Phytoncide: Nature’s Antidote for Humanity

The fast pace of modem life brings great pressure, which lead to physical and mental health issues. Researches have demonstrated that forest bathing can considerably alleviate symptoms of depression and anxiety, eliminate negative emotions and promote mental wellbeing. We presented evidences of the positive impact of forest bathing on mental health in the context rapid urbanization and surging health needs in the post-pandemic era, and outlined the current insights into the related factors affecting the effect of forest bathing, as to provide directions for future interventions or research. The electronic databases PubMed, Cochrane Library, Embase, Web of Science Core Collections and the China Academic Journals (CAJ) offered through the Full-text Database (CNKI) were searched for relevant studies published from the inception of the databases to December 2024. The initial search strategy was performed using keywords, MeSH terms, and free text words such as "forest bathing", "forest medicine", "mental health pressure", "anxiety", "depression", "cortisol", etc. The synthesis of the findings in the included studies revealed that forest bathing interventions might improve mental and physical health, reduce blood pressure, improve sleep quality and boost immunity, as well as alleviate depression, anxiety, and stress. Furthermore, the effect of forest bathing on mental health indicators and the differences in these results among different populations varied. Forest environment, tree species, exposure duration, season, composition and concentration of volatile organic compounds have an impact on the effect of forest bathing. Forest bathing were effective in lowering cortisol levels, reducing sympathetic nerve activity, as well as improving negative mood, which could serve as a non-pharmacological treatment for mental health in the general population.

Identifying robust and reliable volatile organic compounds in human sebum for biomarker discovery

The role of place attachment in recreation experience and outcome preferences among forest bathers

Quantitative characterization of resident’ exposure to typical semi-volatile organic compounds (SVOCs) around a non-ferrous metal smelting plant

Plants have evolved diverse secondary metabolites to counteract biotic stress. Volatile organic compounds (VOCs) are released upon herbivore attack or pathogen infection. Recent studies suggest that VOCs can act as signalling molecules in plant defence and induce resistance in distant organs and neighbouring plants. However, knowledge is lacking on the function of VOCs in biotrophic fungal infection on cereal plants. We analysed VOCs emitted by 13 ± 1-day-old barley plants (Hordeum vulgare L.) after mechanical wounding using passive absorbers and TD-GC/MS. We investigated the effect of pure VOC and complex VOC mixtures released from wounded plants on the barley-powdery mildew interaction by pre-exposure in a dynamic headspace connected to a powdery mildew susceptibility assay. Untargeted metabolomics and lipidomics were applied to investigate metabolic changes in sender and receiver barley plants. Green leaf volatiles (GLVs) dominated the volatile profile of wounded barley plants, with (Z)-3-hexenyl acetate (Z3HAC) as the most abundant compound. Barley volatiles emitted after mechanical wounding enhanced resistance in receiver plants towards fungal infection. We found volatile-mediated modifications of the plant-pathogen interaction in a concentration-dependent manner. Pre-exposure with physiologically relevant concentrations of Z3HAC resulted in induced resistance, suggesting that this GLV is a key player in barley anti-pathogen defence. The complex VOC mixture released from wounded barley and Z3HAC induced e.g. accumulation of chlorophyll, linolenic acid and linolenate-conjugated lipids, as well as defence-related secondary metabolites, such as hordatines in receiving plants. Barley VOCs hence induce a complex physiological response and disease resistance in receiver plants.

Toluene downregulates filaggrin expression via the extracellular signal-regulated kinase and signal transducer and activator of transcription–dependent pathways

Three important groups of semi-volatile organic compounds (SVOCs), polycyclic aromatic hydrocarbons (PAHs), organic chlorinated pesticides (OCPs) and phthalate esters (PAEs), were produced by various human activities and entered the water body. In this study, the pollution profiles of three species including 16 PAHs, 20 OCPs and 15 PAEs in water along the Beijiang River, China were investigated. The concentrations of Σ16PAHs in the dissolved and particulate phases were obtained as 69-1.5×102 ng L-1 and 2.3×103-8.6×104 ngg-1, respectively. The levels of Σ20OCPs were 23-66ng L-1 (dissolved phase) and 19-1.7×103 ngg-1 (particulate phase). Nevertheless, higher levels of PAEs were found both in the dissolved and particulate phases due to abuse use of plastic products. Furthermore, non-cancer and cancer risks caused by these SVOCs through the ingestion absorption and dermal absorption were also assessed. There was no non-cancer risk existed through two kinds of exposure of them at current levels, whereas certain cancer risk existed through dermal absorption of PAHs in the particulate phase in some sampling sites. The results will show scientific insights into the evaluation of the status of combined pollution in river basins, and the determination of strategies for incident control and pollutant remediation.

The ever-growing spread of resistance in medicine and agriculture highlights the need to identify new antimicrobials. Microbial volatile organic compounds (VOCs) are one of the most promising groups of chemicals to meet this need. These rarely exploited molecules exhibit antimicrobial activity and their high vapour pressure makes them ideal for application in surface sterilisation, and in particular, in biofumigation. Therefore, we adapted the previously developed Two Clamp VOCs Assay (TCVA) to a new high-throughput screening for the detection of novel antifungal VOCs from metagenomic clone libraries. As a proof of concept, we tested the new high-throughput TCVA (htTCVA) by sourcing a moss metagenomic library against Fusarium culmorum. This led to the identification of five clones that inhibited the growth of mycelium and spores in vitro by up to 8% and 30% and subsequently, to the identification of VOCs that are potentially, and in part responsible for the clones’ antifungal activity. For these VOCs, the in vitro effect of the pure compounds was as high as 100%. These results demonstrate the robustness and feasibility of the htTCVA, which provides access to completely new and unexplored biosynthetic pathways and their secondary metabolites.

This study was conducted to compare the pathogenesis of acute and latent infections with closely related bovine herpesvirus types 1 (BHV-1) and 5 (BHV-5) in their natural host. Two groups of eight calves were inoculated intranasally with BHV-1 or BHV-5. Although BHV-1 and BHV-5 similarly replicate in the nasal mucosa after inoculation, both viruses differ markedly in their ability to cause disease, BHV-5 being responsible of some fatal encephalitis while BHV-1 inducing rhinotracheitis. Virus isolation and immunohistochemistry demonstrated that BHV-5 replicates extensively in neurons of the central nervous system (CNS) and in respiratory cells of lungs, tracheal and nasal mucosae. Invasion of the CNS likely occurs through the trigeminal and olfactory pathways. Both groups developed cross-neutralising antibodies during this experiment suggesting partial clinical cross-protection afforded by the two infections. Three months after primary infection, experimental reactivation showed that BHV-5 was able to establish latency in the trigeminal ganglia but also the CNS of surviving calves. Moreover, laboratory findings suggested that BHV-5 could also persist in the tracheal and nasal mucosae. These results indicate that, after primary infection, BHV-1 and BHV-5 displayed similar biological features and consequently need to be considered together for the control of BHV-1 infection.

Know where you stand.The odds are African Americans are twice as likely to suffer a stroke as white Americans.Beating the odds isn't about winning, it's about living.You have the power to end stroke.1-888-4-STROKE / StrokeAssociation.org

The amount and specificity of binding ofL-carnosine (β-alanyl-L-histidine) by crude soluble and particulate fractions of several tissues were investigated with proton magnetic resonance ((1)HMR) spectrometry. It was found that the particulate fraction of only nasal olfactory mucosa exhibited a specific binding requiring a particular orientation of the carnosine molecule relative to the binding site. This suggests that whatever role carnosine may play in olfaction is expressed within the nasal olfactory mucosa rather than elsewhere in the olfactory pathway. Possible binding of carnosine to carnosinase was observed in the soluble fractions of nasal olfactory mucosa and kidney. However, the bulk of the carnosine present in the nasal olfactory mucosa in vivo probably is not bound within the cells of this tissue as a complex with soluble protein. These observations are of interest because the nasal olfactory mucosa is the neural tissue that has the highest activities of the enzymes catalyzing the synthesis and degradation of carnosine.The results of this investigation indicate that(1)HMR spectrometry will prove useful for the measurement of transmitter/receptor recognition. The significance of these results in the general context of measurement of "specific" binding interactions by biological samples is discussed, and a basic description of the application of(1)HMR spectrometry to these measurements is presented.

Chapter 37 - Absorption

Septoria nodorum blotch is a major disease of wheat caused by the fungus Parastagonospora nodorum. Recent studies have demonstrated that secondary metabolites, including polyketides and non-ribosomal peptides, produced by the pathogen play important roles in disease and development. However, there is currently no knowledge on the composition or biological activity of the volatile organic compounds (VOCs) secreted by P. nodorum. To address this, we undertook a series of growth and phytotoxicity assays and demonstrated that P. nodorum VOCs inhibited bacterial growth, were phytotoxic and suppressed self-growth. Mass spectrometry analysis revealed that 3-methyl-1-butanol, 2-methyl-1-butanol, 2-methyl-1-propanol, and 2-phenylethanol were dominant in the VOC mixture and phenotypic assays using these short chain alcohols confirmed that they were phytotoxic. Further analysis of the VOCs also identified the presence of multiple sesquiterpenes of which four were identified via mass spectrometry and nuclear magnetic resonance as β-elemene, α-cyperone, eudesma-4,11-diene and acora-4,9-diene. Subsequent reverse genetics studies were able to link these molecules to corresponding sesquiterpene synthases in the P. nodorum genome. However, despite extensive testing, these molecules were not involved in either of the growth inhibition or phytotoxicity phenotypes previously observed. Plant assays using mutants of the pathogen lacking the synthetic genes revealed that the identified sesquiterpenes were not required for disease formation on wheat leaves. Collectively, these data have significantly extended our knowledge of the VOCs in fungi and provided the basis for further dissecting the roles of sesquiterpenes in plant disease.

ABSTRACTBiohydrogen from endophytic fungi constitutes an alternative biofuel resource with considerable advantages over biodiesel and ethanol extracted from existing food crops. Endophytes common in plant tissues mimic host physiological behavior and produce primary and secondary metabolites like oils and fats. Therefore, endophytes from 7 selected biodiesel plants, and 30 endophytic fungi isolated from 170 different plant parts were screened. The methodology included staining, lipid analysis, DNA isolation, molecular characterization, identification of fungal isolates by ITS sequences, biodiesel analysis, characterization of volatile organic compounds (VOCs), and statistical analysis. The fungal endophyte isolate SPSRJ28 was the most significant with an accumulation capacity of more than 20% of the total lipid content of its dry biomass, validating its oleaginous nature. In addition, the endophytes investigated in the present study yielded various VOCs that were validated by chromatography for both standards and isolates. When the VOCs were subsequently analyzed for their prospective usage as myco‐diesel, the presence of methane in the isolate SPSRJ28 was found to be highly significant. These findings remarkably support the investigation of endophytic fungi and their relationship with oleaginous plants as alternative sources of bioactive metabolites from microbial cell factories for myco‐diesel generation.

BackgroundMetabolic syndrome (MetS), which affects one-third of the population of the United States, is a risk factor for chronic diseases such as cardiovascular diseases, stroke, and type 2 diabetes mellitus. Heavy metals (HM) and volatile organic compounds (VOC) are environmental factors typically occurring as mixtures. Although exposures to these substances have been studied separately, the impact of combined HM and VOC exposure on humans and their subsequent risk of developing MetS has not been explored. This study investigates whether combined exposure to HMs and VOCs affects the risk of developing MetS.MethodsThe National Health and Nutrition Examination Survey database from 2011 to 2020 was used to determine exposure to HMs and VOCs detected in urine samples from individuals with MetS. Multiple Chi-squared and t-tests were performed to identify variables significantly associated with MetS. Logistic regression analysis was performed on unmatched and age-matched 1:1 case–control data to evaluate whether an association exists among HMs, VOCs, and demographic factors and MetS. A hierarchical cluster analysis was performed to identify combinations of HMs and VOCs linked with an increased risk of MetS.ResultsLogistic regression analysis on unmatched and matched data showed that increasing age and female sex were significantly associated (p < 0.05) with MetS. Among the HMs and VOCs, only N-acetyl-S-(2-cyanoethyl)-l-cysteine and N-acetyl-S-(2-hydroxyethyl)-l-cysteine were found to be significantly associated with MetS. Cluster analysis showed that Cluster 3 was significantly associated with MetS (p < 0.05; OR = 1.49), suggesting that exposure to barium, cadmium, cesium, lead, and VOCs may increase the risk of MetS. After adjusting for covariates, none of the clusters showed a significant association (p > 0.05). In contrast, age (OR = 1.07) and monthly poverty level index ≤ 1.3 (OR = 1.16) were significantly associated with MetS (p < 0.05).ConclusionThis study revealed that age, lower socioeconomic status, and multiple exposures to combined HM and VOC may have a greater impact with an increased risk of MetS. Cluster analysis highlighted the potential combination of the exposures linked to MetS and the likelihood that demographic factors affect MetS more than exposure to HMs and VOCs. However, further research is needed.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13755-025-00375-1.