Methanolic Extract of Clinacanthus nutans Exerts Antinociceptive Activity via the Opioid/Nitric Oxide-Mediated, but cGMP-Independent, Pathways
Table 2
Effects of MECN on the hot plate test in mice.
Group
Dose (mg/kg)
Latency of discomfort(s) at respective time interval (min)
0 min
60 min
90 min
120 min
150 min
180 min
210 min
10% DMSO
6.29 ± 0.15
6.88 ± 0.29
6.89 ± 0.31
6.28 ± 0.12
6.76 ± 0.43
6.67 ± 0.33
6.46 ± 0.12
Nalox
5
6.55 ± 0.33
6.02 ± 0.34
5.50 ± 0.29
5.53 ± 0.37
5.63 ± 0.09
5.35 ± 0.15
5.20 ± 0.39
MECN
100
6.52 ± 0.24
6.50 ± 0.33
6.23 ± 0.25
6.25 ± 0.21
6.32 ± 0.27
5.99 ± 0.26
6.17 ± 0.22
250
6.08 ± 0.11
6.28 ± 0.28
6.68 ± 0.22
6.78 ± 0.19
6.59 ± 0.32
6.17 ± 0.18
6.39 ± 0.20
500
6.65 ± 0.35
10.28 ± 0.81
9.92 ± 0.55
9.52 ± 1.08
9.14 ± 0.51
9.14 ± 0.36
8.78 ± 0.81
Nalox + MECN
5 + 500
6.60 ± 0.38
5.98 ± 0.38#
5.52 ± 0.57#
5.79 ± 0.27#
5.54 ± 0.30#
5.56 ± 0.32#
5.59 ± 0.32#
Morphine
5
6.02 ± 0.15
17.00 ± 0.90
18.42 ± 0.47
17.25 ± 0.93
13.47 ± 1.31
11.87 ± 1.04
11.15 ± 0.71
Morphine + Nalox
5 + 5
6.58 ± 0.24
7.08 ± 0.24#
7.40 ± 0.21#
7.58 ± 0.40#
7.03 ± 0.36#
7.33 ± 0.40#
7.23 ± 0.40#
Mice were treated with vehicle (10 mL/kg, p.o.), MECN (100, 250, and 500 mg/kg, p.o.), or morphine (5 mg/kg, p.o.) 60 min before the test. Naloxone (Nalox, 5 mg/kg, i.p.) was administered 15 min before MECN (500 mg/kg, p.o.), morphine (5 mg/kg, p.o.), or vehicle (10 mL/kg, p.o.). Data expressed are the mean ± SEM of reaction time (sec) of six mice. Statistical analysis was performed using 2-way ANOVA followed by Tukey’s post hoc test. , , and compared to control; compared to 500 mg/kg MECN or morphine-treated group.
