The aim of the current study was to test the hypothesis that forest bathing would be beneficial for elderly patients with chronic heart failure (CHF) as an adjunctive therapy. Two groups of participants with CHF were simultaneously sent to the forest or an urban control area for a four-day trip, respectively. Subjects exposed to the forest site showed a significant reduction of brain natriuretic peptide (BNP) in comparison to that of the city group and their own baseline levels. The values for the cardiovascular disease related pathological factors, including endothelin-1 (ET-1), and constituents of the renin-angiotensin system (RAS), including renin, angiotensinogen (AGT), angiotensin II (ANGII), and ANGII receptor type 1 or 2 (AT1 or AT2) in subjects exposed to the forest environment were lower than those in the urban control group. Obviously, a decreased level of inflammatory cytokines and improved antioxidant function was observed in the forest group rather than in the city group. The assessment of the profile of mood states (POMS) indicated that the negative emotional mood state was alleviated after forest bathing. As anticipated, a better air quality in the forest site was observed according to the detection of PM_2.5 (particulate matter <2.5 μm) and negative ions. These results provided direct evidence that forest bathing has a beneficial effect on CHF patients, and thus may pave the way for potential development of forest bathing as an effective adjunctive therapy on cardiovascular disorders.

To study the oxidative stress and antioxidative response of Cinnamomum camphora seedlings exposed to nitrogen dioxide (NO₂) fumigation. Measurements were made up of the growth, chlorophyll content, chlorophyll fluorescence, antioxidant system and lipid peroxidation of one-year-old C. camphora seedlings exposed to NO₂ (0.1, 0.5, and 4 μl/L) fumigation in open top chambers over a period of 60 d. After the first 30 d, 0.5 and 4.0 μl/L NO₂ showed insignificant effects on the growth of C. camphora seedlings. However, exposure to 0.5 and 4.0 μl/L NO₂ for 15 d significantly reduced their chlorophyll content (P<0.05), enhanced their malondialdehyde (MDA) content and superoxide dismutase (SOD) activity (P<0.05), and also significantly reduced the maximal quantum yield of PSII in the dark [the ratio of variable fluorescence to maximal fluorescence (F _v/F _m)] (P<0.05). In the latter 30 d, 0.5 μl/L NO₂ showed a positive effect on the vitality of the seedlings, which was reflected by a recovery in the ratio of F _v/F _m and chlorophyll content, and obviously enhanced growth, SOD activity, ascorbate (AsA) content and glutathione reductase (GR) activity (P<0.05); 4.0 μl/L NO₂ then showed a negative effect, indicated by significant reductions in chlorophyll content and the ratio of F _v/F _m, and inhibited growth (P<0.05). Conclusion: The results suggest adaptation of C. camphora seedlings to 60-d exposure to 0.1 and 0.5 μl/L NO₂, but not to 60-d exposure to 4.0 μl/L NO₂. C. camphora seedlings may protect themselves from injury by strengthening their antioxidant system in response to NO₂-induced oxidative stress.

Forest bathing is receiving increased attention due to its health benefits for humans. However, knowledge is scarce about the adjunctive therapeutic effects of forest bathing in different seasons on geriatric hypertension. The aim of the current study was to evaluate the antihypertensive effects of forest bathing in a Cinnamomum camphora (C. camphora) forest environment in four seasons. One group of participants with geriatric hypertension was sent to a C. camphora forest to experience a 3 day trip, while, as a control, another group was sent to the urban center. The participants’ blood pressure, blood routine, and blood biochemistry were assessed. The profile of the mood states (POMS) of the participants was assessed before and after the experiment. The air quality, atmospheric environment, and content of volatile organic compounds (VOCs) at the two experimental sites were monitored during the experiment. This experiment was repeated across four seasons. The advantages of the urban forest groups over the control groups were mainly represented by reductions in diastolic blood pressure (DBP), systolic blood pressure (SBP), and heart rate (HR), as well as increased oxygen saturation (SpO₂). The antihypertensive effects of forest bathing in the C. camphora forest environment changed with the seasons. Compared with the baseline level, SBP and DBP declined after forest bathing across the whole year, except during winter, whereas SpO₂ increased. The effect of forest bathing on lowering blood pressure was particularly pronounced during summer and autumn. The antihypertensive effects of forest bathing in the four seasons were highly consistent with the seasonal dynamics of VOCs and negative air ions (NAIs), which implies that the effect of forest bathing may be attributed to alterations of the atmospheric environment. The antihypertensive effects of C. camphora forest were confirmed in our study, and the results can provide a reference for scheduling bathing trips.

Lagerstroemia indica is a widely used ornamental woody plant known for its summer flowering and significant ornamental and economic value. While L. indica boasts a variety of rich flower colors, the molecular mechanisms underlying this color formation remain unclear. In this study, we selected three different flower colors of L. indica—white (W), red (R), and purple (P)—for transcriptome and metabolome analysis. The metabolome analysis identified 538 flavonoids, with 22 anthocyanins highly accumulated in the red and purple flowers. RNA-seq analysis annotated a total of 35,505 genes. Furthermore, we identified 42 differentially expressed genes (DEGs) involved in anthocyanin biosynthesis, with their expression levels aligning with anthocyanin content. Correlation analysis revealed that 19 MYB and 11 bHLH transcription factors are likely involved in anthocyanin biosynthesis. Additionally, we identified 59 auxin biosynthesis and signaling-related genes that are positively correlated with anthocyanin-related genes and metabolites, suggesting that auxin may play a role in regulating anthocyanin biosynthesis in L. indica. This study provides valuable insights into the regulatory mechanisms underlying anthocyanin accumulation and color formation in L. indica petals and identifies several potential genes, laying the groundwork for further research on regulatory mechanisms and genetic improvement of L. indica.

NAC (NAM, ATAF1/2, CUC1/2) is a plant-specific transcription factor (TF) family that plays important roles in various physiological and biochemical processes of plants. However, the NAC gene family in Lagerstroemia indica and its role in anthocyanin metabolism are still unexplored. In our study, a total of 167 NACs were identified in the L. indica genome via genome-wide analysis and bioinformatics techniques. Amino acid sequence analysis showed that all 167 NAC proteins contained a conserved NAM domain. This domain primarily comprised random coils, extended strands, and alpha helices. Most NACs were found on the nucleus and dispersed over 23 of the 24 plant chromosomes. Based on phylogenetic analysis, the NACs can be categorized into ten subgroups. Furthermore, the promoter homeotropic elements predicted the cis-acting elements in the promoters of these genes related to hormones, development, environmental stress response, and other related responses, demonstrating the diverse regulatory mechanisms underlying gene functions. In addition, a co-expression network was established through RNA sequencing. This network helped identify seven key LiNACs, genes related to anthocyanin expression (CHS) and transcription factors (MYB and bHLH). To identify potential anthocyanin regulatory factors present in L. indica petals, protein interaction prediction was performed, which revealed that LiNACs might participate in anthocyanin regulation by interacting with other proteins, such as MYB, ABF, ABI, bZIP, MYC, etc. Our results provided novel insights and could help in the functional identification of LiNACs in L. indica and the regulation of anthocyanin synthesis.