Modified citrus pectin (MCP) increases the prostate-specific antigen doubling time in men with prostate cancer: a phase II pilot study

Modified pectin with anticancer activity in breast cancer: A systematic review

Breast cancer is the most commonly diagnosed cancer among women worldwide. The current pharmacological treatments for breast cancer have numerous adverse effects and are not always effective. Recently, the anticancer activity of modified pectins (MPs) against various types of cancers, including breast cancer, has been investigated. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model, including scientific articles from the last 22 years that measured the anticancer activity of MPs on breast cancer. The articles were searched in four databases with the terms: "modified pectin" and "breast cancer". Nine articles were included, five in vitro and four mixed (in vitro and in vivo). Different models and methods by which anticancer activity was measured were analyzed. All the studies reported positive results in both cell lines and in vivo murine models of breast cancer. The extracted data suggest a positive effect and provide mechanistic evidence of MPs in the treatment of breast cancer. However, as limited number of studies were included, further in vivo studies are required to obtain more conclusive preclinical evidence.

Modified Citrus Pectin Treatment in Non-Metastatic Biochemically Relapsed Prostate Cancer: Long-Term Results of a Prospective Phase II Study

The optimal therapy for patients with non-metastatic biochemically relapsed prostate cancer (BRPC-M0) after local therapy is elusive. Thus, the evaluation of new non-toxic compounds in BRPC-M0 patients is warranted. PectaSol®-Modified citrus pectin (P-MCP) is a food supplement categorized as GRAS (Generally Recognized As Safe) by the FDA. It is a competitive inhibitor of the galectin-3 protein, which is involved in cancer pathogenesis. In an early report of the present phase 2 study, P-MCP treatment for 6 months led to prostate-specific antigen doubling time (PSADT) improvement in 75% of patients with BRPC-M0. Herein, we report the second long-term treatment phase of an additional 12 months of P-MCP therapy (4.8 g × 3/day orally) in patients without disease progression after the initial 6 months of therapy. Of the 46 patients that entered the second treatment phase, 7 patients withdrew consent and decided to continue therapy out of pocket, and 39 initiated the second treatment phase. After a total of 18 months of P-MCP treatment, 85% (n = 33) had a durable long-term response, with 62% (n = 24) showing decreased/stable PSA, 90% (n = 35) PSADT improvement, and all with negative scans. No patient had grade 3/4 toxicity. In conclusion, P-MCP may have long-term durable efficacy and is safe in BRPC-M0.

The influence of lifestyle changes (diet, exercise and stress reduction) on prostate cancer tumour biology and patient outcomes: A systematic review

Background

The mostly indolent natural history of prostate cancer (PCa) provides an opportunity for men to explore the benefits of lifestyle interventions. Current evidence suggests appropriate changes in lifestyle including diet, physical activity (PA) and stress reduction with or without dietary supplements may improve both disease outcomes and patient's mental health.

Objective

This article aims to review the current evidence on the benefits of all lifestyle programmes for PCa patients including those aimed at reducing obesity and stress, explore their affect on tumour biology and highlight any biomarkers that have clinical utility.

Evidence acquisition

Evidence was obtained from PubMed and Web of Science using keywords for each section on the affects of lifestyle interventions on (a) mental health, (b) disease outcomes and (c) biomarkers in PCa patients. PRISMA guidelines were used to gather the evidence for these three sections (15, 44 and 16 publications, respectively).

Evidence synthesis

For lifestyle studies focused on mental health, 10/15 demonstrated a positive influence, although for those programmes focused on PA it was 7/8. Similarly for oncological outcomes, 26/44 studies demonstrated a positive influence, although when PA was included or the primary focus, it was 11/13. Complete blood count (CBC)-derived inflammatory biomarkers show promise, as do inflammatory cytokines; however, a deeper understanding of their molecular biology in relation to PCa oncogenesis is required (16 studies reviewed).

Conclusions

Making PCa-specific recommendations on lifestyle interventions is difficult on the current evidence. Nevertheless, notwithstanding the heterogeneity of patient populations and interventions, the evidence that dietary changes and PA may improve both mental health and oncological outcomes is compelling, especially for moderate to vigorous PA. The results for dietary supplements are inconsistent, and although some biomarkers show promise, significantly more research is required before they have clinical utility.

Targeting galectin-driven regulatory circuits in cancer and fibrosis

Galectins are a family of endogenous glycan-binding proteins that have crucial roles in a broad range of physiological and pathological processes. As a group, these proteins use both extracellular and intracellular mechanisms as well as glycan-dependent and independent pathways to reprogramme the fate and function of numerous cell types. Given their multifunctional roles in both tissue fibrosis and cancer, galectins have been identified as potential therapeutic targets for these disorders. Here, we focus on the therapeutic relevance of galectins, particularly galectin 1 (GAL1), GAL3 and GAL9 to tumour progression and fibrotic diseases. We consider an array of galectin-targeted strategies, including small-molecule carbohydrate inhibitors, natural polysaccharides and their derivatives, peptides, peptidomimetics and biological agents (notably, neutralizing monoclonal antibodies and truncated galectins) and discuss their mechanisms of action, selectivity and therapeutic potential in preclinical models of fibrosis and cancer. We also review the results of clinical trials that aim to evaluate the efficacy of galectin inhibitors in patients with idiopathic pulmonary fibrosis, nonalcoholic steatohepatitis and cancer. The rapid pace of glycobiology research, combined with the acute need for drugs to alleviate fibrotic inflammation and overcome resistance to anticancer therapies, will accelerate the translation of anti-galectin therapeutics into clinical practice.

Inhibition of galectins in cancer: Biological challenges for their clinical application

Galectins play relevant roles in tumor development, progression and metastasis. Accordingly, galectins are certainly enticing targets for medical intervention in cancer. To date, however, clinical trials based on galectin inhibitors reported inconclusive results. This review summarizes the galectin inhibitors currently being evaluated and discusses some of the biological challenges that need to be addressed to improve these strategies for the benefit of cancer patients.

Pectin: A Bioactive Food Polysaccharide with Cancer Preventive Potential

Pectin is an acidic heteropolysaccharide found in the cell walls and the primary and middle lamella of land plants. To be authorized as a food additive, industrial pectins must meet strict guidelines set forth by the Food and Agricultural Organization and must contain at least 65% polygalacturonic acid to achieve the E440 level. Fruit pectin derived from oranges or apples is commonly used in the food industry to gel or thicken foods and to stabilize acid-based milk beverages. It is a naturally occurring component and can be ingested by dietary consumption of fruit and vegetables. Preventing long-term chronic diseases like diabetes and heart disease is an important role of dietary carbohydrates. Colon and breast cancer are among the diseases for which data suggest that modified pectin (MP), specifically modified citrus pectin (MCP), has beneficial effects on the development and spread of malignancies, in addition to its benefits as a soluble dietary fiber. Cellular and animal studies and human clinical trials have provided corroborating data. Although pectin has many diverse functional qualities, this review focuses on various modifications used to develop MP and its benefits for cancer prevention, bioavailability, clinical trials, and toxicity studies. This review concludes that pectin has anti-cancer characteristics that have been found to inhibit tumor development and proliferation in a wide variety of cancer cells. Nevertheless, further clinical and basic research is required to confirm the chemopreventive or therapeutic role of specific dietary carbohydrate molecules.

Potential of pectin for biomedical applications: a comprehensive review

Pectin is a polysaccharide extracted from various plants, such as apples, oranges, lemons, and it possesses some beneficial effects on human health, including being hypoglycemic and hypocholesterolemic. Therefore, pectin is used in various pharmaceutical and biomedical applications. Meanwhile, its low mechanical strength and fast degradation rate limit its usage as drug delivery devices and tissue engineering scaffolds. To enhance these properties, it can be modified or combined with other organic molecules or polymers and/or inorganic compounds. These materials can be prepared as nano sized drug carriers in the form of spheres, capsules, hydrogels, self assamled micelles, etc., for treatment purposes (mostly cancer). Different composites or blends of pectin can also be produced as membranes, sponges, hydrogels, or 3D printed matrices for tissue regeneration applications. This review is concentrated on the properties of pectin based materials and focus especially on the utilization of these materials as drug carriers and tissue engineering scaffolds, including 3D printed and 3D bioprinted systems covering the studies in the last decade and especially in the last 5 years.

Anti-Cancer Pectins and Their Role in Colorectal Cancer Treatment

A class of plant polysaccharides, pectin is known to display several medicinal properties including in cancer. There is some evidence that pectin from some fruits can reduce the severity of colorectal cancer (CRC) due to its antiproliferative, anti-inflammatory, antimetastatic and pro-apoptotic properties. Pectin fermentation in the colon induces antiproliferative activity via butyrate. Research also showed that pectin acts as a potent inducer of programmed cell death and cell-cycle arrest, thereby selectively targeting cancer cells. Pectin can limit oxidative stress to maintain cellular homeostasis while increasing reactive oxygen species damage to activate cancer cell death. Pectin regulates various signaling cascades, e.g., signal transduction and transcriptional activator and mitogen-activated protein kinase signaling, that contribute to its anticancer activity. By curbing inflammation-activated signaling and bolstering immune-protective mechanisms pectin can eradicate CRC. Due to its chemical structure, pectin can also inhibit galectin-3 and suppress tumor growth and metastasis. Prior reports also suggested that pectin is beneficial to use alongside the CRC standard care. Pectin can increase sensitivity to conventional CRC drugs, alleviate unwanted side effects and reduce drug resistance. Although some preclinical studies are promising, early clinical trials are showing some evidence for pectin's efficacy in tumor growth inhibition and preventing metastasis in some cancers; however, the clinical use of pectin in CRC therapy is not yet well established. Further studies are needed to confirm the efficacy of pectin treatment as a valid clinical therapy for CRC in humans.

Modified Citrus Pectin Treatment in Non-Metastatic Biochemically Relapsed Prostate Cancer: Results of a Prospective Phase II Study

Optimal therapy of biochemically relapsed prostate cancer (BRPC) after local treatment is elusive. An established modified citrus pectin (PectaSol^®, P-MCP), a dietary polysaccharide, is an established antagonist of galectin-3, a carbohydrate-binding protein involved in cancer pathogenesis. Based on PSA dynamics, we report on the safety and the primary outcome analysis of a prospective phase II study of P-MCP in non-metastatic BRPC based. Sixty patients were enrolled, and one patient withdrew after a month. Patients (n = 59) were given P-MCP, 4.8 grams X 3/day, for six months. The primary endpoint was the rate without PSA progression and improved PSA doubling time (PSADT). Secondary endpoints were the rate without radiologic progression and toxicity. Patients that did not progress by PSA and radiologically at six months continued for an additional twelve months. After six months, 78% (n = 46) responded to therapy, with a decreased/stable PSA in 58% (n = 34), or improvement of PSADT in 75% (n = 44), and with negative scans, and entered the second twelve months treatment phase. Median PSADT improved significantly (p = 0.003). Disease progression during the first 6 months was noted in only 22% (n = 13), with PSA progression in 17% (n = 10), and PSA and radiologic progression in 5% (n = 3). No patients developed grade 3 or 4 toxicity.

Pectins and Olive Pectins: From Biotechnology to Human Health

Simple Summary

Pectins comprise complex polysaccharides rich in galacturonic acid, that exert many functions in higher plants as components of the cell walls, together with cellulose or lignin. The food industry has traditionally used pectins as an additive due to their gelling or thickening properties. Pharmaceutical research is also taking advantage of pectin bioactivity, providing evidence of the role of these polysaccharides as health promoters. Fruits and vegetables are natural sources of pectins that can be obtained as by-products during food or beverage production. In line with this, the aim of our study is gathering data on the current methods to extract pectins from fruit or vegetable wastes, optimizing yield and environmentally friendly protocols. Updated information about pectin applications in food or non-food industries are provided. We also point to olives as novel source of pectins that strengthen the evidence that this fruit is as remarkably healthy part of the Mediterranean diet. This work exhibits the need to explore natural bioactive components of our daily intake to improve our health, or prevent or treat chronical diseases present in our society.

Abstract

Pectins are a component of the complex heteropolysaccharide mixture present in the cell wall of higher plants. Structurally, the pectin backbone includes galacturonic acid to which neutral sugars are attached, resulting in functional regions in which the esterification of residues is crucial. Pectins influence many physiological processes in plants and are used industrially for both food and non-food applications. Pectin-based compounds are also a promising natural source of health-beneficial bioactive molecules. The properties of pectins have generated interest in the extraction of these polysaccharides from natural sources using environmentally friendly protocols that maintain the native pectin structure. Many fruit by-products are sources of pectins; however, owing to the wide range of applications in various fields, novel plants are now being explored as potential sources. Olives, the fruit of the olive tree, are consumed as part of the healthy Mediterranean diet or processed into olive oil. Pectins from olives have recently emerged as promising compounds with health-beneficial effects. This review details the current knowledge on the structure of pectins and describes the conventional and novel techniques of pectin extraction. The versatile properties of pectins, which make them promising bioactive compounds for industry and health promotion, are also considered.

Macropinocytosis requires Gal-3 in a subset of patient-derived glioblastoma stem cells

Recently, we involved the carbohydrate-binding protein Galectin-3 (Gal-3) as a druggable target for KRAS-mutant-addicted lung and pancreatic cancers. Here, using glioblastoma patient-derived stem cells (GSCs), we identify and characterize a subset of Gal-3high glioblastoma (GBM) tumors mainly within the mesenchymal subtype that are addicted to Gal-3-mediated macropinocytosis. Using both genetic and pharmacologic inhibition of Gal-3, we showed a significant decrease of GSC macropinocytosis activity, cell survival and invasion, in vitro and in vivo. Mechanistically, we demonstrate that Gal-3 binds to RAB10, a member of the RAS superfamily of small GTPases, and β1 integrin, which are both required for macropinocytosis activity and cell survival. Finally, by defining a Gal-3/macropinocytosis molecular signature, we could predict sensitivity to this dependency pathway and provide proof-of-principle for innovative therapeutic strategies to exploit this Achilles' heel for a significant and unique subset of GBM patients.

Galectin-3: A factotum in carcinogenesis bestowing an archery for prevention

Cancer metastasis and therapy resistance are the foremost hurdles in oncology at the moment. This review aims to pinpoint the functional aspects of a unique multifaceted glycosylated molecule in both intracellular and extracellular compartments of a cell namely galectin-3 along with its metastatic potential in different types of cancer. All materials reviewed here were collected through the search engines PubMed, Scopus, and Google scholar. Among the 15 galectins identified, the chimeric gal-3 plays an indispensable role in the differentiation, transformation, and multi-step process of tumor metastasis. It has been implicated in the molecular mechanisms that allow the cancer cells to survive in the intravascular milieu and promote tumor cell extravasation, ultimately leading to metastasis. Gal-3 has also been found to have a pivotal role in immune surveillance and pro-angiogenesis and several studies have pointed out the importance of gal-3 in establishing a resistant phenotype, particularly through the epithelial-mesenchymal transition process. Additionally, some recent findings suggest the use of gal-3 inhibitors in overcoming therapeutic resistance. All these reports suggest that the deregulation of these specific lectins at the cellular level could inhibit cancer progression and metastasis. A more systematic study of glycosylation in clinical samples along with the development of selective gal-3 antagonists inhibiting the activity of these molecules at the cellular level offers an innovative strategy for primary cancer prevention.

Galectin-3 Inhibition With Modified Citrus Pectin in Hypertension

We investigated the effect of galectin-3 (Gal-3) inhibition with modified citrus pectin on markers of collagen metabolism in a proof-of-concept randomized placebo-controlled trial of participants with elevated Gal-3 levels and hypertension. Although higher Gal-3 levels were associated with female sex, diabetes, and reduced glomerular filtration rate in cross-sectional analyses, treatment with modified citrus pectin did not change collagen markers. The effect of Gal-3 inhibition among individuals with heart failure warrants further investigation.

Efficacy of Jackfruit365™ Green Jackfruit Flour Fortified Diet on Pegfilgrastim to Prevent Chemotherapy-Induced Leukopenia, Irrespective of Tumor Type or Drugs Used-A Retrospective Study

Chemotherapy-Induced Leukopenia (CIL) is associated with increased mortality and economic burden on patients. This study was conducted to evaluate whether inclusion of green jackfruit flour in regular diet of those patients receiving chemotherapy, could prevent CIL. This was a retrospective study conducted among a group of patients undergoing chemotherapy for solid tumors at Renai Medicity Hospital, Palarivattom, Cochin, Kerala, India, since June 2018. The study group comprised of 50 consecutive subjects, who were supplemented with green jackfruit flour diet in their regular diet and further followed up prospectively. The control group was retrospective with 50 subjects prior to June 2018, with no diet supplements. Those who received less than three cycles were excluded from either arm. The mean age of the participants in study group and control group were 53.16 ± 11.06 and 56.96 ± 12.16 years respectively. In the study group, six patients out of 37, and 20 patients out of 50 in the control group, developed CIL. They received 38 and 105 vials of filgrastim respectively. After excluding those cycles in study group patients, where green jackfruit flour was not taken, the mean number of cycles in which CIL developed (p = 0.00) and number of vials of filgrastim taken per cycle (p = 0.00) were significantly different from control group and no patient in the study group developed CIL. Inclusion of green jackfruit flour as a dietary intervention prevents chemotherapy-induced leukopenia in patients undergoing chemotherapy along with pegfilgrastim.

Pleiotropic Effects of Modified Citrus Pectin

Modified citrus pectin (MCP) has a low-molecular-weight degree of esterification to allow absorption from the small intestinal epithelium into the circulation. MCP produces pleiotropic effects, including but not limited to its antagonism of galectin-3, which have shown benefit in preclinical and clinical models. Regarding cancer, MCP modulates several rate-limiting steps of the metastatic cascade. MCP can also affect cancer cell resistance to chemotherapy. Regarding fibrotic diseases, MCP modulates many of the steps involved in the pathogenesis of aortic stenosis. MCP also reduces fibrosis to the kidney, liver, and adipose tissue. Other benefits of MCP include detoxification and improved immune function. This review summarizes the pleiotropic effects of MCP.

Bioactive potential of fruit and vegetable wastes

Fruits and vegetables are essential for human nutrition, delivering a substantial proportion of vitamins, minerals, and fibers in our daily diet. Unfortunately, half the fruits and vegetables produced worldwide end up as wastes, generating environmental issues caused mainly by microbial degradation. Most wastes are generated by industrial processing, the so-called by-products. These by-products still contain many bioactive compounds post-processing, such as macronutrients (proteins and carbohydrates) and phytochemicals (polyphenols and carotenoids). Recently, the recovery of these bioactive compounds from industry by-products has received significant attention, mainly due to their possible health benefits for humans. This chapter focuses on the bioactive potential of fruit and vegetable by-products with possible applications in the food industry (functional foods) and in the health sector (nutraceuticals).

Modified Citrus Pectin as a Potential Sensitizer for Radiotherapy in Prostate Cancer

Background: Radiotherapy is one of the primary therapies for localized prostatic carcinoma. Therefore, there is an emerging need to sensitize prostatic cancer cells to chemotherapy/radiotherapy. Modified citrus pectin (MCP) is an effective inhibitor of galectin-3 (Gal-3), which is correlated with tumor progression, proliferation, angiogenesis, and apoptosis. Purpose: This study was directed to evaluate the efficacy of combining ionizing radiation (IR) with MCP on PCa cells. Study Design: Effects of treatments on PCa cells survival were evaluated using XTT assay, flow cytometry, and clonogenic survival assay. Expression of selected proteins was estimated using western blotting. Cell motility, migration, and invasion were determined. Contribution of reactive oxygen species production to treatment effects on cell viability was tested. Results: Radiotherapy combined with MCP reduced viability and enhanced radiosensitivity associated with a decrease in Gal-3, cleavage of the precursor of caspase-3, increased expression of the pro-apoptotic protein Bax, and downregulation of DNA repair pathways, poly-ADP-ribose polymerase, and proliferating cell nuclear antigen. MCP significantly reduced the invasive and migratory potential of PCa cells. Combining sodium pyruvate with MCP and IR mitigated the effect on cell viability. Conclusion: Our findings demonstrated that MCP sensitized PCa cells to IR by downregulating anti-apoptotic Gal-3, modulating DNA repair pathways, and increasing ROS production. For the first time the correlation between MCP, radiotherapy, and Gal-3 for prostatic cancer treatment was found. In addition, MCP reduced the metastatic properties of PCa cells. These findings provide MCP as a radiosensitizing agent to enhance IR cytotoxicity, overcome radioresistance, and reduce clinical IR dose.

Pectin and Pectin-Based Composite Materials: Beyond Food Texture

Pectins are plant cell wall natural heteropolysaccharides composed mainly of α-1-4 d-galacturonic acid units, which may or may not be methyl esterified, possesses neutral sugars branching that harbor functional moieties. Physicochemical features as pH, temperature, ions concentration, and cosolute presence, affect directly the extraction yield and gelling capacity of pectins. The chemical and structural features of this polysaccharide enables its interaction with a wide range of molecules, a property that scientists profit from to form new composite matrices for target/controlled delivery of therapeutic molecules, genes or cells. Considered a prebiotic dietary fiber, pectins meetmany regulations easily, regarding health applications within the pharmaceutical industry as a raw material and as an agent for the prevention of cancer. Thus, this review lists many emergent pectin-based composite materials which will probably palliate the impact of obesity, diabetes and heart disease, aid to forestall actual epidemics, expand the ken of food additives and food products design.

Ultrasonic Modified Sweet Potato Pectin Induces Apoptosis like Cell Death in Colon Cancer (HT-29) Cell Line

BACKGROUND

Pectin and especially modified citrus pectin possesses anticancer activity. Hence, the current study investigated anticancer activity of ultrasonic-modified sweet potato pectin (SPP) on HT-29 cells to assess its potential as a cancer therapeutic agent.

METHOD

The effect of ultrasonic treatment on SPP molecular weight, galacturonic acid content, degree of methoxylation, and neutral sugar was investigated. Moreover, the effect of sonicated variant on human HT-29 cell proliferation was assessed by MTT assay, cell cytotoxicity, and apoptosis by Annexin V/PI flow cytometer and caspase-3 activity was studied.

RESULTS AND DISCUSSION

Sonication led up to seven-fold decrease in molecular weight. The degree of methoxylation (DM) decreased more than two-fold. Moreover, the galacturonic acid (GalA) content increased up to 92%, arabinose and galactose content increased. The SSPP inhibited cell proliferation with the IC₅₀ values 0.5 mg/ml and 0.75 mg/ml for 400 W and 200 W SSPP, respectively. Moreover, 14.41 ± 1.64% cell cytotoxicity was elicited by 400 W SSPP and 6.83 ± 0.80% by 200 W SSPP. Both SSPPs induced apoptosis with 400 W SSPP eliciting 19.42% and 42.21% apoptosis at 0.1 and 0.5 mg/ml, while 200 W SSPP induced 13.79% and 39.50% apoptosis at 0.1 and 0.5 mg/ml, respectively. SSPP activity increased with both increased concentration and sonication intensity.

Complementary and Integrative Medicine in Hematologic Malignancies: Questions and Challenges

Hematologic malignancies represent 9.7% of all cancers, making them the fourth most common type of cancer in the United States. The aggressive and complex treatments administered in hematologic malignancies result in a high burden of psychological needs. Complementary and integrative medicine (CIM) is becoming one of the options that patients use to address their distress during and after cancer treatments. It is not clear whether appropriate CIM can relieve distress in patients affected by these malignancies. This review covers the potential benefits of CIM as relates to nutrition, nutritional supplements, exercise, circadian rhythm, methods for reducing distress during bone marrow aspiration, massage therapy, and acupuncture, in treating patients with hematological malignancies. This review may provide a framework to enhance patient-doctor dialogue regarding CIM use in hematologic malignancies.

Synergistic Antioxidant and Anti-Inflammatory Effects between Modified Citrus Pectin and Honokiol

Inflammation is a normal physiological process; however, dysregulation of this process may contribute to inflammatory-based chronic disorders and diseases in animals and humans. Therefore, the antioxidant and anti-inflammatory properties of natural products, often recognized in traditional medicine systems, represent therapeutic modalities to reduce or prevent uncontrolled inflammatory processes which in turn potentially ameliorate or prevent sequelae of inflammatory-based symptoms of chronic diseases. We have investigated the antioxidant and anti-inflammatory effects of honokiol (HNK) and modified citrus pectin (MCP) in vitro and examined whether the MCP : HNK combination has synergistic effects on antioxidant and anti-inflammatory properties. Although both HNK and MCP induced a dose-dependent increase in antioxidant activity, the latter has a consistently higher antioxidant effect. The MCP : HNK (9 : 1) combination induced a synergistic effect on antioxidant activity suggesting that the combination is significantly more efficacious than individual compounds. In mouse monocytes, the lipopolysaccharide- (LPS-) induced tumor necrosis-α (TNF-α) synthesis was significantly inhibited by HNK and the MCP : HNK combination in a dose-dependent manner and synergistic effects were clearly demonstrated with the combination on TNF-α inhibition. This combination effect was also evident on inhibition of nuclear factor-kappa B activity, cyclooxygenase-II activity, and lipid peroxidation in mouse monocytes. Further research into the combination is warranted.

Methods for the detection and serum depletion of porcine galectin-3

BACKGROUND

Circulating galectin-3 (Gal-3) is elevated in systemic inflammatory disorders, fibrotic diseases, and in cancers. Gal-3 is a promising cancer target where it promotes tumorigenesis and metastasis, as well as in renal, pulmonary, hepatic, and cardiovascular diseases, because of its role as a driver of fibrotic remodeling. This reports goal was to establish methods for the detection and removal of porcine Gal-3 that will enable further studies of the therapeutic potential of Gal-3 depletion by apheresis in porcine disease models. The long-term aim is to develop a safe, effective method of removing Gal-3 via apheresis as a standalone therapeutic tool and as an adjuvant to other therapies.

METHODS

Purified recombinant porcine Gal-3 was prepared and used as the standard for development of a porcine Gal-3 enzyme-linked immunosorbent assay (ELISA). Different affinity column matrices that incorporated either a rat IgG2a anti-Gal-3 monoclonal antibody or carbohydrate ligand were assessed for depletion of Gal-3 from porcine serum.

RESULTS

A porcine Gal-3 ELISA with a linear range from 0.3 to 20 ng/mL was able to detect native porcine Gal-3 in both fetal (∼150-200 ng/mL) and juvenile (∼5-15 ng/mL) porcine serum samples. Use of an anti-Gal-3 monoclonal antibody affinity column depleted Gal-3 from porcine serum to at least 313 pg/mL, the limit of ELISA detection.

CONCLUSIONS

Methods have been developed for the detection and depletion of porcine Gal-3. These methods will be used to study the specific effects of Gal-3 depletion via apheresis in porcine models of disease.

Apple pectin: A natural source for cancer suppression in 4T1 breast cancer cells in vitro and express p53 in mouse bearing 4T1 cancer tumors, in vivo

PURPOSE

Increase in the number of cancer related deaths has made the study on developing new drugs and treatments essential. One of the main aims in developing new therapies is to use natural resources which have the ability to induce apoptosis. Pectin is one of these natural compounds, a complex polysaccharide found in apples with anti-cancer properties. The aim of this study was to examine anti-cancer properties of pectic acid both in vitro in 4T1 breast cancer cells and in vivo using an animal model of breast cancer.

EXPERIMENTAL DESIGN

MTT cell proliferation assays, double fluorescence staining (acridine orange/ethidium bromide) and cell cycle analysis were employed to measure apoptosis in vitro. 4T1 cells were implanted into female BALB/c mice for in vivo studies. Then tumor volumes, histological analysis and immunohistochemical staining of P53 and tunnel test were applied to evaluate apoptosis in tumors.

RESULTS

The results of in vitro studies showed that concentration of 0.1% of pectic acid could induce apoptosis, inhibit cell growth (p<0.001) and reduce cell attachment, fragmented chromatin, and membrane blebbing as well as blocking the sub-G1 phase (p<0.001). In addition, in vivo studies showed that pectic acid could inhibit the progression of tumors through over-expression of P53 and increasing the number of apoptotic cells.

CONCLUSION

Our results demonstrated that pectic acid, a natural component of apple, can prevent metastasis in both cancer cell lines and primary tumors. This potential effect is mainly due to its ability to induce apoptosis.

Turning-Off Signaling by Siglecs, Selectins, and Galectins: Chemical Inhibition of Glycan-Dependent Interactions in Cancer

Aberrant glycosylation, a common feature associated with malignancy, has been implicated in important events during cancer progression. Our understanding of the role of glycans in cancer has grown exponentially in the last few years, concurrent with important advances in glycomics and glycoproteomic technologies, paving the way for the validation of a number of glycan structures as potential glycobiomarkers. However, the molecular bases underlying cancer-associated glycan modifications are still far from understood. Glycans exhibit a natural heterogeneity, crucial for their diverse functional roles as specific carriers of biologically relevant information. This information is decoded by families of proteins named lectins, including sialic acid-binding immunoglobulin (Ig)-like lectins (siglecs), C-type lectin receptors (CLRs), and galectins. Siglecs are primarily expressed on the surface of immune cells and differentially control innate and adaptive immune responses. Among CLRs, selectins are a family of cell adhesion molecules that mediate interactions between cancer cells and platelets, leukocytes, and endothelial cells, thus facilitating tumor cell invasion and metastasis. Galectins, a family of soluble proteins that bind β-galactoside-containing glycans, have been implicated in diverse events associated with cancer biology such as apoptosis, homotypic cell aggregation, angiogenesis, cell migration, and tumor-immune escape. Consequently, individual members of these lectin families have become promising targets for the design of novel anticancer therapies. During the past decade, a number of inhibitors of lectin–glycan interactions have been developed including small-molecule inhibitors, multivalent saccharide ligands, and more recently peptides and peptidomimetics have offered alternatives for tackling tumor progression. In this article, we review the current status of the discovery and development of chemical lectin inhibitors and discuss novel strategies to limit cancer progression by targeting lectin–glycan interactions.

Chemoprevention of Low-Molecular-Weight Citrus Pectin (LCP) in Gastrointestinal Cancer Cells

Background & Aims: Low-molecular-weight citrus pectin (LCP) is a complex polysaccharide that displays abundant galactosyl (i.e., sugar carbohydrate) residues. In this study, we evaluated the anti-tumor properties of LCP that lead to Bcl-xL -mediated dampening of apoptosis in gastrointestinal cancer cells.

Methods: We used AGS gastric cancer and SW-480 colorectal cancer cells to elucidate the effects of LCP on cell viability, cell cycle and apoptosis in cultured cells and tumor xenografts.

Results: Significantly decreased cell viabilities were observed in LCP treated AGS and SW-480 cells (P<0.05). Cell cycle-related protein expression, such as Cyclin B1, was also decreased in LCP treated groups as compared to the untreated group. The AGS or SW-480 cell-line tumor xenografts were significantly smaller in the LCP treated group as compared the untreated group (P<0.05). LCP treatment decreased Galectin-3 (GAL-3) expression levels, which is an important gene in cancer metastasis that results in reversion of the epithelial-mesenchymal transition (EMT), and increased suppression of Bcl-xL and Survivin to promote apoptosis. Moreover, results demonstrated synergistic tumor suppressor activity of LCP and 5-FU against gastrointestinal cancer cells both in vivo and in vitro.

Conclusions: LCP effectively inhibits the growth and metastasis of gastrointestinal cancer cells, and does so in part by down-regulating Bcl-xL and Cyclin B to promote apoptosis, and suppress EMT. Thus, LCP alone or in combination with other treatments has a high potential as a novel therapeutic strategy to improve the clinical therapy of gastrointestinal cancer.

Phytotherapeutic interventions in the management of biochemically recurrent prostate cancer: a systematic review of randomised trials

OBJECTIVE

To evaluate the evidence from randomised trials for the efficacy and safety of phytotherapeutic interventions in the management of biochemically recurrent (BCR) prostate cancer, indicated by prostate-specific antigen (PSA) progression, numbers progressing to/time to initiation of androgen-deprivation therapy or salvage therapy.

PATIENTS AND METHODS

MEDLINE (Ovid), EMBASE (Ovid), AMED (Ovid), CINAHL (EBSCO) and the Cochrane Library databases were searched. Clinical trials investigating phytotherapeutic interventions as dietary supplements or dietary components, including multi-component herbal formulations, in men with BCR prostate cancer were located. Eight of nine authors contacted for further information responded. Methodological quality was assessed using the Cochrane Collaboration's risk of bias assessment tool. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for reporting systematic reviews was followed.

RESULTS

Of 23 full-text articles assessed for eligibility, five met the criteria for inclusion. Two studies were placebo controlled; two were active control trials; and one a high-/low-dose trial. The interventions were administered as isolated phytochemicals (sulphoraphane), phytotherapeutic extracts [Pomi-T (pomegranate, turmeric, green tea and broccoli sprout extract), soy, lycopene, and POMx (pomegranate extract)], or plant-derived dietary items (soy and lycopene). All studies found serum PSA levels to stabilise, decrease or rise more slowly in a significant number of men, and three studies reported stabilising or lengthening of PSA-doubling time. Studies were generally of good quality, but sample sizes were predominantly small, and durations short.

CONCLUSIONS

High-quality studies in this area are lacking. Sulphoraphane, lycopene, soy isoflavones, POMx, and Pomi-T are safe and well tolerated. There is limited evidence that they can affect PSA dynamics. No recommendation can be made for the use of these agents in managing prostate cancer morbidity and mortality until high-quality, fully powered studies are available. Recommendations are made for improving reproducibility and translation of findings with regard to study population, study endpoints, design, and the reporting of phytotherapeutic interventions.

A phase I trial of mushroom powder in patients with biochemically recurrent prostate cancer: Roles of cytokines and myeloid-derived suppressor cells for Agaricus bisporus-induced prostate-specific antigen responses

BACKGROUND

Each year in the United States, nearly 50,000 prostate cancer patients exhibit a rise in prostate-specific antigen (PSA) levels, which can indicate disease recurrence. For patients with biochemically recurrent prostate cancer, we evaluated the effects of white button mushroom (WBM) powder on serum PSA levels and determined the tolerability and biological activity of WBM.

METHODS

Patients with continuously rising PSA levels were enrolled in the study. Dose escalation was conducted in cohorts of 6; this ensured that no more than 1 patient per cohort experienced dose-limiting toxicity (DLT). The primary objective was to evaluate treatment feasibility and associated toxicity. The secondary objectives were to determine WBM's effect on serum PSA/androgen levels; myeloid-derived suppressor cells (MDSCs); and cytokine levels.

RESULTS

Thirty-six patients were treated; no DLTs were encountered. The overall PSA response rate was 11%. Two patients receiving 8 and 14 g/d demonstrated complete response (CR): their PSA declined to undetectable levels that continued for 49 and 30 months. Two patients who received 8 and 12 g/d experienced partial response (PR). After 3 months of therapy, 13 (36%) patients experienced some PSA decrease below baseline. Patients with CR and PR demonstrated higher levels of baseline interleukin-15 than nonresponders; for this group, we observed therapy-associated declines in MDSCs.

CONCLUSIONS

Therapy with WBM appears to both impact PSA levels and modulate the biology of biochemically recurrent prostate cancer by decreasing immunosuppressive factors.

Polypotency of the immunomodulatory effect of pectins

Pectins are the major component of plant cell walls, and they display diverse biological activities including immunomodulation. The pectin macromolecule contains fragments of linear and branched regions of polysaccharides such as homogalacturonan, rhamnogalacturonan-I, xylogalacturonan, and apiogalacturonan. These structural features determine the effect of pectins on the immune system. The backbones of pectic macromolecules have immunosuppressive activity. Pectins containing greater than 80% galacturonic acid residues were found to decrease macrophage activity and inhibit the delayed-type hypersensitivity reaction. Branched galacturonan fragments result in a biphasic immunomodulatory action. The branched region of pectins mediates both increased phagocytosis and antibody production. The fine structure of the galactan, arabinan, and apiogalacturonan side chains determines the stimulating interaction between pectin and immune cells. This review summarizes data regarding the relationship between the structure and immunomodulatory activity of pectins isolated from the plants of the European north of Russia and elucidates the concept of polypotency of pectins in native plant cell walls to both stimulate and suppress the immune response. The possible mechanisms of the immunostimulatory and anti-inflammatory effects of pectins are also discussed.

Inhibitors of Galectins and Implications for Structure-Based Design of Galectin-Specific Therapeutics

Galectins are a family of galactoside-specific lectins that are involved in a myriad of metabolic and disease processes. Due to roles in cancer and inflammatory and heart diseases, galectins are attractive targets for drug development. Over the last two decades, various strategies have been used to inhibit galectins, including polysaccharide-based therapeutics, multivalent display of saccharides, peptides, peptidomimetics, and saccharide-modifications. Primarily due to galectin carbohydrate binding sites having high sequence identities, the design and development of selective inhibitors targeting particular galectins, thereby addressing specific disease states, is challenging. Furthermore, the use of different inhibition assays by research groups has hindered systematic assessment of the relative selectivity and affinity of inhibitors. This review summarises the status of current inhibitors, strategies, and novel scaffolds that exploit subtle differences in galectin structures that, in conjunction with increasing available data on multiple galectins, is enabling the feasible design of effective and specific inhibitors of galectins.

Anti-cancer activities of pH- or heat-modified pectin

Despite enormous efforts that have been made in the search for novel drugs and treatments, cancer continues to be a major public health problem. Moreover, the emergence of resistance to cancer chemotherapy often prevents complete remission. Researchers have thus turned to natural products mainly from plant origin to circumvent resistance. Pectin and pH- or heat-modified pectin have demonstrated chemopreventive and antitumoral activities against some aggressive and recurrent cancers. The focus of this review is to describe how pectin and modified pectin display these activities and what are the possible underlying mechanisms. The failure of conventional chemotherapy to reduce mortality as well as serious side effects make natural products, such as pectin-derived products, ideal candidates for exerting synergism in combination with conventional anticancer drugs.

Inhibition of galectin-3 reduces atherosclerosis in apolipoprotein E-deficient mice

Atherosclerosis is a major risk factor for cardiovascular disease (CVD) and stroke. Galectin-3 is a carbohydrate-binding lectin implicated in the pathophysiology of CVD and is highly expressed within atherosclerotic lesions in mice and humans. The object of this present study was to use genetic deletion and pharmacological inhibition in a well-characterized mouse model of atherosclerosis to determine the role of galectin-3 in plaque development. Apolipoprotein-E/galectin-3 knockout mice were generated and fed a high-cholesterol "western" diet. Galectin-3 deletion had no consistent effect on the serum lipid profile but halved atherosclerotic lesion formation in the thoracic aorta (57% reduction), the aortic arch (50% reduction) and the brachiocephalic arteries. The aortic plaques were smaller, with reduced lipid core and less collagen. In apolipoprotein E-deficient (ApoE(-/-)) mice, there was a switch from high inducible nitric oxide expression in early lesions (6 weeks) to arginase-1 expression in later lesions (20 weeks), which was reversed in ApoE(-/-)/gal-3(-/-) mice. Administration of modified citrus pectin, an inhibitor of galectin-3, during the latter stage of the disease reduced plaque volume. We conclude that inhibiting galectin-3 causes decreased atherosclerosis. Strategies to inhibit galectin-3 function may reduce plaque progression and potentially represent a novel therapeutic strategy in the treatment of atherosclerotic disease.

Combination effect of PectaSol and Doxorubicin on viability, cell cycle arrest and apoptosis in DU-145 and LNCaP prostate cancer cell lines

The effect of PectaSol on Dox (Doxorubicin) cytotoxicity in terms of apoptosis and cell cycle changes in PCa (prostate cancer) cell lines (DU-145 and LNCaP) has been investigated. Combination of PectaSol and Dox resulted in a viability of 29.4 and 32.6% (P<0.001) in DU-145 and LNCaP cells. The IC₅₀ values decreased 1.5-fold and 1.3-fold in the DU-145 and LNCaP cells respectively. In the DU-145 cells, combination of PectaSol and Dox resulted in a reduction in p27 gene and protein expression (P<0.001). In LNCaP cells, this combination increased p53, p27 and Bcl-2 expression. Treatment with both drugs in DU-145 cells led to an increase in sub-G₁ arrest (54.6% compared with 12.2% in Dox). In LNCaP cells, combination of the drugs led to an increased in G₂/M arrest (61.7% compared with 53.6% in Dox). Based on these findings, progressive cytotoxicity effect of Dox and PectaSol together rapidly induce cell death in DU-145 through apoptosis and in LNCaP cells through cell cycle arrest (G₂/M arrest).

Integrative oncology in the Middle East: from traditional herbal knowledge to contemporary cancer care

BACKGROUND

Based on traditional, historical, ethnobotanical, laboratory, and clinical findings, we present research framework aiming to identify Middle Eastern herbs that are worthy of further research for their anticancer potential.

METHODS

A comprehensive research project was developed by a multinational team comprising family physicians, medicine specialists, oncologists, an Islamic medicine history specialist, a traditional medicine ethnobotanist, and a basic research scientist. The project followed two consecutive phases: (i) historical and ethnobotanical search for cancer-related keywords and (ii) Medline search for in vitro and in vivo studies.

RESULTS

This search yielded 44 herbs associated with cancer care. The Medline search yielded 34 herbs of which 9 herbs were reported in various clinical studies.

CONCLUSIONS

This multidisciplinary survey was found to be a valuable way to identify herbs with potential clinical significance in cancer care. Based on this pilot study, it is suggested that the Middle East can serve as a valuable region for future multicultural-oriented cancer research.

Activation of human T-helper/inducer cell, T-cytotoxic cell, B-cell, and natural killer (NK)-cells and induction of natural killer cell activity against K562 chronic myeloid leukemia cells with modified citrus pectin

BACKGROUND

Modified citrus pectin (MCP) is known for its anti-cancer effects and its ability to be absorbed and circulated in the human body. In this report we tested the ability of MCP to induce the activation of human blood lymphocyte subsets like T, B and NK-cells.

METHODS

MCP treated human blood samples were incubated with specific antibody combinations and analyzed in a flow cytometer using a 3-color protocol. To test functionality of the activated NK-cells, isolated normal lymphocytes were treated with increasing concentrations of MCP. Log-phase PKH26-labeled K562 leukemic cells were added to the lymphocytes and incubated for 4 h. The mixture was stained with FITC-labeled active form of caspase 3 antibody and analyzed by a 2-color flow cytometry protocol. The percentage of K562 cells positive for PKH26 and FITC were calculated as the dead cells induced by NK-cells. Monosaccharide analysis of the MCP was performed by high-performance anion-exchange chromatography with pulse amperometric detection (HPAEC-PAD).

RESULTS

MCP activated T-cytotoxic cells and B-cell in a dose-dependent manner, and induced significant dose-dependent activation of NK-cells. MCP-activated NK-cells demonstrated functionality in inducing cancer cell death. MCP consisted of oligogalacturonic acids with some containing 4,5-unsaturated non-reducing ends.

CONCLUSIONS

MCP has immunostimulatory properties in human blood samples, including the activation of functional NK cells against K562 leukemic cells in culture. Unsaturated oligogalacturonic acids appear to be the immunostimulatory carbohydrates in MCP.

Immune suppression in tumors as a surmountable obstacle to clinical efficacy of cancer vaccines

Human tumors are usually not spontaneously eliminated by the immune system and therapeutic vaccination of cancer patients with defined antigens is followed by tumor regressions only in a small minority of the patients. The poor vaccination effectiveness could be explained by an immunosuppressive tumor microenvironment. Because T cells that infiltrate tumor metastases have an impaired ability to lyse target cells or to secrete cytokine, many researchers are trying to decipher the underlying immunosuppressive mechanisms. We will review these here, in particular those considered as potential therapeutic targets. A special attention will be given to galectins, a family of carbohydrate binding proteins. These lectins have often been implicated in inflammation and cancer and may be useful targets for the development of new anti-cancer therapies.

Microbial utilization and selectivity of pectin fractions with various structures

To evaluate the fermentation properties of oligosaccharides derived from pectins and their parent polysaccharides, a 5-ml-working-volume, pH- and temperature-controlled fermentor was tested. Six pectic oligosaccharides representing specific substructures found within pectins were prepared. These consisted of oligogalacturonides (average degrees of polymerization [DP] of 5 and 9), methylated oligogalacturonides (average DP of 5), oligorhamnogalacturonides (average DP of 10 as a disaccharide unit of galacturonic acid and rhamnose), oligogalactosides (average DP of 5), and oligoarabinosides (average DP of 6). The influence of these carbohydrates on the human fecal microbiota was evaluated. Use of neutral sugar fractions resulted in an increase in Bifidobacterium populations and gave higher organic acid yields. The Bacteroides-Prevotella group significantly increased on all oligosaccharides except oligogalacturonides with an average DP of 5. The most selective substrates for bifidobacteria were arabinan, galactan, oligoarabinosides, and oligogalactosides.

Overexpression of Galectin-3 and its clinical significance in ovarian carcinoma

BACKGROUND

Galectin-3 (Gal-3) is a β-galactoside-binding lectin involved in regulating cell growth, angiogenesis, and tumor progression. We investigated the clinical significance of Gal-3 expression including its possible use as a prognostic marker or therapeutic target in epithelial ovarian carcinoma (EOC).

METHODS

Gal-3 expression was evaluated by immunohistochemistry in 71 patients with 54 serous, 13 endometrioid, and 4 mucinous ovarian carcinomas. We assessed the correlation of Gal-3 expression with clinical characteristics including histology, optimal debulking, chemosensitivity, and survival. In vitro, Gal-3 was inhibited using siRNA to evaluate its role in cell growth and sensitivity to chemotherapeutic agents in ovarian carcinoma cell lines.

RESULTS

Gal-3 protein, which was mainly cytoplasmic in location, was observed in a majority (63/71, 88.7%) of the EOCs but not in normal ovarian tissues (P < 0.001). High Gal-3 expression in EOCs correlated with shorter progression-free survival (PFS) of patients (P = 0.039; 43.1 and 49.5 months, respectively). Moreover, cotreatment with Gal-3 siRNA and paclitaxel showed an enhanced cytotoxic effect compared with control siRNA in SKOV3 cells.

CONCLUSION

These findings suggest that Gal-3 expression can be a prognostic factor for PFS and may be involved in regulating the response to paclitaxel-based chemotherapy in the treatment of EOC.