2.1. Chemicals and apparatus used
The new tested compound (5-amino-3-phenyl-1,3,5-thiadiazine-2-thione) was synthesized in organic chemistry Lab:, ICS (Institute of chemical sciences), University of Peshawar. Diclofenac sodium was used as a standard drug. Tween 80 was used as a suspending agent while DMSO was used as a solvent. Solutions for test compound, carrageenan, and histamine were prepared in normal saline. Harvard apparatus, USA (Hot plat apparatus) was used for hot plat test while Plethesmometer was used for the measurement of histamine and carrageenan-induced paw edema. All the chemicals were of analytical grades and were used without any further purification.
2.2. Animals
All the experiments were performed by using male Swiss Albino mice. These experimental animals were obtained from VRI (Veterinary Research Institute), Peshawar, KPK, Pakistan. Mice weighing between 18 and 40 g were used. The experimental animals were provided with standard laboratory conditions under 25 ° C (room temperature). They were fed on an ad libitum laboratory diet and had open access to water for drinking at standard ambient temperature conditions (25°C) in 12 hrs. Dark/12 hrs. light cycle. The study in animals was sanctioned by the Ethical Review Board of the Faculty of Pharmacy, Gomal University (No. 247/QEC/GU). All experimental animals were handled in conformity with the ethical principles (substantiated in 1979) for animals to be used in a laboratory, to serve humanity, (Lyon, France).
2.3. Anti-nociceptive activity
2.3.1. Hot plate test
Eddy’s hot plate test was used with slight modifications. In this experiment male mice were used. These mice were withdrawn from food two hours before the test begins. These mice were subjected to a pretest on a hot plate with a temperature of 55 ± 1 ℃. To minimize inconsistency, those animals were excluded from having the time of latency greater than 15 seconds. These animals were divided into five groups (n=4). Group-I was administered with 10 ml/kg normal saline, intraperitoneally (i.p), while Group-II was treated with the reference drug “diclofenac sodium” (20mg/kg, i.p). Group-III, IV, and V were i.p inoculated with 30, 60, and 120 mg/kg of the tested compound (5-amino-3-phenyl-1,3,5-thiadiazine-2-thione), respectively. Subsequent to intraperitoneal administration, time of latency (in seconds) was recorded after 30, 60, and 90 mints, until lifting, flicking, jumping, or licking of forepaws. To avoid tissue damages, a cut off time of 30 seconds was set (Masocha et al. 2016).
2.3.1. Writhing test
The antinociceptive property of the synthetic compound (5-amino-3-phenyl-1,3,5-thiadiazine-2-thione) was determined by the writhing test according to Muhammad et al. 2017 with slight modification. In this experiment, male mice were used. These mice were withdrawn from food two hours before the test. The animals were arranged in five groups (n=5, per group). The Group-I i.e. control group was given an intraperitoneal injection of 10 ml/ kg NS (normal saline) and Group-II was administered with 20 mg / kg diclofenac sodium i.p. Furthermore, Group-III, IV, and V were i.p administered with 30, 60, and 120 mg/kg, of the tested compound (5-amino-3-phenyl-1,3,5-thiadiazine-2-thione), respectively. After 30 minutes time interval, the animals were administered with 0.1 ml of acetic acid (1% solution), i.p. Subsequently, for the next 10 minutes number of wriths were noted, after 5 minutes of acetic acid administration.
2.4. Anti-inflammatory activities
2.4.1. Carrageenan induce paw edema
This experiment was performed as portrayed by Saeed et al. 2016, with some necessary modifications. In this experiment male mice were used. The animals were withdrawn from food two hours before the test begins. These were arranged into five different groups i.e. each group having four mice. Group-I received 10 ml/kg saline, while Group II received 20 mg/kg diclofenac sodium as a reference drug. Moreover, the further three groups received 30, 60, and 120 mg/kg, (i.p.) of the tested compound (5-amino-3-phenyl-1,3,5-thiadiazine-2-thione), respectively. 1% suspension of carrageenan (0.1 ml) was administered into the sub planter area of the left hind paw of mice to produce inflammation, 1 hour after intraperitoneal injection of control, standard, and tested compound. The volume of the paw was measured with Plethesmometer by 0, 1, 3, and 5 hours after carrageenan administration.
2.4.2. Histamine induced paw edema
This particular test was performed per Mbiantcha et al. 2010 with some necessary modifications. In this experiment male mice were used. These mice were withdrawn from food two hours before the test begins. These animals were arranged into five different groups i.e. each group having four animals. Group-I received 10 ml/kg saline, while Group II received 20 mg/kg diclofenac sodium as a reference drug. Moreover, the further three groups received 30, 60, and 120 mg/kg, i.p of the test compound (5-amino-3-phenyl-1,3,5-thiadiazine-2-thione), respectively. 1% suspension of histamine (0.1 ml) was administered into the sub planter area of the left hind paw of mice to produce inflammation, 1 hour after intraperitoneal injection of control, standard, and tested compound. The volume of the paw was measured with Plethesmometer by 0, 1, 3, and 5 hrs. after histamine administration.
2.5. Statistical analysis
Data analysis was performed by using ordinary one-way ANOVA as a pre-test and Dunnettʼs multiple comparisons test as a post-test, in which the p < 0.05 value was considered significant. All the behavioral studies were analyzed through Graph Pad Prism 8.