Zhang J et al. (2021) Food Funct "The dopaminergic neuroprotective effects of different phytosterols identified in rice bran and rice bran oil."

Zhang J, Zhang L, Liu R, Chang M, Wang X, Wu Z, Zhang P

[Food Funct, 2021]

Phytosterols are important bioactive compounds in rice bran and rice bran oil, and the compositions of different phytosterols in rice bran and rice bran oil were investigated in our previous research. In this study, the dopaminergic neuroprotective effects and the underlying mechanisms of sitosterol, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate and campesteryl ferulate identified in rice bran and rice bran oil were investigated in a rotenone-treated <i>C. elegans</i> model. The results indicated that the increased oxidative stress resistance induced by the activation of the DAF-16/FOXO pathway and the inhibition of the apoptotic protein CED-3 overexpression might play an important role in protecting the dopaminergic neurons. The results of this research reveal a new bioactivity of different phytosterols and are helpful for the further nutritional evaluation of rice bran and rice bran oil.

Sugawara T et al. (2019) Biosci Biotechnol Biochem "Fermented product of rice with Lactobacillus kefiranofaciens induces anti-aging effects and heat stress tolerance in nematodes via DAF-16."

Abe M, Furuhashi T, Arai M, Kikuchi K, Sugawara T, Sakamoto K, Shibata K

[Biosci Biotechnol Biochem, 2019]

Rice kefiran is superior in functionality, has high concentration of mucilaginous polysaccharide, and low lipid content, compared to conventional kefiran. However, reports on its physiological functionality, especially studies on life expectancy and aging, in model organisms are rare. In this study, nematodes were used as model organisms that were fed rice kefiran, along with Escherichia coli OP50, as a result of which, the lifespan of nematodes was extended and age-related retardation of mobility was suppressed. It also increased the heat stress resistance in nematodes. Experiments using daf-16 deletion mutant revealed that rice kefiran functions via DAF-16. Thus, this study revealed the longevity, anti-aging and heat stress tolerance effects of rice kefiran in nematodes.

Chakrabarti S et al. (2015) Environ Sci Pollut Res Int "Rice husks and their hydrochars cause unexpected stress response in the nematode Caenorhabditis elegans: reduced transcription of stress-related genes."

Chakrabarti S, Kern J, Dicke C, Kalderis D

[Environ Sci Pollut Res Int, 2015]

Currently, char substrates gain a lot of interest since soils amended with such substrates are being discussed to increase in fertility and productivity, water retention, and mitigation of greenhouse gases. Char substrates can be produced by carbonization of organic matter. Among different process conditions, temperature is the main factor controlling the occurrence of organic and inorganic contaminants such as phenols and furfurals, which may affect target and non-target organisms. The hydrochar produced at 200 C contained both furfural and phenol with concentrations of 282 and 324 mg kg(-1) in contrast to the 300 C hydrochar, which contained only phenol with a concentration of 666 mg kg(-1). By washing with acetone and water, these concentrations were significantly reduced. In this study, the potential toxic effects of hydrochars on the free-living nematode Caenorhabditis elegans were investigated via gene transcription studies using the following four matrices: (i) raw rice husk, (ii) unwashed rice char, (iii) acetone/water washed rice char, and (iv) the wash water of the two rice chars produced at 200 and 300 C via hydrothermal carbonization (HTC). Furthermore, genetically modified strains, where the green fluorescent protein (GFP) gene sequence is linked to a reporter gene central in specific anti-stress regulations, were also exposed to these matrices. Transgenic worms exposed to hydrochars showed very weak, if any, fluorescence, and expression of the associated RNAs related to stress response and biotransformation genes was surprisingly downregulated. Similar patterns were also found for the raw rice husk. It is hypothesized that an unidentified chemical trigger exists in the rice husk, which is not destroyed during the HTC process. Therefore, the use of GFP transgenic nematode strains cannot be recommended as a general rapid monitoring tool for farmers treating their fields with artificial char. However, it is hypothesized that the observed reduced transcriptional response with the subsequent lack of energy-consuming stress response is an energy-saving mechanism in the exposed nematodes. If this holds true in future studies, this finding opens the window to an innovative new field of stress ecology.

Li P et al. (2017) Pest Manag Sci "Novel bisthioether derivatives containing a 1,3,4-oxadiazole moiety: Design, synthesis, antibacterial and nematocidal activities."

Hu D, Tian P, Song B, Chen Y, Li P, Song X, Yang S, Jin L, Xue W

[Pest Manag Sci, 2017]

BACKGROUND: Literature revealed that bisthioether and 1,3,4-oxadiazole derivatives exhibited a wide variety of biological activities. In this study, a series of novel bisthioether derivatives containing a 1,3,4-oxadiazole moiety were synthesized and their antibacterial and nematocidal activities were investigated. RESULTS: Among the title compounds evaluated, compound 4f demonstrated the best antibacterial activities against rice bacterial leaf blight, rice bacterial leaf streak and citrus canker caused by Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas oryzae pv. oryzicola (Xoc), and Xanthomonas axonopodis pv. citri (Xac), respectively, with the EC50 values of 4.82, 11.15, and 16.57 g mL(-1) , respectively, which were even better than those of thiodiazole copper and bismerthiazol. Meanwhile, compound 4f revealed better in vitro nematocidal activity against Caenorhabditis elegans (C. elegans) at 48 h, with a LC50 value of 2.89 g mL(-1) , which was superior to those of ethoprophos and fosthiazate. In addition, the greenhouse trials indicated that compound 4f was effective in reducing rice bacterial leaf blight relative to those of thiodiazole copper and bismerthiazol. CONCLUSION: A series of novel bisthioether derivatives containing a 1,3,4-oxadiazole moiety were synthesized and bioassay results showed that compound 4f exhibited the best antibacterial and nematocidal activities.

Chatterjee N et al. (2014) Environ Toxicol "Toxic potentiality of bio-oils, from biomass pyrolysis, in cultured cells and Caenorhabditis elegans."

Chatterjee N, Eom HJ, Choi J, Jung SH, Kim JS

[Environ Toxicol, 2014]

Bio-oils, which are multicomponent mixtures, were produced from two different biomass (rice straw (rice oil) and sawdust of oak tree (oak oil)) by using the slow pyrolysis process, and chemical compositional screening with GC-MS detected several hazardous compounds in both bio-oil samples. The two bio-oils vary in their chemical compositional nature and concentrations. To know the actual hazard potentialities of these bio-oils, toxicological assessments were carried out in a comparative approach by using in vitro (Jurkat T and HepG2 cell) as well as in vivo (Caenorhabditis elegans) systems. A dose-dependent increase in cytotoxicity, cell death (apoptosis), and genotoxicity were observed in cultured cell systems. Similarly, the in vivo system, C. elegans also displayed a dose-dependent decrease in survival. It was found that in comparison with rice oil, oak oil displayed higher toxicity to all models systems, and the susceptibility order of the model systems were Jurkat T &gt; HepG2 &gt; C. elegans. Pursuing the study further toward the underlying mechanism by exploiting the C. elegans mutants screening assay, the bio-oils seem to mediate toxicity through oxidative stress and impairment of immunity. Taken together, bio-oils compositions mainly depend on the feedstock used and the pyrolysis conditions which in turn modulate their toxic potentiality.

Yang YH et al. (2019) Molecules "Griseaketides A-D, New Aromatic Polyketides from the Pathogenic Fungus Magnaporthe grisea."

Yang YH, Lei HM, Zhao PJ, Li GH, Yang DS, Li CY

[Molecules, 2019]

<i>Magnaporthe grisea</i> is the causal agent of rice blast disease, which is the most serious disease of cultivated rice. Aromatic polyketides are its typical metabolites and are involved in the infection process. In the search for novel lead compounds, chemical investigation of the fungus <i>M. grisea</i> M639 has led to the isolation of four new aromatic polyketides (salicylaldehyde skeleton bearing an unsaturated side chain), griseaketides A-D (<b>1</b>-<b>4</b>), as well as 15 known compounds (<b>5</b>-<b>19</b>). The structures of the new compounds were elucidated on the basis of extensive spectroscopic analyses, including HR-MS, 2D NMR. Compound <b>12</b> showed prominent activity that killed 94.5% of <i>C. elegans</i> at 400 ppm and 66.9% at 200 ppm over 24 h. This is the first report describing the nematicidal activity of this type aromatic polyketide.

Chen LQ et al. (2010) Nature "Sugar transporters for intercellular exchange and nutrition of pathogens."

Hou BH, Frommer WB, Takanaga H, Underwood W, Somerville SC, Kim JG, Hartung ML, Qu XQ, Lalonde S, White FF, Guo WJ, Antony G, Mudgett MB, Chaudhuri B, Chermak D, Chen LQ

[Nature, 2010]

Sugar efflux transporters are essential for the maintenance of animal blood glucose levels, plant nectar production, and plant seed and pollen development. Despite broad biological importance, the identity of sugar efflux transporters has remained elusive. Using optical glucose sensors, we identified a new class of sugar transporters, named SWEETs, and show that at least six out of seventeen Arabidopsis, two out of over twenty rice and two out of seven homologues in Caenorhabditis elegans, and the single copy human protein, mediate glucose transport. Arabidopsis SWEET8 is essential for pollen viability, and the rice homologues SWEET11 and SWEET14 are specifically exploited by bacterial pathogens for virulence by means of direct binding of a bacterial effector to the SWEET promoter. Bacterial symbionts and fungal and bacterial pathogens induce the expression of different SWEET genes, indicating that the sugar efflux function of SWEET transporters is probably targeted by pathogens and symbionts for nutritional gain. The metazoan homologues may be involved in sugar efflux from intestinal, liver, epididymis and mammary cells.

Palmieri JR et al. (1985) J Helminthol "The domestic cat as a host for Brugian filariasis in South Kalimantan (Borneo), Indonesia."

Darwis F, Palmieri JR, Tirtokusumo S, Masbar S, Marwoto HA

[J Helminthol, 1985]

Three hundred and twenty-five domestic cats (Felis catus) from six villages of the Hulu Sungai Tengah and Banjar Regency of South Kalimantan (Borneo), Indonesia, were examined for filarial nematodes. Parasites were found in 66 cats, of which 61 (92.4%) had Brugia pahangi, four (6.1%) has B. malayi and one (1.5%) had Dirofilaria repens. Infection rates ranged from 11% to 22% in cats from secondary forest/rice-field habitats, from 15% to 30% in open village/rice-field habitats, to 50% in an open coastal village. In all cases the infection rate of B. malayi in man was greater than in cats from the same collecting area. The number of B. pahangi microfilariae per 20 microliter cat blood ranged from 34 at 1000 hours to 571 at 2200 hours. The results of this study suggest that in this region of Indonesia the domestic cat is not an important host for maintaining B. malayi.

Li X et al. (2022) Comp Biochem Physiol C Toxicol Pharmacol "Black rice anthocyanin extract enhances the antioxidant capacity in PC12 cells and improves the lifespan by activating IIS pathway in Caenorhabditis elegans."

Li X, Wang X, Wang K, Liu X, Yang X, Wang H, Li J, Guo Q, Wang J, Chen J

[Comp Biochem Physiol C Toxicol Pharmacol, 2022]

Black rice is rich in anthocyanins, and the antioxidant effect of anthocyanins is recognized by consumers. The aim of this study was to identify the molecular mechanisms underlying the antioxidant activity of black rice anthocyanin extract (BRAE) in PC12 cells and C. elegans. Results showed that BRAE increased antioxidant enzyme activities and decreased the accumulation of reactive oxygen species (ROS) and malondialdehyde in PC12 cells induced by H₂O₂. Meanwhile, BRAE extended the lifespan, enhanced resistance to stress, increased antioxidant enzyme activities, and reduced lipofuscin, ROS, and MDA accumulation in wild-type C. elegans. The polyQ40 aggregation in AM141, paralysis in CL4176, and chemotaxis deficit in CL2355 were alleviated by BRAE administration. BRAE downregulated the mRNA expression of age-1 and daf-2, while upregulated the daf-16 mRNA level and SOD-3, CTL-1, and GST-4 protein expression. Mutational lifespan tests and molecular docking showed that insulin pathway might be involved in the mechanism of lifespan extension.

Steindler L et al. (2009) Appl Environ Microbiol "LasI/R and RhlI/R quorum sensing in a strain of Pseudomonas aeruginosa beneficial to plants."

Eberl L, Venturi V, Schwager S, Bertani I, Steindler L, De Sordi L

[Appl Environ Microbiol, 2009]

Pseudomonas aeruginosa possesses three quorum-sensing (QS) systems which are key in the expression of a large number of genes, including many virulence factors. Most studies of QS in P. aeruginosa have been performed in clinical isolates and have therefore focused on its role in pathogenicity. P. aeruginosa, however, is regarded as a ubiquitous organism capable of colonizing many different environments and also of establishing beneficial associations with plants. In this study we examined the role of the two N-acyl homoserine lactone systems known as RhlI/R and LasI/R in the environmental rice rhizosphere isolate P. aeruginosa PUPa3. Both the Rhl and Las systems are involved in the regulation of plant growth-promoting traits. The environmental P. aeruginosa PUPa3 is pathogenic in two nonmammalian infection models, and only the double las rhl mutants are attenuated for virulence. In fact it was established that the two QS systems are not hierarchically organized and that they are both important for the colonization of the rice rhizosphere. This is an in-depth genetic and molecular study of QS in an environmental P. aeruginosa strain and highlights several differences with QS regulation in the clinical isolate PAO1.