Neuropathic and
postoperative pain are clinical conditions that impair the patient's quality of life. The current
pharmacotherapy of both painful states is ineffective and accompanied by several side effects. In order to develop new
therapeutics targets, the secondary metabolites of plants have been extensively studied. Acmella oleracea ("jambu") is a native plant from the Amazon region and rich in alkylamides, bioactive compounds responsible for inducing
anesthetic and chemesthetic sensations. We previously demonstrated that the intraplantar administration of an hexanic fraction (HF) rich in alkylamides from jambu and the synthetic isobutylalkyl
amide (IBA) at 0.1 μg/20 μL can promote antinociceptive and anti-inflammatory effects. Thus, this study aimed to evaluate the local effect of HF and IBA (0.1 μg/20 μL) on neuropathic (partial sciatic nerve
ligation, PSNL) and
postoperative pain (plantar incision surgery, PIS) models in mice. Seven days after the PSNL, the mechanical (von Frey test) and cold (
acetone-evoked evaporative cooling)
allodynia, and digital gait parameters were analyzed. The intraplantar HF and IBA treatments attenuated the mechanical and cold
allodynia as well as the static (max. Contact and print area) and dynamic (stand duration) parameters of digital gait analyses. On the day after PIS, the
mechanical allodynia, heat
hyperalgesia (hot plate, 52 ± 0.1°C), and spontaneous nociception scores were evaluated. Topical treatment with HF reduced the
mechanical allodynia, heat
hyperalgesia, and spontaneous nociception scores. In contrast, IBA treatment only partially reduced the
mechanical allodynia. In summary, the local treatment with HF was effective on both neuropathic and
postoperative pain, as opposed to IBA, which only had an effect on
neuropathic pain.