Heart rate (HR) and arterial blood pressure (BP) changes have been reported during conscious sedation with propofol and midazolam. One potential mechanism to explain these changes is that propofol and midazolam affect HR and BP via changes in the cardiac autonomic nervous system. Two specific hypotheses were tested by HR variability analysis: 1) propofol induces predominance of parasympathetic activity, leading to decreased HR and BP, and 2) midazolam induces predominance of sympathetic activity, leading to increased HR and decreased BP. Thirty dental patients were included in a prospective, randomized study. HR, BP, low frequency (LF), high frequency (HF), and entropy were monitored during the awake, sedation, and recovery periods and depth of sedation was assessed using the Observer's Assessment of Alertness/Sedation score. Propofol induced a significant decrease in total power (503 +/- 209 ms(2)/Hz versus 162 +/- 92 ms(2)/Hz) and LF/HF ratio (2.5 +/- 1.2 versus 1.0 +/- 0.4), despite the absence of any change in HR during the sedation period compared with baseline. Midazolam decreased normalized HF (34 +/- 10% versus 10 +/- 4%) but did not significantly change LF/HF ratio (2.3 +/- 1.1 versus 2.2 +/- 1.4) and increased HR in the sedation period. Compared with baseline, propofol was associated with a significant increase in normalized HF in the recovery period (34 +/- 11% versus 44 +/- 12%) and a significant decrease in HR, whereas midazolam was associated with an increase in LF/HF ratio (2.3 +/- 1.1 versus 3.7 +/- 1.8) with no change in HR. These results indicated a dominant parasympathetic effect of propofol and a dominant sympathetic effect of midazolam in both periods. These results should be considered during conscious sedation, especially in patients at risk of cardiovascular complications.

Zingiber officinale (ZO), commonly known as ginger, has been traditionally used in the treatment of diabetes mellitus. Several studies have reported the hypoglycaemic properties of ginger in animal models. The present study evaluated the antihyperglycaemic effect of its aqueous extract administered orally (daily) in three different doses (100, 300, 500 mg/kg body weight) for a period of 30 d to streptozotocin (STZ)-induced diabetic rats. A dose-dependent antihyperglycaemic effect revealed a decrease of plasma glucose levels by 38 and 68 % on the 15th and 30th day, respectively, after the rats were given 500 mg/kg. The 500 mg/kg ZO significantly (P, 0·05) decreased kidney weight (% body weight) in ZO-treated diabetic rats v. control rats, although the decrease in liver weight (% body weight) was not statistically significant. Kidney glycogen content increased significantly (P,0·05) while liver and skeletal muscle glycogen content decreased significantly (P,0·05) in diabetic controls v. normal controls. ZO (500 mg/kg) also significantly decreased kidney glycogen (P,0·05) and increased liver and skeletal muscle glycogen in STZ-diabetic rats when compared to diabetic controls. Activities of glucokinase, phosphofructokinase and pyruvate kinase in diabetic controls were decreased by 94, 53 and 61 %, respectively, when compared to normal controls; and ZO significantly increased (P,0·05) those enzymes' activities in STZ-diabetic rats. Therefore, the present study showed that ginger is a potential phytomedicine for the treatment of diabetes through its effects on the activities of glycolytic enzymes.

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