A genetic screen to uncover mechanisms underlying lipid transfer protein function at membrane contact sites

Lipid transfer proteins mediate the transfer of lipids between organelle membranes, and the loss of function of these proteins has been linked to neurodegeneration. However, the mechanism by which loss of lipid transfer activity leads to neurodegeneration is not understood. In Drosophila photoreceptors, depletion of retinal degeneration B (RDGB), a phosphatidylinositol transfer protein, leads to defective phototransduction and retinal degeneration, but the mechanism by which loss of this activity leads to retinal degeneration is not understood. RDGB is localized to membrane contact sites through the interaction of its FFAT motif with the ER integral protein VAP. To identify regulators of RDGB function in vivo, we depleted more than 300 VAP-interacting proteins and identified a set of 52 suppressors of rdgB The molecular identity of these suppressors indicates a role of novel lipids in regulating RDGB function and of transcriptional and ubiquitination processes in mediating retinal degeneration in rdgB9 The human homologs of several of these molecules have been implicated in neurodevelopmental diseases underscoring the importance of VAP-mediated processes in these disorders.

Reduced graphene oxide-loaded nanocomposite scaffolds for enhancing angiogenesis in tissue engineering applications

Tissue engineering combines cells, scaffolds and signalling molecules to synthesize tissues in vitro. However, the lack of a functioning vascular network severely limits the effective size of a tissue-engineered construct. In this work, we have assessed the potential of reduced graphene oxide (rGO), a non-protein pro-angiogenic moiety, for enhancing angiogenesis in tissue engineering applications. Polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) scaffolds loaded with different concentrations of rGO nanoparticles were synthesized via lyophilization. Characterization of these scaffolds showed that the rGO-loaded scaffolds retained the thermal and physical properties (swelling, porosity and in vitro biodegradation) of pure PVA/CMC scaffolds. In vitro cytotoxicity studies, using three different cell lines, confirmed that the scaffolds are biocompatible. The scaffolds containing 0.005 and 0.0075% rGO enhanced the proliferation of endothelial cells (EA.hy926) in vitro. In vivo studies using the chick chorioallantoic membrane model showed that the presence of rGO in the PVA/CMC scaffolds significantly enhanced angiogenesis and arteriogenesis.

Gentiana lutea exerts anti-atherosclerotic effects by preventing endothelial inflammation and smooth muscle cell migration

BACKGROUND AND AIMS

Studies suggest that Gentiana lutea (GL), and its component isovitexin, may exhibit anti-atherosclerotic properties. In this study we sought to investigate the protective mechanism of GL aqueous root extract and isovitexin on endothelial inflammation, smooth muscle cell migation, and on the onset and progression of atherosclerosis in streptozotocin (STZ)-induced diabetic rats.

METHODS AND RESULTS

Our results show that both GL extract and isovitexin, block leukocyte adhesion and generation of reactive oxygen species in human umbilical vein endothelial cells (HUVECs) and rat aortic smooth muscle cells (RASMCs), following TNF-alpha and platelet derived growth factor-BB (PDGF-BB) challenges respectively. Both the extract and isovitexin blocked TNF-α induced expression of ICAM-1 and VCAM-1 in HUVECs. PDGF-BB induced migration of RASMCs and phospholipase C-γ activation, were also abrogated by GL extract and isovitexin. Fura-2 based ratiometric measurements demonstrated that, both the extact, and isovitexin, inhibit PDGF-BB mediated intracellular calcium rise in RASMCs. Supplementation of regular diet with 2% GL root powder for STZ rats, reduced total cholesterol in blood. Oil Red O staining demonstrated decreased lipid accumulation in aortic wall of diabetic animals upon treatment with GL. Medial thickness and deposition of collagen in the aortic segment of diabetic rats were also reduced upon supplementation. Immunohistochemistry demonstrated reduced expression of vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS), and vascular endothelial cadherin (VE-cadherin) in aortic segments of diabetic rats following GL treatment.

CONCLUSIONS

Thus, our results support that GL root extract/powder and isovitexin exhibit anti-atherosclerotic activities.

Quantitative Mueller matrix fluorescence spectroscopy for precancer detection

Quantitative fluorescence spectroscopic Mueller matrix measurements from the connective tissue regions of human cervical tissue reveal intriguing fluorescence diattenuation and polarizance effects. Interestingly, the estimated fluorescence linear diattenuation and polarizance parameters were considerably reduced in the precancerous tissues as compared to the normal ones. These polarimetry effects of the autofluorescence were found to originate from anisotropically organized collagen molecular structures present in the connective tissues. Consequently, the reduction of the magnitude of these polarimetric parameters at higher grades of precancer was attributed to the loss of anisotropic organization of collagen, which was also confirmed by control experiments. These results indicate that fluorescence spectral diattenuation and polarizance parameters may serve as potentially useful diagnostic metrics.

Effect of artesunate based combination therapy with homeopathic medicine china on liver and kidney of Plasmodium berghei infected mice

Present study has been undertaken to evaluate antimalarial potential and safety of artesunate based combination therapy with homeopathic medicine china (ϕ/30 potency) against Plasmodium berghei (NK-65), a lethal rodent malaria parasite. In combination therapy, the oral administration of artesunate (100 mg/kg) + china ϕ/30 proved to be highly efficacious as it completely cleared the blood stage infection. During the follow up period up to day 28, no recrudescence was observed and the survival rate was 100 %. Combination did not disturb the normal functioning of liver and kidney, as evident from the normal activity of ALP (190.5 ± 0.2 and 174.2 ± 9.12 IU/l), level of bilirubin (0.6 ± 0.33 and 0.73 ± 0.1 mg/dl), urea (28 ± 0.51 and 29.1 ± 0.03 mg/dl) and creatinine (0.9 ± 0.62 and 1.1 ± 0.1 mg/dl) in serum of treated mice on day 7 and 28 respectively. Present study points to better efficacy of china as an alternative drug partner in combination to enhance antimalarial efficacy of artesunate without affecting the liver and kidney functions of P. berghei infected BALB/c mice.

Development and Validation of HPTLC Method for Estimation of Tenoxicam and its Formulations

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the estimation of tenoxicam in the microemulsion gels. Tenoxicam was chromatographed on silica gel 60 F(254) TLC plate, as a stationary phase. The mobile phase was toluene: ethyl acetate: formic acid (6:4:0.3 v/v/v), which gave a dense and compact spot of tenoxicam with a R(f) value of 0.38±0.03. The quantification was carried out at 379 nm. The method was validated in terms of linearity, accuracy, precision and specificity. To justify the suitability, accuracy and precision of the proposed method, recovery studies were performed at three concentration levels. Statistical analysis proved that the proposed method is accurate and reproducible with linearity in the range of 100 to 400 ng. The limit of detection and limit of quantification for tenoxicam were 25 and 50 μg/spot, respectively. The proposed method can be employed for the routine analysis of tenoxicam as well as in pharmaceutical formulations.

Antiplasmodial activity of Ajuga bracteosa against Plasmodium berghei infected BALB/c mice

BACKGROUND & OBJECTIVES

The present work was undertaken to evaluate antiplasmodial activity of ethanolic leaves extract of traditional medicinal plant Ajuga bracteosa in Plasmodium berghei infected BALB/c mice along with its phytochemical screening and acute toxicity test to support its traditional use as a remedy for malaria.

METHODS

Plant extract (ethanolic) 250, 500, 750 mg/kg/day was evaluated in the early and established infection along with repository activity in P. berghei infected BALB/c mice through suppressive, curative and preventive test. The phytochemical screening was carried out by employing standard procedures. The acute toxicity was checked through limit test.

RESULTS

The ethanolic leaves extract of A. bracteosa (250, 500 and 750 mg/kg/day) demonstrated a dose-dependent chemosuppression during early and in established infections, along with significant (P<0.05) repository activity. At a concentration of 750 mg/kg/day maximum 77.7 per cent chemosuppression during early infection and 68.8 per cent chemosuppression in repository activity were found. This dose enhanced significant mean survival period up to 27.4 +/- 0.46 days in established infection. ELEAB was found to be safe up to 5 g/kg weight when administrated orally in the female BALB/c mice, which is upper limit for oral administration of the test material to rodents. ED(50) of ELEAB was 300 mg/kg body weight of mice.

INTERPRETATION & CONCLUSION

ELEAB inhibited parasitaemia and enhanced mean survival time in a dose- dependent manner upto 750 mg/kg/day dose in treated mice. Further studies need to be done to isolate and characterize active constituents of extract and to study their mechanism of action.