Role of miR-204 in segmental cardiac effects of phenylephrine and pressure overload

Cardiotoxicity caused by adrenergic receptor agonists overdosing or stress-induced catecholamine release promotes cardiomyopathy, resembling Takotsubo cardiomyopathy (TC). TC is characterized by transient regional systolic dysfunction of the left ventricle. The animal models of TC and modalities for assessing regional wall motion abnormalities in animal models are lacking. We previously reported the protective role of a small noncoding microRNA-204-5p (miR-204) in cardiomyopathies, but its role in TC remains unknown. Here we compared the impact of miR-204 absence on phenylephrine (PE)-induced and transaortic constriction (TAC)-induced changes in cardiac muscle motion in the posterior and anterior apical, mid, and basal segments of the left ventricle using 2-dimensional speckle-tracking echocardiography (2-STE). Wildtype and miR-204-/- mice were subjected to cardiac stress in the form of PE for four weeks or TAC-induced pressure overload for five weeks. PE treatment increased longitudinal and radial motion in the apex of the left ventricle and shortened the peak motion time of all left ventricle segments. The TAC led to decreased longitudinal and radial motion in the left ventricle segments, and there was no difference in the peak motion time. Compared to wildtype mice, PE-induced peak cardiac muscle motion time in the anterior base of the left ventricle was significantly earlier in the miR-204-/- mice. There was no difference in TAC-induced peak cardiac muscle motion time between wildtype and miR-204-/- mice. Our findings demonstrate that PE and TAC induce regional wall motion abnormalities that 2-STE can detect. It also highlights the role of miR-204 in regulating cardiac muscle motion during catecholamine-induced cardiotoxicity.

Methyldecanoate isolated from marine algae Turbinaria ornata enhances immunomodulation in LPS-induced inflammatory reactions in RAW 264.7 macrophages via iNOS/NFκB pathway

This study identifies the anti-inflammatory, antioxidant, and immunomodulatory potential of a fatty acid methyl ester segregated from the brown algae Turbinaria ornata and identified by nuclear magnetic resonance and mass spectrometry as methyl 6,12-dimethyltridecanoate (ET). Antioxidant and anti-inflammatory effects of ET were studied on lipopolysaccharide (LPS)-induced inflammatory reaction in RAW 264.7 macrophages. Moreover, in silico docking studies of isolated ET with inflammatory markers TNFα, NFκB, and COX-2 showed potent binding scores suggesting anti-inflammatory potential. ET significantly reduced LPO and increased LPS-induced SOD, catalase, and GSH levels. Molecular docking results were further confirmed by checking mRNA levels of selected cytokines (IL6 and IL10), followed by protein expression of iNOS and NFκB in LPS-induced macrophages. ET significantly upregulated the expression of IL10 and downregulated the expression of IL6, iNOS, and NFκB, confirming the inhibition of LPS-induced inflammation via the iNOS/NFκB pathway.

Synthesis, Optimization, and Structure-Activity Relationships of Imidazo[1,2-a]pyrimidines as Inhibitors of Group 2 Influenza A Viruses

The influenza A virus (IAV) is a highly contagious virus that causes pandemics and seasonal epidemics, which are major public health issues. Current anti-influenza therapeutics are limited partly due to the continuous emergence of drug-resistant IAV strains; thus, there is an unmet need to develop novel anti-influenza therapies. Here, we present a novel imidazo[1,2-a]pyrimidine scaffold that targets group 2 IAV entry. We have explored three different regions of the lead compound, and we have developed a series of small molecules that have nanomolar activity against oseltamivir-sensitive and -resistant forms of group 2 IAVs. These small molecules target hemagglutinin (HA), which mediates the viral entry process. Mapping a known small-molecule-binding cavity of the HA structure with resistant mutants suggests that these molecules bind to that cavity and block HA-mediated membrane fusion.

Immunomodulatory activity of brown algae Turbinaria ornata derived sulfated polysaccharide on LPS induced systemic inflammation

BACKGROUND

Inflammation and oxidative stress are common pathologies in a wide range of chronic diseases. Polysaccharides are known to exhibit antioxidant and anti-inflammatory potential and are suggested to possess immunomodulatory potential.

PURPOSE

Herein, the immunomodulatory activity of a sulfated polysaccharide (PS) separated from a brown marine algae Turbinaria ornata is studied in LPS instigated systemic inflammation in experimental rats.

STUDY DESIGN AND METHODS

Male SD rats are pretreated with different doses of PS (2.5, 5, 10 mg/kg bw) for a week followed by inducing systemic inflammation using LPS (10 mg/kg i.p.). Blood withdrawn after 8 h of LPS injection is subjected to hematological analysis (WBC, HCT, and PLT). After 24 h of LPS induction, cardiac tissue was isolated and subjected to biochemical, molecular, and histopathological analysis. Effect of PS pre-treatment (2.5, 5, 10 mg/kg bw) was checked by assessing serum parameters (AST, CK-MB, and γGT), antioxidant markers (LPO, GSH, SOD, Grx) and inflammatory markers (IL1β, IL6, IL10, NFκB), followed by analyzing the iNOS, PI3k and Akt to identify the probable mode of action.

RESULTS

Elevated levels of AST, CK-MB, and γGT in serum were significantly reduced on PS pretreatment. LPS significantly raised the LPO and Grx levels in heart tissue whereas, PS pre-treatment significantly reduced LPO and Grx levels. GSH and SOD levels were reduced upon LPS induction and were brought to near normal by HD of PS. PS also reduced the mRNA levels of IL6, Trx, and increased IL10 levels in the heart tissue substantiating its anti-inflammatory and antioxidant potency. Further, IL1β, NFκB, iNOS, and pPI3k/pAkt expressions were significantly modulated by PS in the cardiac tissue substantiating the immunomodulatory effect. A trend of improvement in the inflammatory pathology was also observed in the heart tissue compared to LPS control, as confirmed by histopathology analysis.

CONCLUSION

Altogether, this study concludes the immunomodulatory potential of PS from the marine macroalgae Turbinaria ornata significantly and prevents LPS induced systemic inflammation in the cardiac tissue presumably influenced by the glucopyranose and fucopyranose subunits in the polysaccharide.

Sulfated polysaccharide from Turbinaria ornata suppress lipopolysaccharide-induced inflammatory response in RAW 264.7 macrophages

BACKGROUND

Marine macroalgae known for its polysaccharides exhibit potent biomedical properties and its potential as an anti-inflammatory agent has increased in the recent past as inflammation is a major pathology noted in many chronic diseases.

PURPOSE

The present study investigates the anti-inflammatory potential of a sulfated polysaccharide (PS) isolated from the marine algae Turbinaria ornata collected from the Indian waters on LPS induced inflammation in RAW 264.7 macrophages.

STUDY DESIGN AND METHODS

PS isolated from the macroalgae was characterized using ESI(MS) and was screened for its antioxidant and anti-inflammatory potential in RAW 264.7 cells by assessing markers of oxidative stress, and inflammation.

RESULTS

LPS significantly increased the levels of LPO and LDH in RAW 264.7 cells which were significantly reduced in PS pre-treatment groups. Pretreatment significantly increased the antioxidants GSH and SOD and significantly reduced mRNA levels of IL6 and TNFα in vitro confirming its anti-inflammatory potential. NFκB and iNOS were significantly modulated by PS confirming the probable mode of action.

CONCLUSION

Altogether, it can be concluded that PS isolated from Turbinaria ornata collected from the Southeast Coast of India exhibits antioxidant and anti-inflammatory potential probably mediated by the sulfated polysaccharide containing glucopyranose and fucopyranose moieties.

Type 5 17-hydroxysteroid dehydrogenase/prostaglandin F synthase (AKR1C3) inhibition and potential anti-proliferative activity of cholest-4-ene-3,6-dione in MCF-7 breast cancer cells

Cholest-4-ene-3,6-dione (KS) is a cholesterol oxidation product which exhibits anti-proliferative activity. However, its precise mechanism of action remains unknown. In this study, the effects of KS on AKR1C3 inhibition and anti-proliferative activities were investigated in the hormone-dependent MCF-7 breast cancer cells. We identified that KS arrested the enzymatic conversion of estrone to 17-β estradiol, by inhibiting AKR1C3 in intact MCF-7 cells. The anti-proliferative effects of KS were evaluated by MTT assay, acridine orange and ethidium bromide dual staining, cell cycle analysis and Western blotting. KS arrested the cell cycle progression in the G1 phase with a concomitant increase of the Sub-G0 population to increase in concentration and time. It also enhanced the p53 and NFkB expression and induced caspase-12, 9 and 3 processing and down-regulated the Bcl-2 expression. Molecular docking studies performed to understand the inhibition mechanism of KS on AKR1C3 revealed that KS occupied the binding region of AKR1C3 with almost similar orientation as indomethacin (IM), thereby acting as an antagonistic agent for AKR1C3. Based on the results it is identified that KS induces inhibition of AKR1C3 and cell death in MCF-7 cells. These results indicate that KS can be used as a molecular scaffold for further development of novel small-molecules with better specificity towards AKR1C3.

Neophytadiene from Turbinaria ornata Suppresses LPS-Induced Inflammatory Response in RAW 264.7 Macrophages and Sprague Dawley Rats

This study investigates the mode of action of Neophytadiene (MT), a molecule isolated from a marine algae Turbinaria ornata in LPS-induced inflammation in both in vitro and in vivo conditions. Neophytadiene (25, 50, 100 μM/mL) was treated to LPS-stimulated RAW 264.7 macrophages cells to identify its anti-inflammatory potential by measuring the level of tumour necrosis factor (TNF-α) by enzyme-linked immunosorbent assay (ELISA) and nitric oxide (NO) using Griess reagent. The mRNA levels of inflammatory cytokines, interleukin (IL-6 and IL-10), and the protein expression of nuclear factor-κB (NF-κB) and inducible nitric oxide synthase (iNOS) were quantified by Western blot analysis. Subsequently, Neophytadiene (12, 25, 50 mg/kg b.wt/p.o) was pre-treated for 7 days to the experimental animals followed by LPS (10 mg/kg) injection interaperitonially. After LPS induction, blood was collected and the haematological parameters were analysed followed by isolation of heart tissue for biochemical molecular and histopathological analysis Neophytadiene significantly inhibited the NO production and inflammatory cytokines TNF-α, IL-6 and IL-10 both in in vitro and in vivo conditions. Further, the expression of TNF-α, IL1β, NF-κB, iNOS, PI3k/Akt and MAPK in the heart tissue was modulated by Neophytadiene significantly confirming the anti-inflammatory potential. Thus, the effect of Neophytadiene on LPS-induced cardiac injury can be attributed to its anti-inflammatory antioxidant and cardioprotective properties.

Protective effect of rutin isolated from Spermococe hispida against cobalt chloride-induced hypoxic injury in H9c2 cells by inhibiting oxidative stress and inducing apoptosis

BACKGROUND

Cardiovascular disease and its related deaths are increasing in the modern world. Therefore, there is a need to identify a plant based nutraceutical supplement with potent activity.

HYPOTHESIS/PURPOSE

Reportedly, the protective effect of the rutin in hypoxia-induced cardiomyocytes is due to the activation of molecular networks related to programmed cell death.

STUDY DESIGN-METHODS

Phytochemical methods and advanced analytical methods were employed to isolate natural products from Spermococe hispida their effects in cardiomyocyets.

RESULTS

We reports herein that CoCl₂-induced hypoxic condition significantly decreased cell viability as evidenced by MTT assay and cell cycle analysis. Western blot studies revealed an up-regulation of HIF-1α, BAX and caspase and down-regulation of BCl-2 expression, followed by modulation of Akt, p-Akt, p38 and p-p38. The oxidative abnormalities were ameliorated by rutin pretreatment, as deduced by the reduced CoCl₂-induced cytotoxicity, MDA concentration and LDH activity and the enhanced levels of GSH and SOD in a dose-dependent manner. Rutin protects H9c2 cells from CoCl₂-induced hypoxic damage by mitigating oxidative stress and preserving cell viability by modulating the antiapoptotic proteins.

CONCLUSION

The overall findings reinforce the cardioprotective action of rutin, a potential source of antioxidant of natural origin, which may help in mitigating the progress of oxidative stress in hypoxic conditions such as myocardial infarction and stroke.

[6]-Gingerol-induced cell cycle arrest, reactive oxygen species generation, and disruption of mitochondrial membrane potential are associated with apoptosis in human gastric cancer (AGS) cells

Ginger (Zingiber officinale Roscoe), a monocotyledonous herb, is widely used as an herbal medicine owing to the phytoconstituents it possesses. In the current study, the quantity of [6]-gingerol, the major phenolic ketone, in the fresh ginger and dried ginger rhizome was found to be 6.11 µg/mg and 0.407 µg/mg. Furthermore, [6]-gingerol was assessed for its antiapoptotic effects in human gastric adenocarcinoma (AGS) cells evidenced by acridine orange/ethidium bromide staining technique and Annexin-V assay. An increase in reactive oxygen species (ROS) generation led to a decrease in mitochondrial membrane potential (MMP) and subsequent induction of apoptosis. Results disclose that perturbations in MMP are associated with deregulation of Bax/Bcl-2 ratio at protein level, which leads to upregulation of cytochrome-c triggering the caspase cascade. These enduringly suggest that [6]-gingerol can be effectively used for targeting the mitochondrial energy metabolism to manage gastric cancer cells.

Attenuation of inflammation by marine algae Turbinaria ornata in cotton pellet induced granuloma mediated by fucoidan like sulphated polysaccharide

Turbinaria ornata, a commonly found marine brown algae along the Gulf of Mannar, Southeast coast of India was evaluated for its anti-inflammatory potential and the bioactive compound present in it was characterized. Cotton pellet induced granuloma model in rats was used to assess the anti-inflammatory potential of the aqueous extract of Turbinaria ornata (ATO) (30, 100 and 300mg/kg, p.o) which was compared with dexamethasone (0.1mg/kg, p.o) a standard anti-inflammatory agent. Granuloma weight, haematological parameters and plasma markers (LDH, GPT, and CRP) were estimated. Further, the levels of oxidative stress markers (SOD, GPx, GSH, LPO, and Nitrite) and inflammatory markers (Cathepsin D and MPO) in the hepatic tissue were measured. ATO decreased the granuloma weight dose dependently. ATO significantly reversed the levels of biochemical and inflammatory markers in comparison to the vehicle treated rats. The active constituent, fucoidan (sulphated polysaccharide) from the aqueous extract was fractionated and characterized using GCMS. The sulphated polysaccharide (TSP) from ATO confirms the presence of sulphates and sugars. The present findings suggest ATO to be a potent inhibitor of both proliferative and exudative phases of inflammation possibly mediated by the sulphated polysaccharides which might inhibit the action of COX-2 enzyme analogous to dexamethasone.

Relative apoptotic potential and specific G1 arrest of stigmasterol and cinnamic acid isolated from the brown algae Padina gymnospora in HeLa and A549 cells

Isolation, characterisation and identification of the molecular mechanism of apoptosis by small molecules from the Padina gymnospora of south east coast of India revealed that they exhibit tumor suppression mediated by p53 activation.