Evaluation of In Vitro and In Silico Anti-Alzheimer Potential of Nonpolar Extracts and Essential Oil from Mentha piperita.

The anticholinesterase and antioxidant activities with chemical composition and molecular docking of essential oil and nonpolar extracts of Mentha piperita were evaluated using enzymatic and chemical methods. Molecular docking tools were used to explain the interaction of the major chemical constituents with the enzymes. GC/MS analyses revealed that the main compounds in M. piperita essential oil were l-menthone (43.601%) followed by pulegone (21.610%), linolenic acid (25.628%), and l-menthone (10.957%), representing the major compounds of the petroleum ether extract. Imidazoquinoline (7.767%) and 17-N-acetyl-oroidine (5.363%) were the major constituents of the chloroform extract. Linolenic acid (19.397%) and l-menthone (6.336%) were the most abundant compounds in the hexane extract. The M. piperita essential oil and nonpolar extracts showed moderate antioxidant activity. The essential oil showed the most promising anticholinesterase activity with IC50 = 10.66 ± 0.12 µg/mL and IC50 = 16.33 ± 0.03 µg/mL against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), respectively, close to galantamine in AChE and more active in BChE, followed by the interesting activity in the petroleum ether extract with IC50 = 23.42 ± 3.06 µg/mL in AChE and IC50 = 62.00 ± 3.22 µg/mL in BChE. The docking experiments showed that among the seven major identified compounds, N-acetyl-17-oroidine showed the highest binding score (63.01 in AChE and 63.68 in BChE). This compound was found to bind the catalytic and peripheral sites, resulting in more potent inhibitory activity than galantamine, which only binds to the catalytic site. These findings suggested the possible use of M. piperita essential oil and nonpolar extracts as a potential source of alternative natural anti-Alzheimer compounds.

Physical and Chemical Barriers in Root Tissues Contribute to Quantitative Resistance to Fusarium oxysporum f. sp. pisi in Pea.

Fusarium wilt caused by Fusarium oxysporum f. sp. pisi (Fop) is one of the most destructive diseases of pea worldwide. Control of this disease is difficult and it is mainly based on the use of resistant cultivars. While monogenic resistance has been successfully used in the field, it is at risk of breakdown by the constant evolution of the pathogen. New sources of quantitative resistance have been recently identified from a wild relative Pisum spp. collection. Here, we characterize histologically the resistance mechanisms occurring in these sources of quantitative resistance. Detailed comparison, of the reaction at cellular level, of eight pea accessions with differential responses to Fop race 2, showed that resistant accessions established several barriers at the epidermis, exodermis, cortex, endodermis and vascular stele efficiently impeding fungal progression. The main components of these different barriers were carbohydrates and phenolic compounds including lignin. We found that these barriers were mainly based on three defense mechanisms including cell wall strengthening, formation of papilla-like structures at penetration sites and accumulation of different substances within and between cells. These defense reactions varied in intensity and localization between resistant accessions. Our results also clarify some steps of the infection process of F. oxysporum in plant and support the important role of cell wall-degrading enzymes in F. oxysporum pathogenicity.

Understanding pea resistance mechanisms in response to Fusarium oxysporum through proteomic analysis.

Fusarium oxysporum f. sp. pisi (Fop) is an important and destructive pathogen affecting pea crop (Pisum sativum) throughout the world. Control of this disease is achieved mainly by integration of different disease management procedures. However, the constant evolution of the pathogen drives the necessity to broaden the molecular basis of resistance to Fop. Our proteomic study was performed on pea with the aim of identifying proteins involved in different resistance mechanisms operating during F. oxysporum infection. For such purpose, we used a two-dimensional electrophoresis (2-DE) coupled to mass spectrometry (MALDI-TOF/TOF) analysis to study the root proteome of three pea genotypes showing different resistance response to Fop race 2. Multivariate statistical analysis identified 132 differential protein spots under the experimental conditions (genotypes/treatments). All of these protein spots were subjected to mass spectrometry analysis to deduce their possible functions. A total of 53 proteins were identified using a combination of peptide mass fingerprinting (PMF) and MSMS fragmentation. The following main functional categories were assigned to the identified proteins: carbohydrate and energy metabolism, nucleotides and aminoacid metabolism, signal transduction and cellular process, folding and degradation, redox and homeostasis, defense, biosynthetic process and transcription/translation. Results obtained in this work suggest that the most susceptible genotypes have increased levels of enzymes involved in the production of reducing power which could then be used as cofactor for enzymes of the redox reactions. This is in concordance with the fact that a ROS burst occurred in the same genotypes, as well as an increase of PR proteins. Conversely, in the resistant genotype proteins responsible to induce changes in the membrane and cell wall composition related to reinforcement were identified. Results are discussed in terms of the differential response to Fop.

Identification of the main toxins isolated from Fusarium oxysporum f. sp. pisi race 2 and their relation with isolates' pathogenicity.

Fusarium oxysporum f. sp. pisi (Fop) is a pathogen of field pea inducing severe vascular wilt worldwide. Plant resistance to races 1, 5, and 6, producing wilt symptoms, is conferred by a single dominant gene, while resistance to race 2, which gives near-wilt symptoms, have been recently showed to be quantitative. Among the virulence factors reported to play a role in the infection process, toxin production is one of the best studied. Thus, five race 2 isolates have been investigated for toxin production in vitro and their relation to isolates' pathogenicity. All the isolates produced different amounts of fusaric and 9,10-dehydrofusaric acids. The content of the two toxins has been quantitated and correlated with the pathogenicity and aggressiveness of isolates on field pea. Results suggested that toxin production is an important determinant of Fop race 2 pathogenicity.