Analgesic effect of apricot kernel oil on neuropathic pain in rats

Abstract

Background: A somatosensory nerve lesion or disease causes neuropathic pain. Presently, prescribed treatments are unsatisfactory or ineffective. The kernel oil of the apricot tree (Prunus armeniaca L) is known for its anti-inflammatory and antioxidant effects. This study investigated the effect of apricot kernel oil in chronic constriction injury (CCI)- induced neuropathic pain in rats.

Materials/methods: Liquid chromatography-electrospray mass spectrometry (LC-ESIMS) analysis was carried out to gain a deeper understanding of the apricot kernel oil's main compounds. Rats were treated daily with apricot kernel oil (2 and 4 ml/kg) or gabapentin (100 mg/kg) for 14 days after CCI induction. Hot plate, acetone drop, and Von Frey hair tests were performed to evaluate thermal and mechanical activity. Spinal cord malondialdehyde (MDA), total thiol, interleukin (IL)-1β, and tumor necrosis factor α (TNF-α) levels were assessed to measure biochemical changes.

Results: The most detected compounds in apricot kernel oil were lipids and fatty acids. CCI produced a significant increase in thermal hyperalgesia, mechanical allodynia, and cold allodynia. Moreover, CCI increased the inflammation and oxidative stress markers in spinal cord samples. Oral administration of apricot kernel oil and gabapentin significantly decreased the CCI-induced nociceptive pain threshold. Besides, spinal cord biochemical changes were attenuated.

Conclusions: Our findings suggest that apricot kernel oil could attenuate neuropathic pain, possibly through anti-inflammatory and antioxidant properties.

Keywords: Apricot kernel oil; Herbal medicine; Inflammation; Neuropathic pain; Oxidative stress.

Fig. 1

LC-ESIMS chromatogram of the apricot kernel oil.

Fig. 2

Effect of apricot kernel oil on (A) mechanical allodynia, (B) heat hyperalgesia (C), and cold allodynia in CCI-induced neuropathic pain in rats. Each point represents the mean ± SEM (n = 8). ###p < 0.001 significantly different from the control group. *p < 0.05, **p < 0.01, and ***p < 0.001, significantly different from the CCI group. ⁺p < 0.05, ⁺⁺p < 0.01, and ⁺⁺⁺p < 0.001 significantly different from the gabapentin group.

Fig. 3

Effect of apricot kernel oil on (A) IL-1β (B) TNF-α levels in CCI-induced neuropathic pain in rats. Each point represents the mean ± SEM (n = 8). ###p < 0.001 significantly different from the control group. *p < 0.05, **p < 0.01, and ***p < 0.001, significantly different from the CCI group.

Fig. 4

Effect of apricot kernel oil on (A) MDA (B) thiol levels in CCI-induced neuropathic pain in rats. Each point represents the mean ± SEM (n = 8). ###p < 0.001 significantly different from the control group. *p < 0.05, **p < 0.01, and ***p < 0.001, significantly different from the CCI group.

Fig. 5

Diagrammatic sketch for the behavioral, and biochemical experiments. CCI: chronic constriction injury; SAC: sacrificed for biochemical experiments. Day 0 refers to the day of surgery.