Bromelain inhibits nuclear factor kappa-B translocation, driving human epidermoid carcinoma A431 and melanoma A375 cells through G(2)/M arrest to apoptosis

Bioactive compounds from Actinidia arguta fruit as a new strategy to fight glioblastoma

In recent years, there has been a significant demand for natural products as a mean of disease prevention or as an alternative to conventional medications. The driving force for this change is the growing recognition of the abundant presence of valuable bioactive compounds in natural products. On recent years Actinia arguta fruit, also known as kiwiberry, has attracted a lot of attention from scientific community due to its richness in bioactive compounds, including phenolic compounds, organic acids, vitamins, carotenoids and fiber. These bioactive compounds contribute to the fruit's diverse outstanding biological activities such as antioxidant, anti-inflammatory, neuroprotective, immunomodulatory, and anti-cancer properties. Due to these properties, the fruit may have the potential to be used in the treatment/prevention of various types of cancer, including glioblastoma. Glioblastoma is the most aggressive form of brain cancer, displaying 90 % of recurrence rate within a span of 2 years. Despite the employment of an aggressive approach, the prognosis remains unfavorable, emphasizing the urgent requirement for the development of new effective treatments. The preclinical evidence suggests that kiwiberry has potential impact on glioblastoma by reducing the cancer self-renewal, modulating the signaling pathways involved in the regulation of the cell phenotype and metabolism, and influencing the consolidation of the tumor microenvironment. Even though, challenges such as the imprecise composition and concentration of bioactive compounds, and its low bioavailability after oral administration may be drawbacks to the development of kiwiberry-based treatments, being urgent to ensure the safety and efficacy of kiwiberry for the prevention and treatment of glioblastoma. This review aims to highlight the potential impact of A. arguta bioactive compounds on glioblastoma, providing novel insights into their applicability as complementary or alternative therapies.

Effect of bromelain on periodontal destruction and alveolar bone in rats with experimental periodontitis

PURPOSE

Several substances that have anti-inflammatory, antiproteinase, and anti-infective properties have been evaluated as modulators of the inflammatory response in periodontal disease. However, evidence for the anti-inflammatory and antioxidative activities of bromelain is limited. This study evaluated the impact of systemically administered bromelain on the progression of experimental periodontitis.

METHODS

Four equal groups of 32 Wistar albino rats were created as follows (n = 8): control, periodontitis + saline, periodontitis + 5 mg/kg/day bromelain, and periodontitis + 10 mg/kg/day bromelain. To quantify the resorption of bone and bone volume/tissue volume, bone surface / bone volume, and connectivity, lower jawbones were fixed and then scanned using microcomputed tomography (micro CT). Blood samples were taken to measure the macrophage colony-stimulating factor(M-CSF) concentrations, receptor activator of nuclear factor kappa-Β ligand (RANKL), osteoprotegerin (OPG), tumor necrosis factor-alpha (TNF-α), matrix metalloproteinase-8 (MMP-8), interleukin-6(IL-6), glutathione peroxidase (GPx), superoxide dismutase (SOD), and malondialdehyde (MDA). Histopathological assessments were made to examine the tissue.

RESULTS

Treatment with bromelain improved the healing of the periodontium by decreasing the number of leukocytes and ligament deterioration in the gingival connective tissue and by supporting reintegration with alveolar bone. Bromelain used in ligature-induced periodontitis reduced alveolar bone (AB) resorption as measured by microCT; reduced inflammatory parameters such as IL-6 and TNF-α; regulated oxidative-antioxidative processes by increasing GPx and SOD and reducing MDA levels; and regulated AB modeling by decreasing M-CSF, RANKL, and MMP-8 and increasing OPG levels.

CONCLUSION

Bromelain may be an option in periodontal therapy by regulating cytokine levels, improving the healing process, and reducing bone resorption and oxidative stress.

Cytotoxic properties of unfractionated and fractionated bromelain alone or in combination with chemotherapeutic agents in colorectal cancer cells

BACKGROUND

Colorectal cancer (CRC) is one of the most lethal cancers worldwide. Long-term survival is not achieved in metastatic CRC despite the current multidisciplinary therapies. Bromelain, a compound extracted from the pineapple plant, has multiple functions and anticancer properties. Previously, bromelain has been chromatographically separated into four fractions. Fraction 3 (F3) exhibits the highest proteolytic activity. The anticancer effects of F3 bromelain in CRC cells is unknown.

METHODS

In vitro cytotoxicity was verified through a sulforhodamine B assay. Apoptosis in CRC cells induced by unfractionated or F3 bromelain was examined using Annexin V-FITC/PI staining and Western blot analysis. ROS status, autophagy and lysosome formation were determined by specific detection kit.

RESULTS

The cytotoxicity of F3 bromelain in CRC cells was found to be comparable to that of unfractionated bromelain. F3 bromelain induces caspase-dependent apoptosis in CRC cells. Treatment with unfractionated or F3 bromelain increased superoxide and oxidative stress levels and autophagy and lysosome formation. ATG5/12 and beclin-1 were upregulated, and the conversion of LC3B-I to LC3B-II was increased significantly by treatment with F3 bromelain. Treated CQ, autophagy inhibitor, with unfractionated or F3 bromelain enhances the cytotoxic effects. Finally, the combination of unfractionated and F3 bromelain with a routine chemotherapeutic agent (5-fluourouracil, irinotecan, or oxaliplatin) resulted in synergistically higher cytotoxic potency in CRC cells.

CONCLUSION

Unfractionated and F3 bromelain inhibits CRC cell proliferation in vitro, and the cytotoxic effects of unfractionated bromelain are equivalent to F3 bromelain. F3 bromelain may be a potential and potent drug for clinical use due to its anticancer efficacy and high synergistic cytotoxicity when combined with a routine chemotherapeutic agent for CRC.

Bromelain mitigates liver fibrosis via targeting hepatic stellate cells in vitro and in vivo

Various therapeutic approaches are conducted for regression of liver fibrosis and prevent possible further carcinogenic transformation. This study was aimed to assess the prospective therapeutic potential of bromelain against thioacetamide (TAA)-induced liver fibrosis using in-vitro and in vivo approaches. In vitro study, HSC-T6 cell line was used to evaluate the effect of bromelain on HSC-T6 cell viability and apoptosis. In vivo, Rats were treated by TAA for 6 weeks for induction of hepatic fibrosis followed by post treatment by different doses of bromelain and silymarin for further 4 weeks to assess the regression of hepatic fibrosis. The in-vitro findings indicated that bromelain hindered the proliferation of HSCs in concentration dependent manner compared with the untreated cells. The in vivo study revealed that treatment of TAA fibrotic rats with different doses of bromelain and silymarin induced a significant restoration in liver function biomarkers, attenuation of oxidative stress, upregulation of total antioxidant capacity and thereby decline of fibrotic biomarkers and improving histopathological and immunohistochemical changes. In conclusion, This study indicates that bromelain can regress TAA induced hepatic fibrosis in rats via inhibiting HSCs activation, α-SMA expression and the ECM deposition in hepatic tissue in addition to its antioxidants pathway, these findings prove the promising therapeutic potential of bromelain as a novel therapeutic approach for chronic hepatic fibrotic diseases.

Anticancer properties of bromelain: State-of-the-art and recent trends

Bromelain is a key enzyme found in pineapple (Ananas comosus (L.) Merr.); a proteolytic substance with multiple beneficial effects for human health such as anti-inflammatory, immunomodulatory, antioxidant and anticarcinogenic, traditionally used in many countries for its potential therapeutic value. The aim of this updated and comprehensive review focuses on the potential anticancer benefits of bromelain, analyzing the cytotoxic, apoptotic, necrotic, autophagic, immunomodulating, and anti-inflammatory effects in cancer cells and animal models. Detailed information about Bromelain and its anticancer effects at the cellular, molecular and signaling levels were collected from online databases such as PubMed/MedLine, TRIP database, GeenMedical, Scopus, Web of Science and Google Scholar. The results of the analyzed studies showed that Bromelain possesses corroborated pharmacological activities, such as anticancer, anti-edema, anti-inflammatory, anti-microbial, anti-coagulant, anti-osteoarthritis, anti-trauma pain, anti-diarrhea, wound repair. Nonetheless, bromelain clinical studies are scarce and still more research is needed to validate the scientific value of this enzyme in human cancer diseases.

Implications of nasal delivery of bromelain on its pharmacokinetics, tissue distribution and pharmacodynamic profile-A preclinical study

Asthma is a polygenic chronic inflammatory respiratory disease devastating the quality of life and state economies. Therefore, utilization of natural products as a therapeutic approach has attained wider consideration for development of novel drugs for asthma management. Bromelain, a mixture of natural bioactive cysteine proteases abundantly found in pineapple stem, has allured attention for its pharmacological activities. However, poor stability in gastric milieu, high dose and immunogenicity associated with prolonged use hinders its oral use. Therefore, need exists to explore alternative route of bromelain administration to achieve its plausible benefits. The present study investigated the preclinical prospects of nasal administration of bromelain on systemic bioavailability, tissue distribution and it's in vivo anti-histaminic, bronchodilator and anti-asthmatic activity in animal models. Pharmacokinetic studies revealed 1.43-fold higher relative bioavailability with faster absorption of bromelain on nasal administration at one-fourth oral dose. The enhanced cellular uptake and localization of bromelain in tissues of lung was observed significantly. Furthermore, faster onset and enhanced antihistaminic, bronchodilator and anti-asthmatic activity on bromelain's nasal administration signified faster absorption and higher in vivo stability of bromelain. Nasal administration significantly achieved decrease in level of oxidative and immunological markers along with restoration of antioxidant enzymes at considerably one-fourth dose administered orally. These findings distinctly manifested that nasal administration could be a substantial and effective route for bromelain delivery with enduring competency in asthma management.

Agri-Food By-Products in Cancer: New Targets and Strategies

The globalization and the changes in consumer lifestyles are forcing us to face a deep transformation in food demand and in the organization of the entire food production system. In this new era, the food-loss and food-waste security nexus is relevant in the global debate and avoiding unsustainable waste in agri-food systems as well as the supply chain is a big challenge. "Food waste" is useful for the recovery of its valuable components, thus it can assume the connotation of a "food by-product". Sustainable utilization of agri-food waste by-products provides a great opportunity. Increasing evidence shows that agri-food by-products are a source of different bioactive molecules that lower the inflammatory state and, hence, the aggressiveness of several proliferative diseases. This review aims to summarize the effects of agri-food by-products derivatives, already recognized as promising therapeutics in human diseases, including different cancer types, such as breast, prostate, and colorectal cancer. Here, we examine products modulating or interfering in the signaling mediated by the epidermal growth factor receptor.

Bromelain inhibits the inflammation and senescence effect in diabetic periodontitis: A preliminary in vitro study

Background/purpose

Diabetes mellitus (DM) is a chronic metabolic disorder that affects millions of people worldwide. A growing evidence suggests that hyperglycemia in DM causes a pre-aging and pro-inflammatory condition known as inflammaging, which increases periodontitis susceptibility. Bromelain has been demonstrated to have anti-inflammatory and anti-aging properties in variety of tissues, but its effects on diabetic periodontitis remain unclear. Thus, the aim of this study is to investigate the its Bromelain's impact in diabetic periodontitis in terms of inflammation and senescence activity.

Materials and methods

We assessed the wound healing capacity, production of pro-inflammatory cytokines Interleukin (IL)-6 and IL-8 and senescence marker p16 in human gingival fibroblasts (HGFs) in response to Advanced glycation end-products (AGEs) stimulant, with or without Bromelain treatment. The expression of p65, p-ERK, and p-p38 were also examined to elucidate whether Bromelain's anti-inflammaging activity is mediated through NF-κB and MAPK/ERK signaling pathway.

Results

Bromelain concentrations ranging from 2.5 to 20 g/mL had no adverse effect on HGF cell proliferation. Bromelain improved wound healing in HGFs with AGEs stimulation. In addition, Bromelain suppressed the production of pro-inflammatory cytokines IL-6 and IL-8 in HGFs elicited by AGEs. Meanwhile, Bromelain treatment also inhibited the senescence activity and expression of p16 in AGEs-stimulated HGFs. Western blot analysis indicated that the upregulation of p-ERK, p-p38 and p65 induced by AGEs were inhibited by Bromelain in HGFs.

Conclusion

These data suggest that excessive AGEs in the gingiva may lead to the accumulation of pro-inflammatory cytokines and marked senescence activity. Bromelain application may be helpful in enhancing wound healing by suppressing inflammaging via downregulation of NF-κB and MAPK/ERK signaling pathways in DM individuals with periodontal disease.

In vitro and in vivo implications of rationally designed bromelain laden core-shell hybrid solid lipid nanoparticles for oral administration in thrombosis management

Bromelain, a dietary supplement of cysteine protease family having promising results against thrombosis, is gaining attention. Yet poor mechanical stability, gastric instability, high oral dose and poor patient compliance restricted its clinical application. Therefore, acid stable bromelain loaded hybrid solid lipid nanoparticles (Br-HNPs) were fabricated and characterized for their contribution to in-vivo stability and therapeutic efficacy in thrombosis management. Comprehensive optimization of various process and formulation variables ensued the formation of nano-sized (120.56 ± 40.12 nm) Br-HNPs with entrapment efficiency of 86.32 ± 5.56%. Spherical core shell framework of Br-HNPs prolonged drug release and provided in-vivo and storage stability at room temperature. Br-HNPs significantly inhibited platelet aggregation without affecting bleeding time and dissolved thrombus at 1.91-fold higher efficacy compared to bromelain. Furthermore, Br-HNPs prevented hypercoagulation states and suppressed cytokines production significantly (P < .05) contributing to its antiplatelet activity. These findings indicated that Br-HNPs could serve as a promising alternative to commercial therapies for management of thrombotic disorders.

A comprehensive overview on the anti-inflammatory, antitumor, and ferroptosis functions of bromelain: an emerging cysteine protease

INTRODUCTION

Bromelain belongs to the cysteine protease endopeptidase class of enzymes isolated from the stem and fruit tissue component of Ananas comosus. The commercial and translational therapeutic potential of bromelain is ever increasing due to its augmented stability, easier purification, and salubrious pan-cancer effects.

AREAS COVERED

This paper presents the current state of knowledge about the isolation methods of bromelain, its safety, efficacy and tolerability. In addition, bromelains<apos;> role in eliciting pharmacological effects and its healing ability to mitigate cancer side effects based on accumulated in vitro, in vivo, and clinical evidence is relatively considerable.

EXPERT OPINION

Identification of molecular targets and crucial signalling pathways that bromelain regulates suggest it genuinely prospects for combating cancer and mitigation of chemotherapy or radiotherapy mediated side effects. Further research on the development of bromelain-entrapped drug delivery systems for augmented enzyme stability, processing ability and translational potential against cancer can be beneficial.

Bromelain and Nisin: The Natural Antimicrobials with High Potential in Biomedicine

Infectious diseases along with various cancer types are among the most significant public health problems and the leading cause of death worldwide. The situation has become even more complex with the rapid development of multidrug-resistant microorganisms. New drugs are urgently needed to curb the increasing spread of diseases in humans and livestock. Promising candidates are natural antimicrobial peptides produced by bacteria, and therapeutic enzymes, extracted from medicinal plants. This review highlights the structure and properties of plant origin bromelain and antimicrobial peptide nisin, along with their mechanism of action, the immobilization strategies, and recent applications in the field of biomedicine. Future perspectives towards the commercialization of new biomedical products, including these important bioactive compounds, have been highlighted.

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.

Radiosensitizing Effect of Bromelain Using Tumor Mice Model via Ki-67 and PARP-1 Inhibition

Recent reports have shown that bromelain (BL), a pineapple extract, acts as an adjuvant therapy in cancer treatment and prevention of carcinogenesis. The present study was designed to investigate the possible mechanisms by which BL could radiosensitize tumor cells in vitro and in a mouse tumor model. BL has shown a significant reduction in the viability of the radioresistant human breast carcinoma (MCF-7) cell line using cell proliferation assay. The in vivo study was designed using the Ehrlich model in female albino mice, treated with BL (6 mg/kg b. wt., intraperitoneal, once daily for 10 days) 1 hour before exposure to a fractionated dose of gamma radiation (5 Gy, 1 Gy for 5 subsequent days). The radiosensitizing effect of BL was evident in terms of a significant reduction in tumor volume, poly ADP ribose polymerase-1 (PARP-1), the proliferation marker Ki-67 and nuclear factor kappa activated B cells (NF-κB) with a significant elevation in the reactive oxygen species (ROS) content and lipid peroxidation (LPO) in tumor cells. The present findings offer a novel insight into the radiosensitizing effect of BL and its potential application in the radiotherapy course.

Investigation the Effect of Encapsulated Bromelain Enzyme in Magnetic Carbon Nanotubes on Colorectal Cancer Cells

Background: Bromelain (BL) is an enzyme extracted from Ananas comosus, which has been known for its therapeutic properties. Objectives: The anticarcinogenic activity of BL was examined with and without the presence of magnetic carbon nanotubes (MCNTs) against HT-29 colorectal cancer cells. Methods: The operational factors affecting BL adsorption, such as contact time (30, 60, 90, 120, and 180 min), adsorbent dosage (1 g/L and 5 g/L), initial bromelain concentration (50, 150, and 300 mg/L), and temperature (35 and 50°C) were studied in details. Then, cancer cells were exposed to various BL concentrations (0.1, 1, 10, and 100 μg/mL), and the cell viability was determined by methylthiazol tetrazolium (MTT) assay after 24, 48, and 72 h. Results: The highest adsorption of BL on nanotubes was at 41.62 mg/L and achieved at 35°C and 90 min at the initial concentration of 50 mg/L and 1 g/L of MCNTs. The adsorption followed the Freundlich model and second-order kinetics. The results indicated that MCNTs could be a potential effective adsorbent for the removal of BL. Conclusions: MTT assay indicated that BL at a concentration of 100 μg/mL alone and in combination with MCNTs efficiently inhibited the HT-29 cancerous cells. However, encapsulated BL had a considerable advantage of slow delivery, which is favorable for cancer treatment.

Anti-Inflammatory and Mineralization Effects of Bromelain on Lipopolysaccharide-Induced Inflammation of Human Dental Pulp Cells

Background and Objectives: Bromelain is a mixture of protease obtained from pineapple fruits or stems. Even though the biological mechanism of action of bromelain has not been completely understood, it is well known that bromelain possesses anticancer, anti-inflammatory and immunomodulatory effects. This study investigated the anti-inflammatory effects of bromelain on lipopolysaccharide (LPS)-induced human dental pulp cells (hDPCs). Materials and Methods: Cell viability after bromelain treatment was measured using WST-1 assay. We exposed hDPCs to 5 µg/mL of LPS with 2.5 or 5 µg/mL of bromelain. We performed reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay to detect interleukin-1β, interleukin-6, and interleukin-8 levels. Western blots were used to detect intercellular adhesion molecules-1 (ICAM-1) and vascular cell adhesion molecules-1 (VCAM-1) levels. Immunofluorescence staining and Western blots were used to determine bromelain’s anti-inflammatory mechanism. We also performed alkaline phosphatase and Alizarin red staining to verify mineralization nodule formation. Results: Bromelain at 2.5, 5, 10, or 20 µg/mL did not affect the viability of hDPCs significantly. LPS increased interleukin-1β, interleukin-6, interleukin-8, ICAM-1 and VCAM-1 expression in hDPCs. Bromelain significantly decreased interleukin-1β, interleukin-6, interleukin-8, ICAM-1, and VCAM-1 levels in hDPCs, which were stimulated by LPS. Bromelain treatment significantly reduced p65 phosphorylation in the cytoplasm and the nucleus. It also significantly decreased phosphorylation levels of extracellular signal-related kinases (ERK) and p38 mitogen-activated protein kinases (p38). Bromelain also promoted ALP activity and mineralized nodule formation. Conclusions: Bromelain inhibits the expression of inflammatory cytokines in LPS-stimulated hDPCs. The inhibitory effect of bromelain on inflammatory mediators is related to decreased NF-κB and the MAPK pathway. Therefore, bromelain might have the potential to be used for regenerative endodontics, including vital pulp therapy.

Targeting the Stromal Pro-Tumoral Hyaluronan-CD44 Pathway in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies. Present-day treatments have not shown real improvements in reducing the high mortality rate and the short survival of the disease. The average survival is less than 5% after 5 years. New innovative treatments are necessary to curtail the situation. The very dense pancreatic cancer stroma is a barrier that impedes the access of chemotherapeutic drugs and at the same time establishes a pro-proliferative symbiosis with the tumor, thus targeting the stroma has been suggested by many authors. No ideal drug or drug combination for this targeting has been found as yet. With this goal in mind, here we have explored a different complementary treatment based on abundant previous publications on repurposed drugs. The cell surface protein CD44 is the main receptor for hyaluronan binding. Many malignant tumors show over-expression/over-activity of both. This is particularly significant in pancreatic cancer. The independent inhibition of hyaluronan-producing cells, hyaluronan synthesis, and/or CD44 expression, has been found to decrease the tumor cell's proliferation, motility, invasion, and metastatic abilities. Targeting the hyaluronan-CD44 pathway seems to have been bypassed by conventional mainstream oncological practice. There are existing drugs that decrease the activity/expression of hyaluronan and CD44: 4-methylumbelliferone and bromelain respectively. Some drugs inhibit hyaluronan-producing cells such as pirfenidone. The association of these three drugs has never been tested either in the laboratory or in the clinical setting. We present a hypothesis, sustained by hard experimental evidence, suggesting that the simultaneous use of these nontoxic drugs can achieve synergistic or added effects in reducing invasion and metastatic potential, in PDAC. A non-toxic, low-cost scheme for inhibiting this pathway may offer an additional weapon for treating pancreatic cancer.

Bromelain a Potential Bioactive Compound: A Comprehensive Overview from a Pharmacological Perspective

Bromelain is an effective chemoresponsive proteolytic enzyme derived from pineapple stems. It contains several thiol endopeptidases and is extracted and purified via several methods. It is most commonly used as an anti-inflammatory agent, though scientists have also discovered its potential as an anticancer and antimicrobial agent. It has been reported as having positive effects on the respiratory, digestive, and circulatory systems, and potentially on the immune system. It is a natural remedy for easing arthritis symptoms, including joint pain and stiffness. This review details bromelain's varied uses in healthcare, its low toxicity, and its relationship to nanoparticles. The door of infinite possibilities will be opened up if further extensive research is carried out on this pineapple-derived enzyme.

Cytotoxic Effect of Bromelain on HepG2 Hepatocellular Carcinoma Cell Line

Cancer is a complicated long-term disease due to computable key molecular players involved in aggravating the disease. Among various kinds of cancer, hepatocellular carcinoma (HCC) is the ninth leading cause of cancer. Recently, plant-based products are gaining a lot of attention in the field of research because of their anti-tumor properties. In our previous study, we reported based on in-silico method that bromelain, a cysteine protease extracted from the stem of the pineapple, has high binding affinity with the transcription factors p53 and β-catenin proteins which are key players in controlling the progression of hepatocellular carcinoma. Bromelain, isolated mainly from the stem of Pineapple (Ananas comosus), belongs to the family Bromeliaceae. The present study deals with preclinical analysis of bromelain as an anti-cancer agent and its intracellular effect on the expression of p53 and β-catenin protein. Our study reports cytotoxic activity, cell proliferation, migration, invasion, arrest in the S-phase, and G2/M phase in cell cycle analysis by treating with bromelain in HepG2 cell lines. We also report up-regulation of p53 protein by drug-induced impediment leading to apoptotic process in HepG2 cells and down-regulation of β-catenin protein in HepG2 cells which interferes in β-catenin/TCF-DNA interaction further, down-regulating Wnt genes and suppressing the canonical pathway. Finally, we conclude that bromelain inhibits tumorigenic potential in HepG2 cell lines.

Exploration of bromelain laden nanostructured lipid carriers: An oral platform for bromelain delivery in rheumatoid arthritis management

Bromelain, a cysteine protease exhibits promising potential in amelioration of wide variety of inflammatory disorders. Its denaturation or aggregation in gastric milieu depletes its therapeutic potential along with unpredictable prophylactic hypersensitivity reactions. Hence, efficient carrier system to improve bromelain's stability and avoid related side effects is of utmost importance. Therefore, present investigation was undertaken to prepare bromelain loaded nanostructured lipid carriers (Br-NCs) with high drug loading, stability and efficacy in rheumatoid arthritis management. Br-NCs fabricated via double emulsion solvent evaporation method were characterized for physical properties, morphology and stability. Optimized batch exhibited spherical shape, nanometric size (298.23 nm) and entrapment efficiency ~77% with sustained release behavior and improved gastric stability. Br-NCs exhibited 4.63-folds improvement in shelf-life compared to bromelain at room temperature. The protective potential of orally administered Br-NCs in rheumatoid arthritis was evaluated via assessing arthritis severity in wistar rats along with biochemical, hematological and immunological parameters. Br-NCs remarkably (p < 0.05) diminished paw edema, joint stiffness, mechanical allodynia and tissue damage along with alleviation of oxidative stress and immunological markers. Radiological joint alterations were also notably preserved with Br-NCs. Thus, preclinical studies distinctly manifested that Br-NCs formulation opens new avenue for development of novel effective therapeutic modality for rheumatoid arthritis management.

Plant-Derived Natural Products in Cancer Research: Extraction, Mechanism of Action, and Drug Formulation

Cancer is one of the main causes of death globally and considered as a major challenge for the public health system. The high toxicity and the lack of selectivity of conventional anticancer therapies make the search for alternative treatments a priority. In this review, we describe the main plant-derived natural products used as anticancer agents. Natural sources, extraction methods, anticancer mechanisms, clinical studies, and pharmaceutical formulation are discussed in this review. Studies covered by this review should provide a solid foundation for researchers and physicians to enhance basic and clinical research on developing alternative anticancer therapies.

Effect of pineapple juice on the pharmacokinetics of celecoxib and montelukast in humans

Aim: To study the influence of pineapple juice on the pharmacokinetics of celecoxib and montelukast in humans. Experimental methods: The research comprised two separate arms. Each arm was randomized, two-crossover periods separated by a 2-week washout period. Subjects received a single dose of celecoxib or montelukast after pretreatment with either water or pineapple juice for 4 days before the study beginning. Results & conclusion: Pineapple juice enhanced the systemic exposure of both drugs without any noticeable adverse effects. For celecoxib, C_max and AUC_0-∞ were increased significantly by 40 and 60%, respectively. Cl/F was decreased by 45% without affecting its t_1/2. For montelukast, C_max and AUC_0-∞ were significantly increased by 21 and 48%, respectively, along with 25% decrease in clearance and 13% increase in t_1/2.

Effect of Bromelain-Based Enzymatic Debridement on Skin Cells

Several reports have concluded that enzymatic debridement based on Bromelain (NX) is selective and efficient. Although clinical trials showed that viable tissue is not damaged at the macroscopic level, the effect on the cellular level is largely unknown. The current study is meant to close this gap by evaluating whether NX has an effect on vital cells of the human dermis on a cellular level. In an experimental in vitro study design, the effect of NX on human keratinocytes, fibroblasts, and macrophages was analyzed. Enzymatic treatment was performed for 4 hours by using either cell culture medium or phosphate-buffered saline as diluting agent for NX. Cell viability and relative cell number in relation to untreated control cells were determined using a resazurin-based assay. In addition, the development of enzyme activity during clinical treatment was analyzed: wound fluid collected from a burn wound at different points of debridement was applied on collagen-elastin disks to prove enzymatic digestion activity. Both keratinocytes and fibroblasts were damaged by NX even at low concentrations. Both cell types showed improved survival when a medium was used for dissolving NX. Macrophages appeared to resist NX treatment more efficiently than the other cell types. In the clinical trial, NX activity in the wound fluid decreased clearly following 4 hours of enzymatic debridement. NX induces toxicity of vital skin cells in vitro. However, macrophages appear to be more resistant against NX treatment in vitro. The inflammatory responses of vital cells in the burn wound itself are likely to inhibit NX activity. The effect of this inflammatory process on NX activity will have to be investigated in future studies.

Evaluation of the Radiosensitizing Potency of Bromelain for Radiation Therapy of 4T1 Breast Cancer Cells

Breast cancer (BC) remains the leading cause of death in women worldwide, despite the improvements of cancer screening and treatment methods. Recently, development of novel anticancer drugs for the improved prevention and treatment of BC is in the center of research. The anticancer effects of bromelain, as enzyme extract derived from the pineapples, contains chemicals that interfere with the growth of tumor cells. The aim of this study was to evaluate the effect of radiosensitizing of bromelain in 4T1 BC cells. This investigation utilized the 3-(4,5-dimethylthiazol-2-yl)-2,5-dimethyltetrazolium bromide assay to characterize the cytotoxicity of bromelain. Colony formation method was used to establish the truth of the capability of bromelain to make sensitive to radiation therapy. Flowcytometry performed to define the contribution the apoptosis effect to bromelain mediated radiosensitization of 4T1 cells. Bromelain reduced growth and proliferation of 4T1 cell as a concentration-dependence manner significantly. The survival of 4T1 cancer cells was decreased after combined treatment in a number and size-dependent manner with regard to the control group (P < 0.05). Combination of bromelain with radiation does not influence 4T1 cell apoptosis. The results suggested that bromelain can inhibit the growth and proliferation and reduce survival of 4T1 BC cells and might be used as a candidate radiosensitizer in BC patient.

Bromelain inhibits the ability of colorectal cancer cells to proliferate via activation of ROS production and autophagy

Advanced colorectal cancer (CRC) survival rates are still low despite advances in cytotoxic and targeted therapies. The development of new effective or alternative therapies is therefore urgently needed. Bromelain, an extract of pineapple, was shown to have anticancer effects, but its mechanisms in CRC have not been fully explored. Therefore, the roles of bromelain in CRC progression were investigated using different CRC cell lines, a zebrafish model, and a xenograft mouse model. The anticancer mechanisms were explored by assessing the role of bromelain in inducing reactive oxygen species (ROS), superoxide, autophagosomes, and lysosomes. The role of bromelain in the induction of apoptosis was also assessed. It was found that bromelain inhibited CRC cell growth in cell lines and tumor growth in the zebrafish and xenograft mouse models. It also induced high levels of ROS and superoxide, plus autophagosome and lysosome formation. High levels of apoptosis were also induced, which were associated with elevated amounts of apoptotic proteins like apoptotic induction factor, Endo G, and caspases-3, -8, and -9 according to a qPCR analysis. In a Western blot analysis, increases in levels of ATG5/12, beclin, p62, and LC3 conversion rates were found after bromelain treatment. Levels of cleaved caspase-3, caspase-8, caspase-9, and poly(ADP ribose) polymerase (PARP)-1 increased after bromelain exposure. This study explored the role of bromelain in CRC while giving insights into its mechanisms of action. This compound can offer a cheap alternative to current therapies.

Bromelain with peroxidase from pineapple are more potent to target leukemia growth inhibition - A comparison with only bromelain

The natural anti-cancer agent bromelain is found to be beneficial for either single or multi-targeted therapy in gastric and skin carcinoma, by inhibiting cancer cell growth. Importantly, the presence of peroxidase enhances its biological efficiency. We have now evaluated a panel of cancer cell lines with bromelain in presence or absence of peroxidase to identify that the combination has higher apoptosis inducing potential in all those cell lines. Bromelain plus peroxidase (BM-PR) inhibited acute myeloid (K562) cell proliferation and altered the morphological features. Incidence of apoptosis was established by using annexin V exposure and this was confirmed that the cell cycle was arrested at G0/G1 phase in a concentration-dependent manner. BM-PR increased the intracellular ROS level and altered the mitochondrial membrane potential, as detected using dichlorofluores cin diacetate (DCFDA). It also regulated the expression of apoptosis-related proteins like Bax, Bcl2, caspase-3 and cytochrome besides causing up-regulation of p53 as determined by western blot analysis. These results suggest that BM-PR from pineapple induces apoptosis better than only bromelain in acute myeloid leukemia cells possibly via mitochondria dependent pathway.

Cysteine Proteases from V. cundinamarcensis (C. candamarcensis) Inhibit Melanoma Metastasis and Modulate Expression of Proteins Related to Proliferation, Migration and Differentiation

Previous studies showed that P1G10, a proteolytic fraction from Vasconcellea cundinamarcensis latex, reduced the tumor mass in animals bearing melanoma, increased in vitro DNA fragmentation and decreased cell adhesion. Here, we present some molecular and cellular events related to the antimetastatic effect induced by the CMS-2 fraction derived from P1G10 in metastatic melanoma B16-F10 and melanocyte Melan-a. Using difference gel electrophoresis and mass spectrometry, we identified four proteins overexpressed in tumor cells, all of them related to proliferation, survival, migration and cell invasion, that had their expression normalized upon treatment with CMS-2: nucleophosmin 1, heat shock protein 65, calcyclin binding protein and eukaryotic translation initiation factor 4H. In addition, some antioxidant and glycolytic enzymes show increased expression after exposure to CMS-2, along with an induction of melanogenesis (differentiation marker). The down regulation of cofilin 1, a protein involved in cell motility, may explain the inhibition of cell migration and dendritic-like outgrowth in B16-F10 and Melan-a, observed after CMS-2 treatment. Taken together, it is argued that CMS-2 modulates the expression of proteins related to metastatic development, driving the cell to a more differentiated-like state. These effects support the CMS-2 antimetastatic activity and place this fraction in the category of anticancer agent.

Bromelain effectively suppresses Kras-mutant colorectal cancer by stimulating ferroptosis

Here, we investigated the possible anti-cancer properties of bromelain in Kras mutant human colorectal carcinoma cell lines and a mouse model harboring a Kras mutation. Cell growth and proliferation were significantly reduced in the Kras mutant colorectal carcinoma cell lines following treatment with 50 μg/mL bromelain as assessed by crystal violet staining and a proliferation assay. To identify the molecules responsible for this action, the expression levels of genes involved in signaling pathways and miRNAs were analyzed by real-time PCR. Among the genes tested, down-regulation of ACSL-4 and up-regulation of miRNAs targeting ASCL-4 were observed in Caco₂ cells. Compared to the Kras wild-type colorectal carcinoma cell lines, Kras mutant colorectal carcinoma cell lines exhibited a remarkably up-regulated expression of ACSL-4, which is responsible for ferroptosis sensitivity. Moreover, the knockdown of ACSL-4 by a specific shRNA inhibited erastin-induced ferroptosis in Kras mutant DLD-1 cells as assessed by propidium iodide staining and lipid reactive oxygen species measurement. Our findings indicate that bromelain effectively exerts cytotoxic effects in Kras mutant colorectal cancer cells compared to in Kras wild-type colorectal cancer cells. Differential expression of ACSL-4 is responsible for the differential action of bromelain in regulating ferroptotic cell death.

Implications of designing a bromelain loaded enteric nanoformulation on its stability and anti-inflammatory potential upon oral administration

The objective of the present investigation was to develop an enteric nano-formulation of bromelain to improve its stability and anti-inflammatory potential. Bromelain loaded nanoparticles (Br-NPs) were developed using a Eudragit L 100 polymer by a double emulsion solvent evaporation method to obtain gastro-resistant properties. Br-NPs were characterized for particle size (248.89 ± 22.76 nm), zeta potential (-27.34 ± 2.17 mV), entrapment efficiency (85.42 ± 5.34%), surface morphology (spherical) and in vitro release profile. Infrared spectroscopy confirmed the entrapment of bromelain while thermal and pXRD analysis concomitantly corroborated the reduced crystallinity of bromelain in nanoparticles. Formulations showed gastro-resistant behavior at gastric pH and sustained bromelain release up to 10 h in phosphate buffer at pH 6.8 and followed Higuchi square root release kinetics. The optimized lyophilized formulation ensured 2 year shelf-life at room temperature. In vivo studies revealed significantly improved performance of entrapped bromelain in inhibiting carrageenan induced paw edema by mitigating leucocyte migration and release of nitric oxide, TNFα and IL-1β in paw compared to bromelain solution. In conclusion, enteric Br-NPs could be a viable drug delivery system for effective oral bromelain delivery in inflammatory conditions.

Differential Noradrenergic Modulation of Monetary Reward and Visual Erotic Stimulus Processing

We recently investigated the effects of the noradrenergic antidepressant reboxetine and the antipsychotic amisulpride compared to placebo on neural correlates of primary reinforcers by visual erotic stimulation in healthy subjects. Whereas, amisulpride left subjective sexual functions and corresponding neural activations unimpaired, attenuated neural activations were observed under reboxetine within the nucleus accumbens (Nacc) along with diminished behavioral sexual functioning. However, a global dampening of the reward system under reboxetine seemed not intuitive considering the complementary role of the noradrenergic to the dopamine system in reward-related learning mediated by prediction error processing. We therefore investigated the sample of 17 healthy males in a mean age of 23.8 years again by functional magnetic resonance imaging (fMRI), to explore the noradrenergic effects on neural reward prediction error signaling. Participants took reboxetine (4 mg/d), amisulpride (200 mg/d), and placebo each for 7 days within a randomized, double-blind, within-subject cross-over design. During fMRI, we used an established monetary incentive task to assess neural reward expectation and prediction error signals within the bilateral Nacc using an independent anatomical mask for a region of interest (ROI) analysis. Activations within the same ROI were also assessed for the erotic picture paradigm. We confirmed our previous results from the whole brain analysis for the selected ROI by significant (p < 0.05 FWE-corrected) attenuated activations within the Nacc during visual sexual stimulation under reboxetine compared to placebo. However, activations in the Nacc concerning prediction error processing and monetary reward expectation were unimpaired under reboxetine compared to placebo, along with unimpaired reaction times in the reward task. For both tasks, neural activations and behavioral processing were not altered by amisulpride compared to placebo. The observed attenuated neural activations within the Nacc during visual erotic stimulation along with unimpaired neural prediction error and monetary reward expectation processing provide evidence for a differential modulation of the neural reward system by the noradrenergic agent reboxetine depending on the presence of primary reinforcers such as erotic stimuli in contrast to secondary such as monetary rewards.

Liver X receptor α (LXRα) promoted invasion and EMT of gastric cancer cells by regulation of NF-κB activity

Aberrant expression of Liver X receptor α (LXRα) has been frequently reported in various types of cancers excluding gastric cancer (GC). Moreover, the role of LXRα in human GC has not been previously reported. In this study, we investigated the effect of LXRα down-regulation on invasion and EMT of GC. The expression of LXRα in GC cell lines was detected by real-time PCR. The LXRα siRNA was transiently transfected into GC cells using Lipofectamine™ 2000 reagent. Subsequently, cell invasive ability was evaluated by Transwell assays. Western blot and real-time PCR were used to determined the expressions of matrix metalloproteinase-2 and -9 (MMP-2 and -9), E-cadherin, N-cadherin, Vimentin, Snail, Slug, and Twist in GC cells. In addition, the effect of LXRα down-regulation on the phosphoinositide 3-kinase (PI3K)/Akt/nuclear factor (NF)-κB signaling pathway was explored by Western blot. From our results, we found that the expression of LXRα was significantly increased in GC tissues and cell lines. Knockdown of LXRα suppressed the invasive ability of GC cells. The levels of MMP-2 and -9 were dramatically decreased by down-regulating LXRα. In addition, we found a decrease of N-cadherin, Twist, and Slug expressions and an increase of E-cadherin expression, but no influence on the expression levels of Vimentin and Snail. We also found that LXRα down-regulation might suppress the phosphorylation of Akt, NF-κB, and IκB. Collectively, our results indicated that down-regulation of LXRα was shown to suppress invasion and EMT of GC cells by decreasing the expressions of related proteins through inhibiting the PI3K/Akt/NF-κB signaling pathway.

Bromelain-Functionalized Multiple-Wall Lipid-Core Nanocapsules: Formulation, Chemical Structure and Antiproliferative Effect Against Human Breast Cancer Cells (MCF-7)

PURPOSE

This study was conducted a promising approach to surface functionalization developed for lipid-core nanocapsules and the merit to pursue new strategies to treat solid tumors.

METHODS

Bromelain-functionalized multiple-wall lipid-core nanocapsules (Bro-MLNC-Zn) were produced by self-assembling following three steps of interfacial reactions. Physicochemical and structural characteristics, in vitro proteolytic activity (casein substrate) and antiproliferative activity (breast cancer cells, MCF-7) were determined.

RESULTS

Bro-MLNC-Zn had z-average diameter of 135 nm and zeta potential of +23 mV. The complex is formed by a Zn-N chemical bond and a chelate with hydroxyl and carboxyl groups. Bromelain complexed at the nanocapsule surface maintained its proteolytic activity and showed anti-proliferative effect against human breast cancer cells (MCF-7) (72.6 ± 1.2% at 1.250 μg mL^-1 and 65.5 ± 5.5% at 0.625 μg mL^-1). Comparing Bro-MLNC-Zn and bromelain solution, the former needed a dose 160-folds lower than the latter for a similar effect. Tripan blue dye assay corroborated the results.

CONCLUSIONS

The surface functionalization approach produced an innovative formulation having a much higher anti-proliferative effect than the bromelain solution, even though both in vitro proteolytic activity were similar, opening up a great opportunity for further studies in nanomedicine.

The biochemical characterization, stabilization studies and the antiproliferative effect of bromelain against B16F10 murine melanoma cells

The current study aims to extract bromelain from different parts (stem, crown, peels, pulp and leaves) of Ananas comosus var. comosus AGB 772; to determine of optimum pH and temperature; to test bromelain stability in disodium EDTA and sodium benzoate, and to investigate its pharmacological activity on B16F10 murine melanoma cells in vitro. The highest enzymatic activity was found in bromelain extracted from the pulp and peel. The optimum bromelain pH among all studied pineapple parts was 6.0. The optimum temperature was above 50 °C in all bromelain extracts. The fluorescence analysis confirmed the stability of bromelain in the presence of EDTA and sodium benzoate. Bromelain was pharmacologically active against B16F10 melanoma cells and it was possible verifying approximately 100% inhibition of tumor cell proliferation in vitro. Since bromelain activity was found in different parts of pineapple plants, pineapple residues from the food industry may be used for bromelain extraction.

Combination of cisplatin and bromelain exerts synergistic cytotoxic effects against breast cancer cell line MDA-MB-231 in vitro

Background

Bromelain, which is a cysteine endopeptidase commonly found in pineapple stems, has been investigated as a potential anti-cancer agent for the treatment of breast cancer. However, information pertaining to the effects of combining bromelain with existing chemotherapeutic drugs remains scarce. This study aimed to investigate the possible synergistic cytotoxic effects of using bromelain in combination with cisplatin on MDA-MB-231 human breast cancer cells.

Method

MDA-MB-231 cells were treated with different concentrations (0.24–9.5 µM) of bromelain or cisplatin alone, as well as four different combinations of these two agents to assess their individual and combination effects after 24 and 48 h. Cell viability was analyzed using an MTT assay. The induction of apoptosis was assessed using cell cycle analysis and an Annexin V-FITC assay. The role of the mitochondrial membrane potential in the apoptotic process was assessed using a JC-1 staining assay. Apoptotic protein levels were assessed by western blot analysis and proteome profiling using an antibody array kit.

Results

Single-agent treatment with cisplatin or bromelain led to dose- and time-dependent decreases in the viability of the MDA-MB-231 cells at 24 and 48 h. Furthermore, most of the combinations evaluated in this study displayed synergistic effects against MDA-MB-231 cells at 48 h, with combination 1 (bromelain 2 µM + cisplatin 1.5 µM) exhibiting the greatest synergistic effect (P = 0.000). The results of subsequent assays indicated that combination 1 treatment induced apoptosis via mitochondria-mediated pathway. Combination 1 also resulted in significant decreases in the levels of several apoptotic proteins such as Bcl-x and HSP70, compared with bromelain (P = 0.002 and 0.000, respectively) or cisplatin (P = 0.000 and 0.001, respectively) single treatment. Notably, MDA-MB-231 cells treated with combination 1 showed increased levels of the pro-apoptotic proteins Bax compared with those treated with bromelain (P = 0.000) or cisplatin single treatment (P = 0.043).

Conclusion

Bromelain in combination with cisplatin synergistically enhanced the induction of apoptosis in MDA-MB-231 cells.

Trehalose, sucrose and raffinose are novel activators of autophagy in human keratinocytes through an mTOR-independent pathway

Trehalose is a natural disaccharide that is found in a diverse range of organisms but not in mammals. Autophagy is a process which mediates the sequestration, lysosomal delivery and degradation of proteins and organelles. Studies have shown that trehalose exerts beneficial effects through inducing autophagy in mammalian cells. However, whether trehalose or other saccharides can activate autophagy in keratinocytes is unknown. Here, we found that trehalose treatment increased the LC3-I to LC3-II conversion, acridine orange-stained vacuoles and GFP-LC3B (LC3B protein tagged with green fluorescent protein) puncta in the HaCaT human keratinocyte cell line, indicating autophagy induction. Trehalose-induced autophagy was also observed in primary keratinocytes and the A431 epidermal cancer cell line. mTOR signalling was not affected by trehalose treatment, suggesting that trehalose induced autophagy through an mTOR-independent pathway. mTOR-independent autophagy induction was also observed in HaCaT and HeLa cells treated with sucrose or raffinose but not in glucose, maltose or sorbitol treated HaCaT cells, indicating that autophagy induction was not a general property of saccharides. Finally, although trehalose treatment had an inhibitory effect on cell proliferation, it had a cytoprotective effect on cells exposed to UVB radiation. Our study provides new insight into the saccharide-mediated regulation of autophagy in keratinocytes.

AkP from mushroom Termitomyces clypeatus is a proteoglycan specific protease with apoptotic effect on HepG2

Termitomyces clypeatus is an edible mushroom, prized for its therapeutic values and as producer of industrially important enzymes. However, the biomedical efficacies of anticancer proteases have not been reported yet. The present study aimed to purify and characterize a serine protease (AkP) from T. clypeatus for investigating cytotoxic potency on HepG2, Hep3B, and compared the effect on normal hepatic L-02 cells. Purification and biochemical characterization of AkP were evaluated by three stage chromatography, 1D/2D-SDS-PAGE, 1D zymography, far-UV CD spectral analysis, N-terminal sequencing, MALDI-TOF/MS-MS analysis and enzyme kinetics studies. AkP could cleave the growth promoting cell surface proteoglycans of HepG2, corroborated by RP-HPLC analysis. AkP (IC50: 75±1.18nM) mediated anti-proliferative activity solely on HepG2 cells through the induction of apoptosis. Augmentation of apoptosis was attributed to up-regulation of p53 and Bax protein expression succeeded by caspase-3 activation. Serine protease inhibitor phenyl methane sulfonyl fluoride (PMSF) inhibited both its proteolytic activity and cytotoxicity on HepG2. These findings demonstrate that AkP could be an effective biomolecule for killing of cancer cells by p53 restoration and surface proteoglycans cleavage.

Bacoside A and bromelain relieve dichlorvos induced changes in oxidative responses in mice serum

Reactive oxygen species (ROS) may be involved in the pathogenesis of serum induced by dichlorvos. Therefore, the rationale of present research was to evaluate the ameliorative efficacy of bacoside A and bromelain on oxidative stress biomarkers in serum of dichlorvos intoxicated mice. Also the level of serum antioxidants viz. catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH) were measured. For experiments, mice were allocated into six groups. First group received saline as a vehicle; second group was administered with dichlorvos (40 mg/kg b.w.); third group was administered with bromelain (70 mg/kg b.w.), fourth group received dose of bacoside A (5 mg/kg b.w.), fifth group was given concomitant exposure of bacoside A and bromelain both and mice of sixth group were exposed to bacoside A, bromelain and dichlorvos for 21 days consecutively. Oxidative stress biomarkers thiobarbituric acid reactive substances (TBARS) and protein carbonyl content (PCC) and antioxidants (CAT, SOD, GPx and GSH) level of serum was determined to elucidate the protective potential of bacoside A and bromelain against dichlorvos intoxication. Significantly increased TBARS and PCC level in second group suggests that dichlorvos enhances the production of free radicals in serum of mice (p < 0.05). Antioxidants treatment significantly decreased the levels of TBARS and PCC (p < 0.05). Dichlorvos administration causes a significant reduction in the level of CAT, SOD, GPx and GSH (p < 0.05) which was restored significantly by co-administration of bromelain and bacoside A in dichlorvos exposed mice (p < 0.05). The bacoside A and bromelain are attributed with antioxidant properties. Finding of research conclude that concomitant exposure of bacoside A and bromelain was much effective in combating oxidative stress induced by dichlorvos.

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.

Shikonin causes cell-cycle arrest and induces apoptosis by regulating the EGFR-NF-κB signalling pathway in human epidermoid carcinoma A431 cells

Shikonin, a naphthoquinone pigment isolated from the Chinese herbal Zicao, has been shown to exhibit antioxidant and anticancer effects. In the present study, we investigated the antiproliferative and pro-apoptotic effects of shikonin on A431 cells and explored the underlying molecular mechanisms. In the present study, our results showed that shikonin significantly inhibited the growth of A431 cells in a concentration- and time-dependent manner, and caused cell cycle arrest by upregulation of p21 and p27, and downregulation of cyclins and cyclin-dependent kinases. In addition, shikonin evidently induced apoptosis due to decreasing Bcl-2 expression, increasing Bax expression, activating caspase and inactivating NF-κB, while pretreatment with a pan-caspase inhibitor Z-Asp-CH2-DCB abrogated shikonin-induced apoptosis. Moreover, EGF could significantly increase the NF-κB DNA-binding activity and reversed the shikonin-induced inactivation of NF-κB. As anticipated AG1478 (EGFR inhibitor) and Bay11-7082 (NF-κB inhibitor) blocked EGF-reversed the inactivation of NF-κB induced by shikonin. Our data also showed that EGF could evidently reverse the shikonin-induced decreases in cell viability and increases in apoptosis. Then, the NF-κB inhibitors such as Bay11-7082, SN50, Helenalin and the EGFR inhibitor AG1478 and its downstream inhibitor such as PI3K inhibitor LY294002 and STAT3 inhibitor Stattic dramatically blocked EGF-reversed decreases in cell viability and increases in apoptosis induced by shikonin. Collectively, our findings indicated that shikonin inhibited cell growth and caused cell cycle arrest of the A431 cells through the regulation of apoptosis. Moreover, these effects were mediated at least partially by suppressing the activation of the EGFR-NF-κB signaling pathways.

Bromelain and N-acetylcysteine inhibit proliferation and survival of gastrointestinal cancer cells in vitro: significance of combination therapy

BACKGROUND

Bromelain and N-acetylcysteine are two natural, sulfhydryl-containing compounds with good safety profiles which have been investigated for their benefits and application in health and disease for more than fifty years. As such, the potential values of these agents in cancer therapy have been variably reported in the literature. In the present study, the efficacy of bromelain and N-acetylcysteine in single agent and combination treatment of human gastrointestinal carcinoma cells was evaluated in vitro and the underlying mechanisms of effect were explored.

METHODS

The growth-inhibitory effects of bromelain and N-acetylcysteine, on their own and in combination, on a panel of human gastrointestinal carcinoma cell lines, including MKN45, KATO-III, HT29-5F12, HT29-5M21 and LS174T, were assessed by sulforhodamine B assay. Moreover, the influence of the treatment on the expression of a range of proteins involved in the regulation of cell cycle and survival was investigated by Western blot. The presence of apoptosis was also examined by TUNEL assay.

RESULTS

Bromelain and N-acetylcysteine significantly inhibited cell proliferation, more potently in combination therapy. Drug-drug interaction in combination therapy was found to be predominantly synergistic or additive. Mechanistically, apoptotic bodies were detected in treated cells by TUNEL assay. Furthermore, Western blot analysis revealed diminution of cyclins A, B and D, the emergence of immunoreactive subunits of caspase-3, caspase-7, caspase-8 and cleaved PARP, withering or cleavage of procaspase-9, overexpression of cytochrome c, reduced expression of anti-apoptotic Bcl-2 and pro-survival phospho-Akt, the emergence of the autophagosomal marker LC3-II and deregulation of other autophagy-related proteins, including Atg3, Atg5, Atg7, Atg12 and Beclin 1. These results were more prominent in combination therapy.

CONCLUSION

We report for the first time to our knowledge the growth-inhibitory and cytotoxic effects of bromelain and N-acetylcysteine, in particular in combination, on a panel of gastrointestinal cancer cell lines with different phenotypes and characteristics. These effects apparently resulted from cell cycle arrest, apoptosis and autophagy. Towards the development of novel strategies for the enhancement of microscopic cytoreduction, our results lay the basis for further evaluation of this formulation in locoregional approaches to peritoneal surface malignancies and carcinomatosis.

Bromelain and N-acetylcysteine inhibit proliferation and survival of gastrointestinal cancer cells in vitro: significance of combination therapy

Background

Bromelain and N-acetylcysteine are two natural, sulfhydryl-containing compounds with good safety profiles which have been investigated for their benefits and application in health and disease for more than fifty years. As such, the potential values of these agents in cancer therapy have been variably reported in the literature. In the present study, the efficacy of bromelain and N-acetylcysteine in single agent and combination treatment of human gastrointestinal carcinoma cells was evaluated in vitro and the underlying mechanisms of effect were explored.

Methods

The growth-inhibitory effects of bromelain and N-acetylcysteine, on their own and in combination, on a panel of human gastrointestinal carcinoma cell lines, including MKN45, KATO-III, HT29-5F12, HT29-5M21 and LS174T, were assessed by sulforhodamine B assay. Moreover, the influence of the treatment on the expression of a range of proteins involved in the regulation of cell cycle and survival was investigated by Western blot. The presence of apoptosis was also examined by TUNEL assay.

Results

Bromelain and N-acetylcysteine significantly inhibited cell proliferation, more potently in combination therapy. Drug-drug interaction in combination therapy was found to be predominantly synergistic or additive. Mechanistically, apoptotic bodies were detected in treated cells by TUNEL assay. Furthermore, Western blot analysis revealed diminution of cyclins A, B and D, the emergence of immunoreactive subunits of caspase-3, caspase-7, caspase-8 and cleaved PARP, withering or cleavage of procaspase-9, overexpression of cytochrome c, reduced expression of anti-apoptotic Bcl-2 and pro-survival phospho-Akt, the emergence of the autophagosomal marker LC3-II and deregulation of other autophagy-related proteins, including Atg3, Atg5, Atg7, Atg12 and Beclin 1. These results were more prominent in combination therapy.

Conclusion

We report for the first time to our knowledge the growth-inhibitory and cytotoxic effects of bromelain and N-acetylcysteine, in particular in combination, on a panel of gastrointestinal cancer cell lines with different phenotypes and characteristics. These effects apparently resulted from cell cycle arrest, apoptosis and autophagy. Towards the development of novel strategies for the enhancement of microscopic cytoreduction, our results lay the basis for further evaluation of this formulation in locoregional approaches to peritoneal surface malignancies and carcinomatosis.

A noncanonical NF-κB pathway through the p50 subunit regulates Bcl-2 overexpression during an oxidative-conditioning hormesis response

Cells can respond to damage and stress by activating various repair and survival pathways. One of these responses can be induced by preconditioning the cells with sublethal stress to provoke a prosurvival response that will prevent damage and death, and which is known as hormesis. Bcl-2, an antiapoptotic protein recognized by its antioxidant and prosurvival functions, has been documented to play an important role during oxidative-conditioning hormesis. Using an oxidative-hormetic model, which was previously established in the L929 cell line by subjecting the cells to a mild oxidative stress of 50 μM H₂O₂ for 9 h, we identified two different transductional mechanisms that participate in the regulation of Bcl-2 expression during the hormetic response. These mechanisms converge in activating the nuclear transcription factor NF-κB. Interestingly, the noncanonical p50 subunit of the NF-κB family is apparently the subunit that participates during the oxidative-hormetic response.

Plant proteolytic enzyme papain abrogates angiogenic activation of human umbilical vein endothelial cells (HUVEC) in vitro

BACKGROUND

Vascular endothelial growth factor (VEGF) is a key regulator of physiologic and pathogenic angiogenesis in diseases such as cancer and diabetic retinopathy. It is known that cysteine proteases from plants, like bromelain and papain are capable to suppress inflammatory activation. Recent studies have demonstrated that they may interfere with angiogenesis related pathways as well. The aim of this study was to investigate the anti-angiogenic effects of papain on human umbilical vein endothelial cells (HUVEC) in vitro.

METHODS

Cell viability after prolonged treatment with papain was investigated by life cell staining and lactate dehydrogenase release assay. Angiogenic activation was assessed by ELISA against phosphorylated proteins AKT, MEK1/2, ERK1/2, SAPK/JNK and p38-MAPK. Growth inhibition was determined by means of an MTT-assay and cell migration by means of a scratch assay. Capability to form a capillary network was investigated using a tube formation assay.

RESULTS

Papain did not induce proteolysis or cell detachment of HUVEC in a concentration range between 0 and 25 μg/mL. Four hours treatment with 10 μg/mL papain resulted in a reduced susceptibility of endothelial cells to activation by VEGF as determined by phosphorylation levels of Akt, MEK1/2, SAPK/JNK. Papain exerted a distinct inhibitory effect on cell growth, cell migration and tube formation with inhibition of tube formation detectable at concentrations as low as 1 μg/mL. Bromelain and ficin displayed similar effects with regard to cell growth and tube formation.

CONCLUSION

Papain showed a strong anti-angiogenic effect in VEGF activated HUVEC. This effect may be due to interference with AKT, MEK1/2 and SAPK/JNK phosphorylation. Two other plant derived cysteine proteases displayed similar inhibition of HUVEC cell growth and tube formation. These findings indicate that plant proteolytic enzymes may have potential as preventive and therapeutic agents against angiogenesis related human diseases.

Cytotoxic effects of bromelain in human gastrointestinal carcinoma cell lines (MKN45, KATO-III, HT29-5F12, and HT29-5M21)

Background

Bromelain is a pineapple stem extract with a variety of therapeutic benefits arising from interaction with a number of different biological processes. Several preclinical studies and anecdotal clinical observations have reported the anticancer properties of bromelain. In the present study, we investigated the cytotoxic effects of bromelain in four human cancer cell lines of gastrointestinal origin and the mechanisms involved.

Methods

The gastric carcinoma cell lines (KATO-III and MKN45) and two chemoresistant subpopulations of the HT29 colon adenocarcinoma cell line (HT29-5M21 and HT29-5F12) were treated with a range of concentrations of bromelain, as well as with cisplatin as a positive control. The effect of bromelain on the growth and proliferation of cancer cells was determined using a sulforhodamine B assay after 72 hours of treatment. Expression of apoptosis-associated proteins in MKN45 cells treated with bromelain was analyzed by Western blotting.

Results

Data from our sulforhodamine B assay showed that bromelain inhibited proliferation of HT29-5F12, HT29-5M21, MKN45, and KATO-III cells, with respective half maximal inhibitory concentration values of 29, 34, 94, and 142 μg/mL. Analyzing the expression of proapoptotic and antiapoptotic proteins in bromelain-treated MKN45 cells, we observed activation of the caspase system, cleavage of PARP and p53, overexpression of cytochrome C, attenuation of phospho-Akt and Bcl2, and removal of MUC1. Apart from the caspase-dependent apoptosis observed, emergence of cleaved p53 supports a direct, extranuclear apoptotic function of p53. Moreover, interrupted Akt signaling and attenuation of Bcl2 and MUC1 oncoproteins suggest impaired survival of cancer cells.

Conclusion

Our findings collectively indicate that bromelain exerts cytotoxic effects in a panel of human gastric and colon carcinoma cells. Our study of MKN45 cells implicated different mechanisms in bromelain-induced cell death. While promoting apoptosis with involvement of the caspase system and extranuclear p53, bromelain also appears to impair cancer cell survival by blocking the Akt pathway and attenuating Bcl2 and MUC1 oncoproteins.

Anticancer property of bromelain with therapeutic potential in malignant peritoneal mesothelioma

Bromelain is a mixture of proteolytic enzymes that is capable of hydrolyzing glycosidic linkages in glycoprotein. Glycoprotein's are ubiquitously distributed throughout the body and serve a variety of physiologic functions. Faulty glycosylation of proteins may lead to cancer. Antitumor properties of bromelain have been demonstrated in both, in vitro and in vivo studies, along with scanty anecdotal human studies. Various mechanistic pathways have been proposed to explain the anticancer properties of bromelain. However, proteolysis by bromelain has been suggested as a main pathway by some researchers. MUC1 is a glycoprotein that provides tumor cells with invasive, metastatic, and chemo-resistant properties. To date, there is no study that examines the effect of bromelain on MUC1. However, the viability of MUC1 expressing pancreatic and breast cancer cells are adversely affected by bromelain. Further, the efficacy of cisplatin and 5-FU are enhanced by adjuvant treatment with bromelain, indicating that the barrier function of MUC1 may be affected. Other studies have also indicated that there is a greater accumulation of 5-FU in the cell compartment on treatment with 5-FU and bromelain. Malignant peritoneal mesothelioma (MPM) expresses MUC1 and initial studies have shown that the viability of MPM cells is adversely affected by exposure to bromelain. Further, bromelain in combination with either 5-FU or cisplatin, the efficacy of the chemotherapeutic drug is enhanced. Hence, current evidence indicates that bromelain may have the potential of being developed into an effective anticancer agent for MPM.

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.