Screening of a polar extract of Paeonia rockii: composition and antioxidant and antifungal activities

Ethnopharmacological relevance

The genus Paeonia (Paeoniaceae), is one of the most important source of crude drugs in traditional Chinese medicine and investigation on many species is large. Up to now studies on Paeonia rockii, one of the eight species recognized in the section Moutan, are very limited.

Aim of the study

This research aimed to investigate the composition of Paeonia rockii roots and to evaluate the in vitro free-radical scavenging and antifungal activities of a polar extract (PPR) and its major constituents.

Materials and methods

PPR was obtained from defatted dried roots of Paeonia rockii using MeOH as extraction solvent. Its n-BuOH soluble portion (PPR-B) was purified by Sephadex LH-20 followed by RP-HPLC to give nineteen compounds belonging to the classes polyphenols, monoterpenes and triterpenes. Their structure were spectrally characterized (UV, 1D and 2D NMR, MS). The polyphenols content of PPR and PPR-B was examined by the Folin-Ciocalteau colorimetric assay and HPLC method. Both extracts (PPR and PPR-B) and their major constituents were tested for the free-radical scavenging activity by DPPH-test, and for the antifungal activity by three methods (micro-broth dilution method, XTT assay and Candida albicans morphological analysis).

Results

5-Butylhydroxy-γ-lactone (1), and ethyl-arabinopyranoside (2) have been isolated for the first time as naturally occurring compounds and taxifolin (3) was reported for the first time in Paeonia spp. Nine polyphenols, four monoterpenes and three triterpenes were also identified. Both the extracts PPR and PPR-B had high polyphenol content, and high concentration of gallic acid derivatives and paeoniflorin, chemotaxonomic characteristic markers of the genus. PPR, gallic acid and methyl-gallate displayed high potency in scavenging free-radicals (DPPH test, EC₅₀ 13.3, 1.2, 1.9 μg/ml, respectively). Both the extracts and gallic acid individually showed an interesting antifungal property (MIC₅₀ at 24 h 25, 0.9 and 30 μg/ml, respectively) and notably, a combination of paeoniflorin/gallic acid (MIC₅₀ = 0.5 + 20 μg/ml, respectively) was more active than the single compound in inhibiting Candida growth.

Conclusion

The polar methanolic extract (PPR), its n-BuOH soluble fraction and constituents of Paeonia rockii were extensively investigated. Both extracts and some of their compounds have the ability to scavenge free-radicals and to inhibit Candida albicans growth.     

Process stationarity and reliability of trunk postural stability

BACKGROUND: Empirical assessments of torso stability can be estimated from postural variability and nonlinear analyses of seated balance tasks. However, processing methods require sufficient signal duration and test-retest experiments require the assessment must be reliable. Our goal was to characterize the reliability and establish the trial duration for torso stability assessment. METHODS: Kinetic and kinematic data were recorded while subjects maintained a seated posture on a wobbly seat pan. Stability was evaluated from dynamic variability and nonlinear stability analyses. Process stationarity of the measured signals characterized the minimum necessary trial duration. Intra-class correlations measured within-session and between-session reliability. FINDINGS: Trial duration necessary to achieve process stationarity was 30.2 s. Shorter time to stationarity was observed with measures that included multi-dimensional movement behavior. Summary statistics of movement variability demonstrated moderate intra-session reliability, intra-class correlation=0.64 (range 0.38-0.87). Inter-session reliability for movement variance was moderate, intra-class correlation=0.42 (range 0.22-0.64). Nonlinear stability measures typically performed better than estimates of variability with inter-session reliability as high as intra-class correlation=0.83. Process stationarity and reliability were improved in more difficult balance conditions. INTERPRETATION: To adequately capture torso dynamics during the stability assessment the trial duration should be at least 30 s. Moderate to excellent test-retest reliability can be achieved in intra-session analyses, but more repeated measurements are required for inter-session comparisons. Stability diffusion exponents, H(S), and the Lyapunov exponents provide excellent measures for intra-session analyses, while H(S) provides excellent inter-session comparisons of torso stability.     

Effects of trunk exertion force and direction on postural control of the trunk during unstable sitting

BACKGROUND: Pushing and pulling exertions have been implicated as risk factors of low-back disorders. In an attempt to investigate the mechanisms by which pushing and pulling influence risk for low-back disorders, the goal of this study was to investigate the effects of trunk exertion force and exertion direction on postural control of the trunk during unstable sitting. METHODS: Seat movements were recorded while subjects maintained a seated posture on a wobbly chair against different exertion forces (0N, 40N, and 80N) and exertion directions (trunk flexion and extension). Postural control of the trunk was assessed from kinematic variability (root-mean-squared amplitude and 95% ellipse area) and non-linear stability analyses (stability diffusion exponent and maximum finite-time Lyapunov exponent). FINDINGS: Kinematic variability and non-linear stability estimates increased as exertion force increased including root-mean-squared amplitude (P<0.001), 95% ellipse area (P<0.001), stability diffusion exponent (P=0.042), and maximum finite-time Lyapunov exponent (P<0.001). A subset of measures indicated postural control of the trunk was poorer during flexion exertions compared to extension exertions including root-mean-squared amplitude (P<0.001), 95% ellipse area (P=0.046), and maximum finite-time Lyapunov exponent (P=0.002). INTERPRETATION: Trunk exertion force and exertion direction affect postural control of the trunk. This study may aid in understanding how pushing and pulling exertions can potentially contribute to low-back disorders.     

Effects of seated whole-body vibration on postural control of the trunk during unstable seated balance

BACKGROUND: Low back disorders and their prevention is of great importance for companies and their employees. Whole-body vibration is thought to be a risk factor for low back disorders, but the neuromuscular, biomechanical, and/or physiological mechanisms responsible for this increased risk are unclear. The purpose of this study was to measure the acute effect of seated whole-body vibration on the postural control of the trunk during unstable seated balance. METHODS: Twenty-one healthy subjects (age: 23 years (SD 4 years)) were tested on a wobble chair designed to measure trunk postural control. Measurements of kinematic variance and non-linear stability control were based on seat angle before and after 30 min of seated whole-body vibration (bandwidth=2-20 Hz, root-mean-squared amplitude=1.15m/s(2)). FINDINGS: All measures of kinematic variance of unstable seated balance increased (P<0.05) after vibration including: ellipse area (35.5%), root-mean-squared radial lean angle (17.9%), and path length (12.2%). Measures of non-linear stability control also increased (P<0.05) including Lyapunov exponent (8.78%), stability diffusion analysis (1.95%), and Hurst rescaled range analysis (5.2%). INTERPRETATION: Whole-body vibration impaired postural control of the trunk as evidenced by the increase in kinematic variance and non-linear stability control measures during unstable sitting. These findings imply an impairment in spinal stability and a mechanism by which vibration may increase low back injury risk. Future work should investigate the effects of whole-body vibration on the anatomical and neuromuscular components that contribute to spinal stability.     

Intra-arterial nimodipine to treat symptomatic cerebral vasospasm following traumatic subarachnoid haemorrhage. Technical case report

Summary  Intra-arterial Nimodipine administration can be an effective alternative to papaverine or balloon angioplasty for the treatment of cerebral vasospasm refractory to medical therapy. It has been used for intractable vasospasm due to aneurysmal subarachnoid haemorrhage (SAH) with convincing results and no significant complications in small case series. This report describes of a patient with symptomatic and angiographically documented vasospasm following traumatic SAH which was refractory to maximal medical therapy and successfully treated with intra-arterial infusion of Nimodipine. This first reported technical note is with special reference to the nimodipine administration modalities, clinical and neuroradiological criteria of selection as well as the follow up of the patient.     

Oxygen consumption is depressed in patients with lactic acidosis due to biguanide intoxication

Introduction  

Lactic acidosis can develop during biguanide (metformin and phenformin) intoxication, possibly as a consequence of mitochondrial dysfunction. To verify this hypothesis, we investigated whether body oxygen consumption (VO₂), that primarily depends on mitochondrial respiration, is depressed in patients with biguanide intoxication.     

Aminophylline blood levels with concomitant erythromycin therapy in relapsed chronic obstructive lung disease

Sixty patients affected by chronic obstructive lung disease (COLD) in relapse were treated with erythromycin and aminophylline. The patients were divided into three groups: Group A received 2 g erythromycin and 1200 mg aminophylline daily, and Group B and C received 2 g erythromycin with respectively 800 mg and 600 mg of aminophylline daily, administered as two oral doses in each case. On day 5 of therapy, we chromatographically evaluated aminophylline in a serum sample taken two hours after morning drug administration which corresponds to the peak plasma level. We also evaluated certain biohumoral, microbiological, radiological and electrocardiographic parameters both before and after therapy. Statistical analysis of the data was performed by the Student's t test. Our data confirm that 600-800 mg oral aminophylline administered simultaneously with erythromycin induce an improvement in the respiratory function of patients with relapsed COLD without elevating blood aminophylline levels and without side-effects.     

Females recruit quadriceps faster than males at multiple knee flexion angles following a weight-bearing rotary perturbation.

OBJECTIVE: To compare the effect of knee angle on muscle response times and neuromuscular recruitment patterns between sexes following a perturbation in single leg stance at 10 degrees, 20 degrees, and 30 degrees. We hypothesized that response times would be faster at lesser knee flexion angles and that females would recruit their quadriceps faster than males at all angles. DESIGN: A repeated-measures design. SETTING: Motion analysis laboratory. PARTICIPANTS: Twenty (10 female; 10 male) healthy, recreationally active volunteers. INTERVENTIONS: A rotary perturbation in single leg stance. OUTCOME MEASUREMENTS: Response times of the medial and lateral quadriceps, hamstrings, and gastrocnemius. RESULTS: There was a trend toward faster response times for all muscles closer toward extension. A consistent neuromuscular recruitment pattern for both males and females was evident for each knee angle tested. Females, however, contracted their quadriceps faster than males at all knee flexion angles. CONCLUSIONS: Small changes in knee angle near extension do not alter muscle response times and hence neuromuscular recruitment patterns in males and females. Regardless of knee flexion angle, following a perturbation in single leg stance, females contract their quadriceps faster than males. CLINICAL RELEVANCE: Earlier contraction of the quadriceps in females may increase anterior tibial translation and hence anterior cruciate ligament strain, thereby heightening injury risk.