Emodin, a Natural Anthraquinone, Increases Uric Acid Excretion in Rats with Potassium Oxonate-Induced Hyperuricemia.

The treatment of hyperuricemia and gout is mostly based on lowering serum uric acid levels using drugs, such as allopurinol, or increasing urinary excretion of uric acid. However, some patients still experience adverse reactions to allopurinol and turn to Chinese medicine as an alternative. Therefore, it is crucial to design a preclinical study to obtain more convincing data on the treatment of hyperuricemia and gout with Chinese medicine. This study aimed to explore the therapeutic effect of emodin, a Chinese herbal extract, in a rat model of hyperuricemia and gout. In this study, we used 36 Sprague-Dawley rats, which were randomly divided into six groups for experimentation. Hyperuricemia was induced in rats by intraperitoneal injections of potassium oxonate. The efficacy of emodin in reducing serum uric acid levels was demonstrated by comparing the positive control group with groups treated with three different concentrations of emodin. The inflammatory profiles, including interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α levels, were unaffected by emodin treatment. In the experimental results, it was observed that the serum uric acid concentration in the vehicle control group was 1.80 ± 1.14, while the concentrations in the moderate and high concentration emodin groups were 1.18 ± 0.23 and 1.12 ± 0.57, resulting in no significant difference in uric acid concentration between these treatment groups and the control group, indicating that emodin has a therapeutic effect on hyperuricemia. The increase in the fractional excretion of uric acid (FEUA) demonstrated that emodin promoted urinary uric acid excretion without significantly affecting the inflammatory profile. Thus, emodin reduced the serum uric acid concentration to achieve effective treatment of hyperuricemia and gout by increasing urinary excretion. These results were supported by the measured serum uric acid and FEUA levels. Our data have potential implications for the treatment of gout and other types of hyperuricemia in clinical practice.

Subjective visual vertical imprecision during lateral head tilt in patients with chronic dizziness.

Most prior studies of the subjective visual vertical (SVV) focus on inaccuracy of subjects' SVV responses with the head in an upright position. Here we investigated SVV imprecision during lateral head tilt in patients with chronic dizziness compared to healthy controls. Forty-five dizzy patients and 45 healthy controls underwent SVV testing wearing virtual reality (VR) goggles, sitting upright (0°) and during head tilt in the roll plane (± 30°). Ten trials were completed in each of three static head positions. The SVV inaccuracy and SVV imprecision were analyzed and compared between groups, along with systematic errors during head tilt, i.e., A-effect and E-effect (E-effect is a typical SVV response during head tilts of ± 30°). The SVV imprecision was found to be affected by head position (upright/right head tilt/left head tilt, p < 0.001) and underlying dizziness (dizzy patients/healthy controls, p = 0.005). The SVV imprecision during left head tilt was greater in dizzy patients compared to healthy controls (p = 0.04). With right head tilt, there was a trend towards greater SVV imprecision in dizzy patients (p = 0.08). Dizzy patients were more likely to have bilateral (6.7%) or unilateral (22.2%) A-effect during lateral head tilt than healthy controls (bilateral (0%) or unilateral (6.7%) A-effect, p < 0.01). Greater SVV imprecision in chronically dizzy patients during head tilts may be attributable to increased noise of vestibular sensory afferents or disturbances of multisensory integration. Our findings suggest that SVV imprecision may be a useful clinical parameter of underlying dizziness measurable with bedside SVV testing in VR.

Test-retest reliability of subjective visual vertical measurements with lateral head tilt in virtual reality goggles.

OBJECTIVE: The objective is to investigate the test-retest reliability of subjective visual vertical (SVV) in the upright position and with lateral head tilts through a computerized SVV measuring system using virtual reality (VR) goggles. MATERIALS AND METHODS: Thirty healthy controls underwent SVV test in upright position, with the head tilted to the right 30°, and with the head tilted to the left 30°. Subjects wore SVV VR goggles, which contained a gyroscope for monitoring the angle of head tilt. Each subject completed 10 adjustments in each head position. The mean value of SVV deviations and SVV imprecision (the intra-individual variability of SVV deviations from the 10 adjustments) were recorded and compared across different head positions. The participants then repeated the same SVV protocol at least 1 week later. The test-retest reliability of SVV deviation and SVV imprecision were analyzed. RESULTS: The SVV deviation (mean ± standard deviation) was 0.22° ± 1.56° in upright position, -9.64° ± 5.91° in right head tilt, and 7.20° ± 6.36° in left head tilt. The test-retest reliability of SVV deviation was excellent in upright position (intra-class correlation coefficient [ICC] = 0.77, P < 0.001), right head tilt (ICC = 0.83, P < 0.001) and left head tilt (ICC = 0.84, P < 0.001). The SVV values from the 10 adjustments made during right and left head tilts were less precise than when measured at upright (P < 0.001). The test-retest reliability of SVV imprecision was poor at upright (ICC = 0.21, P = 0.26) but fair-to-good in right head tilt (ICC = 0.72, P < 0.001) and left head tilt (ICC = 0.44, P = 0.04). CONCLUSION: The test-retest reliability of SVV deviation during lateral head tilts via VR goggles is excellent, which supports further research into the diagnostic value of head-tilt SVV in various vestibular disorders. In addition, the degree of SVV imprecision during head tilt has fair-to-good test-retest reliability, which suggests SVV imprecision may have clinical applicability.