Hot-Plate Test Lab Report

First, the weight of rats used in the experiment and the weight of the AVS022 and its components by weight of rats at various dose. Next, the herbs mixed with sterile water to the volume 40 ml/kg this the safety volume for oral administration140 and dispersed the herbs powder for easy feeding to the rats. The study of the effect of AVS022 and its components on pain and edema in rat used to the standard model as following Figure 4.1

Figure 4.1 Diagram for the investigation of the analgesic effect and anti-edematous effect of Ayurved Siriraj Ha-rak recipe (AVS022) and its components in Wistar rats

4.2.5 Study the central analgesic activity of AVS022 and its components on hot-plate test
Initial studies utilizing the hot-plate test
There were evaluated in early phase and late phase. Early phase is mediate by the central effect via a direct stimulation of C-fiber nociceptor by chemical irritant. Late phase is the inflammatory response mediate by peripheral effect via release some inflammatory mediator/transmitter. The formalin test was performed as described by Hunskaar and Hole 1987.121 The rats weighing 200-250 g were used, one hundred and twenty Wistar rat were randomly divided into twenty groups (N=6) as similar to previous model. The drug administrated by intragastrically of various dose of CM, CP, FR, HP, TT (60, 200 and 600 mg/kg) and AVS022 (300, 1,000 and 3,000 mg/kg) or indomethacin 10 mg/kg (treated once daily) sixty minutes before subcutaneous injection of 2.5% formalin solution (100 µl) into the plantar surface of the right hind paw. After formalin injection, the rat was immediately place individually in Plexiglas wall cylinder for observation. The licking time after injected paw was recorded by digital camera and expressed as total licking time in the early phase (0-5 minutes) and the late phase (20-30 minutes) after formalin injection.44-45 The licking time is the duration time when the rat lick or bit on injected paw to observed in time period. (Figure 4.5) The schematic plan of the formalin test was shown in Figure 4.6. The
Figure 4.7 Diagram illustrating the method for edema formation by Carrageenan induced on right hind paw of AVS022 and its components in rats. 142

Figure 4.8 The picture shows Plethysmometer (Kent scientific corporation, USA.), the instrument for measure paw volume on hind paw of rodent. The data expressed by the water replacement of the paw conducted electrical signaling, and the paw edema induced by carrageenan.

4.3 Statistical Analysis
The behavioral data by observation from hot-plate test and formalin test were expressed as mean ± SD. The data from the measurement of paw edema was expressed as mean ± SEM. All analyses were conducted by using Graph Pad Prism version 5.03 for Windows (Graph Pad Software Inc., San Diego, CA). Statistical comparison was analyzed by using Two-way analysis of variance (ANOVA) and Bonferroni post hoc test. The p value of less than 0.05 were considered