Effects of Hydroethanolic Extract of Adenia lobata (Jacq.) Engl. (Passifloraceae) on Nociception and Subsequent Anxiety-like Behavior: Both Anti-inflammatory and Antioxidant Approaches

Aims: Adenia lobata (Jacq.) Engl. (Passifloraceae) is widely used in Ivorian traditional pharmacopeia to heal various chronic diseases, relieve headache and pain of gingiva inflammation, and facilitate labor. Here, we investigated the effects of hydroethanolic extract Adenia lobata (HEAL) on nociceptive pain and subsequent anxiety-like behavior.

Materials and Methods: We used several experimental pain tests as the writhing, formalin and hot plate to evaluate both antinociceptive and anti-inflammatory actions of the extract. Anxiety related to nociception was tested with open field and elevated plus maze tests. Then, mice were sacrificed for assessing some oxidative stress markers.

Results: The extract of 30 mg/kg, p.o. reduced in the similar manner as reference peripheral drug salcylicacetic acid (ASA, 200 mg/kg, i.p.) the number of writhings induced by acid acetic. In both neurogenic and inflammatory phases of formalin test, the extract demonstrated an effective antinociceptive activity than ASA, but comparable to central analgesic tramadol (50 mg/kg, i.p). However, Adenia lobata reduced lesser thermal-induced pain than tramadol in hot plate test, but significantly compared to ASA. Furthermore, HEAL altered anxiety-like behavior in each case of the pain condition studied. Also, the extract showed the highest antioxidant activity by reduction oxide nitric (NO) and malondialdehyde (MDA), and increase non protein thiol (NP-SH) levels.

Conclusion: In conclusion, HEAL possesses antinociceptive and anti-inflammatory actions on peripheral and central mechanisms of pain. The phytochemicals components of the extract as alkaloids and flavonoids suggest to interact with the opioid system and combat the oxidative stress, respectively. Our findings provide scientific basis for the use of Adenia lobata in traditional medicine against pain and related diseases.