Improvement of the intestinal membrane permeability of low molecular weight heparin by complexation with stem bromelain

Beneficial Properties of Bromelain

Bromelain is a major sulfhydryl proteolytic enzyme found in pineapple plants, having multiple activities in many areas of medicine. Due to its low toxicity, high efficiency, high availability, and relative simplicity of acquisition, it is the object of inexhaustible interest of scientists. This review summarizes scientific reports concerning the possible application of bromelain in treating cardiovascular diseases, blood coagulation and fibrinolysis disorders, infectious diseases, inflammation-associated diseases, and many types of cancer. However, for the proper application of such multi-action activities of bromelain, further exploration of the mechanism of its action is needed. It is supposed that the anti-viral, anti-inflammatory, cardioprotective and anti-coagulatory activity of bromelain may become a complementary therapy for COVID-19 and post-COVID-19 patients. During the irrepressible spread of novel variants of the SARS-CoV-2 virus, such beneficial properties of this biomolecule might help prevent escalation and the progression of the COVID-19 disease.

Development and validation of UPLC-MS/MS method for the simultaneous quantification of anaplastic lymphoma kinase inhibitors, alectinib, ceritinib, and crizotinib in Wistar rat plasma with application to bromelain-induced pharmacokinetic interaction

Bromelain, the aqueous extract of pineapple, has been used as a food supplement with reported nutritional and therapeutic benefits. Bromelain has anti-cancer, anti-inflammatory, antithrombotic, and fibrinolytic effects. Anaplastic lymphoma kinase (ALK) inhibitors, including alectinib (ALC), ceritinib (CER), and crizotinib (CRZ), have been efficiently used in the management of non-small cell lung cancer (NSCLC). The solubility of ALC, CER, and CRZ is much higher at low acidic pH (pH 1) and it decreases as the pH increases affecting their absorption with a subsequent decrease in their bioavailability. It was thought that the intake of bromelain could result in a decrease in the bioavailability of ALC, CER, and CRZ due to bromelain-induced alkalizing effect following digestion. On the contrary, bromelain could possibly increase plasma exposure of the cited drugs due to its known muco-permeation enhancing effect. The therapeutic-anticancer effect of bromelain can be possibly increased/enhanced with concomitant intake of other anticancer medications or it can add to the value of food supplements for its known nutritional benefits. Thus, this work aims at studying the possibility of any PK interaction when bromelain was taken while on ALC/CER/CRZ therapy. In this work, a new UPLC-MS/MS method was developed and validated for the simultaneous determination of ALC, CER, and CRZ in rat plasma. Further application of the proposed method was performed to test the possibility of the PK interaction between bromelain and the selected ALK inhibitors in Wistar rats. Simple protein precipitation with acetonitrile was used for sample preparation. Chromatographic analysis was performed on Waters BEH™ C18 column with a mixture of acetonitrile/water containing 0.1 % formic acid (70: 30, v/v) as the mobile phase. The method permitted the analysis of ALC, CER, and CRZ in concentration ranges of 2-200, 0.4-200, and 4.0-200 ng/mL, respectively. Bromelain administration caused a significant decrease in plasma levels of CER and CRZ with lowered C_max, AUC_0-t and AUC_0-∞, along with an increase in the apparent clearance. However, no significant effect was noticed with ALC. Thus, attention should be paid to avoid the intake of bromelain with CER or CRZ.

Chitosan microencapsulation of the dispersed phase of an O/W nanoemulsion to hydrochlorothiazide delivery

In view of biopharmaceutical limitations of hydrochlorothiazide (HCTZ), Trojan-type mucoadhesive systems were proposed, aiming to improve HCTZ pharmacological properties by modulating its release. Nanoemulsions were formed spontaneously by combining medium-chain triglycerides (Lipoid^® S75 and Pluronic^® F68) and high encapsulation efficiency was obtained. The mucoadhesive properties were provided by chitosan and microencapsulation of nanoemulsions in spray-dryer was successfully achieved by using Aerosil^® as wall material. The rapid redispersion of nanoemulsion in simulated fluids led to a fast and complete release of HCTZ in gastric medium. The pharmacodynamics of HCTZ was improved, extending the diuretic activity. Once a simple and low-energy method contributed to obtain stable mucoadhesive nanoemulsions, advantages in terms of production could also be achieved, allowing easy scaling up. This novel mucoadhesive Trojan particulate system of HCTZ showed to be a promising approach to overcome limitations in terms of absorption and consequently improve the therapeutic efficacy.

Cerebral Microvascular Endothelial Cell Apoptosis after Ischemia: Role of Enolase-Phosphatase 1 Activation and Aci-Reductone Dioxygenase 1 Translocation

Enolase-phosphatase 1 (ENOPH1), a newly discovered enzyme of the methionine salvage pathway, is emerging as an important molecule regulating stress responses. In this study, we investigated the role of ENOPH1 in blood brain barrier (BBB) injury under ischemic conditions. Focal cerebral ischemia induced ENOPH1 mRNA and protein expression in ischemic hemispheric microvessels in rats. Exposure of cultured brain microvascular endothelial cells (bEND3 cells) to oxygen-glucose deprivation (OGD) also induced ENOPH1 upregulation, which was accompanied by increased cell death and apoptosis reflected by increased 3-(4, 5-Dimethylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide formation, lactate dehydrogenase release and TUNEL staining. Knockdown of ENOPH1 expression with siRNA or overexpressing ENOPH1 with CRISPR-activated plasmids attenuated or potentiated OGD-induced endothelial cell death, respectively. Moreover, ENOPH1 knockdown or overexpression resulted in a significant reduction or augmentation of reactive oxygen species (ROS) generation, apoptosis-associated proteins (caspase-3, PARP, Bcl-2 and Bax) and Endoplasmic reticulum (ER) stress proteins (Ire-1, Calnexin, GRP78 and PERK) in OGD-treated endothelial cells. OGD upregulated the expression of ENOPH1’s downstream protein aci-reductone dioxygenase 1 (ADI1) and enhanced its interaction with ENOPH1. Interestingly, knockdown of ENOPH1 had no effect on OGD-induced ADI1 upregulation, while it potentiated OGD-induced ADI1 translocation from the nucleus to the cytoplasm. Lastly, knockdown of ENOPH1 significantly reduced OGD-induced endothelial monolayer permeability increase. In conclusion, our data demonstrate that ENOPH1 activation may contribute to OGD-induced endothelial cell death and BBB disruption through promoting ROS generation and the activation of apoptosis associated proteins, thus representing a new therapeutic target for ischemic stroke.

DNA induced aggregation of stem bromelain; a mechanistic insight

Negatively charged species such as nucleic acids have commonly been found to be associated with the proteinaceous deposits in the tissues of patients with amyloid diseases.

Nano-carrier systems: Strategies to overcome the mucus gel barrier

The present review provides an overview of nanotechnology-based strategies to overcome various mucus gel barriers including the intestinal, nasal, ocular, vaginal, buccal and pulmonary mucus layer without destroying them. It focuses on the one hand on strategies to improve the mucus permeation behavior of particles and on the other hand on systems avoiding the back-diffusion of particles out of the mucus gel layer. Nanocarriers with improved mucus permeation behavior either exhibit a high density of positive and negative charges, bearing mucolytic enzymes such as papain and bromelain on their surface or display a slippery surface due to PEG-ylation. Furthermore, self-nanoemulsifying-drug-delivery-systems (SNEDDS) turned out to exhibit comparatively high mucus permeating properties. Strategies in order to avoid back-diffusion are based on thiolated polymers reacting to a higher extent with cysteine subunits of the mucus at pH 7 in deeper mucus regions than at pH 5 being prevalent in luminal mucus regions of the intestinal and vaginal mucosa. Furthermore, particles changing their zeta potential from negative to positive once they have reached the epithelium seem to be promising carriers. The summarized knowledge should provide a good starting point for further developments in this field.

Intestinal absorption of fucoidan extracted from the brown seaweed, Cladosiphon okamuranus

The aim of this study was to examine the absorption of fucoidan through the intestinal tract. Fucoidan (0.1, 0.5, 1.0, 1.5 and 2.0 mg/mL) was added to Transwell inserts containing Caco-2 cells. The transport of fucoidan across Caco-2 cells increased in a dose-dependent manner up to 1.0 mg/mL. It reached a maximum after 1 h and then rapidly decreased. In another experiment, rats were fed standard chow containing 2% fucoidan for one or two weeks. Immunohistochemical staining revealed that fucoidan accumulated in jejunal epithelial cells, mononuclear cells in the jejunal lamina propria and sinusoidal non-parenchymal cells in the liver. Since we previously speculated that nitrosamine may enhance the intestinal absorption of fucoidan, its absorption was estimated in rats administered N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in their drinking water. Rats were fed 0.2% fucoidan chow (BBN + 0.2% fucoidan rats), 2% fucoidan chow (BBN + 2% fucoidan rats) and standard chow for eight weeks. The uptake of fucoidan through the intestinal tract seemed to be low, but was measurable by our ELISA method. Fucoidan-positive cells were abundant in the small intestinal mucosa of BBN + 2% fucoidan rats. Most fucoidan-positive cells also stained positive for ED1, suggesting that fucoidan was incorporated into intestinal macrophages. The uptake of fucoidan by Kupffer cells was observed in the livers of BBN + 2% fucoidan rats. In conclusion, the absorption of fucoidan through the small intestine was demonstrated both in vivo and in vitro.

Matrix metalloproteinase-2-mediated occludin degradation and caveolin-1-mediated claudin-5 redistribution contribute to blood-brain barrier damage in early ischemic stroke stage

Blood-brain barrier (BBB) disruption occurs early enough to be within the thrombolytic time window, and this early ischemic BBB damage is closely associated with hemorrhagic transformation and thus emerging as a promising target for reducing the hemorrhagic complications of thrombolytic stroke therapy. However, the mechanisms underlying early ischemic BBB damage remain poorly understood. Here, we investigated the early molecular events of ischemic BBB damage using in vitro oxygen-glucose deprivation (OGD) and in vivo rat middle cerebral artery occlusion (MCAO) models. Exposure of bEND3 monolayer to OGD for 2 h significantly increased its permeability to FITC-labeled dextran and promoted the secretion of metalloproteinase-2 and -9 (MMP-2/9) and cytosolic translocation of caveolin-1 (Cav-1). This same OGD treatment also led to rapid degradation of tight junction protein occludin and dissociation of claudin-5 from the cytoskeleton, which contributed to OGD-induced endothelial barrier disruption. Using selective MMP-2/9 inhibitor SB-3CT (2-[[(4-phenoxyphenyl)sulfonyl]methyl]-thiirane) or their neutralizing antibodies or Cav-1 siRNA, we found that MMP-2 was the major enzyme mediating OGD-induced occludin degradation, while Cav-1 was responsible for claudin-5 redistribution. The interaction between Cav-1 and claudin-5 was further confirmed by coimmunoprecipitation. Consistent with these in vitro findings, we observed fluorescence tracer extravasation, increased gelatinolytic activity, and elevated interstitial MMP-2 levels in ischemic subcortical tissue after 2 h MCAO. Moreover, occludin protein loss and claudin-5 redistribution were detected in ischemic cerebromicrovessels. These data indicate that cerebral ischemia initiates two rapid parallel processes, MMP-2-mediated occludin degradation and Cav-1-mediated claudin-5 redistribution, to cause BBB disruption at early stroke stages relevant to acute thrombolysis.

Inhibition of adipogenesis and induction of apoptosis and lipolysis by stem bromelain in 3T3-L1 adipocytes

The phytotherapeutic protein stem bromelain (SBM) is used as an anti-obesity alternative medicine. We show at the cellular level that SBM irreversibly inhibits 3T3-L1 adipocyte differentiation by reducing adipogenic gene expression and induces apoptosis and lipolysis in mature adipocytes. At the molecular level, SBM suppressed adipogenesis by downregulating C/EBPα and PPARγ independent of C/EBPβ gene expression. Moreover, mRNA levels of adipocyte fatty acid-binding protein (ap2), fatty acid synthase (FAS), lipoprotein lipase (LPL), CD36, and acetyl-CoA carboxylase (ACC) were also downregulated by SBM. Additionally, SBM reduced adiponectin expression and secretion. SBM's ability to repress PPARγ expression seems to stem from its ability to inhibit Akt and augment the TNFα pathway. The Akt–TSC2–mTORC1 pathway has recently been described for PPARγ expression in adipocytes. In our experiments, TNFα upregulation compromised cell viability of mature adipocytes (via apoptosis) and induced lipolysis. Lipolytic response was evident by downregulation of anti-lipolytic genes perilipin, phosphodiestersae-3B (PDE3B), and GTP binding protein G_iα₁, as well as sustained expression of hormone sensitive lipase (HSL). These data indicate that SBM, together with all-trans retinoic-acid (atRA), may be a potent modulator of obesity by repressing the PPARγ-regulated adipogenesis pathway at all stages and by augmenting TNFα-induced lipolysis and apoptosis in mature adipocytes.

Prostaglandin E2 produced by Entamoeba histolytica signals via EP4 receptor and alters claudin-4 to increase ion permeability of tight junctions

Entamoeba histolytica is a protozoan parasite that causes amebic dysentery characterized by severe watery diarrhea. Unfortunately, the parasitic factors involved in the pathogenesis of diarrhea are poorly defined. Prostaglandin E(2) (PGE(2)) is a host lipid mediator associated with diarrheal diseases. Intriguingly, E. histolytica produces and secretes this inflammatory molecule. We investigated the mechanism whereby ameba-derived PGE(2) induces the onset of diarrhea by altering ion permeability of paracellular tight junctions (TJs) in colonic epithelia. PGE(2) decreased barrier integrity of TJs in a dose- and time-dependent manner, as measured by transepithelial resistance. PGE(2) signals were selectively transduced via the EP4 receptor. Furthermore, PGE(2) signaling decreased TJ integrity, as revealed by EP receptor-specific agonist and antagonist studies. Loss of mucosal barrier integrity corresponded with increased ion permeability across TJs. Subcellular fractionation and confocal microscopy studies highlighted a significant spatial alteration of an important TJ protein, claudin-4, that corresponded with increased sodium ion permeability through TJs toward the lumen. Moreover, PGE(2)-induced luminal chloride secretion was a prerequisite for alterations at TJs. Thus, the gradient of NaCl created across epithelia could serve as a trigger for osmotic water flow that leads to diarrhea. Our results highlight a pathological role for E. histolytica-derived PGE(2) in the onset of diarrhea.

Resonance light-scattering spectrometric study of interaction between enzyme and MPA-modified CdTe nanoparticles

This paper described a novel assay of enzyme based on the measurement of enhanced resonance light-scattering (RLS) signals resulting from the electrostatic and coordination interaction of functionalized CdTe nanoparticles with enzyme. The CdTe nanoparticles which were modified with 3-mercaptocarboxylic acid (MPA) have abundant carboxylic groups (COOH). So the nanoparticles are water-soluble, stable and biocompatible. At pH 8.3 phosphate buffered saline (PBS), the RLS signals of functionalized nano-CdTe are greatly enhanced by bromelain and papain in the region of 220-800 nm characterized by the peak around 318-314 nm, respectively. The optimization conditions of the reaction were also examined and selected. Under the selected conditions, the enhanced RLS intensity is linearly proportional to the concentration of bromelain and papain. The liner range is (0.09-0.9) x 10(-6)mol/L for bromelain and (0.048-0.702) x 10(-6)mol/L for papain. The influences of some foreign substances were also examined. This method can be applied to the determination of enzyme.