Fungal symbionts of marine sponges from Rameswaram, southern India: species composition and bioactive metabolites

Ten marine sponge species from Rameswaram, southern India were studied for their filamentous fungal symbionts. The results suggest that fungal symbionts of marine sponges are hyperdiverse. Genera such as Acremonium, Alternaria, Aspergillus, Cladosporium, Fusarium and Penicillium were frequently isolated; no true marine fungal species were present. Species of Aspergillus were dominant and co-dominant in all the sponges screened. The fungal isolates produced antialgal, antifungal, antioxidant, antibiotic, antiinsect metabolites. A few fungi produced acetylcholinesterase inhibitors.     

Copper nanoparticles synthesized by polyol process used to control hematophagous parasites

The present study was based on assessments of the anti-parasitic activities of the hematophagous (blood feeding) larvae of malaria vector, Anopheles subpictus Grassi, filariasis vector, Culex quinquefasciatus, Say (Diptera: Culicidae), and the larvae of cattle tick Rhipicephalus (Boophilus) microplus, Canestrini (Acari: Ixodidae). The metallic copper nanoparticles (Cu NPs) synthesized by polyol process from copper acetate as precursor and Tween 80 were used as both the medium and the stabilizing reagent. The efficacy of synthesized Cu NPs was tested against the larvae of blood-sucking parasites. UV-vis spectra characterization was performed, and peak was observed at 575 nm, which is the characteristic to the surface plasmon bond of Cu NPs. The strong surface plasmon absorption band observed at 575 nm may be due to the formation of non-oxidized Cu NPs. X-ray diffraction (XRD) spectral data showed concentric rings corresponding to the 26.79 (111), 34.52 (200), and 70.40 (220) reflections. XRD spectrum of the copper nanoparticles exhibited 2θ values corresponding to the copper nanocrystal. No peaks of impurities are observed in XRD data. The scanning electron micrograph (SEM) showed structures of irregular polygonal, cylindrical shape, and the size range was found to be 35–80 nm. The size of the Cu NPs was measured by atomic force microscope (AFM) in non-contact mode. For imaging by AFM, the sample was suspended in acetone and spins coated on a silicon wafer. The line profile image was drawn by the XEI software and the horizontal line at 6 μm on a 2D AFM image. Research has demonstrated that metallic nanoparticles produce toxicity in aquatic organisms that is due largely to effects of particulates as opposed to release of dissolved ions. Copper acetate solution tested against the parasite larvae exposed to varying concentrations and the larval mortality was observed for 24 h. The larval percent mortality observed in synthesized Cu NPs were 36, 49, 75, 93,100; 32, 53, 63, 73, and 100 and 36, 47, 69, 88, 100 at 0.5, 1.0, 2.0, 4.0, and 8.0 mg/L against A. subpictus, C. quinquefasciatus and R. microplus, respectively. The larval percent mortality shown in copper acetate solution were 16, 45, 57, 66 and 100, 37, 58, 83, 87, and 100 and 41, 59, 79, 100, and 100 at 10, 20, 30, 40, and 50 mg/L against A. subpictus, C. quinquefasciatus, and R. microplus, respectively. The maximum efficacy was observed in Cu NPs and copper acetate solution against the larvae of A. subpictus, C. quinquefasciatus, and R. microplus with LC₅₀ and r ² values of 0.95 and 23.47, 1.01 and 15.24, and 1.06 and 14.14 mg/L with r ² = 0.766; 0.957 and 0.908; 0.946; and 0.816 and 0.945, respectively. The control (distilled water) showed nil mortality in the concurrent assay. The chi-square value was significant at p ≤ 0.05 level. This is the first report on anti-parasitic activity of the synthesized Cu NPs and copper acetate solution.     

Fungal endophytes: an untapped source of biocatalysts

Horizontally transmitted endophytes are an ecological group of fungi that infect living plant tissues and survive in them without causing any disease symptoms. Even as facets of the endophyte-plant symbiotic relationship are being uncovered, there is an increasing appreciation of the different growth substrates exploited by endophytes and the vast repertoire of secreted enzymes of these fungi. These attributes exemplify the striking biodiversity of fungal endophytes and should motivate bioprospecting these organisms to identify novel biocatalysts that might help address challenges in medicine, food security, energy production and environmental quality.     

2-Hydroxy-4-methoxy benzoic acid attenuates the carbon tetra chloride-induced hepatotoxicity and its lipid abnormalities in rats via anti-inflammatory and antioxidant mechanism

Background and aim

Liver inflammation stimulates various inflammatory cytokines and initiates injury through oxidative stress. The aim of this study was to curtaile the liver injury through natural principles such as 2-hydroxy-4-methoxy benzoic acid (HMBA).

Methods

The current study examines the hepatoprotective and lipid lowering effect of HMBA against carbon tetra chloride (CCl₄)-mediated liver toxicity in male Wistar rats.

Results

The hepatoprotective effects of HMBA against CCl₄-induced liver damage, were evident from low serum transaminases activities, reduced hepatic lipid peroxidation and collagen content, restoration of total glutathione, and recouping of the inflammatory cytokines, such as TNF-α, IL-1β, IL-10, and IL-6 levels. Further it was found that the treatment of HMBA, significantly lowered (P<0.01) the levels of total cholesterol, triglycerides, free fatty acids and phospholipids in serum and liver. To investigate the mechanism behind the hepatoprotective and lipid lowering effect, the activities of heme oxygenase (HO1), and myeloperoxidase (MPO) were measured and expression levels were quantified through western blot following HMBA administration. The results showed that HMBA administration significantly decreased the activity of HO1 (P<0.001), and increased the activity of MPO (P<0.001); further similar finding was observed in western analysis. The hepatoprotective, lipid lowering and shifting key defensive enzyme activities are similar to that of standard drug such as N-acetylcysteine.

Conclusion

HMBA is competent of shielding liver from CCl₄-induced hepatotoxicity, and this is associated with the lipid lowering, inflammatory cytokine restoration and induction of defensive enzyme activities.

     

Theoretical predictions of folding pathways by using the proximity rule, with applications to bovine pancreatic trypsin inhibitor.

We propose a phenomenological theory that accounts for entropic effects due to loop formation to predict pathways in the kinetics of protein folding. The theory, the basis of which lies in multiple folding pathways and a three-stage kinetics, qualitatively reproduces most of the kinetic measurements in the refolding of bovine pancreatic trypsin inhibitor. The resulting pathways show that nonnative kinetic transients are involved in the productive routes leading to the formation of native intermediates. Our theory emphasizes the importance of the random origin of chain folding initiation structures in directing protein folding.