Phytoncide – Its Properties and Applications in Practical Use

Abstract

Lately, terms such as ‘free radical’ and ‘active enzyme’ have been used frequently in topics related to health and illness. Under normal conditions, free radicals and active enzymes that are produced within an organism are erased by the antioxidant enzyme SOD (superoxide dismutase). However, under excessive oxidant stress, the biological defense mechanisms become overwhelmed and the role of antioxidants becomes important. This research focuses on the relationship between forest therapy and phytoncide solution (4 varieties), a concentrated volatile component released from trees and plants. The antioxidant potential (via a DPPH radical scavenging effect experiment and active oxygen inhibition experiment), bacterial eradication and deodorization effects of phytoncide and its ability to relieve and reduce restraint stress will be examined. In the DPPH radical scavenging experiment, all four types of phytoncide solution (concentrate) demonstrated a radical scavenging rate that was over 97% and higher than that of the reference material, α-tocopherol (95.0%). Furthermore, the D-type liquid had a 50% radical scavenging concentration (SC50) equal to that of α- tocopherol and proved to possess the highest radical scavenging effect observed. In the active oxygen scavenging experiment, although α-tocopherol, with its ability to inhibit oxidation of unsaturated fatty acid in phosphatide forming the plasma membrane, maintain biomembranes and scavenge free radicals, is a most effective antioxidant agent, an active oxygen scavenging effect for α-tocopherol was not observed. Therefore, an active oxygen scavenging experiment was done on the four types of phytoncide solution, and the AB-type liquid with high bactericidal capacity as the main component was found to show a good active oxygen scavenging rate (60.7%). Because traditional and natural images project a positive image to consumers in the cosmetic market, plant-derived compounds are actively used. Ordinary hand-washing eradicates transient flora and hygienic hand-washing eradicates resident flora. In a test of bacterial eradication during daily activities from the morning commute until lunch time, hand-washing using liquid soaps with phytoncide (AB-type liquid) demonstrated higher eradication effects toward resident microbiota, i.e. the long bacteria that form velutinous colonies, than ordinary liquid soaps. In addition, hand-washing with phytoncide resulted in a remarkable decrease in the number of short bacteria that remained after washing. The four representative elements of bad odor are ammonia, hydrogen sulphide, trimethylamine and methyl mercaptan, and the majority of a bad odor results from the foul odor caused by oxidation. The deodorization ability of phytoncide derives from chemical neutralization, and degradation and detoxification of malodorous components, and it brings a refreshing effect by possessing an odor similar to air in the forest. Therefore, the use of phytoncide will be beneficial in maintaining and controlling a pleasant environment in institutions. As phytoncide is used in aroma therapy, the components of phytoncide are considered to approximate to essential oils. Phytoncide mist does not cause a negative reaction in the circulatory dynamics of normally bred, spontaneously hypertensive rats, and the stress-reducing effect of phytoncide mist toward the highly stress-sensitive disease model animal, the stroke-prone spontaneously hypertensive rat, was examined by monitoring heart rate, systolic blood pressure and diastolic blood pressure. These experiments indicate that under a stress ful environment, inhalation of phytoncide has the function of restraining activation of the circular and sympathetic nervous system, thereby reducing stress and reforming mental function. In this research, phytoncide solution derived from a combination of 118 kinds of plants was assessed in terms of its antioxidant potential, sterilization, odor-eliminating and stress-reducing properties. Clearly, the bioactivity of phytoncide solution, including its terpenoid components, is related to these effects.