2,4-Dihydroxybenzoic Acid, a Novel SA Derivative, Controls Plant Immunity via UGT95B17-Mediated Glucosylation: A Case Study in Camellia Sinensis.

The plant hormone salicylic acid (SA) plays critical roles in plant innate immunity. Several SA derivatives and associated modification are identified, whereas the range and modes of action of SA-related metabolites remain elusive. Here, the study discovered 2,4-dihydroxybenzoic acid (2,4-DHBA) and its glycosylated form as native SA derivatives in plants whose accumulation is largely induced by SA application and Ps. camelliae-sinensis (Pcs) infection. CsSH1, a 4/5-hydroxylase, catalyzes the hydroxylation of SA to 2,4-DHBA, and UDP-glucosyltransferase UGT95B17 catalyzes the formation of 2,4-DHBA glucoside. Down-regulation reduced the accumulation of 2,4-DHBA glucosides and enhanced the sensitivity of tea plants to Pcs. Conversely, overexpression of UGT95B17 increased plant disease resistance. The exogenous application of 2,4-DHBA and 2,5-DHBA, as well as the accumulation of DHBA and plant resistance comparison, indicate that 2,4-DHBA functions as a potentially bioactive molecule and is stored mainly as a glucose conjugate in tea plants, differs from the mechanism described in Arabidopsis. When 2,4-DHBA is applied exogenously, UGT95B17-silenced tea plants accumulated more 2,4-DHBA than SA and showed induced resistance to Pcs infection. These results indicate that 2,4-DHBA glucosylation positively regulates disease resistance and highlight the role of 2,4-DHBA as potentially bioactive molecule in the establishment of basal resistance in tea plants.

(Z)-3-Hexenol integrates drought and cold stress signaling by activating abscisic acid glucosylation in tea plants.

Cold and drought stresses severely limit crop production and can occur simultaneously. Although some transcription factors and hormones have been characterized in plants subjected each stress, the role of metabolites, especially volatiles, in response to cold and drought stress exposure is rarely studied due to lack of suitable models. Here, we established a model for studying the role of volatiles in tea (Camellia sinensis) plants experiencing cold and drought stresses simultaneously. Using this model, we showed that volatiles induced by cold stress promote drought tolerance in tea plants by mediating reactive oxygen species and stomatal conductance. Needle trap microextraction combined with GC-MS identified the volatiles involved in the crosstalk and showed that cold-induced (Z)-3-hexenol improved the drought tolerance of tea plants. In addition, silencing C. sinensis alcohol dehydrogenase 2 (CsADH2) led to reduced (Z)-3-hexenol production and significantly reduced drought tolerance in response to simultaneous cold and drought stress. Transcriptome and metabolite analyses, together with plant hormone comparison and abscisic acid (ABA) biosynthesis pathway inhibition experiments, further confirmed the roles of ABA in (Z)-3-hexenol-induced drought tolerance of tea plants. (Z)-3-Hexenol application and gene silencing results supported the hypothesis that (Z)-3-hexenol plays a role in the integration of cold and drought tolerance by stimulating the dual-function glucosyltransferase UGT85A53, thereby altering ABA homeostasis in tea plants. Overall, we present a model for studying the roles of metabolites in plants under multiple stresses and reveal the roles of volatiles in integrating cold and drought stresses in plants.

Single-cell transcriptome atlas reveals developmental trajectories and a novel metabolic pathway of catechin esters in tea leaves.

The tea plant is an economically important woody beverage crop. The unique taste of tea is evoked by certain metabolites, especially catechin esters, whereas their precise formation mechanism in different cell types remains unclear. Here, a fast protoplast isolation method was established and the transcriptional profiles of 16 977 single cells from 1st and 3rd leaves were investigated. We first identified 79 marker genes based on six isolated tissues and constructed a transcriptome atlas, mapped developmental trajectories and further delineated the distribution of different cell types during leaf differentiation and genes associated with cell fate transformation. Interestingly, eight differently expressed genes were found to co-exist at four branch points. Genes involved in the biosynthesis of certain metabolites showed cell- and development-specific characteristics. An unexpected catechin ester glycosyltransferase was characterized for the first time in plants by a gene co-expression network in mesophyll cells. Thus, the first single-cell transcriptional landscape in woody crop leave was reported and a novel metabolism pathway of catechin esters in plants was discovered.

Eugenol functions as a signal mediating cold and drought tolerance via UGT71A59-mediated glucosylation in tea plants.

Cold and drought stress are the most critical stresses encountered by crops and occur simultaneously under field conditions. However, it is unclear whether volatiles contribute to both cold and drought tolerance, and if so, by what mechanisms they act. Here, we show that airborne eugenol can be taken up by the tea (Camellia sinensis) plant and metabolized into glycosides, thus enhancing cold and drought tolerance of tea plants. A uridine diphosphate (UDP)-glucosyltransferase, UGT71A59, was discovered, whose expression is strongly induced by multiple abiotic stresses. UGT71A59 specifically catalyzes glucosylation of eugenol glucoside in vitro and in vivo. Suppression of UGT71A59 expression in tea reduced the accumulation of eugenol glucoside, lowered reactive oxygen species (ROS) scavenging capacity, and ultimately impaired cold and drought stress tolerance. Exposure to airborne eugenol triggered a marked increase in UGT71A59 expression, eugenol glucoside accumulation, and cold tolerance by modulating ROS accumulation and CBF1 expression. It also promoted drought tolerance by altering abscisic acid homeostasis and stomatal closure. CBF1 and CBF3 play positive roles in eugenol-induced cold tolerance and CBF2 may be a negative regulator of eugenol-induced cold tolerance in tea plants. These results provide evidence that eugenol functions as a signal in cold and drought tolerance regulation and shed new light on the biological functions of volatiles in the response to multiple abiotic stresses in plants.

Tonifying spleen and replenishing kidney method of traditional Chinese medicine for myasthenia gravis: A protocol for systematic review and meta-analysis.

BACKGROUND: Myasthenia gravis (MG) is an autoimmune antibody-mediated disorder caused by dysfunction at the neuromuscular junction spreads. The main clinical features of this disease are fluctuating fatigue, and weakness of the skeletal muscles of the eyes and limbs. At present, the tonifying the spleen and replenishing the kidney method in traditional Chinese medicine has been widely used for MG. The present study was conducted to evaluate the efficacy and safety of the tonifying the spleen and replenishing the kidney method in traditional Chinese medicine for MG. METHODS: The following 10 databases were searched from inception to March 2021: PubMed, Cochrane Library, EMBASE, Web of Science, Springer, China National Knowledge Infrastructure (CNKI), Wan fang, VIP Chinese Science and Technique Journals Database, the Chinese Bio Medical Database (CBM), and Baidu Scholar. The language was limited to the Chinese and English language. Merely randomized controlled trials (RCTs) were included. The Cochrane Collaboration risk-of-bias tool was used for the methodological quality assessment and risk of bias. The meta-analysis was assessed using the Cochrane RevMan 5.3 software. RESULTS: In the present study, a meta-analysis was conducted, and RCTs that met the eligibility criteria were included. Furthermore, the different outcome indicators of different methods were objectively compared. The main outcome indicators included the effective rate, quantitative myasthenia gravis (QMG) scores, adverse events, and quality of life (QOL). The secondary outcome indicators included AchRAb, serum-related immune cells (such as CD3+CD4+cells and CD4+/CD8+cells), the traditional Chinese medicine syndrome score scale (TCMSSS), the serum interleukin-6 level, the level of IFN-γ and its mRNA, and the clinical score that contains the clinical absolute score (CAS) and clinical relative score (CRS). CONCLUSION: This study would provide credible evidence to determine whether the tonifying the spleen and replenishing the kidney method in traditional Chinese medicine is an effective treatment method for MG. TRIAL REGISTRATION NUMBER: INPLASY202110097.

External treatment of traditional Chinese medicine for myasthenia gravis: A protocol for systematic review and meta-analysis.

BACKGROUND: Myasthenia gravis (MG) is an archetypal autoimmune disorder. The conventional treatments for this disease are drugs, plasma exchange, surgical, and so on. However, this disease is difficult to cure. A mass of studies revealed that the external treatment of traditional Chinese medicine (TCM) for MG is a safe and economical approach. The present study conducted a meta-analysis to compare TCM external treatment combined with modern medicine with modern medicine for MG, in order to determine which TCM external treatment intervention has the best relative efficacy, safety, and provide the best evidence for clinical practice. METHODS: PubMed, Cochrane Library, EMBASE, Web of Science, Springer, China National Knowledge Infrastructure (CNKI), Wan-fang database, VIP Chinese Science and Technique Journals Database, the Chinese Bio Medical Database (CBM), and Baidu Scholar were searched. The time of publication was limited from inception to February 28, 2021. Two reviewers independently searched for the selected articles and extract the data. The RevMan V.5.3 statistical software (Cochrane Collaboration) and Stata V.16.0 software were used to conduct the meta-analysis. RESULTS: The results of the systematic review and meta-analysis will be published in a peer-reviewed journal. CONCLUSION: The present study provides a protocol that can be used in the systematic review and meta-analysis, with the intent to inform professionals on the external treatment of TCM for MG. These would lead to investigations on the use of the most external treatment of TCM for MG. TRIAL REGISTRATION NUMBER: INPLASY202110083.

Tenuigenin protects dopaminergic neurons from inflammation via suppressing NLRP3 inflammasome activation in microglia.

BACKGROUND: Emerging evidence indicates that nod-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome-induced inflammation plays a crucial role in the pathogenesis of Parkinson's disease (PD). Thus, inhibition of NLRP3 inflammasome activation may offer a therapeutic benefit in the treatment of PD. Tenuigenin, a major active component of Polygala tenuifolia, has been shown to have potential anti-inflammatory activity, but the underlying mechanisms remain obscure. METHODS: In the present study, the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD was established to explore the effect of tenuigenin on dopaminergic neurons in substantia nigra. We next activated NLRP3 inflammasome in both BV2 microglia cells and adult mice to investigate the mechanisms for the neuroprotective effect of tenuigenin. RESULTS: We demonstrated that treatment with tenuigenin increased striatal dopaminergic levels and improved motor impairment induced by MPTP. Also, tenuigenin significantly ameliorated the degeneration of dopaminergic neurons and inhibited NLRP3 inflammasome activation in substantia nigra of MPTP mouse model. We further found that tenuigenin reduced intracellular reactive oxygen species (ROS) production and suppressed NLRP3 inflammasome activation, subsequent caspase-1 cleavage, and interleukin-1ß secretion in BV2 microglia cells. These data indicate that tenuigenin inhibits the activation of NLRP3 inflammasome via downregulating ROS. Correspondingly, in vivo data showed that tenuigenin attenuates microglia activation induced by lipopolysaccharide (LPS) in substantia nigra via suppressing NLRP3 inflammasome. CONCLUSIONS: Our findings reveal that tenuigenin protects dopaminergic neurons from inflammation partly through inhibition of NLRP3 inflammasome activation in microglia, and suggest the promising clinical use of tenuigenin for PD therapy.

Comparative analysis of the response and gene regulation in cold resistant and susceptible tea plants.

Cold environment is the main constraint for tea plants (Camellia sinensis) distribution and tea farming. We identified two tea cultivars, called var. sinensis cv. Shuchazao (SCZ) with a high cold-tolerance and var. assamica cv. Yinghong9 (YH9) with low cold-tolerance. To better understand the response mechanism of tea plants under cold stress for improving breeding, we compared physiological and biochemical responses, and associated genes expression in response to 7-day and 14-day cold acclimation, followed by 7-day de-acclimation in these two tea cultivars. We found that the low EL50, low Fv/Fm, and high sucrose and raffinose accumulation are responsible for higher cold tolerance in SCZ comparing with YH9. We then measured the expression of 14 key homologous genes, known as involved in these responses in other plants, for each stages of treatment in both cultivars using RT-qPCR. Our results suggested that the increased expression of CsCBF1 and CsDHNs coupling with the accumulation of sucrose play key roles in conferring higher cold resistance in SCZ. Our findings have revealed key genes regulation responsible for cold resistance, which help to understand the cold-resistant mechanisms and guide breeding in tea plants.

[Research progress on therapeutic targets of active components in Chinese herbs for treatment of nonalcoholic fatty liver disease].

Nonalcoholic fatty liver disease(NAFLD) is a kind of metabolic liver injury, which is closely associated with insulin resistance and genetic susceptibility. Traditional Chinese herbs used in the treatment of nonalcoholic fatty liver disease are widely investigated in recent years. A series of recent studies show that the effects of the active components in traditional Chinese herbs on NAFLD are associated with activating AMPK signaling pathway, improving insulin resistance, modulating the activity and expression of peroxisome proliferator-activated receptor γ, antioxidant and anti-inflammatory activities and regulating intestinal flora. In this review, the potential therapeutic targets of the active components from traditional Chinese herbs for NAFLD would be summarized to provide a new thought for further research and clinical treatment of nonalcoholic fatty liver disease.

Post-Marketing Safety Surveillance of the Salvia Miltiorrhiza Depside Salt for Infusion: A Real World Study.

BACKGROUND: Salvia Miltiorrhiza Depside Salt for Infusion (SMDS) is made of a group of highly purified listed drugs. However, its safety data is still reported limitedly. Compared with the clinical trials, its safety in the real world setting is barely assessed. OBJECTIVE: To investigate the safety issues, including adverse events (AEs), adverse events related to SMDS (ADEs), and adverse drug reactions (ADRs) of the SMDS in the real world clinical practice. METHODS: This is a prospective, multicenter, pharmacist-led, cohort study in the real world setting. Consecutive patients prescribed with SMDS were all included in 36 sites. Pharmacists were well trained to standardized collect the patients information, including demographics, medical history, prescribing patterns of SMDS, combined medications, adverse events, laboratory investigations, outcomes of the treatment when discharge, and interventions by pharmacists. Adverse events and adverse drug reactions were collected in details. Multivariate possion regression analysis was applied to identify risk factors associated with ADEs using the significance level (α) 0.05. ClinicalTrials.gov Identifier: NCT01872520. RESULTS: Thirty six hospitals were participated in the study and 30180 consecutive inpatients were included. The median age was 62 (interquartile range [IQR], 50-73) years, and male was 17384 (57.60%) among the 30180 patients. The incidences of the AEs, ADEs and ADRs were 6.40%, 1.57% and 0.79%, respectively. There were 9 kinds of new ADEs which were not on the approved label found in the present study. According to the multivariate analysis, male (RR = 1.381, P = 0.009, 95%CI [1.085~1.759]), more concomitant medications (RR = 1.049, P<0.001, 95%CI [1.041~1.057]), longer duration of SMDS therapy (RR = 1.027, P<0.001, 95%CI [1.013~1.041]), higher drug concentration (RR = 1.003, P = 0.014, 95%CI [1.001~1.006]), and resolvent unapproved (RR = 1.900, P = 0.002, 95%CI [1.260~2.866]) were the independent risk factors of the ADEs. Moreover, following the approved indication (RR = 0.655, P<0.001, 95%CI [0.532~0.807]) was associated with lower incidence of ADEs. CONCLUSIONS: SMDS was well tolerated in the general population. The incidences of the AEs, ADEs and ADRs were 6.40%, 1.57% and 0.79%, respectively. Several risk factors of its ADEs have been identified. It is recommended to follow the instructions when prescribing and administrating SMDS in the real world clinical practice.

Anti-inflammatory effects of tanshinone IIA on atherosclerostic vessels of ovariectomized ApoE mice are mediated by estrogen receptor activation and through the ERK signaling pathway.

AIMS: Estrogen plays a protective role in atherosclerosis. Our preliminary work demonstrated that the active conformation of Tanshinone IIA(TanIIA) is similar to the 17ß-estradiol and it can bind to the estrogen receptor. Here, we hypothesized that Tanshinone IIA might have anti-inflammatory and anti-oxidative effects in atherosclerosis, mediated through estrogen receptor activation. METHODS: Subjects for this study were 120 apoE(-/-) female mice and 20 C57/BL female mice. The apoE(-/-) mice were ovariectomized (OVX) and the C57/BL mice were sham ovariectomized. The sham OVX mice were maintained on a normal diet (NOR) group. The OVX apoE(-/-) mice were fed a high fat diet and randomly divided into 6 groups: Model (MOD) group which was fed a high fat diet only, E2 group were given estrogen (E2) 0.13 mg/kg/d; E2+ICI group were given E2:0.13 mg/kg/d and ICI182780:65 mg/kg/m; TLD group (TanIIA low dose) were given TanIIA: 30 mg/kg/d; THD group (TanIIA high dose) were given TanIIA:60 mg/kg/d; and TLD+ICI group were given TanIIA 30 mg/kg/d and ICI182780 65 mg/kg/m. After three months of treatment, the aorta and the blood of the mice from each group was collected. The aorta were used for testing the lipid deposition by using hematoxylin and eosin(HE) and oil red O staining and for testing the expression of p-ERK1/2 by Western blot. The blood was used for testing the serum cholesterol, superoxide dismutase (SOD), methane dicarboxylic aldehyde (MDA), nuclear factor kappa (NF-κB), soluble intercellular cell adhesion molecule-1 (sICAM-1), activating protein-1 (AP-1), E-selectin and 17ß-estradiol in serum. RESULTS: Tanshinone IIA significantly reduced the lipid deposition in aorta, decreased the levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), very low density lipoprotein (VLDL), MDA, NF-κB, sICAM-1, AP-1, and E-selectin in serum but increased the levels of high density lipoprotein (HDL) and SOD in serum. Tanshinone IIA also suppressed the expression of p-ERK1/2. Tanshinone IIA had no effect of level of serum 17ß-estradiol levels. All of the effects of Tanshinone IIA were similar to estrogen and were inhibited by the estrogen receptor antagonist ICI182780. CONCLUSION: Tanshinone IIA may play an anti-inflammatory and anti-oxidative stress role in OVX atherosclerotic apoE(-/-) mice by activating the estrogen receptor through the ERK signaling pathway. Therefore, Tanshinone IIA, as a phytoestrogen, could be used for estrogen replacement therapy for cardiovascular disease of postmenopausal women.

[The estrogen-like protective effect of ginsenoside Rb3 on oxidative stress and dysfunction of endothelial cells induced by oxidized low-density lipoprotein].

Ginsenoside Rb3 (GRb3) is one of the main components in plasma of Panax quinquefolius Saponin of stem and leaf (PQS), which can be into human plasma. Previous studies have found PQS has estrogen-like vascular protective effects. In the present study, we investigated the estrogen-like protective effect of GRb3 on oxidative stress and dysfunction of endothelial cells induced by oxidized low-density lipoprotein. The activities of SOD, NOS and the contents of MDA in the cell lysate were examined by enzyme method or spectrophotometry. The NO and ET-1 concentrations in the cell culture supernatant were measured by ELISA method. The iNOS and eNOS mRNA expression were measured by real time RT-PCR, while the phosphorylation levels of Akt was measured by Western blotting. The results showed that GRb3 could enhance the activity of SOD, reduce the content of MDA, increase the level of NOS, NO, ET-1 and iNOS mRNA expression while decrease the eNOS mRNA expression and the phosphorylation level of Akt. These effects were blocked by estrogen receptor antagonist ICI182780. GRb3 can play a role in protecting vascular endothelial cells by estrogen receptors, the protective mechanism is similar to 17-ß estrodiol.