Antinociceptive action and redox properties of citronellal, an essential oil present in lemongrass.

Citronellal (CT) is a monoterpenoid and the major constituent of the mixture of terpenoids that give the citronella oil its lemon scent. Citronella oil is widely used around the world for various purposes and is mainly obtained from plants of the Cymbopogon genus, which are known as "lemongrass." Considering these plants have been used worldwide for various medicinal purposes, the interest of researchers to understand the biological activities of monoterpenoids related to the Cymbopogon genus has been increasing. In the present work, we investigated the antinociceptive action and the redox properties of CT. Our results indicate that intraperitoneal injection of CT was effective in reducing nociceptive face-rubbing behavior in both phases of the formalin test, which was also naloxone-sensitive. CT also evoked antinociceptive response in the capsaicin and glutamate tests. The total radical-trapping antioxidant parameter and total antioxidant reactivity assays indicate that CT at doses of 0.1 and 1 mg/mL exerts a significant antioxidant activity, which is probably related to its ability to scavenge superoxide and nitric oxide, but not H(2)O(2) or hydroxyl radicals, as evaluated separately by specific in vitro tests. These results show for the first time the antinociceptive potential of CT and indicate that the antioxidant properties of this compound may rely on its mechanism of biological actions because CT-containing natural products are used to treat various diseases related to oxidative stress and reactive species.