Photoprotective Potential of the Natural Artocarpin against In Vitro UVB-Induced Apoptosis.

Apoptosis, a well-known pattern of programmed cell death, occurs in multicellular organisms not only for controlling tissue homeostasis but also for getting rid of severely damaged cells in order to protect the redundant growth of abnormal cells undergoing cancerous cells. The epidermis of the human skin, composed largely of keratinocytes (KCs), is renewed continuously. Therefore, KCs apoptosis plays a critical role in the maintenance of epidermis structure and function. However, regulated cell death can be disturbed by environmental factors especially ultraviolet radiation (UV) B, leading to the formation of sunburn cells (KCs undergoing UVB-induced apoptosis) and impairing the skin integrity. In the present study, we firstly reported the potential of the natural artocarpin (NAR) to regulate UVB-induced human KCs apoptosis. The NAR showed antilipid peroxidation with an IC50 value of 18.2 ± 1.6 µg/mL, according to TBARS assay while the IC50 value of trolox, a well-known antioxidant, was 7.3 ± 0.8 µg/mL. For cell-based studies, KCs were pretreated with 3.1 µg/mL of the NAR for 24 hr and then exposed to UVB at 55 mJ/cm2. Our data indicated that the NAR pretreatment reduces UVB-induced oxidative stress by scavenging free radicals and nitric oxide and therefore prevents reactive oxygen species (ROS) and reactive nitrogen species- (RNS-) mediated apoptosis. The NAR pretreatment has been shown also to reduce the UVB-induced cyclobutane pyrimidine dimer (CPD) lesions by absorbing UVB radiation and regulating the cell cycle phase. Additionally, the NAR pretreatment was found to modulate the expression of cleaved caspases-3 and 8 that trigger different signalling cascades leading to apoptosis. Thus, these results provide a basis for the investigation of the photoprotective effect of the NAR isolated from A. altilis heartwood and suggest that it can be potentially used as an agent against UVB-induced skin damages.

Discovery of antitumor lectins from rainforest tree root transcriptomes.

Glycans are multi-branched sugars that are displayed from lipids and proteins. Through their diverse polysaccharide structures they can potentiate a myriad of cellular signaling pathways involved in development, growth, immuno-communication and survival. Not surprisingly, disruption of glycan synthesis is fundamental to various human diseases; including cancer, where aberrant glycosylation drives malignancy. Here, we report the discovery of a novel mannose-binding lectin, ML6, which selectively recognizes and binds to these irregular tumor-specific glycans to elicit potent and rapid cancer cell death. This lectin was engineered from gene models identified in a tropical rainforest tree root transcriptome and is unusual in its six canonical mannose binding domains (QxDxNxVxY), each with a unique amino acid sequence. Remarkably, ML6 displays antitumor activity that is >105 times more potent than standard chemotherapeutics, while being almost completely inactive towards non-transformed, healthy cells. This activity, in combination with results from glycan binding studies, suggests ML6 differentiates healthy and malignant cells by exploiting divergent glycosylation pathways that yield naïve and incomplete cell surface glycans in tumors. Thus, ML6 and other high-valence lectins may serve as novel biochemical tools to elucidate the glycomic signature of different human tumors and aid in the rational design of carbohydrate-directed therapies. Further, understanding how nature evolves proteins, like ML6, to combat the changing defenses of competing microorganisms may allow for fundamental advances in the way we approach combinatorial therapies to fight therapeutic resistance in cancer.

Artocarpin induces cell apoptosis in human osteosarcoma cells through endoplasmic reticulum stress and reactive oxygen species.

Osteosarcoma is a malignant primary bone tumor that responds poorly to both chemotherapy and radiation therapy. However, because of side effects and drug resistance in chemotherapy and the insufficiency of an effective adjuvant therapy for osteosarcoma, it is necessary to research novel treatments. This study was the first to investigate the anticancer effects of the flavonoid derivative artocarpin in osteosarcoma. Artocarpin induced cell apoptosis in three human osteosarcoma cell lines-U2OS, MG63, and HOS. Artocarpin was also associated with increased intracellular reactive oxygen species (ROS). Mitochondrial dysfunction was followed by the release of cytochrome c from mitochondria and accompanied by decreased antiapoptotic Bcl-2 and Bcl-xL and increased proapoptotic protein Bak and Bax. Artocarpin triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosol calcium levels and increased glucose-regulated protein 78 and 94 expressions, and also increased calpains expression and activity. Animal studies revealed a dramatic 40% reduction in tumor volume after 18 days of treatment. This study demonstrated a novel anticancer activity of artocarpin against human osteosarcoma cells and in murine tumor models. In summary, artocarpin significantly induced cell apoptosis through ROS, ER stress, mitochondria, and the caspase pathway, and may thus be a novel anticancer treatment for osteosarcoma.

Artocarpin-enriched (Artocarpus altilis) Heartwood Extract Provides Protection Against UVB-induced Mechanical Damage in Dermal Fibroblasts.

This study aimed to evaluate the protective effect of artocarpin-enriched (Artocarpus altilis) heartwood extract on the mechanical properties of UVB-irradiated fibroblasts. Human skin fibroblasts were pretreated with 50 µg/mL-1 extract and later irradiated with UVB (200 mJ/cm-2 ). They were then cultured within three-dimensional of free-floating and tense collagen lattices. The pretreatment of fibroblasts with the extract prior to UVB radiation showed cells protection against UVB-induced suppression of α-SMA expression, fibroblast migration and contraction. These results reveal that the extract prevents mechanical damages induced by UVB irradiation in fibroblast-embedded collagen lattices, and therefore, has a potential as a natural photo-protectant.

Formulation of chitosan patch incorporating Artocarpus altilis heartwood extract for improving hyperpigmentation.

Artocarpus altilis heartwood extract contains the bioactive compound artocarpin which exhibits melanogenesis inhibitory activity. However, the extract has poor solubility which affects the skin permeability of the compound. A chitosan hydrogel patch incorporating A. altilis heartwood extract was formulated to enhance the delivery of an amount of artocarpin sufficient for depigmenting the skin. The extract was prepared as an o/w microemulsion before blending with an aqueous solution of chitosan. The hydrogel patch was formulated by blending in a 1:1 ratio by weight of 4% w/w chitosan solution and 0.04% w/w extract microemulsion which provides optimal values of the mechanical properties of the patch. The release of artocarpin from the formulated patch (artocarpin content, 0.07 mg/cm2) exhibited two phases; the rapid rate (0-15 min) averaged 0.73 µg/min/mm2, and the slow rate (15-240 min) averaged 0.02 µg/min/mm2. The formulated patches significantly improved the hyperpigmented area of the subjects after 3 weeks of application. No adverse events were observed. The results indicate that the formulated chitosan hydrogel patch delivers an effective amount of incorporated artocarpin depigmenting action.

Enhanced autophagic activity of artocarpin in human hepatocellular carcinoma cells through improving its solubility by a nanoparticle system.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common liver cancer worldwide, with poor prognosis and resistance to chemotherapy. This gives novel cancer treatment methods an overwhelming significance. Natural products offer great resources of developing new and effective chemopreventive or chemotherapeutic agents. Artocarpus communis extracts and its active constituent, prenylated flavonoid artocarpin induce human hepatocellular carcinoma cell death. However, the poor water solubility drawbacks of artocarpin restrict its clinical application and bioavailability. PURPOSE: This study developed the artocarpin nanoparticle system to overcome the poor water solubility drawbacks and investigated the improvement of therapeutic efficacy of artocarpin by adopting novel nanoparticle delivery strategy. METHODS: Antiproliferative activity of artocarpin was evaluated by MTT assay. Cell morphology observation by microscope, DNA fragmentation assay, cell cycle analysis, Annexin V apoptosis cell staining, monodansylcadaverine and acridine orange staining and immunoblot analysis were used to evaluate the induction of autophagy by artocarpin. The determination of particle size, amorphous transformation, hydrogen-bond formation, yield, encapsulation efficiency and the solubility study were used to investigate the solubility enhancement mechanism of artocarpin. RESULTS: The present study demonstrates that the anticancer effect of artocarpin in HepG2 and PLC/PRF/5 hepatoma cells is mediated through the autophagic cell death mechanism. Results also demonstrated that artocarpin nanoparticles enhanced the solubility of artocarpin by reducing particle size, transforming high energy amorphous state, and forming hydrogen bond with excipients. Additionally, ArtN exhibited better autophagic cytotoxicity compared to free artocarpin. CONCLUSION: This work reveals the antihepatoma activity of artocarpin by inducing autophagic cell death and the improvement of therapeutic efficacy of artocarpin by adopting novel nanoparticle delivery strategy. The research provided a basis of ArtN could be explored as a low-dose alternative of artocarpin in anticancer treatment and research applications.

Transgenic plants expressing the AaIT/GNA fusion protein show increased resistance and toxicity to both chewing and sucking pests.

The adoption of pest-resistant transgenic plants to reduce yield losses and decrease pesticide use has been successful. To achieve the goal of controlling both chewing and sucking pests in a given transgenic plant, we generated transgenic tobacco, Arabidopsis, and rice plants expressing the fusion protein, AaIT/GNA, in which an insecticidal scorpion venom neurotoxin (Androctonus australis toxin, AaIT) is fused to snowdrop lectin (Galanthus nivalis agglutinin, GNA). Compared with transgenic tobacco and Arabidopsis plants expressing AaIT or GNA, transgenic plants expressing AaIT/GNA exhibited increased resistance and toxicity to one chewing pest, the cotton bollworm, Helicoverpa armigera. Transgenic tobacco and rice plants expressing AaIT/GNA showed increased resistance and toxicity to two sucking pests, the whitefly, Bemisia tabaci, and the rice brown planthopper, Nilaparvata lugens, respectively. Moreover, in the field, transgenic rice plants expressing AaIT/GNA exhibited a significant improvement in grain yield when infested with N. lugens. This study shows that expressing the AaIT/GNA fusion protein in transgenic plants can be a useful approach for controlling pests, particularly sucking pests which are not susceptible to the toxin in Bt crops.

Antihepatoma activity of Artocarpus communis is higher in fractions with high artocarpin content.

Extracts from natural plants have been used in traditional medicine for many centuries worldwide. Artocarpus communis is one such plant that has been used to treat liver cirrhosis, hypertension, and diabetes. To our knowledge, this study is the first to investigate the antihepatoma activity of A. communis toward HepG2 and PLC/PRF/5 cells and the first to explore the relationship between antihepatoma activity and the active compound artocarpin content in different fractions of A. communis. A. communis methanol extract and fractions induced dose-dependent reduction of tumor cell viability. DNA laddering analysis revealed that A. communis extract and fractions did not induce apoptosis in HepG2 and PLC/PRF/5 cells. Instead, acridine orange staining revealed that A. communis triggered autophagic cell death in a dose-dependent manner. The antihepatoma activity of A. communis is attributable to artocarpin. The fractions with the highest artocarpin content were also the fractions with the highest antihepatoma activity in the following order: dichloromethane fraction > methanol extract > ethyl acetate fraction > n-butanol fraction > n-hexane fraction. Taken together, A. communis showed antihepatoma activity through autophagic cell death. The effect was related to artocarpin content. Artocarpin could be considered an indicator of the anticancer potential of A. communis extract.

Antityrosinase and antimicrobial activities from Thai medicinal plants.

Various dermatological disorders and microbial skin infection can cause hyperpigmentation. Therefore, screenings for whitening and antimicrobial agents from Thai medicinal plants have been of research interest. Seventy-seven ethanol plant extracts were investigated for antityrosinase activity, eleven samples showed the tyrosinase inhibition more than 50 % were further preliminary screening for antimicrobial activity by agar disc diffusion and broth micro-dilution methods. Artocarpus integer (Thunb.) Merr. (Moraceae) root extract, which showed the potential of tyrosinase inhibition with 90.57 ± 2.93 % and antimicrobial activity against Staphylococcus aureus, S. epidermidis, Propionibacterium acnes and Trichophyton mentagophytes with inhibition zone as 9.10 ± 0.00, 10.67 ± 0.09, 15.25 ± 0.05 and 6.60 ± 0.17 mm, respectively was selected for phytochemical investigation. Three pure compounds were isolated as artocarpin, cudraflavone C and artocarpanone. And artocarpanone exhibited anti-tyrosinase effect; artocarpin and cudraflavone C also showed the potential of antibacterial activity against S. aureus, S. epidermidis and P. acnes with MIC at 2, 4 and 2 µg/ml, respectively and MBC at 32 µg/ml for these bacteria. So, these pure compounds are interesting for further study in order to provide possibilities of new whitening and antibacterial development. This will be the first report of phytochemical investigation of A. integer root.

Purification, partial characterization and immobilization of a mannose-specific lectin from seeds of Dioclea lasiophylla mart.

Lectin from the seeds of Dioclea lasiophylla (DlyL) was purified in a single step by affinity chromatography on a Sephadex® G-50 column. DlyL strongly agglutinated rabbit erythrocytes and was inhibited by monosaccharides (D-mannose and α-methyl-D-mannoside) and glycoproteins (ovalbumin and fetuin). Similar to other Diocleinae lectins, DlyL has three chains, α, ß and γ, with mass of 25,569 ± 2, 12,998 ± 1 and 12,588 ± 1 Da, respectively, and has no disulfide bonds. The hemagglutinating activity of DlyL was optimal in pH 8.0, stable at a temperature of 70 °C and decreased in EDTA solution, indicating that lectin activity is dependent on divalent metals. DlyL exhibited low toxicity on Artemia sp. nauplii, but this effect was dependent on the concentration of lectin in solution. DlyL immobilized on cyanogen bromide-activated Sepharose® 4B bound 0.917 mg of ovalbumin per cycle, showing the ability to become a tool for glycoproteomics studies.

Artocarpin attenuates ultraviolet B-induced skin damage in hairless mice by antioxidant and anti-inflammatory effect.

Artocarpin, a prenylated flavonoid isolated from an agricultural plant Artocarpus communis, has been documented to possess anti-inflammation and anticancer activities. As oxidative stress and inflammation promote the development of ultraviolet B (UVB) irradiation-induced photodamage, the aim of the present study was to evaluate the photoprotective effect of artocarpin on UVB-induced skin damage in hairless mice. Artocarpin at a topical dose of 0.05% and 0.1% showed a significant photoprotective effect by decreasing histopathological changes, such as desquamation, epidermal thicken and sunburn cell formation, but 0.1% of artocarpin administration did not show better effect. Regarding the antioxidant activities, artocarpin exhibited a significant effect (P<0.05) by decreasing levels of reactive species oxygen and lipid peroxidation. In addition, artocarpin can significant decrease the level of tumor necrosis factor-α and interleukin-1ß for downregulating the inflammation protein, including the synthesis of cytosolic phospholipase A2 and cyclooxygenase-2 (P<0.05). In conclusion, these data suggest that artocarpin can prevent skin damage from UVB irradiation-induced photodamage in hairless mice and this is likely mediated through its antioxidant and anti-inflammation mechanisms. Therefore, we suggested that artocarpin could be a useful photoprotective agent in medicine and/or cosmetics.

In silico analysis of molecular mechanisms of Galanthus nivalis agglutinin-related lectin-induced cancer cell death from carbohydrate-binding motif evolution hypothesis.

Galanthus nivalis agglutinin-related lectins, a superfamily of strictly mannose-binding-specific lectins widespread amongst monotyledonous plants, have drawn a rising attention for their remarkable anti-proliferative and apoptosis-inducing activities toward various types of cancer cells; however, the precise molecular mechanisms by which they induce tumor cell apoptosis are still only rudimentarily understood. Herein, we found that the three conserved motifs "QXDXNXVXY," the mannose-specific binding sites, could mutate at one or more amino acid sites, which might be a driving force for the sequential evolution and thus ultimately leading to the complete disappearance of the three conserved motifs. In addition, we found that the motif evolution could result in the diversification of sugar-binding types that G. nivalis agglutinin-related lectins could bind from specific mannose receptors to more types of sugar-containing receptors in cancer cells. Subsequently, we indicated that some sugar-containing receptors such as TNFR1, EGFR, Hsp90, and Hsp70 could block downstream anti-apoptotic or survival signaling pathways, which, in turn, resulted in tumor cell apoptosis. Taken together, our hypothesis that carbohydrate-binding motif evolution may impact the G. nivalis agglutinin-related lectin-induced survival or anti-apoptotic pathways would provide a new perspective for further elucidating the intricate relationships between the carbohydrate-binding specificities and complex molecular mechanisms by which G. nivalis agglutinin-related lectins induce cancer cell death.

Depigmenting action of a nanoemulsion containing heartwood extract of Artocarpus incisus on UVB-induced hyperpigmentation in C57BL/6 mice.

Melasma hyperpigmentation is an acquired disorder predominantly affecting the female population. The present study was conducted to determine the potential of a botanical extract to reduce observable hyperpigmentation. The extract from heartwood of Artocarpus incisus was formulated into nanoemulsions, and the depigmenting efficacy of the formulated nanoemulsion was determined in vivo. HPLC analysis showed that the extract contained artocarpin in an amount of 44.5 ± 0.1% w/w. The extract exhibited melanogenesis inhibition with an IC(50) value of 30.2 ± 2.4 mg/ml, while kojic acid, a well known lightening agent, exhibited an IC(50) of 51.4 ± 5.1 mg/ml. The nanoemulsion containing the extract was then formulated and prepared by the phase inversion technique. The concentration of the extract used was about six times its IC(50). The optimal formula containing 0.02% w/w extract, 41.6% w/w isopropyl myristate, 0.03% w/w α-tocopherol, 5% w/wglyc-eryl monostearate (co-emulsifier), 8% w/w ceteareth-10 (emulsifier), 0.05% triethanolamine, 0.03% w/w carbopol 940, and water adjusted to 100% w/w provided a homogeneous o/w emulsion with a droplet size of 325 ± 15 nm and a polydispersity of 0.31 ± 0.02. The depigmenting efficacy was then observed following topical application of the formulated nanoemulsion to UVB-stimulated hyperpigmented dorsal skin of C57BL/6 mice. A strongly visible decrease in hyperpigmentation was observed after six weeks of treatment with the formulated nanoemulsion. The degree of pigmentation decreased after the application was 84 ± 4 units, while that after the application of the extracted prepared into solution was 51 ± 3 units. The applied areas would return to their original color after treatment was stopped for four weeks.

Characterization, molecular cloning, and in silico analysis of a novel mannose-binding lectin from Polygonatum odoratum (Mill.) with anti-HSV-II and apoptosis-inducing activities.

Polygonatum odoratum lectin (POL), a novel mannose-binding lectin with anti-viral and apoptosis-inducing activities, was isolated from rhizomes of Polygonatum odoratum (Mill.) Druce. POL was a homo-tetramer with molecular weight of 11953.623Da per subunits as determined by gel filtration, SDS-PAGE and mass spectrometry. Based on its N-terminal 29-amino acid sequence the full-length cDNA sequence of POL was cloned. Subsequent phylogenetic analysis and molecular modeling revealed that POL belonged to the Galanthus nivalis agglutinin (GNA)-related lectin family, which acquired unique mannose-binding specificity. The hemagglutinating activities of POL were metal ion-independent, and were stable within certain range of pH and temperature alterations. Moreover, POL showed remarkable anti-HSV-II activity towards Vero cells, cytotoxicity towards human melanoma A375 cells and induced apoptosis in a caspase-dependent manner.

Conidiogenic effects of mannose-binding lectins isolated from cotyledons of red kidney bean (Phaseolus vulgaris) on Alternaria alternata.

Effect of proteinaceous extracts from red kidney bean cotyledons on mycelium of Alternaria alternata growing on potato dextrose agar (PDA) plates was investigated. Unexpectedly, conidia formation was induced in response to applied crude extracts. A PDA disc method was developed to quantify conidia formed. A purified fraction retaining conidiation inducing effect (CIE) was obtained following several protein purification procedures including the last step of eluting bound proteins from an Affi-gel blue gel column. Based on MALDI (matrix assisted laser desorption/ionization) mass spectrometric analysis, a previously identified mannose-binding lectin (MBL) called PvFRIL (Phaseolus vulgaris fetal liver tyrosine kinase 3-receptor interacting lectin) was present in this conidiation inducing fraction. The PvFRIL was subsequently purified using a single step mannose-agarose affinity column chromatography. When the lectin was applied exogenously to A. alternata, increased conidiation resulted. The conidia produced in response to the MBL were similar to those induced by other methods and their germ tubes were longer after 12 h growth than those induced under white light. To our knowledge this is the first report of exogenous application of a PvFRIL or another purified protein from a plant inducing conidia formation in a fungus.

Synergistic antiviral effect of Galanthus nivalis agglutinin and nelfinavir against feline coronavirus.

Feline infectious peritonitis (FIP) is a fatal disease in domestic and nondomestic felids caused by feline coronavirus (FCoV). Currently, no effective vaccine is available for the prevention of this disease. In searching for agents that may prove clinically effective against FCoV infection, 16 compounds were screened for their antiviral activity against a local FCoV strain in Felis catus whole fetus-4 cells. The results showed that Galanthus nivalis agglutinin (GNA) and nelfinavir effectively inhibited FCoV replication. When the amount of virus preinoculated into the test cells was increased to mimic the high viral load present in the target cells of FIP cats, GNA and nelfinavir by themselves lost their inhibitory effect. However, when the two agents were added together to FCoV-infected cells, a synergistic antiviral effect defined by complete blockage of viral replication was observed. These results suggest that the combined use of GNA and nelfinavir has therapeutic potential in the prophylaxis and treatment of cats with early-diagnosed FIP.

[Effects of cycloartocarpin A and artocarpin extracted from Fructus Artocarpin Heterophylli on apoptosis of SMMC-7721 and SGC-7901 cells].

OBJECTIVE: To investigate the effects of cycloartocarpin A (ACR-2) and artocarpin (ACR-3), monomeric compounds isolated from Fructus Artocarpi Heterophylli, on apoptosis of SMMC-7721 and SGC-7901 cell lines. METHODS: SMMC-7721 and SGC-7901 cells were routinely cultured, and divided into experiment group and control group. The SMMC-7721 cells were treated with different concentrations of ACR-2 (3.46 x 10(-3), 13.82 x (-3), 55.30 x 10(-3) mmol/L) and ACR-3 (6.88 x 10(-3), 27.52 x 10(-3), 110.09 x 10(-3) mmol/L), and the SGC-7901 cells were also treated with different concentrations of ACR-2 (8.06 x 10(-3), 32.26 x 10(-3), 129.03 x 10(-3) mmol/L) and ACR-3 (2.87 x 10(-3), 11.47 x 10(-3), 45.87 x 10(-3) mmol/L), with PBS (DMSO<0.1%) as control treatment. Cell apoptosis was measured by double labeled staining with Hoechst33342/propidium iodide (PI) and TdT-mediated dUTP-biotin nick end labeling (TUNEL) and flow cytometry. RESULTS: ACR-2 and ACR-3 could induce apoptosis of SMMC-7721 and SGC-7901 cells. Some of SMMC-7721 and SGC-7901 cells demonstrated typical apoptosis after being treated with ACR-2 and ACR-3. Hoechst33342/PI staining showed that cells were fraught with overlapping nuclei and nuclear debris or lobule, and the nuclear appeared light blue. TUNEL showed that cells permeated with overlapping nuclei and nuclear debris or lobule, and the nuclear appeared brown. Less apoptotic cells were observed in negative control group, and the nuclear appeared light blue. The apoptosis rates of SMMC-7721 and SGC-7901 cells in the ACR-2 and ACR-3 treated groups were significant higher than those in the control group (P<0.05, P<0.01). CONCLUSION: ACR-2 and ACR-3 can induce apoptosis of SMMC-7721 and SGC-7901 cells.

SUMO fusion facilitates expression and purification of garlic leaf lectin but modifies some of its properties.

Over expression of lectin genes in E. coli often gives inclusion bodies that are solubilised to characterize lectins. We made N-terminal fusion of the Allium sativum leaf agglutinin (ASAL) with SUMO (small ubiquitin related modifier) peptide. The SUMO peptide allowed expression of the recombinant lectin in E. coli, predominantly in soluble form. The soluble fusion protein could be purified by immobilized metal affinity column (IMAC), followed by size exclusion chromatography. The SUMO protease failed to cleave the SUMO peptide from ASAL. This may be due to steric hindrance caused by the homodimer structure of the chimeric ASAL. Some properties like dimerization, haemagglutination and insecticidal properties of the recombinant SUMO-ASAL fusion protein were comparable to the plant derived native lectin. However, glycan array analysis revealed that the carbohydrate binding specificity of the recombinant SUMO-ASAL was altered. Further, the fusion protein was not toxic to E. coli (native ASAL exhibited toxicity). The recombinant lectin was more thermo-labile as compared to the native lectin. Three important findings of this study are: (1) sugar specificity of ASAL can be altered by amino-terminal fusion; (2) anti-E. coli activity of ASAL can be eliminated by N-terminal SUMO fusion and (3) SUMO-ASAL may be a preferred candidate insecticidal protein for the development of transgenic plants.

The lectin KM+ induces corneal epithelial wound healing in rabbits.

Neutrophil influx is essential for corneal regeneration (Gan et al. 1999). KM+, a lectin from Artocarpus integrifolia, induces neutrophil migration (Santos-de-Oliveira et al. 1994). This study aims at investigating a possible effect of KM+ on corneal regeneration in rabbits. A 6.0-mm diameter area of debridement was created on the cornea of both eyes by mechanical scraping. The experimental eyes received drops of KM+ (2.5 microg/ml) every 2 h. The control eyes received buffer. The epithelial wounded areas of the lectin-treated and untreated eyes were stained with fluorescein, photographed and measured. The animals were killed 12 h (group 1, n = 5), 24 h (group 2, n = 10) and 48 h (group 3, n = 5) after the scraping. The corneas were analysed histologically (haematoxylin and eosin and immunostaining for proliferation cell nuclear antigen, p63, vascular endothelial growth factor, c-Met and laminin). No significant differences were found at the epithelial gap between treated and control eyes in the group 1. However, the number of neutrophils in the wounded area was significantly higher in treated eyes in this group. Three control and seven treated eyes were healed completely and only rare neutrophils persisted in the corneal stroma in group 2. No morphological distinction was observed between treated and control eyes in group 3. In treated corneas of group 2, there was an increase in immunostaining of factors involved in corneal healing compared to controls. Thus, topical application of KM+ may facilitate corneal epithelial wound healing in rabbits by means of a mechanism that involves increased influx of neutrophils into the wounded area induced by the lectin.

Bioinformatics analyses of the mannose-binding lectins from Polygonatum cyrtonema, Ophiopogon japonicus and Liparis noversa with antiproliferative and apoptosis-inducing activities.

In the present study, three typical monocot mannose-binding lectins (e.g., Polygonatum cyrtonema lectin [PCL], Ophiopogon japonicus lectin [OJL] and Liparis noversa lectin [LNL]), were reported to possess a similar tertiary structure with three mannose-binding sites and a close phylogenetic relationship. Subsequently, these lectins were found to bear remarkable inhibitory effects on the growth of MCF-7 cells. Further experiments confirmed that there is a link among the hemagglutinating activity, antiproliferative activity and mannose-binding activity. In addition, these lectins were shown to induce MCF-7 cell apoptosis and caspase was found to be involved in this apoptotic pathway. In conclusion, these findings demonstrate that the different antiproliferative effects may be due to the conserved motifs of mannose-binding sites. Furthermore, our results demonstrate that these lectins induce apoptosis in MCF-7 cells via a caspase-dependent pathway.