The phytochemical study was performed in methanol and chloroform extract. As shown in table 1 the amount of tannins, phenols, alkaloids, flavonoids, and glycosides was detected higher in methanol extract, whereas terpenoids, steroids and saponins were more predominant in chloroform extract.
Extraction yield, Total Phenolic Contents (TPC) and Total Flavonoid Content (TFC)
The extraction yield of P. bengalensis leaves obtained by maceration in methanol and chloroform was 3.8% and 4.4% respectively of dry weight. The TPC and TFC were quantified which are expressed in mg of GAE/g and mg of QE/g respectively as shown in Table 1. The methanol extract fraction showed the higher TPC (57.96 ± 19.35 mg of GAE/g extract) compared with the chloroform extract (21.89 ± 2.47 mg GAE/g extract). Similarly, TFC was also found higher in methanol fraction (40.53 ± 1.87 mg of QE/g extract) compared to chloroform fraction (6.90 ± 1.17 mg of QE/g extract).
DPPH radical scavenging assay
The antiradical activity of the extract was measured by the ability to scavenge DPPH free radicals, compared with the standard ascorbic acid. As shown in Figure 1 and Figure 2 both extract PBME (IC50 = 168 ±13.57 µg/ml) and PBCE (IC50 = 280.7 ± 15.49µg/ml) showed the considerable free radical scavenging property as compared to standard ascorbic acid (IC50 = 18.39±4.62 µg/ml),
Acute toxicity study (LD50 determination)
No prominent sign of toxicity and mortality was recorded among experimental animals at all administered dose of the crude methanol and chloroform extract of P. bengalensis. Since no death was recorded at the maximum administered dose, the LD50 of the plant was found to be higher than 5000 mg/kg.
The data presented in Figure 3 shows that PBME (200 mg/kg), and PBCE (200mg/kg), used in this experiment did not increase (P > 0.05) time latency after 30 and 60 min of the hot plate test. The other fractions PBME (400 mg/kg), PBCE (400mg/kg) exhibited significant (P 0.05) increase the time latency. Multiple comparisons of the treatments revealed that PBME (400 mg/kg) comparatively has highest latency time at 90 min compared to tramadol. Whereas, latency time decrease at 120 min but tramadol was still increasing. Similarly, percent analgesia indicated that among extract/fractions; PBME and PBCE 400 mg/kg dose more convincingly (P 0.05) in paw edema volume after 1 h of the carrageenan injection. However, significant (P