Astragalus membranaceus lectin (AML) induces caspase-dependent apoptosis in human leukemia cells

Phytochemical Characterization and Comparative Analysis of Cycloartane-Type Triterpenes in Astragalus adsurgens and Astragalus membranaceus

Astragalus adsurgens, a significant forage plant cultivated in arid regions of northwest China, remains underexplored for its triterpenoid saponins and medicinal properties compared to the extensively studied Astragalus membranaceus. To explore the phytochemical profile of A. adsurgens for its potential application in the medical field, we employed ultra-pressure liquid chromatography coupled with a tandem mass spectrometry-based method to identify cycloartane-type triterpenes. Eventually, five new cycloartane-type triterpenoids, adsurgosides A - D ( 1 - 4: ) and 3-methyl-3,4-seco-cyclostellanol (5: ), together with two known analogs, cycloastragenol (6: ) and cyclopycanthogenin (7: ), were isolated from the roots of A. adsurgens. Their structures were elucidated using 1D and 2D NMR analyses in combination with HRESIMS data. Additionally, a comparative study on the distribution patterns of these compounds revealed qualitative and quantitative variations between A. adsurgens and A. membranaceus. Our findings not only identified an alternative plant for isolating cycloartane-type triterpenoids but also offer new insights into the chemical properties of A. adsurgens.

Heterologous expression of fungal L-asparaginase: a systematic review

Aim: To review the available literature about heterologous expression of fungal L-asparaginase (L-ASNase). Materials & methods: A search was conducted across PubMed, Science Direct, Scopus and Web of Science databases; 4172 citations were identified and seven articles were selected. Results: The results showed that heterologous expression of fungal L-ASNase was performed mostly in bacterial expression systems, except for a study that expressed L-ASNase in a yeast system. Only three publications reported the purification and characterization of the enzyme. Conclusion: The information reported in this systematic review can contribute significantly to the recognition of the importance of biotechnological techniques for L-ASNase production.

Research advances and prospects of legume lectins

Lectins are widely distributed proteins having ability of binding selectively and reversibly with carbohydrates moieties and glycoconjugates. Although lectins have been reported from different biological sources, the legume lectins are the best-characterized family of plant lectins. Legume lectins are a large family of homologous proteins with considerable similarity in amino acid sequence and their tertiary structures. Despite having strong sequence conservation, these lectins show remarkable variability in carbohydrate specificity and quaternary structures. The ability of legume lectins in recognizing glycans and glycoconjugates on cells and other intracellular structures make them a valuable research tool in glycomic research. Due to variability in binding with glycans, glycoconjugates and multiple biological functions, legume lectins are the subject of intense research for their diverse application in different fields such as glycobiology, biomedical research and crop improvement. The present review specially focuses on structural and functional characteristics of legume lectins along with their potential areas of application.

The anti-cancerous activity of adaptogenic herb Astragalus membranaceus

BACKGROUND

Cancer is the most dreadful disease increasing rapidly causing an economic burden globally. A standardized chemotherapy regimen planned with curative intent weakens the immune system and damages healthy cells making the patient prone to infections and severe side effects with pain and fatigue.

PURPOSE

Astragalus membranaceus (AM) has a long history of use in the treatment of severe adverse diseases. For thousands of years, it has been used in mixed herbal decoctions for the treatment of cancer. Due to growing interest in this plant root for its application to treat various types of cancers and tumors, has attracted researcher's interest.

METHOD

The literature search was done from core collections of electronic databases such as Web of Science, Google Scholar, PubMed and Science Direct using keywords given below and terms like pharmacological and phytochemical details of this plant.

OUTCOME

Astragalus membranaceus has demonstrated the ability to modulate the immune system during drug therapy making the patient physically fit and prolonged life. It has become a buzzword of herbalists as it is one of the best of seven important adaptogenic herbs with a protective effect against chronic stress and cancer. It demonstrated significant amelioration of the perilous toxic effects induced by concurrently administered chemo onco-drugs.

CONCLUSION

The natural phytoconstituents of this plant formononetin, astragalus polysaccharide, and astragalosides which show high potential anti-cancerous activity are studied and discussed in detail. One of them are used in clinical trials to overcome cancer related fatigue. Overall, this review aims to provide an insight into Astragalus membranaceus status in cancer therapy.

Anticancer Activity of Lectins from Bauhinia purpurea and Wisteria floribunda on Breast Cancer MCF-7 Cell Lines

BACKGROUND

Individual and collaborative efforts are being made worldwide in search of effective chemical or natural drugs with less severe side-effects for treatment of cancer. Due to the specificity and selectivity properties of lectins for saccharides, several plant lectins are known to induce cytotoxicity into tumor cells.

OBJECTIVE

To study the antiproliferative activity of two N-acetyl galactosamine specific plant lectins from seeds of Bauhinia purpurea and Wisteria floribunda against MCF-7 Breast cancer cell lines.

METHODS

MTT, lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS), and caspase- 3 assays and flow cytometry for cell cycle analysis were performed.

RESULTS

The agglutinins BPL and WFL; 446 μgml-1 (2.2 μM) and 329 μgml-1 (2.8 μM), respectively caused remarkable concentration-dependent antiproliferative effect on MCF-7. The effect was seen to be a consequence of binding of the lectin to the cell surface and triggering S and G2 phase arrest. Apoptosis induced was found to be associated with LDH leakage, cell cycle arrest and ROS generation. The apoptotic signal was observed to be amplified by activation of caspase-3 resulting in cell death.

CONCLUSION

The study provides a base for detailed investigation and further use of lectins in cancer studies.

Research advances and prospects of legume lectins

Lectins are widely distributed proteins having ability of binding selectively and reversibly with carbohydrates moieties and glycoconjugates. Although lectins have been reported from different biological sources, the legume lectins are the best-characterized family of plant lectins. Legume lectins are a large family of homologous proteins with considerable similarity in amino acid sequence and their tertiary structures. Despite having strong sequence conservation, these lectins show remarkable variability in carbohydrate specificity and quaternary structures. The ability of legume lectins in recognizing glycans and glycoconjugates on cells and other intracellular structures make them a valuable research tool in glycomic research. Due to variability in binding with glycans, glycoconjugates and multiple biological functions, legume lectins are the subject of intense research for their diverse application in different fields such as glycobiology, biomedical research and crop improvement. The present review specially focuses on structural and functional characteristics of legume lectins along with their potential areas of application.

Plant lectins in cancer therapeutics: Targeting apoptosis and autophagy-dependent cell death

Plant lectins are non-immunoglobin in nature and bind to the carbohydrate moiety of the glycoconjugates without altering any of the recognized glycosyl ligands. Plant lectins have found applications as cancer biomarkers for recognizing the malignant tumor cells for the diagnosis and prognosis of cancer. Interestingly, plant lectins contribute to inducing cell death through autophagy and apoptosis, indicating their potential implication in cancer inhibitory mechanism. In the present review, anticancer activities of major plant lectins have been documented, with a detailed focus on the signaling circuit for the possible molecular targeted cancer therapy. In this context, several lectins have exhibited preclinical and clinical significance, driving toward therapeutic potential in cancer treatment. Moreover, several plant lectins induce immunomodulatory activities, and therefore, novel strategies have been established from preclinical and clinical investigations for the development of combinatorial treatment consisting of immunotherapy along with other anticancer therapies. Although the application of plant lectins in cancer is still in very preliminary stage, advanced high-throughput technology could pave the way for the development of lectin-based complimentary medicine for cancer treatment.

Phaseolus acutifolius Lectin Fractions Exhibit Apoptotic Effects on Colon Cancer: Preclinical Studies Using Dimethilhydrazine or Azoxi-Methane as Cancer Induction Agents

Phaseolus acutifolius (Tepary bean) lectins have been studied as cytotoxic molecules on colon cancer cells. The toxicological profile of a Tepary bean lectin fraction (TBLF) has shown low toxicity in experimental animals; exhibiting anti-nutritional effects such as a reduction in body weight gain and a decrease in food intake when using a dose of 50 mg/kg on alternate days for six weeks. Taking this information into account, the focus of this work was to evaluate the effect of the TBLF on colon cancer using 1,2-dimethylhydrazine (DMH) or azoxy-methane/dextran sodium sulfate (AOM/DSS) as colon cancer inductors. Rats were treated with DMH or AOM/DSS and then administered with TBFL (50 mg/kg) for six weeks. TBLF significantly decreased early tumorigenesis triggered by DMH by 70%, but without any evidence of an apoptotic effect. In an independent experiment, AOM/DSS was used to generate aberrant cryptic foci, which decreased by 50% after TBLF treatment. TBLF exhibited antiproliferative and proapoptotic effects related to a decrease of the signal transduction pathway protein Akt in its activated form and an increase of caspase 3 activity, but not to p53 activation. Further studies will deepen our knowledge of specific apoptosis pathways and cellular stress processes such as oxidative damage.

Plant Lectins as Medical Tools against Digestive System Cancers

Digestive system cancers-those of the esophagus, stomach, small intestine, colon-rectum, liver, and pancreas-are highly related to genetics and lifestyle. Most are considered highly mortal due to the frequency of late diagnosis, usually in advanced stages, caused by the absence of symptoms or masked by other pathologies. Different tools are being investigated in the search of a more precise diagnosis and treatment. Plant lectins have been studied because of their ability to recognize and bind to carbohydrates, exerting a variety of biological activities on animal cells, including anticancer activities. The present report integrates existing information on the activity of plant lectins on various types of digestive system cancers, and surveys the current state of research into their properties for diagnosis and selective treatment.

Lectin CGL from the sea mussel Crenomytilus grayanus induces Burkitt's lymphoma cells death via interaction with surface glycan

Marine organisms are rich sources of lectins. Lectins are able to bind specifically and reversibly to different types of carbohydrates or glycoproteins. The present study reports the evaluation of glycan binding profile and anti-tumor potential of lectin CGL from the sea mussel Crenomytilus grayanus. Glycan array assay revealed that CGL was able to bind both α and β anomer of galactose, but interaction with the αGal-terminated glycans was stronger. Analysis of most common glycan motifs for CGL showed high affinity to Galα1-4Galβ1-4GlcNAc motif similar to globotriose structure (Gb3: Galα1-4Galβ1-4Glc), the epitope of globotriaosylceramide. CGL recognized Gb3 on the surface of Burkitt's lymphoma Raji cells (high Gb3 expression), leading to dose-dependent cytotoxic effect, G2/M phase cell cycle arrest and apoptosis. Lectin had no effect on erythroleukemia K562 cells (no Gb3 expression). The activity of CGL was specifically blocked by α-galactoside. Our findings suggest the use of CGL in cancer diagnosis and treatment.

Morus alba Leaf Lectin (MLL) Sensitizes MCF-7 Cells to Anoikis by Inhibiting Fibronectin Mediated Integrin-FAK Signaling through Ras and Activation of P38 MAPK

Lectins are a unique class of carbohydrate binding proteins/glycoproteins, and many of them possess anticancer properties. They can induce cell cycle arrest and apoptosis, inhibit protein synthesis, telomerase activity and angiogenesis in cancer cells. In the present study, we have demonstrated the effect of Morus alba leaf lectin (MLL) on anoikis induction in MCF-7 cells. Anoikis induction in cancer cells has a significant role in preventing early stage metastasis. MLL treatment in monolayers of MCF-7 cells caused significant detachment of cells in a time and concentration dependent manner. The detached cells failed to re-adhere and grew even to culture plates coated with different matrix proteins. DNA fragmentation, membrane integrity studies, annexin V staining, caspase 9 activation and upregulation of Bax/Bad confirmed that the detached cells underwent apoptosis. Upregulation of matrix metalloproteinase 9 (MMP-9) caused a decrease in fibronectin (FN) production which facilitated the cells to detach by blocking the FN mediated downstream signaling. On treatment with MLL, we have observed downregulation of integrin expression, decreased phosphorylation of focal adhesion kinase (FAK), loss in FAK-integrin interaction and active Ras. MLL treatment downregulated the levels of phosphorylated Akt and PI3K. Also, we have studied the effect of MLL on two stress activated protein kinases p38 MAPK and JNK. p38 MAPK activation was found to be elevated, but there was no change in the level of JNK. Thus our study substantiated the possible antimetastatic effect of MLL by inducing anoikis in MCF-7 cells by activation of caspase 9 and proapoptotic Bax/Bad by blockage of FN mediated integrin/FAK signaling and partly by activation of p38 MAPK.

Structural analysis and unique molecular recognition properties of a Bauhinia forficata lectin that inhibits cancer cell growth

Lectins have been used at length for basic research and clinical applications. New insights into the molecular recognition properties enhance our basic understanding of carbohydrate-protein interactions and aid in the design/development of new lectins. In this study, we used a combination of cell-based assays, glycan microarrays, and X-ray crystallography to evaluate the structure and function of the recombinant Bauhinia forficata lectin (BfL). The lectin was shown to be cytostatic for several cancer cell lines included in the NCI-60 panel; in particular, it inhibited growth of melanoma cancer cells (LOX IMVI) by over 95%. BfL is dimeric in solution and highly specific for binding of oligosaccharides and glycopeptides with terminal N-acetylgalactosamine (GalNAc). BfL was found to have especially strong binding (apparent Kd  = 0.5-1.0 nm) to the tumor-associated Tn antigen. High-resolution crystal structures were determined for the ligand-free lectin, as well as for its complexes with three Tn glycopeptides, globotetraose, and the blood group A antigen. Extensive analysis of the eight crystal structures and comparison to structures of related lectins revealed several unique features of GalNAc recognition. Of special note, the carboxylate group of Glu126, lining the glycan-binding pocket, forms H-bonds with both the N-acetyl of GalNAc and the peptide amido group of Tn antigens. Stabilization provided by Glu126 is described here for the first time for any GalNAc-specific lectin. Taken together, the results provide new insights into the molecular recognition of carbohydrates and provide a structural understanding that will enable rational engineering of BfL for a variety of applications.

DATABASE

Structural data are available in the PDB under the accession numbers 5T50, 5T52, 5T55, 5T54, 5T5L, 5T5J, 5T5P, and 5T5O.

The Effectiveness of Traditional Chinese Medicine in Treating Patients with Leukemia

Leukemia is the most common malignancy among all childhood cancers and is associated with a low survival rate in adult patients. Since 1995, the National Health Insurance (NHI) program in Taiwan has been offering insurance coverage for Traditional Chinese Medicine (TCM), along with conventional Western medicine (WM). This study analyzes the status of TCM utilization in Taiwan, in both pediatric and adult patients with leukemia. A retrospective cohort study was conducted using population-based National Health Insurance Research Database of Registry of Catastrophic Illness, involving patient data from 2001 to 2010 and follow-up data through 2011. The effectiveness of TCM use was evaluated. Relevant sociodemographic data showed that both pediatric and adult patients who were TCM users one year prior to leukemia diagnosis were more likely to utilize TCM services for cancer therapy. A greater part of medical expenditure of TCM users was lower than that of TCM nonusers, except little discrepancy in drug fee of adult patients. The survival rate is also higher in TCM users. Altogether, these data show that TCM has the potential to serve as an adjuvant therapy when combined with conventional WM in the treatment of patients with leukemia.

Lunatin, a novel lectin with antifungal and antiproliferative bioactivities from Phaseolus lunatus billb

A novel lectin with a molecular mass of 24.3kDa, designated Lunatin, was isolated from edible seeds of Phaseolus lunatus billb. The purification scheme consisted of ammonium sulfate precipitation, affinity chromatography, ion exchange chromatography, and gel filtration chromatography. The lectin is a glycoprotein, as determined by staining with periodic acid-Schiff (PAS), and its N-terminal amino acid sequence was determined to be DAVIYRGPGDLHTGS. Lunatin exhibited hemagglutinating activity towards human blood group A erythrocytes, which was mostly preserved up to 50°C and retained at ambient temperature at pH 2.0-11.0. d-fructose, d-galactose, d-glucose, and mannitol were capable of inhibiting its hemagglutinating activity. Lunatin was found to be a metal-dependent protein, as its activity was inhibited by the metallic compounds K2Cr2O7, SnCl2, and LiCl, though it was unaffected by MgCl2, ZnCl2, BaCl2, CuCl2, FeCl3, or CaCl2. In addition, Lunatin exerted potent antifungal activity toward a variety of fungal species, including Sclerotium rolfsii, Physalospora piricola, Fusarium oxysporum, and Botrytis cinerea. Finally, proliferation of K562 leukemia cells was strongly inhibited by Lunatin, with an IC50 of 13.7μM, whereas HeLa and HepG2 cells were only weakly affected. These findings further the identification and understanding of functional factors in edible plant seeds.

A systematic review of anticancer effects of radix astragali

OBJECTIVE

To review the anticancer effects of Radix astragali (RA), one of the most commonly used herbs to manage cancer in East Asia, and its constituents and to provide evidence of clinical usage through previously performed clinical studies.

METHODS

Preclinical and clinical studies related to the anticancer effects of RA were searched from inception to November 2013 in electronic databases. Two reviewers independently investigated 92 eligible studies, extracted all the data of studies and appraised methodological quality of clinical trials. The studies were categorized into in vitro and in vivo experimental studies and clinical studies, and analyzed by saponins, polysaccharides, and flavonoids of RA constituents, RA fraction, and whole extract.

RESULTS

In preclinical studies, RA was reported to have tumor growth inhibitory effects, immunomodulatory effects, and attenuating adverse effects by cytotoxic agents as well as chemopreventive effects. Saponins seemed to be the main constituents, which directly contributed to suppression of tumor growth through the activation of both intrinsic and extrinsic apoptotic pathway, modulation of intracellular signaling pathway, and inhibition of invasion and angiogenesis. Flavonoids suppressed tumor growth through the similar mechanisms with saponins. Polysaccharides showed immunomodulatory effects, contributing tumor shrinkages in animal models, despite the low cytotoxicity to cancer cells. Most of the clinical studies were performed with low evidence level of study designs because of various limitations. RA whole extracts and polysaccharides of RA were reported to improve the quality of life and ameliorate myelosuppression and other adverse events induced by cytotoxic therapies.

CONCLUSION

The polysaccharides, saponins, and flavonoids of RA, and the whole extract of RA have been widely reported with their anticancer effects in preclinical studies and showed a potential application as a adjunctive cancer therapeutics with the activities of immunomodulation, anti-proliferation and attenuation of adverse effects induced by cytotoxic therapy.

Formononetin suppresses the proliferation of human non-small cell lung cancer through induction of cell cycle arrest and apoptosis

Formononetin is a novel herbal isoflavonoid isolated from Astragalus membranaceus and possesses antitumorigenic properties. In the present study, we investigated the anti-proliferative effects of formononetin on human non-small cell lung cancer (NSCLC), and further elucidated the molecular mechanism underlying the anti-tumor property. MTT assay showed that formononetin treatment significantly inhibited the proliferation of two NSCLC cell lines including A549 and NCI-H23 in a time- and dose-dependent manner. Flow cytometric analysis demonstrated that formononetin induced G1-phase cell cycle arrest and promoted cell apoptosis in NSCLC cells. On the molecular level, we observed that exposure to formononetin altered the expression levels of cell cycle arrest-associated proteins p21, cyclin A and cyclin D1. Meanwhile, the apoptosis-related proteins cleaved caspase-3, bax and bcl-2 were also changed following treatment with formononetin. In addition, the expression level of p53 was dose-dependently upregulated after administration with formononetin. We also found that formononetin treatment increased the phosphorylation of p53 at Ser15 and Ser20 and enhances its transcriptional activity in a dose-dependent manner. Collectively, these results demonstrated that formononetin might be a potential chemopreventive drug for lung cancer therapy through induction of cell cycle arrest and apoptosis in NSCLC cells.

Cytotoxic and antiproliferative effect of tepary bean lectins on C33-A, MCF-7, SKNSH, and SW480 cell lines

For many years, several studies have been employing lectin from vegetables in order to prove its toxic effect on various cell lines. In this work, we analyzed the cytotoxic, antiproliferative, and post-incubatory effect of pure tepary bean lectins on four lines of malignant cells: C33-A; MCF-7; SKNSH, and SW480. The tests were carried out employing MTT and 3[H]-thymidine assays. The results showed that after 24 h of lectin exposure, the cells lines showed a dose-dependent cytotoxic effect, the effect being higher on MCF-7, while C33-A showed the highest resistance. Cell proliferation studies showed that the toxic effect induced by lectins is higher even when lectins are removed, and in fact, the inhibition of proliferation continues after 48 h. Due to the use of two techniques to analyze the cytotoxic and antiproliferative effect, differences were observed in the results, which can be explained by the fact that one technique is based on metabolic reactions, while the other is based on the 3[H]-thymidine incorporated in DNA by cells under division. These results allow concluding that lectins exert a cytotoxic effect after 24 h of exposure, exhibiting a dose-dependent effect. In some cases, the cytotoxic effect is higher even when the lectins are eliminated, however, in other cases, the cells showed a proliferative effect.

Antileukemic activity of Tillandsia recurvata and some of its cycloartanes

BACKGROUND

Approximately 250,000 deaths were caused by leukemia globally in 2012 and about 40%-50% of all leukemia diagnoses end-up in death. Medicinal plants are a rich source for the discovery of new drugs against leukemia and other types of cancers. To this end, we subjected the Jamaican ball moss (Tillandsia recurvata) and its cycloartanes, as well as some analogs, to in vitro screening against a number of leukemia cell lines. The WST-1 anti-proliferation assay was used to determine the anticancer activity of ball moss and two cycloartanes isolated from ball moss and four of their analogs against four leukemia cell lines (HL-60, K562, MOLM-14, monoMac6). Ball moss crude methanolic extract showed activity with a 50% inhibition concentration (IC50) value of 3.028 μg/ml against the Molm-14 cell line but was ineffective against HL-60 cells. The six cycloartanes tested demonstrated varying activity against the four leukemia cancer cell lines with IC50 values ranging from 1.83 μM to 18.3 μM. Five out of the six cycloartanes demonstrated activity, while one was inactive against all four cell lines. The preliminary activity demonstrated by the Jamaican ball moss and its cycloartanes against selected leukemia cell lines continues to throw light on the broad anticancer activity of ball moss. Further studies to evaluate the efficacy of these molecules in other leukemia cell lines are required in order to validate the activity of these molecules, as well as to determine their mechanisms of action and ascertain the activity in vivo in order to establish efficacy and safety profiles.

Abrus agglutinin suppresses human hepatocellular carcinoma in vitro and in vivo by inducing caspase-mediated cell death

AIM

Abrus agglutinin (AGG) from the seeds of Indian medicinal plant Abrus precatorius belongs to the class II ribosome inactivating protein family. In this study we investigated the anticancer effects of AGG against human hepatocellular carcinoma in vitro and in vivo.

METHODS

Cell proliferation, DNA fragmentation, Annexin V binding, immunocytofluorescence, Western blotting, caspase activity assays and luciferase assays were performed to evaluate AGG in human liver cancer cells HepG2. Immunohistochemical staining and TUNEL expression were studied in tumor samples of HepG2-xenografted nude mice.

RESULTS

AGG induced apoptosis in HepG2 cells in a dose- and time-dependent manner. AGG-treated HepG2 cells demonstrated an increase in caspase 3/7, 8 and 9 activities and a sharp decrease in the Bcl-2/Bax ratio, indicating activation of a caspase cascade. Co-treatment of HepG2 cells with AGG and a caspase inhibitor or treatment of AGG in Bax knockout HepG2 cells decreased the caspase 3/7 activity in comparison to HepG2 cells exposed only to AGG. Moreover, AGG decreased the expression of Hsp90 and suppressed Akt phosphorylation and NF-κB expression in HepG2 cells. Finally, AGG treatment significantly reduced tumor growth in nude mice bearing HepG2 xenografts, increased TUNEL expression and decreased CD-31 and Ki-67 expression compared to levels observed in the untreated control mice bearing HepG2 cells.

CONCLUSION

AGG inhibits the growth and progression of HepG2 cells by inducing caspase-mediated cell death. The agglutinin could be an alternative natural remedy for the treatment of human hepatocellular carcinomas.

Bauhinia forficata lectin (BfL) induces cell death and inhibits integrin-mediated adhesion on MCF7 human breast cancer cells

BACKGROUND

Plant lectins have attracted great interest in cancer studies due to their antitumor activities. These proteins or glycoproteins specifically and reversibly bind to different types of carbohydrates or glycoproteins. Breast cancer, which presents altered glycosylation of cell surface glycoproteins, is one of the most frequent malignant diseases in women. In this work, we describe the effect of the lectin Bauhinia forficata lectin (BfL), which was purified from B. forficata Link subsp. forficata seeds, on the MCF7 human breast cancer cellular line, investigating the mechanisms involved in its antiproliferative activity.

METHODS

MCF7 cells were treated with BfL. Viability and adhesion alterations were evaluated using flow cytometry and western blotting.

RESULTS

BfL inhibited the viability of the MCF7 cell line but was ineffective on MDA-MB-231 and MCF 10A cells. It inhibits MCF7 adhesion on laminin, collagen I and fibronectin, decreases α1, α6 and β1 integrin subunit expression, and increases α5 subunit expression. BfL triggers necrosis and secondary necrosis, with caspase-9 inhibition. It also causes deoxyribonucleic acid (DNA) fragmentation, which leads to cell cycle arrest in the G2/M phase and a decrease in the expression of the regulatory proteins pRb and p21.

CONCLUSION

BfL shows selective cytotoxic effect and adhesion inhibition on MCF7 breast cancer cells.

GENERAL SIGNIFICANCE

Cell death induction and inhibition of cell adhesion may contribute to understanding the action of lectins in breast cancer.

Biochemical characterization of a novel L-Asparaginase with low glutaminase activity from Rhizomucor miehei and its application in food safety and leukemia treatment

A novel fungal gene encoding the Rhizomucor miehei l-asparaginase (RmAsnase) was cloned and expressed in Escherichia coli. Its deduced amino acid sequence shared only 57% identity with the amino acid sequences of other reported l-asparaginases. The purified l-asparaginase homodimer had a molecular mass of 133.7 kDa, a high specific activity of 1,985 U/mg, and very low glutaminase activity. RmAsnase was optimally active at pH 7.0 and 45°C and was stable at this temperature for 30 min. The final level of acrylamide in biscuits and bread was decreased by about 81.6% and 94.2%, respectively, upon treatment with 10 U RmAsnase per mg flour. Moreover, this l-asparaginase was found to potentiate a lectin's induction of leukemic K562 cell apoptosis, allowing lowering of the drug dosage and shortening of the incubation time. Overall, our findings suggest that RmAsnase possesses a remarkable potential for the food industry and in chemotherapeutics for leukemia.

Isolation and antiproliferative activity of Lotus corniculatus lectin towards human tumour cell lines

The objective of the study was to investigate the anti cancer activity of a lectin isolated from Lotus corniculatus seeds. A tetrameric 70kDa galactose specific lectin was purified using two step simple purification protocol which involved affinity chromatography on AF-BlueHC650M and gel filtration on Sephadex G-100. The lectin was adsorbed on AF-BlueHC650M and desorbed using 1M NaCl in the starting buffer. Gel filtration on Sephadex G-100 yielded a major peak absorbance that gave two bands of 15kDa and 20kDa in SDS PAGE. Hemagglutination activity was completely preserved, when the temperature was in the range of 20-60°C. However, drastic reduction in activity occurred at temperatures above 60°C. Full hemagglutination activity was retained at ambient pH 4-12. Thereafter no activity was observed above pH 13. Hemaglutination of the lectin was inhibited by d-galactose. The lectin showed a strong antiproliferative activity towards human leukemic (THP-1) cancer cells followed by lung cancer (HOP62) cells and HCT116 with an IC50 of 39μg/ml and 50μg/ml and 60μg/ml respectively. Flow cytometry analysis showed an increase in the percentage of cells in sub G0G1 phase confirming that Lotus corniculatus lectin induced apoptosis. Morphological observations showed that Lotus corniculatus lectin (LCL) treated THP-1 cells displayed apparent apoptosis characteristics such as nuclear fragmentation, appearance of membrane enclosed apoptotic bodies and DNA fragmentation. Lotus corniculatus lectin (LCL) effectively inhibits the cell migration in a dose dependent manner as indicated by the wound healing assay.

The effects of Gamijinhae-tang on elastase/lipopolysaccharide-induced lung inflammation in an animal model of acute lung injury

Background

Gamijinhae-tang (GJHT) has long been used in Korea to treat respiratory diseases. The therapeutic effect of GJHT is likely associated with its anti-inflammatory activity. However, the precise mechanisms underlying its effects are unknown. This study was conducted to evaluate the protective effects of GJHT in a porcine pancreatic elastase (PPE) and lipopolysaccharide(LPS) induced animal model of acute lung injury (ALI).

Methods

In this study, mice were intranasally exposed to PPE and LPS for 4 weeks to induce chronic obstructive pulmonary disease (COPD)-like lung inflammation. Two hours prior to PPE and LPS administration, the treatment group was administered GJHT extracts via an oral injection. The numbers of neutrophils, lymphocytes, macrophages and total cells in the bronchoalveolar lavage (BAL) fluid were counted, and pro-inflammatory cytokines were also measured. For histologic analysis, hematoxylin and eosin (H&E) stains and periodic acid-Schiff (PAS) stains were evaluated.

Results

After inducing ALI by treating mice with PPE and LPS for 4 weeks, the numbers of neutrophils, lymphocytes and total cells were significantly lower in the GJHT group than in the ALI group. In addition, the IL-1β and IL-6 levels were significantly decreased in the GJHT group. The histological results also demonstrated the attenuation effect of GJHT on PPE- and LPS-induced lung inflammation.

Conclusions

The results of this study indicate that GJHT has significantly reduces PPE- and LPS-induced lung inflammation. The remarkable protective effects of GJHT suggest its therapeutic potential in COPD treatment.