Sleep deprivation in obesogenic setting alters lipidome and microbiome toward suboptimal inflammation in acute heart failure.

Sleep is a fundamental medicine for cardiac homeostasis, and sleep-deprived individuals are prone to higher incidences of heart attack. The lipid-dense diet (obesogenic diet-OBD) is a cumulative risk factor for chronic inflammation in cardiovascular disease; thus, understanding how sleep fragmentation (SF) in an obesity setting impacts immune and cardiac health is an unmet medical need. We hypothesized whether the co-existence of SF with OBD dysregulates gut homeostasis and leukocyte-derived reparative/resolution mediators, thereby impairing cardiac repair. Two-month-old male C57BL/6J mice were randomized first into two groups, then four groups; Control, control + SF, OBD, and OBD + SF mice subjected to myocardial infarction (MI). OBD mice had higher levels of plasma linolenic acid with a decrease in eicosapentaenoic and docosahexaenoic acid. The OBD mice had lower Lactobacillus johnsonii indicating a loss of probiotic microbiota. SF in OBD mice increased Firmicutes/Bacteroidetes ratio indicative of a detrimental change in SF-directed microbiome. OBD + SF group increased in the neutrophil: lymphocyte ratio suggestive of suboptimal inflammation. As a result of SF, resolution mediators (RvD2, RvD3, RvD5, LXA4 , PD1, and MaR1) decreased and inflammatory mediators (PGD2 , PGE2 , PGF2a , 6k-PGF1a ) were increased in OBD mice post-MI. At the site of infarction, the proinflammatory cytokines Ccl2, IL1ß, and IL-6 were amplified in OBD + SF indicating a robust proinflammatory milieu post-MI. Also, brain circadian genes (Bmal1, Clock) were downregulated in SF-subjected control mice, but remained elevated in OBD mice post-MI. SF superimposed on obesity dysregulated physiological inflammation and disrupted resolving response thereby impaired cardiac repair and signs of pathological inflammation.

Interaction of aging with lipoxygenase deficiency initiates hypersplenism, cardiac dysfunction, and profound leukocyte directed non-resolving inflammation.

In the process of physiological cardiac repair, splenic leukocyte-activated lipoxygenases (LOXs) are essential for the biosynthesis of specialized pro-resolving lipid mediators as a segment of an active process of acute inflammation in splenocardiac manner. In contrast, young 12/15LOX-/- mice use a compensatory mechanism that amplifies epoxyeicosatrienoic acid mediators after myocardial infarction, improving cardiac repair, function, and survival. Next, we tested whether deletion of 12/15LOX impacted the genesis of chronic inflammation in progressive aging. To test the risk factor of aging, we used the inter-organ hypothesis and assessed heart and spleen leukocyte population along with the number of inflammation markers in age-related 12/15LOX-/- aging mice (2 months, 6 months, 13 months) and compared with C57BL/6 J (WT; wild type) as controls (2 months). The 12/15LOX-/- aging mice showed an age-related increase in spleen mass (hypersplenism) and decreased marginal zone area. Results suggest increased interstitial fibrosis in the heart marked with the inflammatory mediator (PGD2) level in 12/15LOX-/- aging mice than WT controls. From a cellular perspective, the quantitative measurement of immune cells indicates that heart and spleen leukocytes (CD11b+ and F4/80+ population) were reduced in 12/15LOX-/- aging mice than WT controls. At the molecular level, analyses of cytokines in the heart and spleen suggest amplified IFN-γ, with reduced COX-1, COX-2, and ALOX5 expression in the absence of 12/15LOX-derived mediators in the spleen. Thus, aging of 12/15LOX-/- mice increased spleen mass and altered spleen and heart structure with activation of multiple molecular and cellular pathways contributing to age-related integrative and inter-organ inflammation.

Redox-Sensitive Linear and Cross-Linked Cystamine-Based Polymers for Colon-Targeted Drug Delivery: Design, Synthesis, and Characterisation.

Cystamine-based polymers may help to achieve controlled and targeted drug delivery to the colon due to their susceptibility to breakage of the disulfide linkage in the low redox potential environment of the colon. In this study, two linear cystamine-based polymers with similar repeating units (LP1 and LP2) and a cross-linked cystamine-based polymer (BP) were synthesised and their kinetics and the various physical conditions underlying cystamine-based polymerisation were evaluated. In brief, N1, N6-bis(2-(tritylthio)ethyl)adipamide (2) was synthesised from the reaction of triphenylmethanol and cysteamine. Next, the trityl group of 2 was removed with trifluoroacetic acid and triethylsilane before proceeding to oxidative polymerisation of the end product, N1, N6-bis(2-mercaptoethyl)adipamide (3) to LP1. The Schotten-Bauman reaction was applied to synthesise LP2 and BP from the reaction of cystamine with adipoyl chloride or trimesoyl chloride. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and mapping showed that oxygen, nitrogen, sulfur, and carbon were homogenously distributed in the polymers, with LP2 and BP having less porous morphologies compared to LP1. Results of zinc-acetic acid reduction showed that all polymers began to reduce after 15 min. Moreover, all synthesised polymers resisted stomach and small intestine conditions and only degraded in the presence of bacteria in the colon environment. Thus, these polymers have great potential for drug delivery applications. LP2 and BP, which were synthesised using the Schotten-Bauman reaction, were more promising than LP1 for colon-targeted drug delivery.

Docetaxel-Loaded Disulfide Cross-Linked Nanoparticles Derived from Thiolated Sodium Alginate for Colon Cancer Drug Delivery.

In this study, fluorescein-labelled wheat germ agglutinin (fWGA)-conjugated disulfide cross-linked sodium alginate nanoparticles were developed to specifically target docetaxel (DTX) to colon cancer cells. Different amounts of 3-mercaptopropionic acid (MPA) were covalently attached to sodium alginate to form thiolated sodium alginate (MPA1-5). These polymers were then self-assembled and air-oxidised to form disulfide cross-linked nanoparticles (MP1-5) under sonication. DTX was successfully loaded into the resulting MP1-5 to form DTX-loaded nanoparticles (DMP1-5). DMP2 had the highest loading efficiency (17.8%), thus was chosen for fWGA surface conjugation to form fWGA-conjugated nanoparticles (fDMP2) with a conjugation efficiency of 14.1%. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses showed spherical nanoparticles, and an in vitro drug release study recorded a cumulative drug release of 48.6%. Dynamic light scattering (DLS) analysis revealed a mean diameter (MD) of 289 nm with a polydispersity index (PDI) of 0.3 and a zeta potential of -2.2 mV for fDMP2. HT-29 human colon cancer cells treated with fDMP2 showed lower viability than that of L929 mouse fibroblast cells. These results indicate that fDMP2 was efficiently taken up by HT-29 cells (29.9%). Fluorescence and confocal imaging analyses also showed possible internalisation of nanoparticles by HT-29 cells. In conclusion, fDMP2 shows promise as a DTX carrier for colon cancer drug delivery.

Optimization of biogenic synthesis of silver nanoparticles from flavonoid-rich Clinacanthus nutans leaf and stem aqueous extracts.

Background: Silver nanoparticles (AgNPs) are widely used in food industries, biomedical, dentistry, catalysis, diagnostic biological probes and sensors. The use of plant extract for AgNPs synthesis eliminates the process of maintaining cell culture and the process could be scaled up under a non-aseptic environment. The purpose of this study is to determine the classes of phytochemicals, to biosynthesize and characterize the AgNPs using Clinacanthus nutans leaf and stem extracts. In this study, AgNPs were synthesized from the aqueous extracts of C. nutans leaves and stems through a non-toxic, cost-effective and eco-friendly method. Results: The formation of AgNPs was confirmed by UV-Vis spectroscopy, and the size of AgNP-L (leaf) and AgNP-S (stem) were 114.7 and 129.9 nm, respectively. Transmission electron microscopy (TEM) analysis showed spherical nanoparticles with AgNP-L and AgNP-S ranging from 10 to 300 nm and 10 to 180 nm, with average of 101.18 and 75.38 nm, respectively. The zeta potentials of AgNP-L and AgNP-S were recorded at -42.8 and -43.9 mV. X-ray diffraction analysis matched the face-centred cubic structure of silver and was capped with bioactive compounds. Fourier transform infrared spectrophotometer analysis revealed the presence of few functional groups of phenolic and flavonoid compounds. These functional groups act as reducing agents in AgNPs synthesis. Conclusion: These results showed that the biogenically synthesized nanoparticles reduced silver ions to silver nanoparticles in aqueous condition and the AgNPs formed were stable and less toxic.

Biocompatible disulphide cross-linked sodium alginate derivative nanoparticles for oral colon-targeted drug delivery.

The application of layer-by-layer (LbL) approach on nanoparticle surface coating improves the colon-specific drug delivery of insoluble drugs. Here, we aimed to formulate a self-assembled cysteamine-based disulphide cross-linked sodium alginate with LbL self-assembly to improve the delivery of paclitaxel (PCX) to colonic cancer cells. Cysteamine was conjugated to the backbone of oxidized SA to form a core of self-assembled disulphide cross-linked nanospheres. P3DL was selected for PCX loading and fabricated LbL with poly(allylamine hydrochloride) (PAH) and poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSSCMA) resulting from characterization and drug release studies. P3DL-fabricated PCX-loaded nanospheres (P3DL/PAH/PSSCMA) exhibited an encapsulation efficiency of 77.1% with cumulative drug release of 45.1%. Dynamic light scattering analysis was reported at 173.6 ± 2.5 nm with polydispersity index of 0.394 ± 0.105 (zeta potential= -58.5 mV). P3DL/PAH/PSSCMA demonstrated a pH-dependent swelling transition; from pH 1 to 7 (102.2% increase). The size increased by 33.0% in reduction response study after incubating with 10 mM glutathione (day 7). HT-29 cells showed high viabilities (86.7%) after treatment with the fabricated nanospheres at 0.8 µg/mL. Cellular internalization was successful with more than 70.0% nanospheres detected in HT-29 cells. Therefore, this fabricated nanospheres may be considered as potential nanocarriers for colon cancer-targeted chemotherapeutic drug delivery.

Characterisation and Evaluation of Trimesic Acid Derivatives as Disulphide Cross-Linked Polymers for Potential Colon Targeted Drug Delivery.

Discovery and use of biocompatible polymers offers great promise in the pharmaceutical field, particularly in drug delivery systems. Disulphide bonds, which commonly occur in peptides and proteins and have been used as drug-glutathione conjugates, are reductively cleaved in the colon. The intrinsic stability of a disulphide relative to thiol groups is determined by the redox potential of the environment. The objective of this study was to synthesise a trimesic acid-based disulphide cross-linked polymer that could potentially be used for targeted delivery to the colon. The monomer was synthesised by an amide coupling reaction between trimesic acid and (triphenylmethyl) thioethylamine using a two-step synthesis method. The s-trityl group was removed using a cocktail of trifluoroacetic acid and triethylsilane to expose the thiols in preparation for further polymerisation. The resulting polymers (P10, P15, P21, P25, and P51, generated using different molar ratios) were reduced after 1.5 h of reduction time. Scanning electron microscopy images of the polymers showed spherical, loose, or tight patterns depending on the molar ratio of polymerisation. These polymers also exhibited efficient dissolution under various gastrointestinal conditions. Of the five polymers tested, P10 and P15 appeared to be promising drug delivery vehicles for poorly soluble drugs, due to the hydrophobic nature of the polymers.

Pharmacognostic and Antioxidant Properties of Dracaena sanderiana Leaves.

Endogenous and exogenous antioxidants are used to neutralise free radicals and protect the body from free radicals by maintaining the redox balance. The antioxidant properties of Dracaena sanderiana leaves were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and the total phenolic and flavonoid contents were measured. The classes of secondary metabolites were evaluated through pharmacognostic studies, and active compounds were identified by gas chromatography mass-spectrometry (GC-MS). All ethanol-water extracts and D. sanderiana leaf powder were positive for tannins, saponins, terpenoids, cardiac glycosides, and quinones. Flavonoids were present in 100%, 80%, 60%, and 40% ethanol extracts (E100, E80, E60, and E40). E100 showed the highest total flavonoid content, whereas E60 extract showed the highest antioxidant activity and total phenolic content. GC-MS revealed the presence of glycerol, 2,3-dihydro-3,5-dihydroxy-6-methyl-(4H)-pyran-4-one, n-dodecanoic acid, tetradecanoid acid, (n-) hexadecanoid acid, and n-octadecanoic acid in the E60 extract.