Plant antifungal proteins and their applications in agriculture.

Fungi are far more complex organisms than viruses or bacteria and can develop numerous diseases in plants that cause loss of a substantial portion of the crop every year. Plants have developed various mechanisms to defend themselves against these fungi which include the production of low-molecular-weight secondary metabolites and proteins and peptides with antifungal activity. In this review, families of plant antifungal proteins (AFPs) including defensins, lectins, and several others will be summarized. Moreover, the application of AFPs in agriculture will also be analyzed.

Differential inhibitory potencies and mechanisms of the type I ribosome inactivating protein marmorin on estrogen receptor (ER)-positive and ER-negative breast cancer cells.

Breast cancer is the second most common cancer with a high incidence rate worldwide. One of the promising therapeutic approaches on breast cancer is to use the drugs that target the estrogen receptor (ER). In the present investigation, marmorin, a type I ribosome inactivating protein from the mushroom Hypsizigus marmoreus, inhibited the survival of breast cancer in vitro and in vivo. It evinced more potent cytotoxicity toward estrogen receptor (ER)-positive MCF7 breast cancer cells than ER-negative MDA-MB-231 cells. Further study disclosed that marmorin undermined the expression level of estrogen receptor α (ERα) and significantly inhibited the proliferation of MCF7 cells induced by 17ß-estradiol. Knockdown of ERα in MCF7 cells significantly attenuated the inhibitory effect of marmorin on proliferation, suggesting that the ERα-mediated pathway was implicated in the suppressive action of marmorin on ER-positive breast cancer cells. Moreover, marmorin induced time-dependent apoptosis in both MCF7 and MDA-MB-231 cells. It brought about G2/M-phase arrest, mitochondrial membrane potential depolarization and caspase-9 activation in MCF7 cells, and to a lesser extent in MDA-MB-231 cells. Marmorin triggered the death receptor apoptotic pathway (e.g. caspase-8 activation) and endoplasmic reticulum stress (ERS, as evidenced by phosphorylation of PERK and IRE1α, cleavage of caspase-12, and up-regulation of CHOP expression) in both MCF7 and MDA-MB-231 cells. In summary, marmorin exhibited inhibitory effect on breast cancer partially via diminution of ERα and apoptotic pathways mediated by mitochondrial, death receptor and ERS. The results advocate that marmorin is a potential candidate for breast cancer therapy.

Antifungal and antiviral products of marine organisms.

Marine organisms including bacteria, fungi, algae, sponges, echinoderms, mollusks, and cephalochordates produce a variety of products with antifungal activity including bacterial chitinases, lipopeptides, and lactones; fungal (-)-sclerotiorin and peptaibols, purpurides B and C, berkedrimane B and purpuride; algal gambieric acids A and B, phlorotannins; 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)phenol, spongistatin 1, eurysterols A and B, nortetillapyrone, bromotyrosine alkaloids, bis-indole alkaloid, ageloxime B and (-)-ageloxime D, haliscosamine, hamigeran G, hippolachnin A from sponges; echinoderm triterpene glycosides and alkene sulfates; molluscan kahalalide F and a 1485-Da peptide with a sequence SRSELIVHQR; and cepalochordate chitotriosidase and a 5026.9-Da antifungal peptide. The antiviral compounds from marine organisms include bacterial polysaccharide and furan-2-yl acetate; fungal macrolide, purpurester A, purpurquinone B, isoindolone derivatives, alterporriol Q, tetrahydroaltersolanol C and asperterrestide A, algal diterpenes, xylogalactofucan, alginic acid, glycolipid sulfoquinovosyldiacylglycerol, sulfated polysaccharide p-KG03, meroditerpenoids, methyl ester derivative of vatomaric acid, lectins, polysaccharides, tannins, cnidarian zoanthoxanthin alkaloids, norditerpenoid and capilloquinol; crustacean antilipopolysaccharide factors, molluscan hemocyanin; echinoderm triterpenoid glycosides; tunicate didemnin B, tamandarins A and B and; tilapia hepcidin 1-5 (TH 1-5), seabream SauMx1, SauMx2, and SauMx3, and orange-spotted grouper ß-defensin. Although the mechanisms of antifungal and antiviral activities of only some of the aforementioned compounds have been elucidated, the possibility to use those known to have distinctly different mechanisms, good bioavailability, and minimal toxicity in combination therapy remains to be investigated. It is also worthwhile to test the marine antimicrobials for possible synergism with existing drugs. The prospects of employing them in clinical practice are promising in view of the wealth of these compounds from marine organisms. The compounds may also be used in agriculture and the food industry.

A potential human hepatocellular carcinoma inhibitor from Bauhinia purpurea L. seeds: from purification to mechanism exploration.

A 20-kDa Kunitz-type trypsin-chymotrypsin inhibitor, Bauhinia purpurea trypsin inhibitor (BPLTI), has been isolated from the seeds of B. purpurea L. by using liquid chromatography procedures that involved ion exchange chromatography on Sp-Sepharose and Mono S and gel filtration on Superdex 75. BPLTI demonstrated protease inhibitory activities of 7226 BAEE units/mg and 65 BTEE units/mg toward trypsin and α-chymotrypsin, respectively. BPLTI was relatively thermal (0-60°C) and pH (3-10) stable and its activity could be decreased by dithiothreitol treatment. BPLTI exhibited a wide spectrum of anti-proliferative and pro-apoptotic activities especially on human hepatocellular carcinoma Hep G2 cells. However, it was devoid of a significant antiproliferative effect on immortal human hepatic WRL 68 cells. We show here that BPLTI stimulates apoptosis in Hep G2 cells, including (1) evoking DNA damage including the production of chromatin condensation and apoptotic bodies; (2) induction of cell apoptosis/necrosis; (3) mitochondrial membrane depolarization; and (4) increasing the production of cytokines. Taken together, our findings show for the first time that purified protease inhibitor from B. purpurea L. seeds is a promising candidate for the treatment of human hepatocellular carcinoma.

Glyceollin, a soybean phytoalexin with medicinal properties.

This review covers the biosynthesis of glyceollin and its biological activities including antiproliferative/antitumor action (toward B16 melanoma cells, LNCaP prostate cancer cells, and BG-1 ovarian cancer cells), anti-estrogenic action (through estrogen receptors α- and ß-), antibacterial action (toward Erwinia carotovora, Escherichia coli, Bradyrhizobium japonicum, Sinorhizobium fredii ), antinematode activity, and antifungal activity (toward Fusarium solani, Phakospora pachyrhizi, Diaporthe phaseolorum, Macrophomina phaseolina, Sclerotina sclerotiorum, Phytophthora sojae, Cercospora sojina, Phialophora gregata, and Rhizoctonia solani). Other activities include insulinotropic action and attenuation of vascular contractions in rat aorta.

A new Phaseolus vulgaris lectin induces selective toxicity on human liver carcinoma Hep G2 cells.

We describe here the purification and characterization of a new Phaseolus vulgaris lectin that exhibits selective toxicity to human hepatoma Hep G2 cells and lacks significant toxicity on normal liver WRL 68 cells. This polygalacturonic acid-specific lectin (termed BTKL) was purified from seeds of P. vulgaris cv. Blue tiger king by liquid chromatography techniques. The 60-kDa dimeric lectin showed strong and broad-spectrum hemagglutinating activity toward human, rabbit, rat, and mouse erythrocytes. Bioinformatic analysis unveils substantial N-terminal sequence similarity of BTKL to other Phaseolus lectins. Among a number of tumor cells tested, BTKL exhibits potent anti-Hep G2 activity which is associated with (1) induction of DNA fragmentation, (2) production of apoptotic bodies and chromatin condensation, (3) triggering of cell apoptosis and necrosis, and (4) depolarization of mitochondrial membrane (low ΔΨm). Furthermore, BTKL could induce inducible nitric oxide synthase (iNOS) expression and subsequent nitric oxide production in vitro in mouse macrophages, which may contribute to its antitumor activity. In addition, BTKL could bring about a significant dose-dependent increase in the production of mRNAs of proinflammatory cytokines including interleukin-1 beta, interleukin-2, tumor necrosis factor alpha, and interferon-gamma. In sum, the antitumor activity and mechanism of BTKL provided here suggest that it has potential therapeutic value for human liver cancer.

Antitumor and HIV-1 Reverse Transcriptase Inhibitory Activities of a Hemagglutinin and a Protease Inhibitor from Mini-Black Soybean.

Protease inhibitors (PIs) and hemagglutinins are defense proteins produced by many organisms. From Chinese mini-black soybeans, a 17.5-kDa PI was isolated using chromatography on Q-Sepharose, SP-Sepharose, and DEAE-cellulose. A 25-kDa hemagglutinin was purified similarly, but using Superdex 75 instead of DEAE-cellulose in the final step. The PI inhibited trypsin and chymotrypsin (IC(50) = 7.2 and 8.8 µM). Its trypsin inhibitory activity was stable from pH 2 to pH 13 and from 0°C to 70°C. The hemagglutinin activity of the hemagglutinin was stable from pH 2 to pH 13 and from 0°C to 75°C. The results indicated that both PI and hemagglutinin were relatively thermostable and pH-stable. The trypsin inhibitory activity was inhibited by dithiothreitol, signifying the importance of the disulfide bond to the activity. The hemagglutinating activity was inhibited most potently by D (+)-raffinose and N-acetyl-D-galactosamine, suggesting that the hemagglutinin was specific for these two sugars. Both PI and hemagglutinin inhibited HIV-1 reverse transcriptase (IC(50) = 3.2 and 5.5 µM), proliferation of breast cancer cells (IC(50) = 9.7 and 3.5 µM), and hepatoma cells (IC(50) = 35 and 6.2 µM), with relatively high potencies.

A novel lectin with highly potent antiproliferative and HIV-1 reverse transcriptase inhibitory activities from cicada (Cicada flammata).

A dimeric lectin with a molecular weight of 60 kDa and high hemagglutinating activity was isolated from dried cicadas. It was adsorbed on Q-Sepharose and unadsorbed on Affi-Gel Blue gel. Its hemagglutinating activity was stable up to 55 degrees C and between pH 2 and 13. The activity was inhibited by glucuronic acid and raffinose, K(+) ions, and Mg(2+) ions. Cicada lectin potently inhibited proliferation of HepG2 hepatoma and MCF 7 breast cancer cells, with an IC(50) value of 0.76 and 0.49 microM, respectively. It potently inhibited HIV-1 reverse transcriptase activity with an IC(50) of 0.36 microM but was devoid of mitogenic activity on spleen cells. Its N-terminal sequence exhibited slight similarity to a conserved hypothetical protein from Culex quinquefasciatus and a gene product from transcript GH19834-RA of Drosophila grimshawi, but there was no resemblance to lectins from other insects, including Drosophila, Sarcophaga, Glossina, and Aedes species.

Urolithin A Prevents Focal Cerebral Ischemic Injury via Attenuating Apoptosis and Neuroinflammation in Mice.

Neuroinflammation contributes to neuronal death in cerebral ischemia. Urolithin A (UA), a gut microbial metabolite of ellagic acid, has emerged as a potential anti-inflammatory agent. However, its roles and precise mechanisms in stroke remain unknown. Here we found that UA treatment ameliorated infarction, neurological deficit scores, and spatial memory deficits after cerebral ischemia. Furthermore, UA significantly reduced neuron loss and promoted neurogenesis after ischemic stroke. We also found that UA attenuated apoptosis by regulating apoptotic-related proteins. Meanwhile, UA treatment inhibited glial activation via affecting inflammatory signaling pathways, specifically by enhancing cerebral AMPK and IκBa activation while decreasing the activation of Akt, P65NFκB, ERK, JNK, and P38MAPK. Our findings reveal a key role of UA against ischemic stroke through modulating apoptosis and neuroinflammation in mice.

[Application Value of Combined Detection of Urinary Amino Acid Metabolite and Tumor Specific Growth Factor in Evaluation of Curative Efficacy for Acute Leukemia].

OBJECTIVE: To investigate the clinical importance of combined detection of urinary amino acid metabolite --urinary tyrosine (UT) and tumor specific growth factor (TSGF) in the disease observation and curative effect evaluation of acute leukemia（AL）. METHODS: In 87 cases of AL, the UT and TSGF levels were detected by using chemical chromogenic method and continuous monitoring method respectively. The 2 indicators of each treatment group were statistically analyzed and compared with that of 50 healthy control group. RESULTS: In 87 AL patients, the levels of UT and TSGF after treatment were significantly lower than those before treatment (P<0.01). The level of UT in non-remission(NR) group and partial remission(PR) group was significantly higher than that in completely remission(CR) group(P<0.01，P<0.05) and control group (P<0.01, P<0.01), The UT level in NR group was significantly higher than that in PR group (P<0.05), the UT level in CR group was significantly higher than that in control group (P<0.05). The levels of TSGF in NR and PR groups were significantly higher than those in CR and control groups(P<0.01, P<0.01). The level of TSGF in NR group was significantly higher than that in PR group(P<0.05), but no significant difference existed between CR group and control group(P>0.05). CONCLUSION: UT and TSGF levels are related with the metabolism of tumor cells in AL patients. UT level can be used to predict the recurrence of patients with CR. The combined dynamical monitoring of these 2 indicators can be used as the indexes for observation of AL status, evaluation of therapeutic efficacy, prediction of prognosis and relapse of AL.

Cathelicidins: peptides with antimicrobial, immunomodulatory, anti-inflammatory, angiogenic, anticancer and procancer activities.

The family of peptides designated as cathelicidins was identified over a decade ago. Cathelicidins have since gained increasing recognition, both as endogenous antibiotics and as effector molecules of the innate immune system. The human cathelicidin LL-37 is widely expressed in human tissues and plays diverse biological roles. It contributes substantially to host defense and impacts multiple aspects of immunity. In view of the escalating importance of cathelicidins, the activities of LL-37 with an emphasis on antimicrobial, immunomodulatory, anti-inflammatory, angiogenic, anticancer and procancer effects are discussed in this review article.

Antimicrobial activity of defensins and defensin-like peptides with special emphasis on those from fungi and invertebrate animals.

Living organisms are in perpetual contact with pathogenic microbes, and in encounter with parasites and predators. In order to protect themselves, they produce a variety of antimicrobial proteins and peptides. One family of such protective or defensive proteins is known as defensins, characterized by a cationic character, a low molecular mass, and an abundance of cysteine residues. Defensins from mammals and plants have been succinctly reviewed by a number of experts in this ever-growing field. This review encompasses the defensin plectasin from the saprophytic fungus Pseudoplectania nigrella as well as defensins and defensin-like peptides from invertebrate animals such as jellyfish, sponges, nematodes, crustaceans, arachnids, insects, bivalves, snails, and sea urchins. Big defensins from mollusks are mentioned together with amphioxus big defensin. The structures and activities of these defense proteins are discussed.

Momordica Charantia lectin, a type II ribosome inactivating protein, exhibits antitumor activity toward human nasopharyngeal carcinoma cells in vitro and in vivo.

The incidence of nasopharyngeal carcinoma (NPC) remains high in endemic regions, including southern China, northern Africa, and North America. One of the promising therapeutic approaches on NPC is drug screening from natural products, such as components from traditional Chinese medicine. In this study, the antitumor activity of Momordica charantia lectin (MCL), a type II ribosome inactivating protein from bitter gourd, on NPC was investigated. MCL evinced potent cytotoxicity toward NPC CNE-1 (IC(50) = 6.9) and CNE-2 (IC(50) = 7.4) cells but minimally affected normal NP 69 cells. Further investigation disclosed that MCL induced apoptosis, DNA fragmentation, G(1)-phase arrest, and mitochondrial injury in both types of NPC cells. The reduction of cyclin D1 and phosphoretinoblastoma (Rb) protein expression contributed to arrest at G(1)-phase of the cell cycle. These events were associated with regulation of mitogen-activated protein kinases (MAPK; including p38 MAPK, JNK, and ERK) phosphorylation and promoted downstream nitric oxide (NO) production. Concurrent administration of the p38 MAPK inhibitor SB-203580 significantly diminished NO production and lethality of MCL toward NPC cells. Further studies revealed that MCL increased cytochrome c release into the cytosol, activated caspases-8, -9, and -3, and enhanced production of cleaved PARP, subsequently leading to DNA fragmentation and apoptosis. Finally, an intraperitoneal injection of MCL (1.0 mg/kg/d) led to an average of 45% remission of NPC xenograft tumors subcutaneously inoculated in nude mice. This is the first article that unveils the potential of a type II RIP, MCL, for prevention and therapy of NPC.

Pharmacotherapy approaches to antifungal prophylaxis.

INTRODUCTION: Invasive fungal infection (IFI) is a serious problem due to difficulties in early diagnosis and high mortality. Different approaches are adopted for the treatment and management of IFI, including prophylactic, empiric, preemptive and directed strategies. AREAS COVERED: This paper reviews the type of pharmacotherapy used for antifungal prophylaxis in infants with extremely low birth weights, pediatric patients with cardiac disease, preterm neonates, pediatric oncology patients, adult cancer patients with neutropenia, adult patients with hematologic malignancy, hematopoietic stem-cell transplantation recipients, organ transplant recipients, HIV-infected patients, immunosuppressed patients treated with moderate or high doses of corticosteroids, and patients with invasive fusariosis, candidemia, invasive candidiasis, systemic mycoses and immunocompromised patients. EXPERT OPINION: Azole drugs are the drugs most often used in cost-effective antifungal prophylaxis of patients with conditions such as immunodeficiency and cancer, which render them highly susceptible to IFI. Fluconazole is the most outstanding example. However, there are many azoles with different pharmacological characteristics that the physician can choose from. Echinocandins have favorable characteristics that make them useful for treating Candida infections. Antibodies, or their engineered derivatives directed against cell-wall polysaccharides and glycopeptides, and some protein epitopes of Candida albicans, appear to be a promising novel approach for prophylaxis against Candida infection and deserve further in-depth investigations.

Protein from red cabbage (Brassica oleracea) seeds with antifungal, antibacterial, and anticancer activities.

A 30 kDa antifungal protein was purified from red cabbage ( Brassica oleracea ) seeds. It exhibited a molecular mass and N-terminal amino acid sequence disinct from those of previously isolated Brassica antifungal proteins. The protocol used entailed ion exchange chromatography on Q-Sepharose and SP-Sepharose followed by fast protein liquid chromatography on Mono S. The protein hindered mycelial growth in Mycosphaerella arachidicola (with an IC50=5 µM), Setospaeria turcica, and Bipolaris maydis. It also inhibited the yeast Candida albicans with an IC50=96 µM. It exerted its antifungal action by permeabilizing the fungal membrane as evidenced by staining with Sytox green. The antifungal activity was stable from pH 3 to 11 and from 0 to 65 °C. It manifested antibacterial activity against Pseudomonas aeruginosa (IC50=53 µM). Furthermore, after 48 h of culture, it suppressed proliferation of nasopharyngeal cancer and hepatoma cells with IC50=50 and 90 µM, respectively.

In vitro evaluation of physiological activity of vinegar produced from barley-, sweet potato-, and rice-shochu post-distillation slurry.

Vinegar was produced from barley-, sweet potato-, and rice-shochu post-distillation slurry using jar fermentor within 19 hrs. All the vinegars showed radical-scavenging activity, angiotensin I converting enzyme (ACE) inhibition and advanced glycation endproducts (AGE) inhibition in vitro. The radical-scavenging activity of the vinegar produced from sweet potato-shochu post-distillation slurry was higher than that of other two kinds of vinegar on the organic matter basis. The ACE inhibitory activities of all the vinegars were higher than that of each post-distillation slurry. The main components that showed ACE inhibitory activity would be peptides, and their content increased during acetic acid fermentation. Regarding AGE inhibition, only rice-shochu post-distillation slurry did not show such activity, but the other two post-distillation slurries and all the vinegars showed clear inhibitory activity. The activity appeared to depend on the concentration of amino groups except for sweet potato-shochu post-distillation slurry and the vinegar produced from it.