Elucidation of marine fungi derived anthraquinones as mycobacterial mycolic acid synthesis inhibitors: an in silico approach.

Tuberculosis (TB) is a leading cause of mortality amongst infectious diseases. While the anti-TB drugs can cure TB, the non-compliance and rapidly increasing resistance is of serious concern. The study aimed to search novel potent inhibitor(s) against MabA and PKS18 targets of Mycobacterium tuberculosis (M.tb.) by virtual screening of anthraquinones from marine fungi. The target proteins MabA and PKS18 involved in M.tb. mycolic acid biosynthesis were retrieved from RCSB Protein Data Bank. Chemical structures of 100 marine fungal anthraquinones were retrieved from the PubChem database. These were filtered through Lipinski's rule of five (for druglikeness) and in silico ADME/Tox analysis (for pharmacokinetic properties) and subjected to molecular docking analysis using AutoDock 4.2. The molecular interaction revealed averufin to possess dual inhibitory potential against M.tb. MabA and PKS18 with binding energy of - 8.84 kcal/mol and - 8.23 kcal/mol, and Ki values of 1.79 and 3.12 µM respectively. Averufin exhibits improved drug-like properties, ADMET profile and binding affinity to both targets as compared to control drugs. Our study suggests that averufin a natural anthraquinone, satisfies all the in silico parameters tested and is expected to efficiently inhibit M.tb. mycolic acid pathway. It might therefore emerge as a promising dual-targeted, novel natural anti-TB lead in future.

Anti-Cancerous Effect of Rutin Against HPV-C33A Cervical Cancer Cells via G0/G1 Cell Cycle Arrest and Apoptotic Induction.

BACKGROUND: Nowadays, the potential therapeutic role of various bioflavonoids including Curcumin, Luteolin and Resveratrol has currently been well-documented in a vast range of fatal complications including synaptic failure and cancers. These bioflavonoids are widely being implemented for the treatment of various cancers as they possess anti-cancerous, anti-oxidant and anti-inflammatory properties. Moreover, they are also used as a better alternative to conventional therapies since; these are non-toxic to cells and having no or least side effects. Notably, the pertinent therapeutic role of Rutin in cervical cancer is still unsettled however, its anti-cancerous role has already been reported in other cancers including prostate and colon cancer. Rutin (Vitamin P or Rutoside) is a polyphenolics flavonoid exhibiting multi-beneficial roles against several carcinomas. OBJECTIVE: Despite the evidence for its several biological activities, the anticancer effects of Rutin on human cervical cancer (C33A) cells remain to be explored. In this study, the anticancer potential of Rutin was investigated by employing the key biomarkers such as nuclear condensation reactive oxygen species (ROS), apoptosis, and changes in mitochondrial membrane potential (MMP). RESULTS: Our findings showed that Rutin treatment reduced the cell viability, induced significant increase in ROS production and nuclear condensation in dose-dependent manner. Moreover, Rutin provoked apoptosis by inducing decrease in MMP and activation of caspase-3. Cell cycle analysis further confirmed the efficacy of Rutin by showing cell cycle arrest at G0/G1 phase. CONCLUSION: Thus, our study is envisaged to open up interests for elucidating Rutin as an anticancerous agent against cervical cancer.

Nano-Rifabutin entrapment within glucan microparticles enhances protection against intracellular Mycobacterium tuberculosis.

Recently, yeast-derived glucan particles (GP) have emerged as novel drug delivery agents that provide for receptor-mediated uptake by phagocytic cells expressing ß-glucan receptors. In our previous study, we prepared GP loaded with high payload (40.5 + 1.9%) of rifabutin (RB) nano-particles [(RB-NPs)-GP]. We investigated the anti-mycobacterial efficacy and cellular activation responses within Mycobacterium tuberculosis (M. tuberculosis) infected J774 macrophage cells following exposure to the (RB-NPs)-GP formulation. The exposure was seen to augment a robust innate immune response including the induction of reactive oxygen and nitrogen species, autophagy and apoptosis within M. tuberculosis infected macrophage. Further, the efficacy testing of these particles in murine macrophage exhibited that the (RB-NPs)-GP formulation enhanced the efficacy of RB drug by ∼2.5 fold. The study suggests that the set of innate responses conducive to killing intracellular bacteria evoked by (RB-NPs)-GP play a pivotal role in impeding the intracellular M. tuberculosis survival, resulting in enhanced efficacy of the formulation. Our results establish that the (RB-NPs)-GP formulation not only activate M. tuberculosis infected, immune-suppressed macrophage, but also adds significantly to the efficacy of loaded drug, and thus forms a promising approach that should be explored further as an alternative or adjunct form of TB therapy. Highlights Nano-Rifabutin loaded Glucan microparticles [(RB-NPs)-GP] administered to M. tuberculosis infected macrophage. (RB-NPs)-GP induces appropriate innate immune responses in host macrophage. Mycobactericidal Effect of Rifabutin was markedly enhanced by its nano-entrapment in GP. Intracellular drug delivery supplements the innate response in M. tuberculosis infected macrophage.

Preparation and characterization of beta-glucan particles containing a payload of nanoembedded rifabutin for enhanced targeted delivery to macrophages.

ß-glucan particles (GP) are polymeric carbohydrates, mainly found as components of cell wall fungi, yeast, bacteria and also in cereals such as barley and oat, and have been recently shown to have application in macrophage-targeted drug delivery. The aim of this study was to prepare and characterize GP containing a large payload of Rifabutin (RB), an anti-tuberculosis drug effective against MDR-TB at lower MIC than Rifampicin. GP were prepared from yeast cells by acidic and alkaline extraction were either spray dried or lyophilized, prior to RB loading and alginate sealing. The FTIR and 13C-NMR spectra of the GP confirmed a ß-(1→3) linked glucan structure, with a triple-helical conformation. The spray dried GP exhibited better characteristics in terms of uniformity, size range (2.9 to 6.1 µm) and more than 75 % particles were below 3.5 µm. The RP-HPLC analysis of spray dried GP revealed drug entrapment and drug loading up to 81.46 ± 4.9 % and ~40.5 ± 1.9 %, respectively, as compared to those dried by lyophilization. Electron microscopy showed nearly spherical and porous nature of GP, and the presence of drug 'nanoprecipitates' filling the pore spaces. The formulation showed adequate thermal stability for pharmaceutical application. The particles were readily phagocytosed by macrophage(s) within 5 min of exposure. Drug release occurred in a sustained manner via diffusion, as the release kinetics best fit for drug release was obtained using Higuchi's equation. Thus, the spray dried GP-based-formulation technology holds promise for enhanced targeted delivery of anti-TB drug(s) to macrophage within a therapeutic window for the clearance of intracellular bacteria.