In the present study, two phyto-compounds phenyl aldehyde (cinnamaldehyde) and propanoid (eugenol) were selected to explore their modes of action against Candida albicans. Electron microscopy, flow cytometry and spectroscopic assays were employed to determine the targets of these compounds. Treatment of C. albicans (CA04) with sub-MICs of cinnamaldehyde (50 μg/mL) and eugenol (200 μg/mL) indicated multiple sites of action including damages to cell walls, cell membranes, cytoplasmic contents and other membranous structures as observed under electron microscopy. Concentration and time dependent increase in the release of cytoplasmic contents accompanied with change in extracellular K+ concentration was recorded. Exposure of Candida cells at 4 × MIC of cinnaamldehyde and eugenol resulted in 40.21% and 50.90% dead cells, respectively as revealed by flow cytometry analysis. Treatment of Candida cells by cinnamaldehyde and eugenol at 0.5 × MIC showed 67.41% and 76.23% reduction in ergosterol biosynthesis, respectively. The binding assays reflected the ability of compounds to bind with the ergosterol. Our findings have suggested that the membrane damaging effects of phenyl aldehyde and propanoids class of compounds is attributed to their ability to inhibit ergosterol biosynthesis and simultaneously binding with ergosterol. Indirect or secondary action of these compounds on cell wall is also expected as revealed by electron microscopic studies.
Candida albicans has remained the main etiological agent of candidiasis, challenges clinicians with high mortality and morbidity. The emergence of resistance to antifungal drugs, toxicity and lower... Lay abstract Over the last decade, candidiasis has remained a major problematic disease worldwide. In spite of the existence of many antifungal drugs, the treatment of such diseases has still remai... Graphical abstract
Neurodegenerative diseases (NDs) are characterized by the accumulation of misfolded proteins. The hallmarks of protein aggregation in NDs proceed with impairment in the mitochondrial function, besides causing an enhancement in endoplasmic reticulum (ER) stress, neuroinflammation and synaptic loss. As accumulation of misfolded proteins hampers normal neuronal functions, it triggers ER stress, which leads to the activation of downstream effectors formulating events along the signaling cascade—referred to as unfolded protein response (UPRER) —thereby controlling cellular gene expression. The absence of disease-modifying therapeutic targets in different NDs, and the exponential increase in the number of cases, makes it critical to explore new approaches to treating these devastating diseases. In one such approach, osmolytes (low molecular weight substances), such as taurine have been found to promote protein folding under stress conditions, thereby averting aggregation of the misfolded proteins. Maintaining the structural integrity of the protein, taurine-mediated resumption of protein folding prompts a shift in folding homeostasis more towards functionality than towards aggregation and degradation. Together, taurine enacts protection in NDs by causing misfolded proteins to refold, so as to regain their stability and functionality. The present study provides recent and useful insights into understanding the progression of NDs, besides summarizing the genetics of NDs in correlation with mitochondrial dysfunction, ER stress, neuroinflammation and synaptic loss. It also highlights the structural and functional aspects of taurine in imparting protection against the aggregation/misfolding of proteins, thereby shifting the focus more towards the development of effective therapeutic modules that could avert the development of NDs.
15 September 2014 in BMC Complementary and Alternative Medicine
Emergence of drug-resistant strains of Candida and inefficiency of conventional antifungal therapy has necessitated the search for alternative and new antifungal agents. Inhibition of virulence and biofilm are the potential drug targets. In this study, the oils of Carum copticum, Thymus vulgaris and their major active compound thymol as revealed by Gas chromatography and gas chromatography–mass spectrometry (GC-GC/MS) analysis were tested for their inhibitory activity against growth to determine sub-MIC values against 27 drug-resistant strains of Candida spp. Brothmacrodilution method was used for determination of MIC of test oils against Candida strains. The spectrophotometric methods were used for detection and inhibition assays for virulence factors in Candida spp. Light and electron microscopy was performed to observe morphological effects of oils on biofilms. GC-GC/MS were used to evaluate the major active compounds of test oils. Virulence factors like proteinase and haemolysin were detected in 18 strains, both in solid and liquid media. A 70% of the test strains exhibited hydrophobicity and formed moderate to strong biofilms (OD280 0.5- > 1.0). Test oils exhibited MICs in the range of 45–360 μg.mL−1 against the majority of test strains. All the oils at 0.25× and 0.5× MICs induced >70% reduction in the cell surface hydrophobicity, proteinase and haemolysin production. At 0.5× MIC, thymol and T. vulgaris were most inhibitory against biofilm formation. At sub-MICs electron microscopic studies revealed the deformity of complex structures of biofilms formed and cell membranes appeared to be the target site of these agents. Therefore, our findings have highlighted the concentration dependent activity of oils of C. copticum and T. vulgaris against virulence factors and biofilms in proteinase and haemolysin producing drug-resistant strains of Candida spp. The above activities of test oils are supposed to be mainly contributed due to their major active compound thymol. Further mechanism involving anti-proteinase, anti-haemolysin and anti-biofilm activities of these oils and compounds are to be explored for possible exploitation in combating Candida infections.
Cancer is one of the major leading causes of death worldwide. Designing the new anticancer drugs is remained a challenging task due to ensure complexicity of cancer etiology and continuosly emerging drug resistance. Glycolipid biosurfactants are known to possess various biological activities including antimicrobial, anticancer and antiviral properties. In the present study, we sought to decipher the mechanism of action of the glycolipids (lactonic-sophorolipd, acidic-sophorolipid, glucolipid, and bolalipid) against cancer cells using lung cancer cell line (A549), breast cancer cell line (MDA-MB 231), and mouse skin melanoma cell line (B16F10). Scratch assay and fluorescence microscopy revealed that glycolipids inhibit tumorous cell migration possibly by inhibiting actin filaments. Fluorescence activated cell sorter (FACS) analysis exhibited that lactonic sophorolipid and glucolipid both induced the reactive oxygen species, altered the mitochondrial membrane potential (ΔΨ) and finally led to the cell death by necrosis. Furthermore, combinatorial effect of lactonic-sophorolipd and glucolipid demonstrated synergistic interaction on A549 cell line whereas additive effect on MDA-MB 231 and B16F10 cell lines. Our study has highlighted that lactonic-sophorolipd and glucolipid could be useful for developing new anticancer drugs either alone or in combination.