Scavenging of reactive oxygen species effectively reduces Pseudomonas aeruginosa biofilms through disrupting policing.

Biofilm formation is likely to contribute greatly to antibiotic resistance in bacteria and therefore the efficient removal of bacterial biofilms needs addressing urgently. Here, we reported that the supplement of non-inhibitory concentration of N-acetyl-L-cysteine (NAC), a common reactive oxygen species (ROS) scavenger, can significantly reduce the biomass of mature Pseudomonas aeruginosa biofilms (corroborated by crystal violet assay and laser scanning confocal microscopy). 1 mM NAC increased the cheater (ΔlasR mutant) frequency to 89.4 ± 1.5% in the evolved PAO1 after the 15-day treatment. Scavenging of ROS by NAC induced the collapse of P. aeruginosa biofilms, but it did not alter quorum sensing-regulated genes expression (e.g., hcnC and cioAB) and hydrogen cyanide production. The replenishment of public good protease contributed to the recovery of biofilm biomass, indicating the role of disrupting policing in biofilm inhibition. Furthermore, 7 typical ROS scavengers (e.g., superoxide dismutase, catalase and peroxidase, etc.) also effectively inhibited mature P. aeruginosa biofilms. This study demonstrates that scavenging of ROS can promote the selective control of P. aeruginosa biofilms through policing disruption as a targeted biofilm control strategy in complex water environments.

Identification of Flavonoids from Scutellaria barbata D. Don as Inhibitors of HIV-1 and Cathepsin L Proteases and Their Structure-Activity Relationships.

Scutellaria barbata D. Don (SB, Chinese: Ban Zhi Lian), a well-known medicinal plant used in traditional Chinese medicine, is rich in flavonoids. It possesses antitumor, anti-inflammatory, and antiviral activities. In this study, we evaluated the inhibitory activities of SB extracts and its active components against HIV-1 protease (HIV-1 PR) and SARS-CoV2 viral cathepsin L protease (Cat L PR). UPLC/HRMS was used to identify and quantify the major active flavonoids in different SB extracts, and fluorescence resonance energy transfer (FRET) assays were used to determine HIV-1 PR and Cat L PR inhibitions and identify structure-activity relationships. Molecular docking was also performed, to explore the diversification in bonding patterns of the active flavonoids upon binding to the two PRs. Three SB extracts (SBW, SB30, and SB60) and nine flavonoids inhibited HIV-1 PR with an IC50 range from 0.006 to 0.83 mg/mL. Six of the flavonoids showed 10~37.6% inhibition of Cat L PR at a concentration of 0.1 mg/mL. The results showed that the introduction of the 4'-hydroxyl and 6-hydroxyl/methoxy groups was essential in the 5,6,7-trihydroxyl and 5,7,4'-trihydroxyl flavones, respectively, to enhance their dual anti-PR activities. Hence, the 5,6,7,4'-tetrahydroxyl flavone scutellarein (HIV-1 PR, IC50 = 0.068 mg/mL; Cat L PR, IC50 = 0.43 mg/mL) may serve as a lead compound to develop more effective dual protease inhibitors. The 5,7,3',4'-tetrahydroxyl flavone luteolin also showed a potent and selective inhibition of HIV-1 PR (IC50 = 0.039 mg/mL).

Dual Inhibition of HIV-1 and Cathepsin L Proteases by Sarcandra glabra.

The COVID-19 pandemic continues to impose a huge threat on human health due to rapid viral mutations. Thus, it is imperative to develop more potent antivirals with both prophylactic and treatment functions. In this study, we screened for potential antiviral compounds from Sarcandra glabra (SG) against Cathepsin L and HIV-1 proteases. A FRET assay was applied to investigate the inhibitory effects and UPLC-HRMS was employed to identify and quantify the bioactive components. Furthermore, molecular docking was carried out to get a glimpse of the binding of active compounds to the proteases. Our results showed that the SG extracts (SGW, SG30, SG60, and SG85) inhibited HIV-1 protease with an IC50 of 0.003~0.07 mg/mL and Cathepsin L protease with an IC50 of 0.11~0.26 mg/mL. Fourteen compounds were identified along with eight quantified from the SG extracts. Chlorogenic acid, which presented in high content in the extracts (12.7~15.76 µg/mg), possessed the most potent inhibitory activity against HIV-1 protease (IC50 = 0.026 mg/mL) and Cathepsin L protease (inhibition: 40.8% at 0.01 mg/mL). Thus, SG extracts and the active ingredients could potentially be used to prevent/treat viral infections, including SARS-CoV-2, due to their dual-inhibition functions against viral proteases.

Antiviral activity and active components of the leaves from Sabia parviflora Wall. ex Roxb.

Sabia parviflora (SP, "xiao hua qing feng teng" in Chinese) was recorded as an important ethnic medicine to be used for treating viral hepatitis. The antiviral activity of four SP extracts and potent antiviral compounds evaluated with cathepsin L protease (Cat L PR) and HIV-1 protease (HIV-1 PR). UPLC-HRMS was used for identifying the bioactive components. In addition, the possible inhibitory mechanism of the identified compounds on viral protease was further discussed by molecular docking. As a result, four extracts of SP exhibited inhibitory activity of HIV-1 PR and Cat L PR with IC50 range from 0.015 to 0.80 mg/mL. Meanwhile, six compounds inhibited HIV-1 PR with IC50 range from 0.032 to 0.80 mg/mL. Moreover, procyanidin B2 had good affinity for HIV-1 PR and CatL PR protein, respectively. These findings suggest S. parviflora leaves can be used for treating HIV and procyanidin B2 may play a role in antiviral protease.

Investigation of a Progressive Relaxation Training Intervention on Precompetition Anxiety and Sports Performance Among Collegiate Student Athletes.

This study aims to investigate whether simple and convenient progressive relaxation training (PRT) is effective in enhancing collegiate student athletes' mental health and sports performance. An experimental group of 14 (6 female) and a control group of 10 (5 female) collegiate student athletes were recruited from among track and field athletes who were preparing for provincial competition. The experimental group was exposed to a PRT intervention in 30-min sessions conducted twice per week for a duration of one month. At baseline, the Competitive State Anxiety Inventory-2 (CSAI-2), State-Trait Anxiety Inventory (STAI), and Eysenck Personality Questionnaire-Revised Short Scale for Chinese (EPQ-RSC) were completed, while only the CSAI-2 was reassessed at one, two, and three weeks after initiation of the intervention. Additionally, within half a day after completing all one's individual competition events, the CSAI-2 was again assessed in the two groups recalling their memory of their precompetition state anxiety. Then, the differences in the three dimensions of the CSAI-2 between the two groups at the five time points introduced above were compared. This study also explored whether PRT affected sports performance, defined by the athletes reaching their best records or not, by logistic regressive analysis. This study found significant between-group differences in the self-confidence dimension score at the second and third time points. Through logistic regression analysis, a positive effect of PRT was found for the enhancement of sports performance. In sum, PRT showed positive effects on precompetition state self-confidence and enhanced sports performance among collegiate student athletes.

Conditional quorum-sensing induction of a cyanide-insensitive terminal oxidase stabilizes cooperating populations of Pseudomonas aeruginosa.

Pseudomonas aeruginosa, an opportunistic pathogen of humans, uses quorum sensing (QS) to regulate the production of extracellular products that can benefit all members of the population. P. aeruginosa can police QS-deficient cheaters by producing hydrogen cyanide, which is also QS regulated; however, the mechanism by which cooperators selectively protect themselves from the toxicity of cyanide remained unresolved. Here, we show that a cyanide-insensitive terminal oxidase encoded by cioAB provides resistance to cyanide, but only in QS-proficient strains. QS-deficient cheaters do not activate cioAB transcription. QS-mediated regulation of cioAB expression depends on production of both cyanide by cooperators (which is QS regulated) and reactive oxygen species (ROS) from cheaters (which is not QS regulated). This type of regulatory system allows cooperating populations to respond, via ROS, to the presence of cheaters, and might allow them to defer the substantial metabolic cost of policing until cheaters are present in the population.

[Clinical observation of hand-assisted laparoscopic live donor nephrectomy].

OBJECTIVE: To investigate the feasibility and advantage of hand-assisted laparoscopic live donor nephrectomy in renal transplantation. METHODS: Six living relative donors received retroperitoneal left-side laparoscopic nephrectomy. The operating time of nephrectomy, the warm ischemic time, the recovery time of allograft and donors were recorded and analyzed. RESULTS: The mean operating time of nephrectomy was 150 minutes, the mean warm ischemic time was 3.5 minutes, and the mean time of micturition after graft reperfusion was 82 seconds. The donors recovered rapidly and returned to normal within 30 days . The urine volume and renal function of the 6 recipients were normal without complications in the following 3 months. CONCLUSION: Hand-assisted laparoscopic live donor nephrectomy is feasible with short operating time and warm ischemic time; the donors experience less pain, and recover rapidly. This technique may be widely used in living donor nephrectomy.