A thermostable chitin‐binding protein (14.3 kDa) with antifungal activity was isolated from Moringa oleifera seeds by affinity chromatography on chitin followed by ion exchange chromatography. NH2‐CPAIQRCCQQLRNIQPPCRCCQ (Mo‐CBP3) is a glycoprotein with 2.5% sugar, pI 10.8, without hemagglutination, chitinase or β‐glucanase activities. Mo‐CBP3 possesses in vitro antifungal activity against the phytopathogenic fungi Fusarium solani, F. oxysporum, Colletotrichum musae and C. gloesporioides. Contrarily, Mo‐CBP3 did not affect Pythium oligandrum, an oomycete. At 0.05 mg/ml, Mo‐CBP3 showed to be fungistatic against F. solani, but at 0.1 mg/ml Mo‐CBP3 behaved as a potent fungicidal agent as it inhibited both the spore germination and mycelial growth of F. solani. Surprisingly, the effect of Mo‐CBP3 against spore germination was observed even when the protein was heated at 100°C for 1 h or pretreated with 0.15MN‐acetyl‐D‐glucosamine. Mo‐CBP3 inhibited the glucose‐stimulated acidification of the incubation medium by F. solani. This is apparently caused by structural plasma membrane disarrangement induced by Mo‐CBP3. Altogether, these results suggest that Mo‐CBP3 might be involved in plant defense mechanisms and could be used as potential antifungal agent for controlling fungal pathogens in plants. © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 406–415, 2012.

Croton zehntneri, a plant native to northeastern Brazil, is widely used in folk medicine to treat gastrointestinal problems and has rich essential oil content. The effects of the essential oil of Croton zehntneri (EOCZ) and its main constituent anethole on several models of gastric lesions were studied in mice and rats. Oral treatment with EOCZ and anethole, both at doses of 30-300 mg/kg, caused similar and dose-dependent gastroprotection against ethanol- and indomethacin-induced gastric damage, but did not change cold-restraint stress-induced ulcers in rats. Furthermore, EOCZ and anethole (both at 30 and 300 mg/kg) similarly and significantly increased the mucus production by the gastric mucosa, measured by Alcian blue binding, in ethanol-induced ulcer model. However, at the same doses, neither EOCZ nor anethole promoted significant alteration in gastric production of non-protein sulfhydryl groups. In pylorus-ligated model, neither EOCZ nor anethole (both at 30 and 300 mg/kg) had a significant effect on the volume of gastric juice, pH, or total acidity. The results of this study show for the first time that EOCZ possesses a gastroprotective potential, an effect mostly attributed to the action of anethole. This activity is related predominantly to the ability of EOCZ and anethole to enhance the production of gastric wall mucus, an important gastroprotective factor. Furthermore, they suggest that EOCZ has potential therapeutic application for the treatment of gastric ulcers.

No abstract

No abstract

No abstract

No abstract

No abstract

Several studies have described the effects of seed exudates against microorganisms, but only few of them have investigated the proteins that have defensive activity particularly against nematode parasites. This study focused on the proteins released in the exudates of soybean seeds and evaluated their nematicidal properties against Meloidogyne incognita. A proteomic approach indicated the existence of 63 exuded proteins, including β-1,3-glucanase, chitinase, lectin, trypsin inhibitor, and lipoxygenase, all of which are related to plant defense. The presence of some of these proteins was confirmed by their in vitro activity. The soybean exudates were able to reduce the hatching of nematode eggs and to cause 100% mortality of second-stage juveniles (J2). The pretreatment of J2 with these exudates resulted in a 90% reduction of the gall number in tobacco plants. These findings suggest that the exuded proteins are directly involved in plant defense against soil pathogens, including nematodes, during seed germination.