Antioxidative and antifungal response of woody species to environmental conditions in the urban area

Biogenic volatile organic compounds (BVOCs) emissions and physiological changes in Pinus densiflora and Quercus acutissima seedlings under elevated particulate matter (PM)

Urban trees effectively reduce air pollution, including particulate matter (PM), which is a major concern in East Asia. While acting as biofilters, urban trees can be affected by PM exposure, which hinders their growth and physiological functions, thereby reducing their pollution mitigation ability. Trees absorb pollutants but also emit biogenic volatile organic compounds (BVOCs), which can act as precursors to other forms of air pollution. To better understand the effects of PM on urban trees, this study examined how two tree species, Pinus densiflora and Quercus acutissima, respond to elevated PM levels under controlled conditions at a concentration of 300 μg m-3. The aim was to investigate how increased PM levels affect BVOCs emissions and physiological responses in seedlings, and how these physiological changes influence BVOCs emission pattern. The results revealed species-specific responses in BVOCs emissions under PM stress with being especially oxygenated monoterpenes more than non‑oxygenated monoterpenes. Increased PM adsorption was found to reduce photosynthetic abilities, including photosynthesis (Anet), carboxylation capacity (Vcmax), and electron transport rate (J). This reduction in photosynthetic efficiency was further evidenced by decreased chlorophyll content and light absorption, which were assessed through chlorophyll fluorescence measurements. Additionally, the study evaluated oxidative stress indicators, such as lipid peroxidation and the accumulation of reactive oxygen species (ROS), to provide a comprehensive understanding of the species' responses to elevated PM conditions. The study found that elevated PM conditions were closely linked to an increase in oxygenated monoterpenes, which was associated with both oxidative stress and impaired physiological function. These observations emphasize the need for strategic urban tree selection to enhance air quality and suggest that understanding species-specific BVOCs emissions in response to PM is crucial for optimizing urban green spaces for health and environmental benefits.

Bornyl acetate: A promising agent in phytomedicine for inflammation and immune modulation

BACKGROUND

Bornyl acetate (BA), as a bicyclic monoterpene, is an active volatile component widely found in plants across the globe. BA can be used as essence and food flavor agent and is widely used in perfumes and food additives. It remains a key component in several proprietary Chinese medicines.

PURPOSE

This review summarized the pharmacological activity and research prospects of BA, making it the first of its kind to do so. Our aim is to provide a valuable resource for those pursuing research on BA.

METHODS

Databases including PubMed, Web of Science, and CNKI were used based on search formula "(bornyl acetate) NOT (review)" from 1967 to 2022. For the relevant knowledge of TCM, we quoted Chinese literature. Articles related to agriculture, industry, and economics were excluded.

RESULTS

BA showed rich pharmacological activities: It inhibits the NF-κB signal pathway via affecting the phosphorylation of IKB and the production of IKKs, inhibits the MAPK signal pathway via inhibiting the phosphorylation of ERK, JNK, and p38, down-regulates pro-inflammatory cytokines such as TNF-α, IL-1β, IL-6, up-regulates IL-11, reduces NO production, regulates immune response via up-regulating CD86⁺, decreases catecholamine secretion, and reduces tau protein phosphorylation. In addition to the pharmacological activities of BA, its toxicity and pharmacokinetics were also discussed in this paper.

CONCLUSION

BA has promising pharmacological properties, especially anti-inflammatory and immunomodulatory effects. It also has sedative properties and potential for use in aromatherapy. Compared to traditional NSAIDs, it has a more favorable safety profile while maintaining efficacy. BA has potential for developing novel drugs for treating various conditions.

Surface-Based Analysis of Leaf Microstructures for Adsorbing and Retaining Capability of Airborne Particulate Matter in Ten Woody Species

We evaluated surface-based analysis for assessing the possible relationship between the microstructural properties and particulate matter (i.e., two size fractions of PM2.5 and PM10) adsorption efficiencies of their leaf surfaces on ten woody species. We focused on the effect of PM adsorption capacity between micro-morphological features on leaf surfaces using a scanning electron microscope and a non-contact surface profiler as an example. The species with higher adsorption of PM10 on leaf surfaces were Korean boxwood (Buxus koreana Nakai ex Chung & al.) and evergreen spindle (Euonymus japonicus Thunb.), followed by yulan magnolia (Magnolia denudata Desr.), Japanese yew (Taxus cuspidata Siebold & Zucc.), Japanese horse chestnut (Aesculus turbinata Blume), retusa fringetree (Chionanthus retusus Lindl. & Paxton), maidenhair tree (Ginkgo biloba L.), and royal azalea (Rhododendron schlippenbachii Maxim.). There was a higher capacity for the adsorption of PM2.5 on the leaf surfaces of B. koreana and T. cuspidata, followed by A. turbinata, C. retusus, E. japonicus, G. biloba, and M. denudata. In wax layer tests, T. cuspidata, A. turbinata, R. schlippenbachii, and C. retusus showed a statistically higher PM2.5 capturing capacity than the other species. Different types of trichomes were distributed on the adaxial and abaxial leaves of A. turbinata, C. retusus, M. denudata, pagoda tree (Styphnolobium japonicum (L.) Schott), B. koreana, and R. schlippenbachii; however, these trichomes were absent on both sides of the leaves of G. biloba, tuliptree (Liriodendron tulipifera L.), E. japonicus, and T. cuspidata. Importantly, leaf surfaces of G. biloba and S. japonicum with dense or thick epicuticular leaf waxes and deeper roughness revealed lower PM adsorption. Based on the overall performance of airborne PM capture efficiency, evergreen species such as B. koreana, T. cuspidata, and E. japonicus showed the best results, whereas S. japonicum and L. tulipifera had the lowest capture. In particular, evergreen shrub species showed higher PM2.5 depositions inside the inner wall of stomata or the periphery of guard cells. Therefore, in leaf microstructural factors, stomatal size may be related to notably high PM2.5 holding capacities on leaf surfaces, but stomatal density, trichome density, and roughness had a limited effect on PM adsorption. Finally, our findings indicate that surface-based microstructures are necessarily not a correlation for corresponding estimates with leaf PM adsorption.