Quantitative analysis and expression of salivary opiorphin in painful oral soft-tissue conditions: A descriptive study

Abstract

Objectives: Opiorphin is an enkephalinase inhibitor which suppresses pain by acting on the opioid system. The levels of opiorphin in plasma and saliva have shown to vary in patients with burning mouth syndrome. This descriptive study was designed to estimate the salivary levels of opiorphin among individuals with painful oral soft-tissue conditions. Materials and Methods: Unstimulated whole saliva was collected from 60 individuals (20 controls, 20 traumatic and inflammatory conditions, and 20 patients with oral potentially malignant disorders [OPMDs] and oral cancer). The salivary levels of opiorphin were assessed through competitive enzyme-linked immunosorbent assay. Results: The mean level of opiorphin among controls was 7.108 ± 2.535 ng/ml, among individuals with traumatic and inflammatory conditions was 9.409 ± 2.369 ng/ml, and in individuals with OPMDs and oral cancer was 8.268 ± 2.414 ng/ml. A positive correlation was observed between salivary opiorphin levels and age of the patient (r = 0.028). Conclusion: The varying levels of opiorphin in painful oral mucosal conditions and with age indicate its role in local pain modulating mechanisms.

Assessment of salivary opiorphin in oral lichen planus

“…Nejad et al 6 (2020) study revealed that salivary opiorphin levels in the patients, who had painful oral soft tissue lesions including traumatic and inflammatory conditions, as well as, in patients with oral pre-malignant or malignant lesions, were higher than in healthy subjects; their study confirmed that the severity and type of pain could effect on opiorphin levels. Therefore, assessment of patients' salivary opiorphin could be an indicator of the severity of pain.…”

Opiorphin as a biomarker of orofacial conditions: a meta-analysis

“…The proportion of women in the studies ranged from 40 31 to 90.4% 30 . Studies were conducted in Croatia 27 , 29 , France 30 , India 8 , 46 , Iraq 38 , and Turkey 31 , 34 . All studies were published in English.…”

“…Efforts to diagnose and treat OFP would benefit from the development of biomarkers in the context of the various inflammatory, infectious, autoimmune, and premalignant/malignant conditions that can affect the orofacial region. Saliva offers numerous advantages as a source of biomarkers of orofacial (and other) abnormalities, including pain 8 – 10 . For example, saliva and its constituents have been under investigation for more than a century, and collecting saliva samples is non-invasive and convenient 11 – 13 .…”

“…In humans, several studies have assessed variations of salivary opiorphin levels under different conditions including pain and stress 27 , 28 . Opiorphin's potential as a biomarker has been explored in various pathologies such as Temporomandibular Disorder (TMD) 27 , Burning Mouth Syndrome (BMS) 29 , 30 , Oral Potentially Malignant Disorders (OPMD) 8 , dental pain as Symptomatic Irreversible Pulpitis (SIP) 31 and Symptomatic Apical Periodontitis (SAP) 31 , anorexia nervosa 32 , 33 , ocular pain with Corneal Foreign Body (CFB) 34 , and depressive 19 and erectile disorders 35 – 37 . However, the medical literature's results are yet to be fully integrated, sometimes showing apparent contradictions across conditions.…”

Expression of salivary immunoglobulins and their association with analgesic neuropeptide opiorphin in anorexia nervosa during adolescence

“…They concluded that opiorphin release occurred primarily as a pain control mechanism, although no additional stress biomarkers were measured [ 52 ]. Other studies indicate that opiorphin's level might correlate with the levels of oral pain and stress [ 14 , 53 – 56 ]. Recently a cohort study of 503 healthy schoolchildren where opiorphin levels were higher and correlated to prior stress exposure [ 49 ] suggested the use of opiorphin to evaluate stress-related changes in children [ 49 ].…”