Investigations on the antinociceptive effect of Psidium guajava leaf essential oil and its major constituents

✍ Scribed by F. A. Santos; V. S. N. Rao; E. R. Silveira

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 110 KB
• Volume: 12
• Category: Article
• ISSN: 0951-418X
• DOI: 10.1002/(sici)1099-1573(19980201)12:1<24::aid-ptr181>3.0.co;2-b

✦ Synopsis

The antinociceptive effect of leaf essential oil from Psidium guajava and its major constituents, ␤-caryophyllene and ␣-pinene was assessed using chemical (formalin and acetic acid) and thermal (hot-plate) nociceptive tests in adult male albino mice. Oral administration of 100, 200 and 400 mg/kg of essential oil produced a significant antinociceptive effect in the formalin test and at 200 and 400 mg/kg in the acetic acid-induced writhing test. Of the major components only ␣-pinene, but not the ␤-caryophyllene, demonstrated significant antinociception in the formalin test. Neither the essential oil nor the major components could exert any significant effect in the hotplate test. Pretreatment of mice with caffeine (20 mg/kg, i.p.), significantly inhibited the antinociceptive effect of essential oil in the formalin test. Naloxone (1 mg/kg, s.c.), the opioid antagonist, however, failed to antagonize it. These results suggest that the antinociceptive effect of P. guajava essential oil is probably mediated by endogenously released adenosine.