Effect of aromatherapy on animals with chronic neuropathic pain and its comorbidities with depression, anxiety, and cognitive impairments

• Grant number: 24/06083-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2024
• End date: November 30, 2025
• Field of knowledge: Health Sciences - Nursing - Psychiatric Nursing
• Principal Investigator: Priscila Medeiros de Freitas
• Grantee: Leticia Longatto
• Host Institution: Escola de Enfermagem de Ribeirão Preto (EERP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Chronic pain (CP) is a global health problem. CP is related to the presence of comorbidities such as anxiety, cognitive changes, and depressive symptoms. Thus, it presents itself as a challenging pathology, especially in terms of its multifaceted mechanisms and treatment. Although pain management is done with the use of pharmacological treatments, the use of non-pharmacological practices has been widely used to relieve pain. Clinical aromatherapy has been beneficial in the hospital or outpatient setting for managing symptoms of pain, nausea, general well-being, anxiety, depression, stress, and insomnia. Therefore, the objective of this project will be to study the psychopharmacological and neuromolecular bases of aromatherapy with lavender, tangerine, or copaiba essential oils in animals with chronic neuropathic pain and its comorbidities. Male Wistar rats will be used for this. NP will be induced by chronic constriction injury (CCI) of the right sciatic nerve, and the Sham ("sham-operated") procedure will be considered the control. At the end of 21 days of surgery to induce CCI or sham procedure, the animals will be exposed to aromatherapy with essential oil of lavender (100ul), tangerine (100ul), or Copaíba (100ul) or (vehicle) for 30 minutes. After this procedure, experimental tests will be carried out to evaluate neuropathy (mechanical allodynia - the von Frey test, and thermal hypersensitivity to cold (acetone test). In order to evaluate treatment with comorbidities related to chronic NP, affective behavioral tests will be carried out. -cognitive (Anxiety test in elevated plus maze, open field test; Depression - forced swimming test; Cognitive - Y maze and Object Recognition Test. Biochemical and neuronal changes will be evaluated through microdialysis in the medial prefrontal cortex (MPFC) regions. At the end of the experiments, the animals will be sacrificed to quantify neuronal activation through the test). expression of the protooncogenesis protein c-FOS in the prelimbic and infralimbic medial prefrontal cortex (MPFC) regions, amygdaloid complex (AMg), olfactory bulb, dentate gyrus of the dorsal hippocampus and periaqueductal gray matter (PAG).