Methyl jasmonate ameliorates pain-induced learning and memory impairments through regulating the expression of genes involved in neuroinflammation.

OBJECTIVE: Orofacial pain with high prevalence is one of the substantial human health issues. The importance of this matter became more apparent when it was revealed that orofacial pain, directly and indirectly, affects cognition performances. Currently, researchers have focused on investigating pharmaceutics to alleviate pain and ameliorate its subsequent cognitive impairments. DESIGN: In this study, the rats were first treated with the central administration of methyl jasmonate (MeJA), which is an antioxidant and anti-inflammatory bio-compound. After 20 min, orofacial pain was induced in the rats by the injection of capsaicin in their dental pulp. Subsequently, the animals' pain behaviors were analyzed, and the effects of pain and MeJA treatments on rats learning and memory were evaluated/compared using the Morris water maze (MWM) test. In addition, the expression of tumor necrosis factor-α (TNF-α), IL-1ß, BDNF, and COX-2 genes in the rats' hippocampus was evaluated using real-time polymerase chain reaction. RESULTS: Experiencing orofacial pain resulted in a significant decline in the rats learning and memory. However, the central administration of 20 µg/rat of MeJA effectively mitigated these impairments. In the MWM, the performance of the MeJA-treated rats showed a two- to threefold improvement compared to the nontreated ones. Moreover, in the hippocampus of pain-induced rats, the expression of pro-inflammatory factors TNF-α, IL-1ß, and COX-2 significantly increased, whereas the BDNF expression decreased. In contrast, MeJA downregulated the pro-inflammatory factors and upregulated the BDNF by more than 50%. CONCLUSIONS: These findings highlight the notable antinociceptive potential of MeJA and its ability to inhibit pain-induced learning and memory dysfunction through its anti-inflammatory effect.

Asymbiotic mass production of the arbuscular mycorrhizal fungus Rhizophagus clarus.

Arbuscular mycorrhizal (AM) symbiosis is a mutually beneficial interaction between fungi and land plants and promotes global phosphate cycling in terrestrial ecosystems. AM fungi are recognised as obligate symbionts that require root colonisation to complete a life cycle involving the production of propagules, asexual spores. Recently, it has been shown that Rhizophagus irregularis can produce infection-competent secondary spores asymbiotically by adding a fatty acid, palmitoleic acid. Furthermore, asymbiotic growth can be supported using myristate as a carbon and energy source for their asymbiotic growth to increase fungal biomass. However, the spore production and the ability of these spores to colonise host roots were still limited compared to the co-culture of the fungus with plant roots. Here we show that a combination of two plant hormones, strigolactone and jasmonate, induces the production of a large number of infection-competent spores in asymbiotic cultures of Rhizophagus clarus HR1 in the presence of myristate and organic nitrogen. Inoculation of asymbiotically-generated spores promoted the growth of host plants, as observed for spores produced by symbiotic culture system. Our findings provide a foundation for the elucidation of hormonal control of the fungal life cycle and the development of inoculum production schemes.

The effect of autocrine motility factor alone and in combination with methyl jasmonate on liver cancer cell growth.

Neoplastic cells secrete autocrine motility factor (AMF) to stimulate the motility of cancer cells. In this study, AMF secreted from HT-29 colorectal cancer cells selectively suppressed liver cancer cells by downregulating pAKT and ß-catenin. In addition, HT-29 AMF significantly augmented the activity of methyl jasmonate against liver cancer cells and is a promising alternative for liver cancer therapy.

Synergistic effects of autocrine motility factor and methyl jasmonate on human breast cancer cells.

Autocrine motility factor (AMF) stimulates the motility of cancer cells via an autocrine route and has been implicated in tumor progression and metastasis. Overexpression of AMF is correlated with the aggressive nature of breast cancer and is negatively associated with clinical outcomes. In contrast, AMF also has the ability to suppress cancer cells. In this study, AMFs from different cancer cells were demonstrated to have suppressive activity against MCF-7 and MDA-MB-231 breast cancer cells. In a growth and colony formation assay, AMF from AsPC-1 pancreatic cancer cells (ASPC-1:AMF) was determined to be more suppressive compared to other AMFs. It was also demonstrated that AsPC-1:AMF could arrest breast cancer cells at the G0/G1 cell cycle phase. Quantified by Western blot analysis, AsPC-1:AMF lowered levels of the AMF receptor (AMFR) and G-protein-coupled estrogen receptor (GPER), concomitantly regulating the activation of the AKT and ERK signaling pathways. JAK/STAT activation was also decreased. These results were found in estrogen receptor (ER)-positive MCF-7 cells but not in triple-negative MDA-MB-231 cells, suggesting that AsPC-1:AMF could work through multiple pathways led to apoptosis. More importantly, AsPC-1:AMF and methyl jasmonate (MJ) cooperatively and synergistically acted against breast cancer cells. Thus, AMF alone or along with MJ may be a promising breast cancer treatment option.

Molecular Pathways Linking Oxylipins to Nociception in Rats.

Oxylipins are lipid peroxidation products that participate in nociceptive, inflammatory, and vascular responses to injury. Effects of oxylipins depend on tissue-specific differences in accumulation of precursor polyunsaturated fatty acids and the expression of specific enzymes to transform the precursors. The study of oxylipins in nociception has presented technical challenges leading to critical knowledge gaps in the way these molecules operate in nociception. We applied a systems-based approach to characterize oxylipin precursor fatty acids, and expression of genes coding for proteins involved in biosynthesis, transport, signaling and inactivation of pro- and antinociceptive oxylipins in pain circuit tissues. We further linked these pathways to nociception by demonstrating intraplantar carrageenan injection induced gene expression changes in oxylipin biosynthetic pathways. We determined functional-biochemical relevance of the proposed pathways in rat hind paw and dorsal spinal cord by measuring basal and stimulated levels of oxylipins throughout the time-course of carrageenan-induced inflammation. Finally, when oxylipins were administered by intradermal injection we observed modulation of nociceptive thermal hypersensitivity, providing a functional-behavioral link between oxylipins, their molecular biosynthetic pathways, and involvement in pain and nociception. Together, these findings advance our understanding of molecular lipidomic systems linking oxylipins and their precursors to nociceptive and inflammatory signaling pathways in rats. PERSPECTIVE: We applied a systems approach to characterize molecular pathways linking precursor lipids and oxylipins to nociceptive signaling. This systematic, quantitative evaluation of the molecular pathways linking oxylipins to nociception provides a framework for future basic and clinical research investigating the role of oxylipins in pain.

Methyljasmonate and salicylic acid contribute to the control of Tilletia controversa Kühn, causal agent of wheat dwarf bunt.

Tilletia controversa Kühn (TCK) is the causal agent of dwarf bunt of wheat, a destructive disease in wheat-growing regions of the world. The role of Meja, SA and Meja + SA were characterized for their control of TCK into roots, coleoptiles and anthers. The response of the defence genes PR-10a, Catalase, COI1-1, COII-2 and HRin1 was upregulated by Meja, SA and Meja + SA treatments, but Meja induced high level of expression compared to SA and Meja + SA at 1, 2, and 3 weeks in roots and coleoptiles, respectively. The severity of TCK effects in roots was greater at 1 week, but it decreased at 2 weeks in all treatments. We also investigated TCK hyphae proliferation into coleoptiles at 3 weeks and into anthers to determine whether hyphae move from the roots to the upper parts of the plants. The results showed that no hyphae were present in the coleoptiles and anthers of Meja-, SA- and Meja + SA-treated plants, while the hyphae were located on epidermal and sub-epidermal cells of anthers. In addition, the severity of hyphae increased with the passage of time as anthers matured. Bunted seeds were observed in the non-treated inoculated plants, while no disease symptoms were observed in the resistance of inducer treatments and control plants. Plant height was reduced after TCK infection compared to that of the treated inoculated and non-inoculated treatments. Together, these results suggested that Meja and SA display a distinct role in activation of defence genes in the roots and coleoptiles and that they eliminate the fungal pathogen movement to upper parts of the plants with the passage of time as the anthers mature.

Role of purinergic signaling pathways in the adaptogenic-like activity of methyl jasmonate in rats exposed to unpredictable chronic mild stress.

Objectives Purinergic signaling pathway has been implicated in maladaptation of animals subjected to chronic stress. Previous studies have shown that methyl jasmonate (MJ) exhibited adaptogenic properties in mice exposed to unpredictable chronic mild stress (UCMS) via antioxidant and neuroprotective-related mechanisms. Methods This study evaluated the role of purinergic system in adaptogenic-like activity of MJ. Male Wistar rats were treated intraperitoneally with vehicle (10 mL/kg) or MJ (25, 50, or 100 mg/kg) 30 min prior exposure to UCMS. Thereafter, rats were assessed for swimming endurance in forced swim test (FST) and post-swimming motor coordination on beam walk test (BWT) apparatus. The rats' brains were processed for adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine deaminase, and arginase quantification. Hematological parameters, cholesterol, triglyceride, creatinine, and urea nitrogen were also determined. Results MJ prolonged swimming endurance time and reversed stress-induced post-swimming motor dysfunction. The altered hematological parameters induced by UCMS in rats were significantly (p<0.05) attenuated by MJ. MJ also reversed UCMS-induced alterations of total cholesterol, triglyceride, creatinine, and urea nitrogen levels. MJ averted UCMS-induced alterations in purinergic system by decreasing ATP and ADP hydrolysis, adenosine deaminase, and arginase activities in rats' brains. Conclusions Overall, these findings further suggest that MJ has adaptogenic-like activity in rats exposed to UCMS, which may be related to modulation of the purinergic signaling pathway.

Enhanced bioactive compound production in broccoli cells due to coronatine and methyl jasmonate is linked to antioxidative metabolism.

Elicited broccoli suspension-cultured cells (SCC) provide a useful system for obtaining bioactive compounds, including glucosinolates (GS) and phenolic compounds (PCs). In this work, coronatine (Cor) and methyl jasmonate (MJ) were used to increase the bioactive compound production in broccoli SCC. Although the use of Cor and MJ in secondary metabolite production has already been described, information concerning how elicitors affect cell metabolism is scarce. It has been suggested that Cor and MJ trigger defence reactions affecting the antioxidative metabolism. In the current study, the concentration of 0.5 µM Cor was the most effective treatment for increasing both the total antioxidant capacity (measured as ferulic acid equivalents) and glucosinolate content in broccoli SCC. The elicited broccoli SCC also showed higher polyphenol oxidase activity than the control cells. Elicitation altered the antioxidative metabolism of broccoli SCC, which displayed biochemical changes in antioxidant enzymes, a decrease in the glutathione redox state and an increase in lipid peroxidation levels. Furthermore, we studied the effect of elicitation on the protein profile and observed an induction of defence-related proteins. All of these findings suggest that elicitation not only increases bioactive compound production, but it also leads to mild oxidative stress in broccoli SCC that could be an important factor triggering the production of these compounds.

Oxylipins in triglyceride-rich lipoproteins of dyslipidemic subjects promote endothelial inflammation following a high fat meal.

Elevated triglyceride-rich lipoproteins (TGRL) in circulation is a risk factor for atherosclerosis. TGRL from subjects consuming a high saturated fat test meal elicited a variable inflammatory response in TNFα-stimulated endothelial cells (EC) that correlated strongly with the polyunsaturated fatty acid (PUFA) content. This study investigates how the relative abundance of oxygenated metabolites of PUFA, oxylipins, is altered in TGRL postprandially, and how these changes promote endothelial inflammation. Human aortic EC were stimulated with TNFα and treated with TGRL, isolated from subjects' plasma at fasting and 3.5 hrs postprandial to a test meal high in saturated fat. Endothelial VCAM-1 surface expression stimulated by TNFα provided a readout for atherogenic inflammation. Concentrations of esterified and non-esterified fatty acids and oxylipins in TGRL were quantified by mass spectrometry. Dyslipidemic subjects produced TGRL that increased endothelial VCAM-1 expression by ≥35%, and exhibited impaired fasting lipogenesis activity and a shift in soluble epoxide hydrolase and lipoxygenase activity. Pro-atherogenic TGRL were enriched in eicosapentaenoic acid metabolites and depleted in esterified C18-PUFA-derived diols. Abundance of these metabolites was strongly predictive of VCAM-1 expression. We conclude the altered metabolism in dyslipidemic subjects produces TGRL with a unique oxylipin signature that promotes a pro-atherogenic endothelial phenotype.

Comparative effect of elicitors on the physiology and secondary metabolites in broccoli plants.

Elicitation is an economic and sustainable technique for increasing the content of secondary metabolites, mainly bioactive compounds, in plants grown for better human nutrition. The aim of this study was to compare the physiological responses (water relations and mineral nutrition) and the enrichment in glucosinolates (GLSs) and phenolic compounds of broccoli plants (Brassica oleracea L. var. italica) receiving different elicitation treatments. The treatments involved the priming of seeds with KCl and the exposure of plants to elicitors, including K2SO4 and NaCl solutions and foliar sprays of methyl jasmonate (MeJA), salicylic acid (SA), and methionine (Met). The physiological response of the plants in terms of root hydraulic conductance was improved by priming with KCl and elicitation with MeJA or Met. Foliar application of Met significantly increased the plant biomass and enhanced mineral nutrition. In general, all treatments increased the accumulation of indole GLSs, but K2SO4 and MeJA gave the best response and MeJA also favored the formation of a newly described compound, cinnamic-GLS, in the plants. Also, the use of Met and SA as elicitors and the supply of K2SO4 increased the abundance of phenolic compounds; K2SO4 also enhanced growth but did not alter the water relations or the accumulation of mineral nutrients. Therefore, although the response to elicitation was positive, with an increased content of bioactive compounds, regulation of the water relations and of the mineral status of the broccoli plants was critical to maintain the yield.

Comparative analysis of B-BOX genes and their expression pattern analysis under various treatments in Dendrobium officinale.

BACKGROUND: Studies have demonstrated that BBX (B-BOX) genes play crucial roles in regulatory networks controlling plant growth, developmental processes and stress response. Nevertheless, comprehensive study of BBX genes in orchids (Orchidaceae) is not well studied. The newly released genome sequences of Dendrobium officinale and Phalaenopsis equestris have allowed a systematic analysis of these important BBX genes in orchids. RESULTS: Here we identified 19 (DoBBX01-19) and 16 (PeBBX01-16) BBX genes from D. officinale and P. equestris, respectively, and clustered into five clades (I-V) according to phylogenetic analysis. Thirteen orthologous, two DoBBXs paralogous and two PeBBXs paralogous gene pairs were validated. This gene family mainly underwent purifying selection, but five domains experienced positive selection during evolution. Noteworthy, the expression patterns of root, root_tips, stem, leaf, speal, column, lip, and flower_buds revealed that they might contribution to the formation of these tissues. According to the cis-regulatory elements analysis of BBX genes, qRT-PCR experiments were carried out using D. officinale PLBs (protocorm-like bodies) and displayed that these BBX genes were differentially regulated under AgNO3, MeJA (Methyl Jasmonate), ABA (abscisic acid) and SA (salicylic acid) treatments. CONCLUSIONS: Our analysis exposed that DoBBX genes play significant roles in plant growth and development, and response to different environmental stress conditions of D. officinale, which provide aid in the selection of appropriate candidate genes for further functional characterization of BBX genes in plants.

Methyl jasmonate-induced compositional changes of volatile organic compounds in Polygonum minus leaves.

Polygonum minus Huds. is a medicinal aromatic plant rich in terpenes, aldehydes, and phenolic compounds. Methyl jasmonate (MeJA) is a plant signaling molecule commonly applied to elicit stress responses to produce plant secondary metabolites. In this study, the effects of exogenous MeJA treatment on the composition of volatile organic compounds (VOCs) in P. minus leaves were investigated by using a metabolomic approach. Time-course changes in the leaf composition of VOCs on days 1, 3, and 5 after MeJA treatment were analyzed through solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). The VOCs found in MeJA-elicited leaves were similar to those found in mock-treated leaves but varied in quantity at different time points. We focused our analysis on the content and composition of monoterpenes, sesquiterpenes, and green leaf volatiles (GLVs) within the leaf samples. Our results suggest that MeJA enhances the activity of biosynthetic pathways for aldehydes and terpenes in P. minus. Hence, the production of aromatic compounds in this medicinal herb can be increased by MeJA elicitation. Furthermore, the relationship between MeJA elicitation and terpene biosynthesis in P. minus was shown through SPME-GC-MS analysis of VOCs combined with transcriptomic analysis of MeJA-elicited P. minus leaves from our previous study.

Pre-harvest methyl jasmonate treatments increase antioxidant systems in lemon fruit without affecting yield or other fruit quality parameters.

BACKGROUND: Jasmonic acid (JA) and its volatile derivative methyl jasmonate (MeJA) are hormones involved in the regulation of many processes in plants and act (when applied as a post- or pre-harvest treatment) to increase fruit bioactive compounds with antioxidant potential. However, there is no literature available regarding the effect of pre-harvest MeJA treatment on lemon fruit antioxidant systems, which was the aim of the present study. RESULTS: MeJA treatment (0.1, 0.5 and 1.0 mmol L-1 ) increased antioxidant compounds, such as phenolics, in the juice and flavedo of 'Fino' and 'Verna' lemons at harvest, with the most effective concentration being 0.1 mmol L-1 in both cultivars. In addition, catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities were also increased by MeJA treatment, with the highest increases being also found with 0.1 mmol L-1 . The increases in APX and CAT were maintained from one treatment to another during fruit development on the tree, whereas the increase on POD disappeared after 8-10 days of each treatment. For both antioxidant systems, the highest increases were found in lemon harvested at the commercial ripening stage. By contrast, crop yield, fruit ripening process and quality parameters were generally not affected by MeJA treatment. CONCLUSION: Preharvest MeJA treatment could be a useful tool for increasing antioxidant potential and the health beneficial effects of lemon fruit consumption, given the relationship between these properties and phenolic content. Moreover, the increased concentration of phenolics and the activity of antioxidant enzymes in the flavedo of MeJA treated fruit could increase lemon tolerance to chilling injury and decay during postharvest storage. © 2019 Society of Chemical Industry.

Effect of methyl jasmonate (MeJA)-induced defenses in rice against the rice leaffolder Cnaphalocrocis medinalis (Guenèe) (Lepidoptera: Pyralidae).

BACKGROUND: Methyl jasmonate (MeJA) activates host defense mechanisms against insect pests of agricultural importance, and regulates defense responses against living and non-living stresses in various plant species. Rice leaf-folder (Cnaphalocrocis medinalis Guenèe, Lepidoptera: Pyralidae) feeding activity and mortality were evaluated after MeJA treatment of rice plants ASD-16. RESULTS: Rice plant resistance was activated through the topical application of MeJA to rice leaves. Feeding deterrence occurred with application of 2.5 and 5 mm MeJA solution. Feeding activity and consumption rates were significantly different, being reduced compared with controls post MeJA treatment. Significantly greater mortality was seen in second instars post treatment with 2.5 and 5 mm MeJA. Survival was significantly reduced for larvae and adults post treatment. CONCLUSION: Application of MeJA as a topical spray onto rice plants significantly altered the biology and survival of the leaf-folder, having an effect on all life stages. © 2018 Society of Chemical Industry.

Effect of jasmonic acid and yeast extract elicitation on low-molecular antioxidants and antioxidant activity of marjoram (Origanum majorana L.).

BACKGROUND: Elicitation, which is a way of inducing plant secondary metabolism, may be an effective method for improving the quality of plant food. The aim of this study was to determine how the application of jasmonic acid (as an abiotic elicitor) and yeast extract (as a biotic elicitor) influences the production of some bioactive compounds in marjoram and the antioxidant activity of this herb. METHODS: Elicitation with 0.01 µM and 1 µM jasmonic acid as well as 0.1% and 1% yeast extracts was used for improving the health-benefiting quality of marjoram. The study focused on the effects of eliciting the level of some phytochemicals and the antioxidant activity of marjoram. RESULTS: There were no significant differences in total phenolic content between the elicited and control plants. In turn, the elicitation with 0.1% and 1% yeast extracts caused 1.8- and 2.5-fold increases in the ascorbic acid content in marjoram leaves, respectively. Both biotic and abiotic elicitation resulted in elevation of chlorophyll content, but only the abiotic elicitor (jasmonic acid) caused a significant increase (by over 50%) in the carotenoid content of marjoram leaves. The antiradical activity of marjoram was increased by the abiotic and biotic elicitation, whereas only the abiotic elicitation resulted in improving the reducing power of this herb. CONCLUSIONS: In conclusion, biotic and abiotic elicitation could be an effective strategy for improving the level of some phytochemicals, as well as the antioxidant activity of marjoram. A particularly valuable finding obtained in this study is that natural elicitors e.g. yeast extract can be equally effective in elevating the content of some bioactive compounds in herbs e.g. marjoram as an abiotic one.

Molecular cloning and expression analysis of two key genes, HDS and HDR, in the MEP pathway in Pyropia haitanensis.

The 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate synthase (HDS) gene and the 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate reductase (HDR) gene are two important genes in the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. In this study, we reported the isolation and characterization of full-length HDS (MF101802) and HDR (MF159558) from Pyropia haitanensis. Characteristics of 3-D structures of the PhHDS and PhHDR proteins were analysed respectively. The results showed that the full-length cDNA of PhHDS, which is 1801 bp long, contained a 1455 bp open reading frame (ORF) encoding a putative 484 amino acid residue protein with a predicted molecular mass of 51.60 kDa. Meanwhile, the full-length cDNA of PhHDR was 1668 bp and contained a 1434 bp ORF encoding a putative 477 amino acid 2 residue protein with a predicted molecular mass of 51.49 kDa. The expression levels of the two genes were higher in conchocelis than that in leafy thallus. Additionally, the expression levels could be influenced by light, temperature and salinity and induced by methyl jasmonate (MJ) and salicylic acid (SA). This study contributed to our in-depth understanding of the roles of PhHDS and PhHDR in terpenoid biosynthesis in Pyropia haitanensis and the regulation of the two genes by external environments.

Methyl jasmonate-induced emission of biogenic volatiles is biphasic in cucumber: a high-resolution analysis of dose dependence.

Methyl jasmonate (MeJA) is a key airborne elicitor activating jasmonate-dependent signaling pathways, including induction of stress-related volatile emissions, but how the magnitude and timing of these emissions scale with MeJA dose is not known. Treatments with exogenous MeJA concentrations ranging from mild (0.2 mM) to lethal (50 mM) were used to investigate quantitative relationships among MeJA dose and the kinetics and magnitude of volatile release in Cucumis sativus by combining high-resolution measurements with a proton-transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) and GC-MS. The results highlighted biphasic kinetics of elicitation of volatiles. The early phase, peaking in 0.1-1 h after the MeJA treatment, was characterized by emissions of lipoxygenase (LOX) pathway volatiles and methanol. In the subsequent phase, starting in 6-12 h and reaching a maximum in 15-25 h after the treatment, secondary emissions of LOX compounds as well as emissions of monoterpenes and sesquiterpenes were elicited. For both phases, the maximum emission rates and total integrated emissions increased with applied MeJA concentration. Furthermore, the rates of induction and decay, and the duration of emission bursts were positively, and the timing of emission maxima were negatively associated with MeJA dose for LOX compounds and terpenoids, except for the duration of the first LOX burst. These results demonstrate major effects of MeJA dose on the kinetics and magnitude of volatile response, underscoring the importance of biotic stress severity in deciphering the downstream events of biological impacts.

Methyl Jasmonate Ameliorates Unpredictable Chronic Mild Stress-Induced Behavioral and Biochemical Alterations in Mouse Brain.

Preclinical Research The effects of methyl jasmonate (MJ; 5, 10, 20 mg/kg, i.p), a natural product widely used for the relief of stress, depression, and exhaustion on unpredictable chronic mild stress (UCMS)-induced depression-like behaviors in mice was assessed and compared to those of imipramine (IMP; 10 mg/kg, i.p). MJ and IMP were given 30 min before exposure to UCMS with the procedure repeated daily for 2 weeks; 24 h after the stress session, the tail suspension test (TST) and sucrose preference test were assessed. MJ decreased immobility time in the TST and reversed impaired intake of sucrose relative to the stressed control suggesting antidepressant-like activity. MJ also reduced UCMS-induced increases in corticosterone and MDA (malondialdehyde) levels and attenuated UCMS-induced decreases in GSH and TNF-α levels and SOD activity. These findings suggest that MJ attenuated UCMS-induced depressive-like behaviors through decreased levels of corticosterone and decreasing oxidative stress and neuroinflammation in mouse brain.Drug Dev Res 78 : 381-389, 2017. © 2017 Wiley Periodicals, Inc.

Effects of changes in leaf properties mediated by methyl jasmonate (MeJA) on foliar absorption of Zn, Mn and Fe.

Background and Aims: Foliar fertilization to overcome nutritional deficiencies is becoming increasingly widespread. However, the processes of foliar nutrient absorption and translocation are poorly understood. The present study aimed to investigate how cuticular leaf properties affect the absorption of foliar-applied nutrients in leaf tissues. Methods: Given that methyl jasmonate (MeJA) can cause alterations in leaf properties, we applied 1 mm MeJA to sunflower (Helianthus annuus), tomato (Solanum lycopersicum) and soybean (Glycine max) to assess changes in leaf properties. Using traditionally analytical approaches and synchrotron-based X-ray fluorescence microscopy, the effects of these changes on the absorption and translocation of foliar-applied Zn, Mn and Fe were examined. Key Results: The changes in leaf properties caused by the application of MeJA increased foliar absorption of Zn, Mn and Fe up to 3- to 5-fold in sunflower but decreased it by 0·5- to 0·9-fold in tomato, with no effect in soybean. These changes in the foliar absorption of nutrients could not be explained by changes in overall trichome density, which increased in both sunflower (86%) and tomato (76%) (with no change in soybean). Similarly, the changes could be not attributed to changes in stomatal density or cuticle composition, given that these properties remained constant. Rather, the changes in the foliar absorption of Zn, Mn and Fe were related to the thickness of the cuticle and epidermal cell wall. Finally, the subsequent translocation of the absorbed nutrients within the leaf tissues was limited (<1·3mm) irrespective of treatment. Conclusions: The present study highlights the potential importance of the combined thickness of the cuticle and epidermal cell wall in the absorption of foliar-applied nutrients. This information will assist in increasing the efficacy of foliar fertilization.

Probable mechanisms involved in the antipsychotic-like activity of methyl jasmonate in mice.

Psychosis is a chronic neuropsychiatric disorder that affects millions of individuals worldwide and impairs the quality of life and productivity of the patients. The clinical efficacy of antipsychotic drugs has been compromised by adverse effects, relapse, and therapeutic failures, thus necessitating search for alternative agents. Methyl jasmonate (MJ) is a bioactive compound reported to have beneficial effects in various neurological disorders. This study was undertaken to investigate the antipsychotic-like effects of MJ in mice. Male Swiss mice were pretreated intraperitoneally with MJ (25-100 mg/kg) or vehicle (10 mL/kg) 60 min prior to bromocriptine (5 mg/kg) or acute injection of ketamine (10 mg/kg). Thereafter, each mouse was observed for stereotype behaviors for 2 min at 10, 15, 20, 30, and 45 min post-bromocriptine injection. Another set of mice received MJ (25-100 mg/kg) or vehicle (10 mL/kg) 60 min after chronic ketamine injection (20 mg/kg, i.p) once daily for 14 consecutive days. Afterwards, locomotor activity and memory function in this sequence were evaluated using open field and Y-maze tests. The levels of malondialdehyde (MDA) and glutathione (GSH) and activity of catalase and superoxide dismutase (SOD) in the brain were determined. MJ significantly inhibited stereotypy behavior induced by bromocriptine or acute ketamine injection, which suggest antipsychotic-like activity. It also attenuated hyper-locomotion and memory deficits induced by chronic injection of ketamine in mice. The increased oxidative stress as shown by the altered brain levels of MDA, GSH, and activity of antioxidant enzymes induced by chronic injection of ketamine was reduced by MJ. Taken together, these findings suggest that MJ demonstrated antipsychotic-like property via mechanism related to its antioxidant property and interference with dopaminergic neurotransmission.