Abstract The polyphenol oxidase (PPO) is an enzyme that is responsible for the enzymatic browning of fruits and vegetables. This is generally undesired process and need to be prevented in food technology. PPO from purslane was purified, characterised and the kinetic parameters for three substrates namely, catechol, L-Dopa and 4-methylcatechol were determined. The optimum pH and temperature values were found to be pH 7.0 and 50 °C, respectively using the catechol as substrate. The apparent molecular weight of the PPO from purslane was determined as high as 163 kDa by partially denaturing SDS-PAGE. Moreover, the inhibition kinetics of the purified PPO were determined, using both synthetic and natural inhibitors. Among inhibitors tested, ascorbic acid was the most effective inhibitor with the lowest Ki value of 0.36 mM. This is the first study on the purification and characterisation of PPO from purslane (Portulaca oleracea) that may provide new insight into how to overcome the enzymatic browning.

PURPOSE: A considerable percentage of patients with benign prostatic hyperplasia (BPH) also have additional cardiac pathologies, which often require anticoagulant therapy. The aim of this study was to evaluate the efficacy and safety of photoselective vaporization of the prostate (PVP) for BPH in cardiac patients receiving anticoagulant therapy. MATERIALS AND METHODS: A total of 67 patients suffering from BPH and high risk cardiac pathologies were operated on using laser prostatectomy. All patients had cardiac pathologies with bleeding disorders requiring anticoagulant use, and underwent standard urologic evaluation for BPH. Patients were treated with laser prostatectomy for relief of the obstruction using the KTP/532 laser energy at 80 W. RESULTS: The mean patient age was 71.4 years (range 55-80). Mean prostate volume on transrectal ultrasonography was 73.2 mL (range 44-120). Operation time ranged from 40 to 90 min, with an average value of 55 min. The average hospital stay was 48 hours (range 12-72) and the Foley catheters were removed within 48 hours, with a mean catheterization time of 34.2 ± 5.9 hours (0-48). No patient required an additional procedure due to severe bleeding necessitating intervention during the early postoperative phase. Mean International symptoms scoring system (IPSS) values and post voiding residual volume decreased and peak urinary flow rate increased (p < 0.001). Our results showed that the mean prostate volume had decreased by 53% at 6 months. CONCLUSIONS: High-power photo selective laser vaporization prostatectomy is a feasible, safe, and effective alternative for the minimal invasive management of BPH, particularly in cardiac patients receiving anticoagulant therapy.