Chattonella marina blooms in a trophic gradient system: Interaction with environmental drivers.

For coastal eutrophication, lots of studies focused on the influence from environmental factors, especially nitrogen and phosphorus, on algae blooms. The interaction between algae and environmental factors has been often ignored. Using Chattonella marina, a dominant species in marine algal blooms, we established a trophic gradient system that simulated C. marina blooms at three trophic levels: eutrophic, mesotrophic, and oligotrophic, and examined the life history patterns of C. marina and the interactions with environmental factors. Increased trophic levels influenced the growth potential of C. marina, while its unique cyst reproduction allowed it to thrive in nutrient-limited environments. Adequate nutrients caused changes in dissolved oxygen (DO) and pH led by C. marina, with the carbonate system playing a crucial role in regulating pH under nutrient-limited conditions. Limiting the growth of C. marina in areas with low nutrient by manipulating reactive silicate (SiO32-) availability may prove effective. Nitrate (NO3-) was the preferred nutrient for C. marina when its concentration exceeded that of ammonium (NH4+). Phosphorus played a crucial role in the growth and proliferation of C. marina, especially when other nutrients were scarce. The findings of this study may provide valuable insights into the effective management and prevention of algae blooms.

Light and Potassium Improve the Quality of Dendrobium officinale through Optimizing Transcriptomic and Metabolomic Alteration.

BACKGROUND: Dendrobium officinale is a perennial epiphytic herb in Orchidaceae. Cultivated products are the main alternative for clinical application due to the shortage of wild resources. However, the phenotype and quality of D. officinale have changed post-artificial cultivation, and environmental cues such as light, temperature, water, and nutrition supply are the major influencing factors. This study aims to unveil the mechanisms beneath the cultivation-induced variation by analyzing the changes of the metabolome and transcriptome of D. officinale seedlings treated with red- blue LED light and potassium fertilizer. RESULTS: After light- and K-treatment, the D. officinale pseudobulbs turned purple and the anthocyanin content increased significantly. Through wide-target metabolome analysis, compared with pseudobulbs in the control group (P), the proportion of flavonoids in differentially-accumulated metabolites (DAMs) was 22.4% and 33.5% post light- and K-treatment, respectively. The gene modules coupled to flavonoids were obtained through the coexpression analysis of the light- and K-treated D. officinale transcriptome by WGCNA. The KEGG enrichment results of the key modules showed that the DEGs of the D. officinale pseudobulb were enriched in phenylpropane biosynthesis, flavonoid biosynthesis, and jasmonic acid (JA) synthesis post-light- and K-treatment. In addition, anthocyanin accumulation was the main contribution to the purple color of pseudobulbs, and the plant hormone JA induced the accumulation of anthocyanins in D. officinale. CONCLUSIONS: These results suggested that light and potassium affected the accumulation of active compounds in D. officinale, and the gene-flavone network analysis emphasizes the key functional genes and regulatory factors for quality improvement in the cultivation of this medicinal plant.

[Rhein inhibits hydrogen peroxide-induced apoptosis of human umbilical vein endothelial cells and its mechanism].

This study investigated the effect of rhein(RH) on the apoptosis and autophagy of human umbilical vein endothelial cells(HUVECs) induced by hydrogen peroxide(H_2O_2) and its underlying mechanism. The oxidative damage model in HUVECs was established and the cells were divided into different treatment groups. Cell survival rate was detected by MTT assay, apoptosis by Annexin V-FITC/PI double staining and Hoechst 33258 fluorescence staining, autophagy by Ad-mCherry-GFP-LC3 B adenovirus transfection, and protein expression by Western blot. The results showed that RH could protect cells by increasing the cell survival rate in a dose-dependent manner, decreasing the expression of apoptosis-related proteins(Bax and cleaved caspase-3) and the ratio of Bax/Bcl-2, elevating the expression of Bcl-2, up-regulating the expression of microtubule-associated protein 1 light chain 3(LC3)-Ⅱ, and down-regulating the expression of p62. Adenovirus transfection results showed that RH could increase the green and red spots, as well as the yellow spots. However, after the addition of autophagy inhibitor 3-MA, autophagy was reduced and apoptosis was increased. RH could enhance the expression of silent information regulator 2 related enzyme 1(SIRT1). The addition of SIRT1 inhibitor EX-527 reduced the protective effect of RH and cell viability. The addition of 3-MA had no effect on the expression of SIRT1 protein, but the expression of SIRT1 and LC3-Ⅱ proteins decreased and the expression of p62 increased after the addition of EX-527. After RH treatment, the phosphorylation of adenosine monophosphate-activated protein kinase(AMPK) increased, while that of the mechanistic target of rapamycin(mTOR) decreased in a dose-dependent manner. Moreover, this effect could be weakened by the AMPK inhibitor compound C. RH may enhance autophagy through SIRT1/AMPK/mTOR pathway to reduce H_2O_2-induced apoptosis of HUVECs.

Effects of light and water disturbance on the growth of Microcystis aeruginosa and the release of algal toxins.

Eutrophication of water constitutes a serious threat to global water quality. Light intensity and water disturbance are important factors affecting the growth of algae and the release of algal toxins. In this study, algal growth indicators, algal enzyme systems, and algal toxin release in Microcystis aeruginosa under different light intensities and water disturbances were determined. The results showed that 2500 lx and 120 rpm were the optimal conditions for the growth of M. aeruginosa. The growth of algal cells was inhibited by high light intensity and high water disturbance. However, the optimal conditions for algal growth were not favorable conditions for the release of algal toxin. The highest concentration of microcystin-LR (MC-LR), observed at 4500 lx and 80 rpm, was 198.1 µg/L, whereas the highest single cell toxin production reached up to 10.49 × 10-9  µg/cell at 7000 lx and 120 rpm. Redundancy analysis results showed that the concentration of MC-LR was positively correlated with algal cell density and antioxidant enzyme activities (superoxide dismutase, catalase, peroxidase, and malondialdehyde [MDA]) and negatively correlated with the total nitrogen and total phosphorus consumption rates and MDA. Single cell toxin production was negatively correlated with algal cell density and antioxidant enzyme activity but positively correlated with MDA content. PRACTITIONER POINTS: There was an optimal water disturbance condition for algae growth affected by the light intensity. Optimal conditions for algae cell growth are not necessarily the optimal conditions for algal toxin release. Enzyme indicators have correlation with the release of algae toxins and the growth of algae cells.

Pharmacokinetic, bioavailability and tissue distribution study of astilbin in rats.

OBJECTIVE: The purpose of this study is to reveal the pharmacokinetic profiles of astilbin with various doses in rats and investigate the oral absolute bioavailability and tissue distribution of astilbin after oral administration. METHODS: Wistar rats were orally administered astilbin 12, 24 mg/kg and intravenous administered astilbin 6 mg/kg randomly. The concentration of astilbin in rat plasma and various tissue samples was determined by LC-MS/MS method. Noncompartmental pharmacokinetic parameters including AUC and t1/2 were calculated from plasma concentration-time data of astilbin with the DAS 3.0. KEY FINDINGS: After oral administration of astilbin 12 and 24 mg/kg to rats, the oral absolute bioavailability of astilbin were 1.16 ± 0.695% and 1.27 ± 0.379%; the plasma elimination half-lives (t1/2 ) were 101 ± 35.8 and 109 ± 25.3 min, respectively. Astilbin had a rapid absorption and a wide distribution throughout the whole body except liver and fat following oral administration. Astilbin could penetrate the blood-brain barrier of rat. CONCLUSIONS: The oral absolute bioavailability of astilbin is poor because of the low permeability and solubility. Both oral absorption and clearance of astilbin in rats are rapid after oral administration.

[Effects of electroacupuncture on morphology of neovascularization and expression of angiogenesis-related factors in ischemic brain tissue of cerebral ischemia rats].

OBJECTIVE: To observe the change of neovascular morphology and angiogenesis related factors in the ischemic cerebral area after cerebral infarction and the intervention effect of electroacupuncture (EA). METHODS: Wistar rats were randomly divided into model group(n=90), EA group(n=90), sham operation group(n=90) and control group(n=10). The first three groups were further divided into 1 h, 3 h, 6 h, 9 h, 12 h, 24 h, 3 d, 7 d and 12 d subgroups(n=10 in each subgroup). The cerebral infarction model was established by middle cerebral artery occlusion(MCAO). EA(15 Hz, 2 mA) was applied to "Shuigou"(GV26) for 20 min in the EA group. The 1, 3, 6, 9, 12, 24 h subgroups were treated immediately after modeling, the 3, 7, 12 d subgroups were treated once daily for 3, 7 or 12 days. The neovascular endothelial cells were displayed by immunofluorescence double labeling staining. Quantitive real-time PCR and Western blot were applied to detect the changes of basic fibroblast growth factor (bFGF), angiogenin (Ang) -1, 2, platelet-derived growth factor b (PDGF-b) in ischemic brain tissue, respectively. RESULTS: After modeling, CD31 and Ki67 positive cells were first observed at 24 h in the model group, and reached the peak at 3 d, decreased at 7 d. While in the EA group, the CD31 and Ki67 positive cells were first observed at 12 h, and reached the peak at 3 d, and gradually decreased until 12 d. Compared with the control group, the mRNA expressions of bFGF at 9 h-12 h, Ang-1 at 12 h-12 d, Ang-2 at 1 h-12 d and PDGF-b at 1 h, 6 h, 9 h, 24 h-12 d were increased in the model group(P<0.01, P<0.05). After EA, the mRNA expressions of bFGF at 24 h-12 d, Ang-1 at 3 d-12 d, Ang-2 at 3 h-24 h and PDGF-b at 3 h, 6 h, 3 d-12 d were increased(P<0.05, P<0.01). In comparison with the control group, the proteins of bFGF at 24 h, Ang-1 at 6 h-12 d, Ang-2 at 1 h-12 d and PDGF-b at 1 h-7 d were increased in the model group(P<0.05, P<0.01). After EA, the proteins of bFGF at 3 d-12 d, Ang-1 at 3 d-12 d, Ang-2 at 3 h-12 h and PDGF-b at 6 h, 3 d-12 d were increased compared with the model group(P<0.05, P<0.01). CONCLUSION: EA can up-regulate the expression of angiogenesis-related factors in MCAO rats, which has an important role in the establishment of blood vessel regeneration and collateral circulation, and thus promote the recovery of neurological function.

[Selection of optimized treatment plan of acupuncture for lateral femoral cutaneous neuritis].

OBJECTIVE: To select the optimized treatment plan of acupuncture for lateral femoral cutaneous neuritis by using multiple indexes decision-making method based on the clinical evidence. METHODS: The randomized control trials (RCTs) regarding acupuncture for lateral femoral cutaneous neuritis in the CNKI database, CBM database, WANFANG database, VIP database, PubMed, Cochrane Library and Embase published before December 31, 2017 were comprehensively collected. The modified Jadad scale was used to evaluate the quality of the RCTs. Then the evaluation indexes were selected and the dimensions of evaluation indexes were standardized by using extreme difference transformation method. The weight of each index was determined by using relative comparison method and the standardized matrix was weighted. Thus, the ideal solution and the negative ideal solution were obtained, and the relatively degree of each treatment plan to the ideal solution was calculated to propose the optimized plan of acupuncture for lateral femoral cutaneous neuritis. RESULTS: A total of 18 RCTs were included, the optimized plan of acupuncture for lateral femoral cutaneous neuritis was using thin fire needle to rapidly prick the abnormal skin region with fast needle insertion-withdrawal technique; the fire needle was applied repeatedly; intensive pricking to form a treatment area; the treatment was given once every 5 days. CONCLUSION: Based on the current clinical evidence, the optimized plan of acupuncture for lateral femoral cutaneous neuritis is using thin fire needle to prick the abnormal skin region; the multiple methods of plum-blossom needling met the characteristic of lateral femoral cutaneous neuritis and is suitable for clinical selection. The main acupoints are ashi points in the abnormal skin area or the acupoints in the foot-yangming meridian and foot-shaoyang meridian, combined with lumbar Jiaji (EX-B2) points.