Department of Hygiene and Public Health, Nippon Medical School, Bunkyo-ku, Tokyo, Japan.
J Biol Regul Homeost Agents. 2010 Apr-Jun;24(2):157-65.
We previously reported that 2-night/3-day trips to forest parks enhanced human NK activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that this increased NK activity lasted for more than 7 days after the trip in both male and female subjects. In the present study, we investigated the effect of a day trip to a forest park on human NK activity in male subjects. Twelve healthy male subjects, aged 35-53 years, were selected after giving informed consent. The subjects experienced a day trip to a forest park in the suburbs of Tokyo. They walked for two hours in the morning and afternoon, respectively, in the forest park on Sunday. Blood and urine were sampled in the morning of the following day and 7 days after the trip, and the NK activity, numbers of NK and T cells, and granulysin, perforin, and granzyme A/B-expressing lymphocytes, the concentration of cortisol in blood samples, and the concentration of adrenaline in urine were measured. Similar measurements were made before the trip on a weekend day as the control. Phytoncide concentrations in the forest were measured. The day trip to the forest park significantly increased NK activity and the numbers of CD16(+) and CD56(+) NK cells, perforin, granulysin, and granzyme A/B-expressing NK cells and significantly decreased CD4(+) T cells, the concentrations of cortisol in the blood and adrenaline in urine. The increased NK activity lasted for 7 days after the trip. Phytoncides, such as isoprene, alpha-pinene, and beta-pinene, were detected in the forest air. These findings indicate that the day trip to the forest park also increased the NK activity, number of NK cells, and levels of intracellular anti-cancer proteins, and that this effect lasted for at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity.
我们之前报道过，两晚三天的森林公园之旅可以提高人类自然杀伤细胞（NK 细胞）的活性、NK 细胞数量和淋巴细胞内的抗癌蛋白，而且这种增强的 NK 细胞活性在旅行结束后超过 7 天仍能持续，无论男性还是女性参与者都是如此。在本研究中，我们调查了男性一日森林公园之旅对人类 NK 细胞活性的影响。在获得知情同意后，我们选择了 12 名年龄在 35-53 岁之间的健康男性作为研究对象。这些研究对象在东京郊区的森林公园进行了一日游。他们分别在周日的上午和下午在森林公园内步行两个小时。在旅行后的次日上午和第 7 天采集血液和尿液样本，并测量 NK 细胞活性、NK 和 T 细胞数量、颗粒酶、穿孔素和 granzyme A/B 表达的淋巴细胞、血液样本中皮质醇的浓度和尿液中肾上腺素的浓度。在周末旅行前的同一时间点进行了类似的测量作为对照。还测量了森林中的植物杀菌素浓度。森林公园一日游显著提高了 NK 细胞活性以及 CD16(+)和 CD56(+)NK 细胞、穿孔素、颗粒酶、granzyme A/B 表达的 NK 细胞的数量，并显著降低了 CD4(+)T 细胞的数量、血液中的皮质醇浓度和尿液中的肾上腺素浓度。这种 NK 细胞活性的增强在旅行结束后持续了 7 天。森林空气中检测到了异戊二烯、α-蒎烯和β-蒎烯等植物杀菌素。这些发现表明，森林公园一日游也可以提高 NK 细胞活性、NK 细胞数量和细胞内抗癌蛋白水平，这种效应至少在旅行结束后持续 7 天。树木释放的植物杀菌素和降低的应激激素水平可能部分促成了 NK 细胞活性的增强。
