Biochemical and immunological markers of the adaptive response in olfacto-odorimetric studies

The purpose of the study is to determine whether exposure to odours of model food odourants can lead to a change in biochemical and immunological parameters that we previously used when examining the population in the area of food industry enterprises location using the method of quantitative olfacto-odorimetry.

Methods. The specified concentrations of aerosols of three food flavours (orange, cognac and coffee) were supplied to the participants of the studies with a help of ECOMA T08 olfactometer. Quantitative composition of the aerosols was controlled by GC/MS. In participants saliva samples taken before, during and at the end of each experiment, the intensity of luminol-dependent chemiluminescence, the content of secretory IgA, IL-1β, IL-6 and IL-8, the activity of α-amylase and N-acetyl-β-D-glucosaminidase were determined. For data analysis, paired Friedman and Wilcoxon tests were used with Bonferroni correction for the problem of multiple comparisons.

Results. A reliable effect of the smell of food odourants was found on one indicator only — the activity of salivary α-amylase – when combining data from 5 separate experiments (n=45): 93.3[24.3;160.0] U/ml at the end of the experiments against background values of 109.9 [42.5; 216.7] U/ml;, p=0.0096 with a significance level of p=0.05/3=0.017. A decrease in the average values of salivary α-amylase activity was shown to hide opposite changes in individual values: an increase in activity in people with low background values (below the median of the initial distribution) and an amplitude-dominant decrease — in people with high background values (above median). The revealed phenotypic polymorphism of α-amylase regulation contributes to one of relevant Post-COVID areas — the study of the ability of people to perceive odours and react to them.

Limitations. The use of olfacto-odorimetry to study effect of odours on human health indicators is promising, but requires design of protocols with extended exposure time.

Conclusion. A decrease in average values of salivary α-amylase activity with distinctive forestall of the upper quartile may be a sign of human reflex response to the emission of odourous substances in the areas of food industry.

Contributions:
Khripach L.V. — research concept and design, determination of biochemical and immunological markers in saliva samples;
Budarina O.V. — research concept and design;
Knyazeva T.D. — determination of biochemical and immunological markers in saliva samples;
Makovetskaya A.K. — determination of biochemical and immunological markers in saliva samples;
Koganova Z.I. — determination of biochemical and immunological markers in saliva samples;
Andryushin I.B. — olfactometry.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest. Moscow, 119992, Russian Federation

Acknowledgement. The study was carried out as part of the State Assignment of the Centre for Strategic Planning of FMBA of Russia.

Received: May 16, 2022 / Accepted: June 08, 2022 / Published: July 31, 2022