L-arginine mitigates bleomycin-induced pulmonary fibrosis in rats through regulation of HO-1/PPAR-γ/ß-catenin axis.

Pulmonary fibrosis is a chronic and progressively deteriorating lung condition that can be replicated in laboratory animals by administering bleomycin, a chemotherapeutic antibiotic known for its lung fibrosis-inducing side effects. L-arginine, a semi-essential amino acid, is recognized for its diverse biological functions, including its potential to counteract fibrosis. This study aimed to evaluate the antifibrotic properties of L-arginine on bleomycin-induced pulmonary fibrosis in rats. The administration of a single intratracheal dose of bleomycin resulted in visible and microscopic damage to lung tissues, an uptick in oxidative stress markers, and an elevation in inflammatory, apoptotic, and fibrotic indicators. A seven-day treatment with L-arginine post-bleomycin exposure markedly improved the gross and histological architecture of the lungs, prevented the rise of malondialdehyde and carbonyl content, and enhanced total antioxidant capacity alongside the activities of antioxidant enzymes. Also, L-arginine attenuated the expression of the pro-fibrotic factors, transforming growth factor-ß and lactate dehydrogenase in bronchoalveolar lavage fluid. In the lung tissue, L-arginine reduced collagen deposition, hydroxyproline concentration, and mucus production, along with decreasing expression of α-smooth muscle actin, tumor necrosis factor-α, caspase-3, matrix metalloproteinase-9, and ß-catenin. Moreover, it boosted levels of nitric oxide and upregulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), heme oxygenase-1 (HO-1), and E-cadherin and downregulating the expression of ß-catenin. These findings suggest that L-arginine has preventive activities against bleomycin-induced pulmonary fibrosis. This effect can be attributed to the increased production of nitric oxide, which modulates the HO-1/PPAR-γ/ß-catenin axis.

A new cirrhotic animal protocol combining carbon tetrachloride with methotrexate to address limitations of the currently used chemical-induced models.

Background: Chemically induced cirrhotic animal models are commonly used. However, they have limitations such as high mortalities and low yield of cirrhotic animals that limit their uses. Aims: To overcome limitations of the chemically induced cirrhotic animal model via combined administration of methotrexate (MTX) with CCl4 and decrease their commonly used doses depending on the proposed synergetic cirrhotic effect. Methods: Rats were divided into six groups: normal (4 weeks), normal (8 weeks), MTX, CCl4 (4 weeks), CCl4 (8 weeks), and MTX + CCl4 (4 weeks) groups. Animals' hepatic morphology and histopathological characterization were explored. Hepatic Bcl2 and NF-κB-p65 tissue contents were determined using the immunostaining technique, and hepatic tissue damage, oxidative status, and inflammatory status biochemical parameters were determined. Results: CCl4 + MTX combined administration produced prominent cirrhotic liver changes, further confirmed by a substantial increase in oxidative stress and inflammatory parameters, whereas mortalities were significantly lower than in other treated groups. Conclusion: The present study introduced a new model that can significantly improve the major limitations of chemically induced cirrhotic animal models with new pathological features that mimic human cirrhosis. Compared to other chemically induced methods, the present model can save time, cost, and animal suffering.

Novel topoisomerase II/EGFR dual inhibitors: design, synthesis and docking studies of naphtho[2',3':4,5]thiazolo[3,2-a]pyrimidine hybrids as potential anticancer agents with apoptosis inducing activity.

Topoisomerases II are ubiquitous enzymes with significant genotoxic effects in many critical DNA processes. Additionally, epidermal growth factor receptor (EGFR) plays pivotal role in tumour growth and angiogenesis. A novel series of naphtho[2',3':4,5]thiazolo[3,2-a]pyrimidine hybrids have been designed, synthesised and evaluated for their topo IIα/EGFR inhibitory and apoptotic inducer activities. Cytotoxicity of the synthesised hybrids was evaluated against MCF-7, A549 and HCT-116 cell lines. Of the synthesised hybrids, 6i, 6a and 6c experienced superior cytotoxic activity compared to doxorubicin and erlotinib against the tested cancer cells. The molecular mechanism of these hybrids revealed their ability to successfully inhibit topo IIα and EGFR activities in micromolar concentration and may serve as topo II catalytic inhibitor. Moreover, these hybrids significantly arrested cell cycle at G2/M phase together with increased p53, caspae-7, caspase-9 levels and Bax/Bcl-2 ratio. The synthesised hybrids showed efficient binding pattern in molecular docking study and have acceptable drug likeness characters.

Fasudil Ameliorates Methotrexate-Induced Hepatotoxicity by Modulation of Redox-Sensitive Signals.

Methotrexate (MTX) is one of the most widely used cytotoxic chemotherapeutic agents, and it is used in the treatment of different autoimmune disorders. However, the clinical applications of MTX are limited by its hepatic toxicity. Hence, the present study was conducted to evaluate the efficacy of fasudil (Rho-Kinase inhibitor) in the amelioration of MTX hepatotoxicity and the possible underlying mechanisms. Experimentally, 32 male Sprague Dawley rats were used and divided into four groups: control, MTX (20 mg/kg, i.p., single dose), fasudil (10 mg/kg/day i.p.) for one week, and fasudil plus MTX. It was found that MTX significantly induced hepatitis and hepatocellular damage, as shown by abnormal histological findings and liver dysfunction (ALT and AST), with up-regulation of the inflammatory mediators NF-κB-p65 and IL-1ß. Moreover, MTX remarkably disrupted oxidant/antioxidant status, as evidenced by malondialdehyde (MDA) up-regulation associated with the depletion of superoxide dismutase (SOD), catalase, and reduced glutathione (GSH) levels. Moreover, MTX reduced the hepatic expression of B-cell lymphoma 2 (Bcl-2). On the contrary, the i.p. administration of fasudil significantly ameliorated MTX hepatotoxicity by histopathological improvement, restoring oxidant/antioxidant balance, preventing hepatic inflammation, and improving the hepatic anti-apoptotic capability. Furthermore, fasudil hepatic concentration was determined for the first time using the validated RP-HPLC method. In conclusion, the present study revealed that fasudil has a reliable hepatoprotective effect against MTX hepatotoxicity with underlying antioxidant, anti-inflammatory, and anti-apoptotic mechanisms. It also introduced a new method for the determination of fasudil hepatic tissue concentration using the RP-HPLC technique.

Nano-Structured Lipid Carrier-Based Oral Glutathione Formulation Mediates Renoprotection against Cyclophosphamide-Induced Nephrotoxicity, and Improves Oral Bioavailability of Glutathione Confirmed through RP-HPLC Micellar Liquid Chromatography.

The study aimed to develop a new glutathione (GSH) oral formulation to enhance the delivery of GSH and counter the nephrotoxicity of the anticancer drug, cyclophosphamide (CP). A nanostructured lipid carrier glutathione formulation (GSH-NLCs) composed of glutathione (500 mg), stearic and oleic acid (300 mg, each), and Tween® 80 (2%, w/v) was prepared through the emulsification-solvent-evaporation technique, which exhibited a 452.4 ± 33.19 nm spheroidal-sized particulate material with narrow particle size distributions, -38.5 ± 1.4 mV zeta potential, and an entrapment efficiency of 79.8 ± 1.9%. The GSH formulation was orally delivered, and biologically tested to ameliorate the CP-induced renal toxicity in a rat model. Detailed renal morphology, before and after the GSH-NLCs administration, including the histopathological examinations, confirmed the ameliorating effects of the prepared glutathione formulation together with its safe oral delivery. CP-induced oxidative stress, superoxide dismutase depletion, elevation of malondialdehyde levels, depletion of Bcl-2 concentration levels, and upregulated NF-KB levels were observed and were controlled within the recommended and near normal/control levels. Additionally, the inflammatory mediator marker, IL-1ß, serum levels were marginally normalized by delivery of the GHS-NLCs formulation. Oral administration of the pure glutathione did not exhibit any ameliorating effects on the renal tissues, which suggested that the pure glutathione is reactive and is chemically transformed during the oral delivery, which affected its pharmacological action at the renal site. The protective effects of the GSH-NLCs formulation through its antioxidant and anti-inflammatory effects suggested its prominent role in containing CP-induced renal toxicity and renal tissue damage, together with the possibility of administrating higher doses of the anticancer drug, cyclophosphamide, to achieve higher and effective anticancer action in combination with the GSH-NLCs formulation.

Enhanced anticancer effect of Combretastatin A-4 phosphate when combined with vincristine in the treatment of hepatocellular carcinoma.

Tubulin targeting agents have received considerable interest as a potential tumor-selective vascular disrupting agents, which represent another avenue for cancer growing therapeutic opportunities. Hence, the present study was conducted to investigate the anti-tumor activity of Combretastatin A-4 phosphate (CA4-P) and vincristine against hepatocellular carcinoma in rats, by individual administration and in combination. In vitro study was conducted using human hepatocellular carcinoma cell lines, showed that CA4-P and vincristine have a potent cell cytotoxic and tubulin inhibitory effect. In addition, a remarkable synergistic effect was observed by the simultaneous application of both drugs. Whereas in vivo study was conducted using model of rat liver cancer initiated with DENA and promoted by CCl4, showed that CA4-P and vincristine were significantly decreased liver relative weight, number of hepatic nodules and there relative volumes, tubulin content of the hepatic tissue, GSH and AFP. On the other hand, co-administration of both drugs exhibited significant further decrements in these parameters. Whereas a marked increase in MDA, carbonyl content and TNF-α inside hepatic tissue were observed in the treated groups and these increments were more prominent by co-administration of both drugs. In conclusion CA4-P showed a potential anti-cancer activity against hepatocellular carcinoma and this effect was greatly enhanced by co-administration with vincristine. Additionally, our new findings provided an important evidence that the anticancer activity of drugs with a narrow therapeutic window such as vincristine can be greatly improved by its co-administration with CA4-P providing more enhanced activity with less side effects.

Protective effect of hydrogen sulfide against cold restraint stress-induced gastric mucosal injury in rats.

Hydrogen sulfide (H2S) is an endogenous gaseous mediator plays a potential role in modulating gastric inflammatory responses. However, its putative protective role remains to be defined. The present study aimed to evaluate role of the exogenously released and endogenously synthesized H2S in cold restraint stress (CRS)-induced oxidative gastric damage in rats. Rats were restrained, and maintained at 4 °C for 3 h. The H2S donor, sodium hydrosulfide (NaHS) (60 µmol/kg) was injected intraperitoneally (i.p.) before CRS. Our results revealed that NaHS pretreatment significantly attenuated ulcer index, free and total acid output, and pepsin activity in gastric juice along with decreased gastric mucosal carbonyl content and reactive oxygen species production. This was accompanied by increased gastric juice pH and mucin concentration in addition to restoring the deficits in the gastric reduced glutathione, catalase as well as superoxide dismutase enzyme activities. NaHS pretreatment markedly reduced the serum level of tumor necrosis factor (TNF-α) and myeloperoxidase activity compared to CRS-non-treated. Moreover, NaHS preadministration significantly abrogated the inflammatory and the deleterious responses of gastric mucosa in CRS. The protective effects of H2S were confirmed by gastric histopathological examination. However, pretreatment with the H2S-synthesizing enzyme, cystathionine-gamma-lyase inhibitor, beta-cyano-L-alanine (50 mg/kg, i.p.) reversed the gastroprotection afforded by the endogenous H2S. Collectively, our results suggest that H2S can protect rat gastric mucosa against CRS-induced gastric ulceration possibly through mechanisms that involve anti-oxidant and anti-inflammatory actions alongside enhancement of gastric mucosal barrier and reduction in acid secretory parameters.