Fenretinide induces apoptosis and synergises the apoptosis inducing effect of gemcitabine through inhibition of key signalling molecules involved in A549 cell survival in in silico and in vitro analyses

Fenretinide is a synthetic retinoid compound, which induces apoptosis via generating reactive oxygen species (ROS) and modulating PI3K/Akt/mTOR signalling pathway. We hypothesise that fenretinide's mechanism of action in triggering apoptosis may involve other targets, beside mTOR signalling pathway and it may augment apoptosis inducing effects of chemotherapeutic drugs in lung cancer. Time-lapse microscopy and Western blotting were used to evaluate apoptosis and apoptotic marker cleaved-Caspase 3 in A549 cells. Relative levels of protein phosphorylation and ROS were quantified by Human Phospho-Kinase Array Kit and CellROX® Green Reagent, respectively. Docking and simulation analyses of proteins and fenretinide interactions were identified and visualised by Discovery Studio Visualizer and AutoDock Vina software. Our results showed that fenretinide induced apoptosis in a dose dependant manner and combinations of fenretinide (5 μg/mL) and gemcitabine (1, 2, 4, 8 and 16 μg/mL) synergistically enhanced apoptosis in A549 cells. Fenretinide caused significant increase of cleaved-Caspase 3, de-phosphorylated p-S473 of Akt and failed to inhibit mTORC1 downstream targets. In silico results revealed that Akt required the lowest energy (-10.2 kcal/mol) to interact with fenretinide in comparison with other proteins. In conclusion, Akt may be exploited as a good target for induction of apoptosis in A549 cells and fenretinide has great potentials to fulfil this task. The mechanism by which fenretinide boosts the apoptosis inducing effects of gemcitabine, which is likely expected to be via inhibiting mTORC2 downstream targets. However, docking investigation revealed that fenretinide lacks specificity as it may also interact with several secondary targets beside Akt.

Diclofenac sodium and dexamethasone co-therapy restores brain neuron-specific enolase (NSE), S-100 Beta and glial fibrillary acid protein (GFAP) proteins in experimental rat's model: A possible inhibition of P-glycoprotein

Non-steroidal anti-inflammatory drugs decrease pain and fever while corticosteroids regulate inflammation and immune response, both are prescribed to reduce inflammation and control pain. The present study aimed to study the effects of their monotherapy and co-administration on the brain tissue structure of experimental rats. P-glycoprotein (PGP), a transporter membrane protein, plays an important role in various physiological and physio-pathological conditions, drug-drug and drug-food interactions, and multi-drug resistance. Male rats were divided into four groups and received normal saline, dexamethasone, diclofenac sodium and their dual therapy respectively, then after one-month rats were sacrificed and brain tissues proceeded for hematoxylin and eosin staining to study their histopathology and immunohistochemically staining of NSE, S100-B and GFAP biomarkers were performed. Additionally, in silico molecular docking studies were conducted to elucidate interactions between PGP and used compounds. Resultsshowed that dexamethasone or diclofenac sodium treatments showed abnormalities like edema, neuronal vacuoles, astrocytes hyperplasia and microglial cells with positive reaction to NSE, S100 and GFAP antibodies while the dual therapy displayed less edema and other signs of damage with negative and weak positive staining of NSE, S100 and GFAP antibodies respectively. The molecular docking showed that there were different affinities toward the involved PGP active site. These interaction results were great with Dexamethasone -9.6 kcal/mol forming hydrophobic interactions with the highest affinity when compared with Diclofenac sodium which gave -8.4 kcal/mol. In conclusion, the side effects of the two types of anti-inflammatory drugs may be minimized through their interactions. However, Molecular Dynamic Simulations studies are required to explain the exact dynamic behaviors and protein-ligand stability.

Gastroprotective activity of Hypericum perforatum extract in ethanol-induced gastric mucosal injury in Wistar rats: A possible involvement of H+/K+ ATPase α inhibition

Hypericum perforatum (HP) is a plant native to Asia and Europe. It has been documented to enclose medical effects against many disorders such as anxiety, depression and burns. This experiment was performed to evaluate the gastro-protective effect of Hypericum perforatum leaf extract in ethanol induced gastric ulcer in rats as compared to esomeprazole (the drug of choice for stomach ulcers). The mechanism of action was performed by Auto Dock Vina method.

Ethanol ingestion up regulated the inflammatory reaction as demonstrated by rise of gastric proinflammatory TNF-α with a decline of IL-1β. On the other hand, the phytochemical screening of HP revealed the presence of alkaloids, flavonoids, tannins, phenols, steroids and saponins. The high dose of HP group shows mild injuries to the gastric mucosa which is comparable to the esomeprazole group, in contrast, severe damages are observed in the gastric mucosa of the ulcer control rats group. In silico results revealed that Amentoflavone and Quercitrin have highest affinity and very good interactions with H+/K+ ATPase α active site. This study showed that HP is nearly as effective as esomeprazole to prevent ethanol induced gastric ulcer the plant extract and it has more binding affinity than esomeprazole to gastric proton pumps.

Docking Study to Predict the Efficacy of Phosphatidylinositol 3-Kinase α Inhibitors

The phosphatidylinositol 3-kinase (PI3K) family comprises lipid kinases that cross-link signals between living cells and their surroundings. PI3Ks are classified into several groups and isoforms with specific characteristics and functions. Genes encoding PI3Ks are mutated in several types of cancer, and their isoforms have varying capacity in promoting cell signaling and cancer progression. Many compounds have been introduced as PI3Kα inhibitors, but not all of them have the same inhibitory effects. For successful PI3K-related biomedical experiments, it is vital to select the most specific and potent compounds with the highest inhibitory effects for targeting this kinase. In this study, we investigate 28 well-recognized PI3Kα inhibitors through predicting their specificity and potency using the docking software AutoDock Vina. Our data showed that PF 05212384 had the highest docking score (−9.2 kcal/mol), and 3-methyladenine had the lowest docking score (−4.8 kcal/mol). Our data also showed different types of interactions and bonds formed between the inhibitors and protein residues. In conclusion, PF 05212384 and AZD 6482 compounds are the best candidates for targeting PI3Kα. In addition to hydrophobic interactions in the PI3Kα binding pocket, the formation of hydrogen bonds between these inhibitors and binding pocket residues was confirmed.