Bromelain improves decrease in defecation in postoperative rats: modulation of colonic gene expression of inducible nitric oxide synthase

Exploring the Therapeutic Potential of Bromelain: Applications, Benefits, and Mechanisms

Bromelain is a mixture of proteolytic enzymes primarily extracted from the fruit and stem of the pineapple plant (Ananas comosus). It has a long history of traditional medicinal use in various cultures, particularly in Central and South America, where pineapple is native. This systematic review will delve into the history, structure, chemical properties, and medical indications of bromelain. Bromelain was first isolated and described in the late 19th century by researchers in Europe, who identified its proteolytic properties. Since then, bromelain has gained recognition in both traditional and modern medicine for its potential therapeutic effects.

Effects of Proteases from Pineapple and Papaya on Protein Digestive Capacity and Gut Microbiota in Healthy C57BL/6 Mice and Dose-Manner Response on Mucosal Permeability in Human Reconstructed Intestinal 3D Tissue Model

Cysteine proteases obtained from the stem of pineapple or papaya latex, bromelain and papain, respectively, exhibit a broad spectrum of beneficial effects on human health. However, their effects on gut microbiota composition or dose-manner effects on the intestinal integrity of healthy tissue have not been evaluated. In this study, C57BL/6 young, healthy mice were fed bromelain or papain in a dose of 1 mg per animal/day for three consecutive days, followed by the assessment of digestive protein capacity, intestinal morphology and gut microbiota composition. Furthermore, a human reconstructed 3D tissue model EpiIntestinal (SMI-100) was used to study the effects of 1, 0.1 and 10 mg/mL doses of each enzyme on tissue integrity and mucosal permeability using TEER measurements and passage of Lucifer Yellow marker from the apical to the basolateral side of the mucosa. The results indicated that fruit proteases have the potential to modulate gut microbiota with decreasing abundance of Proteobacteria and increasing beneficial Akkermansia muciniphila. The enhancement of pancreatic trypsin was observed in bromelain and papain supplementation, while bromelain also increased the thickness of the ileal mucosa. Furthermore, an in vitro study showed a dose-dependent interruption in epithelial integrity, which resulted in increased paracellular permeability by the highest doses of enzymes. These findings define bromelain and papain as promising enzymatic supplementation for controlled enhancement of paracellular uptake when needed, together with beneficial effects on the gut microbiota.

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.

Bromelain reduced pro-inflammatory mediators as a common pathway that mediate antinociceptive and anti-anxiety effects in sciatic nerve ligated Wistar rats

The involvement of pro-inflammatory mediators complicates the complex mechanism in neuropathic pain (NP). This study investigated the roles of bromelain against pro-inflammatory mediators as a mechanism that underpins its antinociceptive and anti-anxiety effects in the peripheral model of NP. Sixty-four male Wistar rats randomly divided into eight groups, were used for the study. A chronic constriction injury model of peripheral neuropathy was used to induce NP. Tail-immersion and von Frey filaments tests were used to assess hyperalgesia while open field and elevated plus mazes were used to assess anxiety-like behaviour. NF-кB, iNOS, nitrate, and pro-inflammatory cytokines were investigated in the plasma, sciatic nerve, and brain tissues using ELISA, spectrophotometer, and immunohistochemistry techniques after twenty-one days of treatment. Bromelain significantly (p < 0.05) improved the cardinal signs of NP and inhibited anxiety-like behaviours in ligated Wistar rats. It mitigated the increases in cerebral cortex interleukin (IL) -1β, IL-6, and PGE₂ levels. Bromelain reduced NF-кB, IL-1β, IL-6, TNF-α, PGE_2, and nitrate concentrations as well as the expression of iNOS in the sciatic nerve. Hence, the antinociceptive and anxiolytic effects of bromelain in the sciatic nerve ligation model of NP is in part due to its ability to reduce nitrosative and inflammatory activities.

Lactobacillus plantarum KSFY06 and geniposide counteract montmorillonite-induced constipation in Kunming mice

Constipation is a common clinical manifestation of digestive system disorders and occurs worldwide. This study investigated the ability of Lactobacillus plantarum KSFY06 (LP-KSFY06) to promote the action of geniposide in preventing montmorillonite-induced constipation in Kunming mice, with the aim of providing a successful solution. The effects of LP-KSFY06 and geniposide on constipation were measured, and the results showed that the protective effect of geniposide on constipation was enhanced by LP-KSFY06 and that the combination resulted in increased weight, moisture content, and particle number of feces. The first black stool defecation time was decreased from 182 min to 87 min, which clearly indicates that defecating difficulty was alleviated in constipated mice. The synergic intervention of LP-KSFY06 and geniposide (LP + G) assisted in maintaining the body weight of constipated mice. The LP + G intervention significantly increased serum levels of motilin (MTL, 167.8 pg/ml), acetylcholinesterase (AChE, 45.3 pg/ml), substance P (SP, 61.0 pg/ml), vasoactive intestinal peptide (VIP, 70.5 pg/ml), endothelin-1 (ET-1, 16.1 pg/ml), and gastrin (73.0 pg/ml) and remarkably decreased somatostatin (SS, 35.2 pg/ml) when compared to those indexes in the LP-KSFY06 group and geniposide group. The LP + G treatment also significantly increased the mRNA expression of cluster of differentiation 117 (c-Kit), stem cell factor (SCF), glial cell-derived neurotrophic factor (GDNF), and remarkably downregulated the expression of inducible nitric oxide synthase (iNOS), transient receptor potential vanilloid-1 (TRPV1), and cyclooxygenase-2 (COX-2). The experimental results showed that the combination treatment has the strongest prevention effect against constipation, and LP-KSFY06 promotes the ability of geniposide to prevent constipation. Therefore, LP-KSFY06 is a potential probiotic strain with the capacity to prevent montmorillonite-induced constipation.

Babao Dan attenuates hepatic fibrosis by inhibiting hepatic stellate cells activation and proliferation via TLR4 signaling pathway

Babao Dan (BBD), a traditional Chinese medicine, has been widely used as a complementary and alternative medicine to treat chronic liver diseases. In this study, we aimed to observe the protective effect of BBD on rat hepatic fibrosis induced by diethylnitrosamine (DEN) and explore it possible mechanism. BBD was administrated while DEN was given. After eight weeks, values of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) indicated that BBD significantly protected liver from damaging by DEN and had no obvious side effect on normal rat livers. Meanwhile, BBD attenuated hepatic inflammation and fibrosis in DEN-induced rat livers through histopathological examination and hepatic hydroxyproline content. Furthermore, we found that BBD inhibited hepatic stellate cells activation and proliferation without altering the concentration of lipopolysaccharide (LPS) in portal vein. In vitro study, serum from BBD treated rats (BBD-serum) could also significantly suppress LPS-induced HSCs activation through TLR4/NF-κB pathway. In addition, BBD-serum also inhibited the proliferation of HSCs by regulating TLR4/ERK pathway. Our study demonstrated that BBD may provide a new therapy strategy of hepatic injury and hepatic fibrosis.

Fruit bromelain ameliorates rat constipation induced by loperamide

Fruit bromelain ameliorates rat constipation. MLCK, myosin light chain kinase;p-MLC₂₀, phosphorylation of 20 kDa myosin light chain.

The role of S-methylisothiourea hemisulfate as inducible nitric oxide synthase inhibitor against kidney iron deposition in iron overload rats

Background:

Iron dextran is in common use to maintain iron stores. However, it is potentially toxic and may lead to iron deposition (ID) and impair functions of organs. Iron overload can regulate the expression of inducible nitric oxide synthase (iNOS) in some cells that has an important role in tissue destruction. S-methylisothiourea hemisulfate (SMT) is a direct inhibitor of iNOS, and this study was designed to investigate the effect of SMT against kidney ID in iron overload rats.

Materials and Methods:

24 Wistar rats (male and female) were randomly assigned to two groups. Iron overloading was performed by iron dextran 100 mg/kg/day every other day for 2 weeks. In addition, during the study, groups 1 and 2 received vehicle and SMT (10 mg/kg, ip), respectively. Finally, blood samples were obtained, and the kidneys were prepared for histopathological procedures.

Results:

SMT significantly reduced the serum levels of creatinine and blood urea nitrogen. However, SMT did not alter the serum levels of iron and nitrite, and the kidney tissue level of nitrite. Co-administration of SMT with iron dextran did not attenuate the ID in the kidney.

Conclusion:

SMT, as a specific iNOS inhibitor, could not protect the kidney from ID while it attenuated the serum levels of kidney function biomarkers.

Modulation of Lipopolysaccharide Stimulated Nuclear Factor kappa B Mediated iNOS/NO Production by Bromelain in Rat Primary Microglial Cells

Background:

Microglial cells act as the sentinel of the central nervous system .They are involved in neuroprotection but are highly implicated in neurodegeneration of the aging brain. When over-activated, microglia release pro-inflammatory factors, such as nitric oxide (NO) and cytokines, which are critical in eliciting neuroinflammatory responses associated with neurodegenerative diseases. This study examined whether bromelain, the pineapple-derived extract, may exert an anti-inflammatory effect in primary microglia and may be neuroprotective by regulating microglial activation.

Methods:

Following the isolation of neonatal rat primary microglial cells, the activation profile of microglia was investigated by studying the effects of bromelain (5, 10, 20, and 30 µg/ml) on the levels of NO, inducible nitric oxide synthase (iNOS), and nuclear factor kappa B (NF-κB) in microglia treated with lipopolysaccharide (LPS) (1 µg/ml). Data were analyzed using Student's t-test. P values less than 0.05 were considered to be statistically significant, compared with the LPS-treated group without bromelain.

Results:

Results showed that pretreatment of rat primary microglia with bromelain, decreased the production of NO induced by LPS (1 µg/ml) treatment in a dose-dependent manner. Bromelain (30 µg/ml) also significantly reduced the expression of iNOS at mRNA level and NF-κB at protein level. Moreover, the study of mitochondrial activity in microglia indicated that bromelain had no cytotoxicity at any of the applied doses, suggesting that the anti-inflammatory effects of bromelain are not due to cell death.

Conclusion:

Bromelain can be of potential use as an agent for alleviation of symptoms in neurodegenerative diseases.

The early changes of colon motility in the rats after liver transplantation

The purpose of this study was to explore the early changes of colon motility in rats after liver transplantation. Thirty Wistar rats were divided into a sham operation group (n = 10) and a liver transplantation group (n = 10 pairs). The number of stools, the contractility of muscle strips, the length of smooth muscle cells, the levels of plasma endotoxin, the morphological changes, and the expression of inducible nitric oxide synthase (iNOS) in the colon of the rats were observed in the two groups. N(6)-(iminoethyl)-L-lysine (L-NIL, a selective iNOS antagonist) was used to confirm the activity of iNOS in the contractility of colonic motility. We observed the changes of nitrogen monoxide (NO) in plasma and colon mucosa of the two groups. Results showed that the liver transplantation group compared with the sham operation group showed significantly decreased contractility of the colon with significant differences in the morphological changes in rat colon. The expression of iNOS protein and iNOSmRNA was significantly increased in the liver transplantation group. The concentrations of plasma and colon mucosa NO and the levels of endotoxin were higher among the liver transplantation group than the sham operation group (P < .05). When the strips and cells of smooth muscle from the liver transplantation group were treated with L-NIL, their contractility increased. We concluded that colon motility decreased in the rats after transplantation, which could be related to the levels of plasma endotoxin and iNOS expressing in the colon.