tolerance test was performed at the end of study. Fasting glucose, triglycerides (TG), total cholesterol (TC), HDL and insulin levels in serum, MDA, and GSH levels in pancreatic tissue were measured and HOMA-IR was calculated. Immunoexpression of apoptosis markers BAX, and BCL2 was measured in pancreatic tissues and BAX/BCL2 ratio was calculated. Histopathological examination of pancreatic tissues was also performed. Pancreatic weight, serum HDL, pancreatic GSH, and BCL2 were decreased while serum glucose, insulin, TG, TC levels, AUC of OGGT, HOMA-IR, pancreatic MDA, BAX, and BAX/BCL2 ratio were increased in IR rats. Histopathological examination showed congestion, vacuolation and hemorrhage in pancreatic islets. These changes were reversed by metformin and the high dose of coriander oil treatments. The obtained activities could be attributed to the presence of 21 volatile compounds, identified by GC-MS. Our study indicates that coriander oil can be used as an adjuvant antihyperglycemic agent in type 2 diabetes. Further experiments are needed to determine the therapeutic dose and the treatment time.

Pentagalloyl Glucose, a Major Compound in Mango Seed Kernel, Exhibits Distinct Gastroprotective Effects in Indomethacin-Induced Gastropathy in Rats via Modulating the NO/eNOS/iNOS Signaling Pathway.

Gastric ulcers are a common health disorder that affect up to 10% of the world's population. The gastroprotective potential of pentagalloyl glucose (PGG) against indomethacin-induced ulcer in rats and the possible underlying mechanisms were investigated. Gastric ulceration was induced by indomethacin (single dose, 60 mg/kg). Pretreatment with PGG (100 or 200 mg/kg, orally) for 8 days prior to the administration of indomethacin furnished significant reductions in gastric mucosal lesions as well as a significant increase in mucus concentration. Also, PGG significantly declined the elevations in gastric mucosal MDA, TNF-α, IL-6, PECAM-1, VEGF, and iNOS expression. It also mitigated the decrease in GSH and GPx and eNOS expression observed with indomethacin. The protective effects furnished by PGG were comparable to that of famotidine. The obtained results suggested that the anti-ulcer effects of PGG are mediated by increasing mucus production, scavenging free radicals, decreasing inflammation, and attenuating the NO/NOS signaling in favor of eNOS. To sum up, PGG could provide a potential therapy for gastric ulcer after evaluating its efficacy and effectiveness.

Modulation of autophagy and transient receptor potential vanilloid 4 channels by montelukast in a rat model of hemorrhagic cystitis.

AIMS: Hemorrhagic cystitis (HC) is a major urotoxic complication of cyclophosphamide (CPA) therapy. This study investigated the uroprotective effect of montelukast on CPA-induced HC, compared to the efficacy of 2-mercaptoethane sulfonate sodium (MESNA). MAIN METHODS: Male albino rats were pretreated with MESNA (40 mg/kg/day, IP) or montelukast (10 mg/kg/day, orally) for three days then received a single dose of CPA (200 mg/kg, IP), 1 h after the last dose, and compared to CPA-treated rats receiving drug vehicle. Age-matched rats were used as controls. Bladders of rats were assessed biochemically, macroscopically and microscopically by light and electron microscope 24 h later. KEY FINDINGS: CPA injection contributed to increased bladder weight, urothelial ulceration, vascular congestion, hemorrhage, increased collagen deposition and mast cell infiltration, compared to control rats. Montelukast preconditioning suppressed mast cell infiltration and inflammatory mediators to greater extent than MESNA. Also, montelukast enhanced autophagosomes formation in detrusor myocytes and up-regulated the autophagy-related proteins (beclin-1 & LC3-II), likely through inhibition of phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. Montelukast preconditioning offset the up-regulation of transient receptor potential vanilloid 4 (TRPV4) in urothelial tissue of CPA-treated rats, to greater extent than MESNA. SIGNIFICANCE: These results demonstrate the uroprotective effect of montelukast on CPA-induced HC, which appears to be more superior to MESNA. These findings suggest that montelukast can emerge as a novel strategy to protect against CPA-induced urotoxicity.

Cilostazol preconditioning alleviates cyclophosphamide-induced cardiotoxicity in male rats: Mechanistic insights into SIRT1 signaling pathway.

AIMS: Cyclophosphamide (CYP) is a potent anticancer agent with well-known cardiotoxicity that limits its clinical applications. Cilostazol is a vosodilating drug, showing a cardioprotective effect in some cardiac disorders; however its effect in CYP-induced cardiotoxicity is still uncertain. We investigated the effect of cilostazol against CYP-induced cardiotoxicity and the contribution of SIRT1 signaling. MATERIALS AND METHODS: 7 week-old male Wistar albino rats were treated with cilostazol (30 mg/kg/day, orally) in the absence or presence of SIRT1 inhibitor, EX-527 (5 mg/kg/day, IP) for 10 days and injected with CYP (200 mg/kg, IP) on the 7th day of the study. Age-matched rats were used as control group. On the 11th day, hearts were harvested for biochemical, immunoblotting and histological analyses. Markers of cardiac injury were assessed in plasma samples. KEY FINDINGS: CYP injection contributed to cardiac injury manifested as significant increases in plasma activities of heart enzymes and cardiac troponin I levels. Cilostazol attenuated cardiac injury and minimized the histological lesions in hearts of CYP-treated rats. Cilostazol induced 3 fold up-regulation of SIRT1 and promoted the antioxidant defense response through FoxO1-related mechanism in hearts of CYP-treated rats. Cilostazol suppressed the CYP-induced up-regulation of PARP1 and p53, and blocked the NF-kB p65-mediated inflammatory response in hearts of CYP-treated rats. All the beneficial effects of cilostazol were almost abolished by EX-527. SIGNIFICANCE: These data provided insights into the mechanism underlying the cardioprotective effect of cilostazol in CYP-treated rats through upregulation of SIRT1 signaling, suggesting that cilostazol might be a candidate modality for CYP-induced cardiotoxicity.

Stromal cell-derived factor-1α predominantly mediates the ameliorative effect of linagliptin against cisplatin-induced testicular injury in adult male rats.

Stromal cell-derived factor-1α (SDF-1α) plays a key role in trafficking of stem cells and regeneration of injured tissue through interaction with its receptor, CXCR4. This study investigated the probable therapeutic effect of linagliptin (LG) against cisplatin (CP)-induced testicular injury and the underlying mechanisms. 12 week old male Sprague-Dawley rats were randomly assigned into 6 groups (n = 10 each) as follow: (i) Control, (ii) LG-treated control, (iii) CP-exposed rats, (iv) CP-exposed rats received LG, (v) CP-exposed rats received AMD3100, as CXCR4 antagonist, and (vi) CP-exposed rats received AMD3100 prior to LG. After 15 days, blood, testes and epididymides were collected for analyses. There were significant increases in both circulatory and testicular levels of SDF-1α in LG-treated rats. Conversely, higher levels of incretin hormones were found in serum but not in testicular tissue of rats, following LG therapy. CP injection significantly reduced body, testicular and epididymal weights of rats, and were restored by LG therapy. Treatment of CP-exposed rats with LG improved the deteriorated testicular architecture, reconstructed spermatogenesis, increased sperm count and quality, and normalized testosterone levels. LG therapy increased gene expression of Lin28a and Mvh, but did not alter the expressions of somatic-related genes. Additionally, LG therapy promoted germ cells survival and proliferation likely via activation of extracellular signal-regulated kinase1/2 (ERK1/2) signaling. These positive effects of LG therapy were almost blunted by administration of AMD3100. These results provided mechanistic insights into the ameliorative effect of LG on CP-induced testicular injury, through activation of SDF-1α/CXCR4 signaling pathway. Our findings suggest that LG can be a promising therapeutic candidate for CP-induced testicular injury.

A novel protective role of sacubitril/valsartan in cyclophosphamide induced lung injury in rats: impact of miRNA-150-3p on NF-κB/MAPK signaling trajectories.

Cyclophosphamide (CP) is a chemotherapeutic agent that induces oxidative stress causing multiple organ damage. Sacubitril/valsartan, is a combined formulation of neprilysin inhibitor (sacubitril) and angiotensin II receptor blocker (valsartan), that induces the protective effect of brain natriuretic peptide. The aim of the current study is to investigate the prophylactic impacts of sacubitril/valsartan versus valsartan against CP-induced lung toxicity in rats. Rats were assigned randomly into 6 groups; control; received corn oil (2 ml/kg/day; p.o. for 6 days), sacubitril/valsartan (30 mg/kg; p.o. for 6 days), valsartan (15 mg/kg; p.o. for 6 days), CP (200 mg/kg; i.p. on day 5), sacubitril/valsartan + CP (30 mg/kg; p.o. for 6 days, 200 mg/kg; i.p. single dose on day 5, respectively), valsartan + CP (15 mg/kg; p.o. for 6 days, 200 mg/kg; i.p. single dose on day 5, respectively). Both sacubitril/valsartan and valsartan produced a significant decrease in the inflammation and fibrosis markers in the BALF, in comparison with the CP group. Both sacubitril/valsartan and valsartan produced an apparent decrease in the relative genes expression of miR-150-3p and NF-κB, as well as a significant decrease in the relative expression of P38 and ERK1/2 MAPKs and an increase in the relative gene expression of Nrf-2, compared to CP group. Intriguingly, sacubitril/valsartan , showed subtle superiority in almost all investigated parameters, compared to valsartan. In conclusion, sacubitril/valsartan effectively abrogated the CP induced lung inflammation and fibrosis, providing a potential promising protection that could be linked to their ability to inhibit miR-150-3p via inhibition of NF-κB and MAPK signaling pathways.

Inhibition of tumor necrosis factor-α enhanced the antifibrotic effect of empagliflozin in an animal model with renal insulin resistance.

Insulin resistance (IR) has emerged as one of the main risk factors for renal fibrosis (RF) that represents a common stage in almost all chronic kidney disease. The present study aims to investigate the inhibitory effect of empagliflozin (EMPA "a sodium-glucose co-transporter 2 inhibitor") and infliximab [IFX "a tumor necrosis factor-α (TNF-α) antibody"] on RF in rats with induced IR. IR was induced by adding 10% fructose in drinking water for 20 weeks. Thereafter, fructose-induced IR rats were concurrently treated with EMPA (30 mg/kg), IFX (1 dose 5 mg/kg), or EMPA + IFX for 4 weeks, in addition to IR control group (received 10% fructose in water) and normal control (NC) group. Rats with IR displayed hyperglycemia, deterioration in kidney functions, glomerulosclerosis, and collagen fiber deposition in renal tissues as compared to NC. This was associated with downregulation of the renal sirtuin 1 (Sirt 1) expression along with higher renal tissue TNF-α and transforming growth factor-ß1 (TGF-ß1) levels. Both EMPA and IFX significantly modulated the aforementioned fibrotic cytokines, upregulated the renal Sirt 1 expression, and attenuated RF compared to IR control group. Of note, IFX effect was superior to that of EMPA. However, the combination of EMPA and IFX alleviated RF to a greater extent surpassing the monotherapy. This may be attributed to the further upregulation of renal Sirt 1 in addition to the downregulation of fibrotic cytokines. These findings suggest that the combination of EMPA and IFX offers additional benefits and may represent a promising therapeutic option for RF.

The concurrent exposure to aluminium and fructose induces liver injury in rats: Protection by monoammonium glycyrrhizinate.

Aluminium is a ubiquitous element that occurs naturally in the soil making human exposure to it unavoidable. It is implicated in the aetiology of different neurodegenerative diseases and can induce liver injury. In addition, insulin resistance (IR) plays an essential role in the pathogenesis and the progression of liver disorders. The increased consumption of fructose contained in soft drinks and western pattern diet results in IR that along with the wide distribution of aluminium make the concurrent exposure conceivable and increase the risk of liver injury. Therefore, the present study explores the hepatotoxic effects of aluminium and fructose administered concurrently and evaluates the possible protection by monoammonium glycyrrhizinate (MAG). Liver injury was induced by the administration of aluminium chloride (34 mg/kg/d) plus 10% (w/v) fructose in drinking water. Male rats were treated with either MAG (40 mg/kg/d) or silymarin (SIL, 100 mg/kg/d). The concurrent administration of aluminium and fructose (FRUAL) induced liver injury manifested as a significant elevation of serum liver enzymes activities, bilirubin level, and prothrombin time, as well as reduction of albumin level. On the other hand, the administration of MAG improved the FRUAL-induced aberrations of liver function tests and hepatic cytoarchitecture. We assume that the MAG-induced suppression of oxidative stress, toll-like receptor 4 pathway activation, inflammation, and apoptosis might play a crucial role in the hepatoprotective effect of MAG in this model. Intriguingly, the hepatoprotective effect MAG against FRUAL-induced liver injury surpasses that of the gold standard SIL, suggesting MAG as a better alternative to SIL.

Chemical composition, antioxidant and hepatoprotective activities of methanol extracts from leaves of Terminalia bellirica and Terminalia sericea (Combretaceae).

BACKGROUND: Plants belonging to the genus Terminalia such as Terminalia bellirica and Terminalia sericea are used traditionally to treat several diseases and health disorders. Up to this date, the roots of Terminalia sericea and the fruits of Terminalia bellirica are the mostly studied plant parts. The phytochemical composition and the biological activities of the leaves of both species are not well identified so far. METHODS: The secondary metabolites of Terminalia bellirica and Terminalia sericea leaves were identified using HPLC-PDA-MS/MS. The antioxidant activities of the leaves extracts were determined by DPPH and FRAP assays. The hepatoprotective potential was evaluated in rats with D-galactosamine induced liver damage. The effect of the extracts on the expression of the anti-apoptotic marker Bcl-2 was measured in an immunohistochemical study. The most abundant compounds identified in the studied extracts were docked into Bcl-2: Bim (BH3) interaction surface using molecular operating environment software. RESULTS: A total of 85 secondary metabolites were identified in the leaf extracts of both species. Ellagitannins such as corilagin, chebulagic acid, galloylpunicalagin, and digalloyl-hexahydroxydiphenoyl-hexoside were found to be the major components in Terminalia bellirica whereas flavonoid glycosides including quercetin rutinoside and quercetin galloyl-glucoside were highly abundant in Terminalia sericea. The studied extracts exhibited pronounced antioxidant activities, moderate anti-apoptotic and hepatoprotective potential. In silico docking experiments revealed that the compounds abundant in the extracts were able to bind to Bcl-2: Bim (BH3) interaction surface with an appreciable binding free energy. DISCUSSION: The antioxidant and hepatoprotective activities exhibited by the studied extracts might be attributed to the high content of the polyphenols. The anti-apoptotic activity could be due to the interference with the apoptotic pathway mediated by Bcl-2: Bim interaction. These findings support the medicinal relevance of Terminalia bellirica and Terminalia sericea and provide a rational base for their utilization in folk medicine.

Tannin-rich extracts from Lannea stuhlmannii and Lannea humilis (Anacardiaceae) exhibit hepatoprotective activities in vivo via enhancement of the anti-apoptotic protein Bcl-2.

The potential hepatoprotective activities of two Lannea species were explored in vivo. Furthermore, the binding activities of their main polyphenols to the antiapoptotic protein Bcl-2 were investigated. Based on HPLC-MS/MS results, 22 secondary metabolites were characterized in L. stuhlmannii (mainly tannins), while 20 secondary metabolites (mainly sulphated tannins) were identified in L. humilis. Both extracts exhibited substantial antioxidant activities in vitro and counteracted D-galactosamine induced intoxication in rats in vivo and increased the total antioxidant capacity (TAC) of liver tissues. In addition to reducing the elevated levels of AST and total bilirubin, both extracts significantly attenuated the deleterious histopathologic changes in liver after D-galactosamine-intoxication. Also, both extracts protected hepatocytes from apoptotic cell death and increased the expression of the anti-apoptotic protein Bcl-2. The identified compounds from both extracts can bind to the Bcl-2: Bim (BH3) interface with an appreciable binding free energy. Hydrogen and ionic bonds and hydrophobic interactions with amino acid residues in the hydrophobic face of Bim (BH3) domain were discovered. To sum up, L. humilis and L. stuhlmanni exhibited promising hepatoprotective activities in vivo against D-GalN-induced liver injury and their hepatoprotection is due to the antioxidant and anti-apoptotic effects of tannins and proanthocyanidins.

Senna singueana: Antioxidant, Hepatoprotective, Antiapoptotic Properties and Phytochemical Profiling of a Methanol Bark Extract.

Natural products are considered as an important source for the discovery of new drugs to treat aging-related degenerative diseases and liver injury. The present study profiled the chemical constituents of a methanol extract from Senna singueana bark using HPLC-PDA-ESI-MS/MS and 36 secondary metabolites were identified. Proanthocyanidins dominated the extract. Monomers, dimers, trimers of (epi)catechin, (epi)gallocatechin, (epi)guibourtinidol, (ent)cassiaflavan, and (epi)afzelechin represented the major constituents. The extract demonstrated notable antioxidant activities in vitro: In DPPH (EC50 of 20.8 µg/mL), FRAP (18.16 mM FeSO4/mg extract) assays, and total phenolic content amounted 474 mg gallic acid equivalent (GAE)/g extract determined with the Folin-Ciocalteu method. Also, in an in vivo model, the extract increased the survival rate of Caenorhabditis elegans worms pretreated with the pro-oxidant juglone from 43 to 64%, decreased intracellular ROS inside the wild-type nematodes by 47.90%, and induced nuclear translocation of the transcription factor DAF-16 in the transgenic strain TJ356. Additionally, the extract showed a remarkable hepatoprotective activity against d-galactosamine (d-GalN) induced hepatic injury in rats. It significantly reduced elevated AST (aspartate aminotransferase), and total bilirubin. Moreover, the extract induced a strong cytoplasmic Bcl-2 expression indicating suppression of apoptosis. In conclusion, the bark extract of S. sengueana represents an interesting candidate for further research in antioxidants and liver protection.

Curcumin and hemopressin treatment attenuates cholestasis-induced liver fibrosis in rats: role of CB1 receptors.

Curcumin exerts hepatoprotective effects via poorly defined mechanisms. Recently, some studies suggested that this effect was mediated by antagonizing CB1 receptors in hepatic stellate cells. The current study aimed to investigate whether CB1 antagonist, hemopressin, could potentiate the hepatoprotective effect of curcumin, in comparison with silymarin in bile duct-ligated (BDL) rats. Curcumin and hemopressin each alone and in combination ameliorated biochemical and structural fibrotic injury, and downregulated cyclooxygenase-2 (COX-2) and both mRNA and protein levels of nuclear factor kappa B (NF-κB) in fibrotic liver. In contrast to the previous studies, curcumin alone did not affect the gene expression of cannabinoid receptors. However, the combination of hemopressin and curcumin reduced the expression of CB1 in fibrotic liver. Surprisingly, silymarin upregulated CB2 receptors and downregulated CB1 at mRNA level more than all the administered drugs. Both curcumin and hemopressin each alone decreased lipid peroxidation product, malondialdehyde (MDA), while the combination increased the reduced glutathione content. All the administered drugs increased the hepatic antiapoptotic marker, Bcl2. Our study suggests that hemopressin potentiates the hepatoprotective effect of curcumin on fibrotic liver. We identified a new mechanism of the hepatoprotective effect of silymarin via modulation of cannabinoid receptors in fibrotic liver.

Neuroprotective effect of resveratrol in diabetic cerebral ischemic-reperfused rats through regulation of inflammatory and apoptotic events.

BACKGROUND: Diabetes and cerebral ischemic-reperfusion are among the most common causes of neurological complications in Egypt. The prevalence of diabetes in Egypt is high and it can be considered as a major clinical and public health problem. METHODS: Blood glucose, lipid profile, oxidative stress makers (cerebral MDA & GSH), cerebral interleukin-4 (IL-4) level and cerebral cyclooxygenase-2 (COX-2) gene expression were measured in male albino rats weighing 200 ± 20 g. The rats were divided into five groups, normal control group, diabetic group (diabetes was induced by single dose of streptozotocin [STZ]), diabetic cerebral ischemic-reperfused group, two treated groups (diabetic and diabetic ischemic-reperfused), both groups treated with resveratrol. Histological study was done using H&E, AgNOR and cresyl violet stains. Immunohistochemistry for Bax and COX-2 was done with morphometric study. RESULTS: Diabetic and diabetic cerebral ischemic- reperfused rats showed significant increase in serum glucose level, serum TAG, serum LDL-C, atherogenic index, cerebral MDA and upregulation of COX-2 gene expression. These groups showed significant decrease in serum HDL, cerebral IL-4 and depletion of cerebral GSH when compared to normal control rats. Treating these groups with resveratrol resulted in significant decrease in serum glucose level, serum TAG, TC, serum LDL-C, atherogenic index, cerebral MDA and downregulation of COX-2 gene expression. The results of COX-2 gene expression were confirmed by COX-2 immunohistochemistry. Also, significant increase in serum HDL, cerebral IL-4 and cerebral GSH contents could be observed in these treated groups as compared to normal control group. Cerebral apoptotic index and optical density of Bax reaction revealed significant increase in diabetic and diabetic cerebral ischemic-reperfused rats while treatment of these groups with resveratrol resulted in significant decrease in cerebral apoptotic index and optical density of Bax reaction. These apoptotic results were confirmed with AgNOR and cresyl violet stains. CONCLUSION: The results of this research suggest that upregulation of cerebral COX-2 gene along with the decrease in cerebral IL-4 and enhanced cerebral apoptosis is critically involved in cerebral damage associated with diabetes and cerebral ischemic-reperfusion. Resveratrol can ameliorate these effects and has promising neuroprotective effect in diabetic-induced cerebral complications.

Role of cannabinoid receptors in hepatic fibrosis and apoptosis associated with bile duct ligation in rats.

This study assessed the effect of stimulation of CB2 receptors or CB1 blockade on fibrosis and apoptosis in rats subjected to bile duct ligation (BDL). It was performed in sham and BDL rats for four weeks. Fibrosis-induced rats received a CB2 receptor agonist ß-caryophyllene, CB1 receptor antagonist, hemopressin, combination of ß-caryophyllene and CB2 antagonist, AM630 or vehicle daily during the last 2 weeks of the BDL ligation. Transaminases activity, bilirubin levels, hepatic collagen content, hydroxyproline level, Bcl2 positive hepatocytes, and mRNA expression of CB1, CB2 receptors and matrix metalloproteinase-1 (MMP-1) genes were measured in all animals. Bile duct ligated rats showed increased bilirubin levels, elevated transaminases activity, increased hepatic collagen content, and hydroxyproline level, reduced Bcl2 positive hepatocytes and increased expression of the assessed messengers in comparison with sham rats. However, fibrotic rats treated with either ß-caryophyllene or hemopressin had reduced hepatic collagen content, improved transaminase activity and reduced bilirubin level, ameliorated CB1 gene expression, and increased MMP-1 gene expression compared with untreated fibrotic rats. These results were associated with attenuated apoptosis with only ß-caryophyllene administration. CB2 receptor blockade by AM630 prevents the effects of ß-caryophyllene on CB1 receptor and MMP-1 genes expression. This study points out that either stimulation of CB2 receptors or CB1 blockade can attenuate hepatic fibrosis in bile duct ligated rats. The mechanisms underlying these incidents may open new avenues for attenuating fibrosis and apoptosis of cholestasis- induced liver diseases.