Effects of lianas on forest biogeochemistry during their lives and afterlives.

Climate change and other anthropogenic disturbances are increasing liana abundance and biomass in many tropical and subtropical forests. While the effects of living lianas on species diversity, ecosystem carbon, and nutrient dynamics are receiving increasing attention, the role of dead lianas in forest ecosystems has been little studied and is poorly understood. Trees and lianas coexist as the major woody components of forests worldwide, but they have very different ecological strategies, with lianas relying on trees for mechanical support. Consequently, trees and lianas have evolved highly divergent stem, leaf, and root traits. Here we show that this trait divergence is likely to persist after death, into the afterlives of these organs, leading to divergent effects on forest biogeochemistry. We introduce a conceptual framework combining horizontal, vertical, and time dimensions for the effects of liana proliferation and liana tissue decomposition on ecosystem carbon and nutrient cycling. We propose a series of empirical studies comparing traits between lianas and trees to answer questions concerning the influence of trait afterlives on the decomposability of liana and tree organs. Such studies will increase our understanding of the contribution of lianas to terrestrial biogeochemical cycling, and help predict the effects of their increasing abundance.

A meta-analysis on the efficacy of vacuum sealing drainage combined with autologous platelet-rich plasma in the treatment of Grade 2 and Grade 3 diabetic foot ulcers.

This meta-analysis aims to systemically evaluate the efficacy of vacuum sealing drainage (VSD) combined with autologous platelet-rich plasma (PRP) in the treatment of diabetic foot ulcers (DFU). The China HowNet, China Biomedical Literature, VIP periodical resource integration service platform, Wanfang, Embase, Cochrane Central, and PubMed databases were retrieved using the computer. The retrieval period was up to July 2021. Randomised controlled trials on VSD combined with PRP in the treatment of DFU were collected. Those trials that met the inclusion criteria were included for meta-analysis using RevMan 5.3 software. A total of 13 articles were included. In the trial group, 477 patients with DFU were treated with VSD combined with PRP, while in the control group, 482 patients with DFU were treated with conventional dressings and/or VSD. The meta-analysis showed that, compared with the control group, VSD combined with PRP has significant advantages in shortening healing time (standardised mean difference [SMD] = -0.87, 95% confidence interval [CI]: -1.07 to -0.67, P < .00001), improving ulcer healing rates (odds ratio = 4.01, 95% CI: 2.95 ~ 5.46, P < .00001), and reducing hospital stays (mean difference = -15.29, 95% CI: -16.05 to -14.54, P < .00001), but the differences in dressing change times (SMD = -1.27, 95% CI: -2.71 to 0.17, P = .08) and hospitalisation expenses (SMD = -0.16, 95% CI: -13.40 to 13.07, P = .98) were not statistically significant. VSD combined with autologous PRP has good curative efficacy in the treatment of DFU and is a better treatment option. However, this treatment is limited in patients with platelet dysfunction, thrombocytopenia, leukaemia, and poor general condition.

A multi-targeting drug design strategy for identifying potent anti-SARS-CoV-2 inhibitors.

The COVID-19, caused by SARS-CoV-2, is threatening public health, and there is no effective treatment. In this study, we have implemented a multi-targeted anti-viral drug design strategy to discover highly potent SARS-CoV-2 inhibitors, which simultaneously act on the host ribosome, viral RNA as well as RNA-dependent RNA polymerases, and nucleocapsid protein of the virus, to impair viral translation, frameshifting, replication, and assembly. Driven by this strategy, three alkaloids, including lycorine, emetine, and cephaeline, were discovered to inhibit SARS-CoV-2 with EC50 values of low nanomolar levels potently. The findings in this work demonstrate the feasibility of this multi-targeting drug design strategy and provide a rationale for designing more potent anti-virus drugs.

Small Airway Dysfunction in Asthma Is Associated with Perceived Respiratory Symptoms, Non-Type 2 Airway Inflammation, and Poor Responses to Therapy.

BACKGROUND: Emerging evidence has indicated that small airway dysfunction (SAD) contributes to the clinical expression of asthma. OBJECTIVES: The aim of the study was to explore the relationships of SAD assessed by forced expiratory flow between 25 and 75% (FEF25-75%), with clinical and inflammatory profile and treatment responsiveness in asthma. METHOD: In study I, dyspnea intensity (Borg scale), chest tightness, wheezing and cough (visual analog scales, VASs), and pre- and post-methacholine challenge testing (MCT) were analyzed in asthma patients with SAD and non-SAD. In study II, asthma subjects with SAD and non-SAD underwent sputum induction, and inflammatory mediators in sputum were detected. Asthma patients with SAD and non-SAD receiving fixed treatments were prospectively followed up for 4 weeks in study III. Spirometry, Asthma Control Questionnaire (ACQ), and Asthma Control Test (ACT) were carried out to define treatment responsiveness. RESULTS: SAD subjects had more elevated ΔVAS for dyspnea (p = 0.027) and chest tightness (p = 0.032) after MCT. Asthma patients with SAD had significantly elevated interferon (IFN)-γ in sputum (p < 0.05), and Spearman partial correlation found FEF25-75% significantly related to IFN-γ and interleukin-8 (both having p < 0.05). Furthermore, multivariable regression analysis indicated SAD was significantly associated with worse treatment responses (decrease in ACQ ≥0.5 and increase in ACT ≥3) (p = 0.022 and p = 0.032). CONCLUSIONS: This study indicates that SAD in asthma predisposes patients to greater dyspnea intensity and chest tightness during bronchoconstriction. SAD patients with asthma are characterized by non-type 2 inflammation that may account for poor responsiveness to therapy.

Vogesella urethralis sp. nov., isolated from human urine, and emended descriptions of Vogesella perlucida and Vogesella mureinivorans.

A novel Vogesella strain, YM-1T, was recovered from human urine in PR China in 2017. Cells of strain YM-1T were Gram-stain-negative, rod-shaped, aerobic, motile, non-spore-forming and poly-ß-hydroxybutyrate-accumulating. The strain contained C16:1ω6c/C 16:1ω7c, C16:0 and C18:0ω7c as major fatty acids; phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified phospholipid as major polar lipids; and ubiquinone-8 as the predominant respiratory quinone. Comparison of 16S rRNA gene sequences indicated that this strain had highest similarities to Vogesella perlucida DS-28T (98.8 %) and Vogesella mureinivorans 389T (98.1 %). The results of phylogenetic analysis based on the 16S rRNA gene sequences revealed that the novel strain was clustered and well separated with V. perlucida DS-28T and V. mureinivorans 389T within the genus Vogesella. The average nucleotide identity (ANI) and amino acid identity (AAI) analyses showed that this strain was not identified as V. perlucida DS-28T or V. mureinivorans 389T, with values well below the threshold limit for species demarcation (ANI <88.1 %, AAI <88.6 %). Based on the above results, strain YM-1T is proposed to be a novel species of the genus Vogesella with the name Vogesella urethralis sp. nov. (YM-1T=NBRC 113779=CGMCC 1.17135).

Discovery and biological evaluation of N-(3-(7-((2-methoxy-4-(4-methylpiperazin-1-yl)phenyl)amino)-4-methyl-2-oxo-2H-pyrimido[4,5-d][1,3]oxazin-1(4H)-yl)phenyl)acrylamide as potent Bruton's tyrosine kinase inhibitors.

Bruton's tyrosine kinase (BTK) is a key component of the B cell receptor (BCR) signaling pathway and plays a crucial role in B cell malignancies and autoimmune disorders; thus, it is an attractive target for the treatment of B cell related diseases. Here, we evaluated the BTK inhibitory activity of a series of pyrimido[4,5-d][1,3]oxazin-2-one derivatives. Combining this evaluation with structure-activity relationship (SAR) analysis, we found that compound 2 exhibited potent BTK kinase inhibitory activity, with an IC50 of 7 nM. This derivative markedly inhibited BTK activation in TMD8 B cell lymphoma cells and thus inhibited the in vitro growth of the cells. Further studies revealed that compound 2 dose dependently arrested TMD8 cells at G1 phase, accompanied by decreased levels of Rb, phosphorylated Rb, and cyclin D1. Moreover, following treatment with compound 2, TMD8 cells underwent apoptosis associated with PARP and caspase 3 cleavage. Interestingly, the results of the kinase activity assay on a small panel of 35 kinases showed that the kinase selectivity of compound 2 was superior to that of the first-generation inhibitor ibrutinib, suggesting that compound 2 could be a second-generation inhibitor of BTK. In conclusion, we identified a potent and highly selective BTK inhibitor worthy of further development.

C11, a novel fibroblast growth factor receptor 1 (FGFR1) inhibitor, suppresses breast cancer metastasis and angiogenesis.

The fibroblast growth factor receptors (FGFRs) are increasingly considered attractive targets for therapeutic cancer intervention due to their roles in tumor metastasis and angiogenesis. Here, we identified a new selective FGFR inhibitor, C11, and assessed its antitumor activities. C11 was a selective FGFR1 inhibitor with an IC50 of 19 nM among a panel of 20 tyrosine kinases. C11 inhibited cell proliferation in various tumors, particularly bladder cancer and breast cancer. C11 also inhibited breast cancer MDA-MB-231 cell migration and invasion via suppression of FGFR1 phosphorylation and its downstream signaling pathway. Suppression of matrix metalloproteinases 2/9 (MMP2/9) was associated with the anti-motility activity of C11. Furthermore, the anti-angiogenesis activity of C11 was verified in endothelial cells and chicken chorioallantoic membranes (CAMs). C11 inhibited the migration and tube formation of HMEC-1 endothelial cells and inhibited angiogenesis in a CAM assay. In sum, C11 is a novel selective FGFR1 inhibitor that exhibits potent activity against breast cancer metastasis and angiogenesis.

In Vitro Human Dihydroorotate Dehydrogenase Inhibitory, Anti-inflammatory and Cytotoxic Activities of Alkaloids from the Seeds of Nigella glandulifera.

Four new dolabellane-type diterpene alkaloids, glandulamines A - D (1:  - 4: ), together with twelve known compounds (5:  - 16: ), were isolated from the seeds of Nigella glandulifera using repeated column chromatography and semipreparative HPLC. The structures of 1:  - 16: were elucidated based on NMR data analysis, HRMS experiments and other spectroscopic interpretations. The absolute configuration of 5: was determined by single-crystal X-ray diffraction data for the first time. Compounds 10: and 12: showed human dihydroorotate dehydrogenase inhibitory activity with IC50 values of 61.1 ± 5.3 and 45.9 ± 3.0 µM, respectively. Molecular docking of the active compound 12: and positive control teriflunomide on the inhibitor-binding site of human dihydroorotate dehydrogenase was subsequently performed to visualize the interaction pattern. In addition, compounds 8: and 10: exhibited inhibitory effects against lipopolysaccharide-induced nitric oxide production with inhibition rates of 61 and 41%, respectively, at the concentration of 10 µM. Compounds 9: and 12: showed cytotoxic activities with cell viability varying from 29 ~ 57% at 100 µM against T98G, U87, U251, and GL261 glioma cancer cell lines. These data provide new insights on the pharmacologically active compounds of this plant widely used in folk medicine.

[Design, synthesis and structure-activity relationship studies of human dihydroorotate dehydrogenase inhibitors].

In this study, 1-(3-(4-chlorophenyl)-5-methylthio-1H-1,2,4-triazol-1-yl)-butan-1-one discovered previously in our lab was selected as a inhibitor of human dihydroorotate dehydrogenase ( HsDHODH) for structural optimization. The co-crystal of HsDHODH with the hit was obtained and analyzed for guiding the subsequent structural optimization. As a result, a series of novel triazole derivatives were designed and synthesized as potent HsDHODH inhibitors. Among them, compound (3-(4-chlorophenyl)-5-ethylthio-1H- 1,2,4-triazol-1-yl)-furan-2-yl-methanone displayed high potency in the inhibition of HsDHODH with an IC50 value of 1.50 µmol·L−1. Meanwhile, the structure-activity relationships were analyzed based on the biological data and the co-crystal structure. These results provide a valuable reference for optimization of 1H-1,2,4- triazole derivatives as HsDHODH inhibitors in the future.

Anxiety but not depression symptoms are associated with greater perceived dyspnea in asthma during bronchoconstriction.

OBJECTIVE: To determine whether anxiety and depression are associated with greater respiratory discomfort in asthma. METHODS: Adults with asthma (n = 230) underwent methacholine (Mch) challenge. Anxiety and depression, asthma control, and quality of life were evaluated at study entry by using the Hospital Anxiety and Depression Scale, Asthma Control Test, and Asthma Quality of Life Questionnaire, respectively. Qualitative descriptors of breathlessness, dyspnea intensity (modified Borg scale and visual analog scale [VAS]), and other respiratory symptoms were evaluated before and after Mch challenge. RESULTS: Patients were classified as neither anxiety nor depression (NAD), anxiety only, depression only (D), or both anxiety and depression (AD) according to the Hospital Anxiety and Depression Scale score. Asthma Control Test and Asthma Control Test, and Asthma Quality of Life Questionnaire scores were lowest in the AD group (both p < 0.001). VAS scores for dyspnea and wheezing before Mch challenge were highest in the AD group (both p < 0.05). The increase in the modified Borg scale score after Mch challenge was higher in the AD group (mean [standard deviation] 2.5 ± 2.0) than in the NAD (1.5 ± 1.5) and D (0.8 ± 0.9) groups (p = 0.006 and p = 0.003, respectively). Most descriptors of breathlessness were more prevalent in the anxiety only, D, and AD groups than in the NAD group. Multivariable logistic regression models indicated that anxiety increased the risk of dyspnea (odds ratio 1.10, p < 0.001 for the Borg score; odds ratio 3.84, p = 0.032 for the VAS score) but not for other respiratory symptoms. CONCLUSIONS: Anxiety but not depression was associated with greater perceived dyspnea intensity but not other measures of respiratory discomfort in individuals with asthma. Anxiety may shape the quality and intensity of dyspnea at a given respiratory load.

Bifidobacteria stabilize claudins at tight junctions and prevent intestinal barrier dysfunction in mouse necrotizing enterocolitis.

Whether intestinal barrier disruption precedes or is the consequence of intestinal injury in necrotizing enterocolitis (NEC) remains unknown. Using a neonatal mouse NEC model, we examined the changes in intestinal permeability and specific tight-junction (TJ) proteins preceding NEC and asked whether these changes are prevented by administration of Bifidobacterium infantis, a probiotic known to decrease NEC incidence in humans. Compared with dam-fed controls, pups submitted to the NEC protocol developed i) significantly increased intestinal permeability at 12 and 24 hours (as assessed by 70-kDa fluorescein isothiocyanate-dextran transmucosal flux); ii) occludin and claudin 4 internalization at 12 hours (as assessed by immunofluorescence and low-density membrane fraction immunoblotting); iii) increased claudin 2 expression at 6 hours and decreased claudin 4 and 7 expression at 24 hours; and iv) increased claudin 2 protein at 48 hours. Similar results were seen in human NEC, with claudin 2 protein increased. In mice, administration of B. infantis micro-organisms attenuated increases in intestinal permeability, preserved claudin 4 and occludin localization at TJs, and decreased NEC incidence. Thus, an increase in intestinal permeability precedes NEC and is associated with internalization of claudin 4 and occludin. Administration of B. infantis prevents these changes and reduces NEC incidence. The beneficial effect of B. infantis is, at least in part, due to its TJ and barrier-preserving properties.

Acupuncture for radicular pain: a review of analgesic mechanism.

Radicular pain, a common and complex form of neuropathic pain, presents significant challenges in treatment. Acupuncture, a therapy originating from ancient traditional Chinese medicine and widely utilized for various pain types, including radicular pain, has shown promising outcomes in the management of lumbar radicular pain, cervical radicular pain, and radicular pain due to spinal stenosis. Despite its efficacy, the exact mechanisms through which acupuncture achieves analgesia are not fully elucidated and are the subject of ongoing research. This review sheds light on the current understanding of the analgesic mechanisms of acupuncture for radicular pain, offering valuable perspectives for both clinical application and basic scientific research. Acupuncture is postulated to relieve radicular pain by several mechanisms: peripherally, it reduces muscle spasms, lessens mechanical pressure on nerve roots, and improves microcirculation; at the molecular level, it inhibits the HMGB1/RAGE and TLR4/NF-κB signaling pathways, thereby decreasing the release of pro-inflammatory cytokines; within the spinal cord, it influences synaptic plasticity; and centrally, it modulates brain function, particularly affecting the medial prefrontal cortex, anterior cingulate cortex, and thalamus within the default mode network. By acting across these diverse biological domains, acupuncture presents an effective treatment modality for radicular pain, and deepening our understanding of the underlying mechanisms regarding analgesia for radicular pain is crucial for enhancing its clinical efficacy and advancement in pain management.

Estimation of Protein and Amino Acid Requirements in Layer Chicks Depending on Dynamic Model.

Four trials were conducted to establish a protein and amino acid requirement model for layer chicks over 0-6 weeks by using the analytical factorization method. In trial 1, a total of 90 one-day-old Jing Tint 6 chicks with similar body weight were selected to determine the growth curve, carcass and feather protein deposition, and amino acid patterns of carcass and feather proteins. In trials 2 and 3, 24 seven-day-old and 24 thirty-five-day-old Jing Tint 6 chicks were selected to determine the protein maintenance requirements, amino acid pattern, and net protein utilization rate. In trial 4, 24 ten-day-old and 24 thirty-eight-day-old Jing Tint 6 chicks were selected to determine the standard terminal ileal digestibility of amino acids. The chicks were fed either a corn-soybean basal diet, a low nitrogen diet, or a nitrogen-free diet throughout the different trials. The Gompertz equation showed that there is a functional relationship between body weight and age, described as BWt(g) = 2669.317 × exp(-4.337 × exp(-0.019t)). Integration of the test results gave a comprehensive dynamic model equation that could accurately calculate the weekly protein and amino acid requirements of the layer chicks. By applying the model, it was found that the protein requirements for Jing Tint 6 chicks during the 6-week period were 21.15, 20.54, 18.26, 18.77, 17.79, and 16.51, respectively. The model-predicted amino acid requirements for Jing Tint 6 chicks during the 6-week period were as follows: Aspartic acid (0.992-1.284), Threonine (0.601-0.750), Serine (0.984-1.542), Glutamic acid (1.661-1.925), Glycine (0.992-1.227), Alanine (0.909-0.961), Valine (0.773-1.121), Cystine (0.843-1.347), Methionine (0.210-0.267), Isoleucine (0.590-0.715), Leucine (0.977-1.208), Tyrosine (0.362-0.504), Phenylalanine (0.584-0.786), Histidine (0.169-0.250), Lysine (0.3999-0.500), Arginine (0.824-1.147), Proline (1.114-1.684), and Tryptophan (0.063-0.098). In conclusion, this study constructed a dynamic model for the protein and amino acid requirements of Jing Tint 6 chicks during the brooding period, providing an important insight to improve precise feeding for layer chicks through this dynamic model calculation.

Jatropholane-type diterpenes from Euphorbia sikkimensis.

Four new jatropholane-type diterpenes (1-4), named sikkimenoids A-D, were isolated from the aerial parts of Euphorbia sikkimensis. The structural elucidations of 1-4 were accomplished by extensive NMR analyses, and their absolute configurations were established by ECD calculations. Compound 2 exhibited weak antiangiogenic activity with an IC(50) value of 43.0 µM when evaluated using a zebrafish model.

[Research of inhibition of compound gan shu kang on hepatitis B virus].

OBJECTIVE: To study the anti-HBV effect in vitro of each extract from compound Gan Shu Kang. METHODS: The toxicity was investigated with cytopathic effect (CPE) by enzyme linked immuno-adsorbed assay (ELISA), the inhibitory effect of each extract on HBsAg and HBeAg secreted by 2215 cell line infected by HBV DNA was evaluated. RESULTS: The half of the toxic concentration (TC50) of petroleum ether, ethyl acetate and n-butanol was 125, 375 and 62.5 microg/mL, respectively. The maximum nontoxic concentration (TC0) was 62.5, 125 and 31.3 microg/mL, respectively. The medium effective concentration (IC50) of petroleum ether and ethyl acetate on 2215 cellular HBsAg express the inhibitory effect was 48.6 and 14.0 microg/mL, HBeAg was 52.4 and 19.7 microg/mL, while the IC50 of n-butanol for HBsAg and HBeAg was more than 125 microg/mL. The therapeutic index (TI) of petroleum ether was 2.57 and 2.43, ethyl acetate was 26.7 and 19.04, n-butanol was both less than 2. CONCLUSION: The anti-HBV effect of ethyl acetate extract of compound Gan Shu Kang is better than that of petroleum ether, while the n-butanol extract shows no effect.

[Effects of enriched environment and impoverished environment on learning and memory ability of manganese-exposed mice].

OBJECTIVE: To investigate the effects of enriched environment and impoverished environment on the learning and memory ability of manganese-exposed mice and the mechanism. METHODS: Forty female Kunming mice were randomly and equally divided into 4 group: control group (CG), standard environment and manganese exposure group (SEG), enriched environment and manganese exposure group (EEG), and impoverished environment and manganese exposure group (IEG). The mouse model of manganese poisoning was established by intraperitoneal injection of manganese chloride. The learning and memory ability was tested by Morris water maze. The expression of cAMP response element-binding protein (CREB) in area CA1 of the hippocampus was measured by immunohistochemistry. RESULTS: In place navigation test, the SEG had a significantly longer escape latency than the CG (P < 0.05), and the EEG had a significantly shorter escape latency than the SEG (P < 0.05); there was no significant difference in escape latency between IEG and SEG (P > 0.05). In spatial probe test, the EEG had a significantly greater number of platform crossings than the SEG (P < 0.05), and the IEG had a significantly smaller number of platform crossings than the SEG (P < 0.05). The expression of CREB in area CA1 of the hippocampus was significantly lower in IEG and SEG than in CG (P < 0.05), and it was significantly higher in EEG than in SEG (P < 0.05). CONCLUSION: In the enriched environment, the learning and memory ability of manganese-exposed mice can be improved, which may be due to the increased expression of CREB in the hippocampus.

Drug compatibility with various closed intravenous infusion containers.

Objective: The aim was to systematically compare the drug compatibility with various closed intravenous (i.v.) infusion containers, to provide a reference for selecting a relatively superior infusion container and improve the medication safety for patients in clinical practice. Methods: The compatibility of four commonly used clinical injections (ceftazidime, pantoprazole sodium, ambroxol hydrochloride, edaravone) with three representative closed i. v. infusion containers (non-PVC infusion bags, upright polypropylene infusion bags, inner sealed polypropylene infusion bags) prefilled with infusion fluids (0.9% sodium chloride or 5% dextrose) in the Chinese market were investigated in this study. The particle counts of both infusion fluids and diluted chemical injections by infusion fluids in various infusion containers were determined by the light obscuration method. At 0, 2 and 6 h after four injections following dilution with infusion fluids in each container, the pH of the solutions was detected, and the physical properties were examined by visual inspection. Meanwhile, the drug concentrations were assessed by high performance liquid chromatography (HPLC). Results: As for either infusion fluids or diluted injections by infusion fluids, the particle counts in non-PVC infusion bags were significantly greater than those in the other two bags under some circumstances. The particle counts in diluted injections by infusion fluids increased dramatically compared with those in infusion fluids in all infusion containers, especially for the small-size particles. But pH, physical properties and drug concentrations of diluted infusion solutions in all infusion containers remained nearly unchanged over the test period. Conclusion: Closed i. v. infusion containers included in this study are all well-compatible with four injections. Moreover, the closed infusion containers produced by Chinese manufacturers have met the international quality standard. Particularly, the intravenous admixture preparation process needs to be optimized to reduce the overall particulate contaminants.

Erratum: [Corrigendum] MicroRNA­23a inhibits endometrial cancer cell development by targeting SIX1.

[This corrects the article DOI: 10.3892/ol.2019.10694.].

Leflunomide treatment for patients hospitalised with COVID-19: DEFEAT-COVID randomised controlled trial.

OBJECTIVE: To evaluate the clinical efficacy and safety of leflunomide (L) added to the standard-of-care (SOC) treatment in COVID-19 patients hospitalised with moderate/critical clinical symptoms. DESIGN: Prospective, open-label, multicentre, stratified, randomised clinical trial. SETTING: Five hospitals in UK and India, from September 2020 to May 2021. PARTICIPANTS: Adults with PCR confirmed COVID-19 infection with moderate/critical symptoms within 15 days of onset. INTERVENTION: Leflunomide 100 mg/day (3 days) followed by 10-20 mg/day (7 days) added to standard care. PRIMARY OUTCOMES: The time to clinical improvement (TTCI) defined as two-point reduction on a clinical status scale or live discharge prior to 28 days; safety profile measured by the incidence of adverse events (AEs) within 28 days. RESULTS: Eligible patients (n=214; age 56.3±14.9 years; 33% female) were randomised to SOC+L (n=104) and SOC group (n=110), stratified according to their clinical risk profile. TTCI was 7 vs 8 days in SOC+L vs SOC group (HR 1.317; 95% CI 0.980 to 1.768; p=0.070). Incidence of serious AEs was similar between the groups and none was attributed to leflunomide. In sensitivity analyses, excluding 10 patients not fulfilling the inclusion criteria and 3 who withdrew consent before leflunomide treatment, TTCI was 7 vs 8 days (HR 1.416, 95% CI 1.041 to 1.935; p=0.028), indicating a trend in favour of the intervention group. All-cause mortality rate was similar between groups, 9/104 vs 10/110. Duration of oxygen dependence was shorter in the SOC+L group being a median 6 days (IQR 4-8) compared with 7 days (IQR 5-10) in SOC group (p=0.047). CONCLUSION: Leflunomide, added to the SOC treatment for COVID-19, was safe and well tolerated but had no major impact on clinical outcomes. It may shorten the time of oxygen dependence by 1 day and thereby improve TTCI/hospital discharge in moderately affected COVID-19 patients. TRIAL REGISTRATION NUMBERS: EudraCT Number: 2020-002952-18, NCT05007678.