Effect of extracted garlic powder ingestion for two months on exercise-induced immunological responses

Introduction. Exhaustive exercise is associated with an increased risk of upper respiratory tract infection. Previously, allicin supplementation has been reported to reduce the incidence of common cold symptoms and production of exercise-induced interleukin (IL)-6. However, it is not clear if daily ingestion of the edible portion of whole garlic (Allium sativum) alters the exercise-induced immunological response. The present study investigated the effects of extracted garlic powder ingestion for 2 months on immune cell counts, natural killer cell activity (NKCA), as well as changes in cytokines, cortisol, and lactic acid in response to high-intensity cycling exercise. Methods. The present study employed a before-after study design. Six sedentary male participants (age, 22.0±0.3 years) consumed extracted garlic powder for 2 months, and underwent 45 minutes of cycling exercise at 80% of the heart rate reserve once before and once after the supplementation period. A thousand milligrams of extracted garlic powder, comparable to 6 g (1 clove) of raw garlic, was ingested every day. Blood samples were obtained at the following five time points: before exercise, 0 min, 30 min, 60 min, and 120 min after exercise. We measured NKCA, leukocyte counts, neutrophil counts, lymphocyte counts, as well as levels of serum IL-6, IL-10, cortisol, and lactic acid. Repeated measures ANOVA was used for statistical analyses. When interaction effects were significant, measurement values at the various time points were compared between pre- and post-supplementation period using the paired t-test. Changes were deemed statistically significant when p\u3c0.05. Results. We observed no significant difference in pre-exercise measurements between pre- and post-supplementation periods. In addition, we found no significant interaction effect for leukocytes, neutrophils, NKCA, IL-10, and cortisol. However, we did identify a significant interaction effect for lymphocytes, IL-6, and lactic acid (p=0.033, p=0.030, and p\u3c0.001, respectively). Lymphocyte counts were significantly lower post-supplementation relative to pre-supplementation immediately after exercise (p=0.014). In addition, IL-6 was significantly lower post-supplementation relative to pre-supplementation immediately and 30 minutes after exercise (p=0.015 and p=0.018, respectively). Lactic acid levels were significantly lower post-supplementation relative to pre-supplementation immediately after exercise (p=0.018). Conclusions. The extracted garlic powder did not significantly influence exercise-induced responses by leukocytes, neutrophils, NKCA, IL-10, or cortisol. However, exercise-induced responses by lymphocytes, IL-6, and lactic acid were suppressed after ingestion of extracted garlic powder. Thus, daily ingestion of the edible portion of whole garlic may suppress exercise-induced immunological responses and lactic acid levels

ムシュウ ニンニク 2カゲツカン ノ セッシュ ハ ウンドウ ユウハツセイ IL-6 ジョウショウ ヲ ヨクセイ スル：ゼンゴ ヒカク シケン

ニンニクに含まれるアリシンはヒトで運動誘発性インターロイキン（IL）6産生を抑制することが報告されている。しかし，アリシンは特有の強い臭気を持つため，実生活を考えると日常的に使用することが難しい。我々はそこで，無臭ニンニク（odorless garlic ; OG）2か月間摂取が運動誘発性IL-6産生と他の免疫応答を減弱する可能性について検討することを目的とした。日頃からあまり活動的でない6名の健康な男性（22.0±0.7歳）を対象に一日当たり1 gのOGを2か月間にわたって摂取させた。研究での運動負荷条件は推定最大心拍数の80％強度の自転車運動とし，45分間実施した。運動負荷は，実験開始前（control群 ; CON-Ex）とニンニク摂取2か月後（odorless garlic supplementation and exercise群 ; OG-Ex）に実施した。血液サンプルは運動負荷を行う前，運動負荷直後（0 min），30分後，60分後に採取し，IL-6，IL-10，白血球数，好中球数，リンパ球数，Natural Killer Cell Activity （NKCA），コルチゾールを測定した。運動負荷前から運動負荷60分後までの上昇曲線下面積（iAUC）を算出し，統計解析には繰り返しのある二元配置分散分析（ANOVA）およびHolm’s methodを用いた対応のあるt検定を行った。運動負荷前の生化学値にはCON-ExとOG-Exの間に有意な差は見られなかった。運動負荷後の白血球数，好中球数，リンパ球数，NKCA，IL-10，およびコルチゾールに交互作用は見られなかったものの，IL-6には交互作用が見られた（p＝0.011）。OG-Ex 群の運動誘発性IL-6 iAUC値はCON-Ex群に比べて有意な低下がみられた（CON-Ex, 82.5±12.2 min･pg/mL ; OG-Ex, 55.5±14.2 min･pg/mL ; p＝0.018）。今回の結果は2か月間のOG摂取が運動誘発性IL-6上昇を抑制するという仮説を支持する結果となった。しかしながら，OG摂取は他の免疫指標に影響を及ぼすことはなかった。OG摂取が運動誘発性の免疫機能に及ぼす影響については，今後のさらなる研究が必要である。Allicin, which is a primary compound in crushed garlic, inhibits exercise-induced interleukin (IL)-6 production in humans. However, the daily use of crushed garlic or stabilized allicin is not practical due to the strong odor of allicin. We therefore investigated the possibility that odorless garlic (OG) supplementation for 2 months attenuates exercise-induced IL-6 and other immunological responses. Six healthy untrained men (aged 22.0±0.7 years) consumed 1 g of OG per day for 2 months. Participants underwent two 45-min periods of acute cycling exercise at 80% intensity of heart rate reserve (HRR). The first period was at baseline (control exercise ; CON-Ex) and the second after 2 months of OG supplementation (odorless garlic supplementation and exercise ; OG-Ex). To assess levels of IL-6, IL-10, leukocytes, neutrophils, lymphocytes, Natural Killer Cell Activity (NKCA) and cortisol, blood samples were collected before and immediately (0 min), and 30 and 60 min after each 45-min period of exercise. Two-way repeated measures analysis of variance (ANOVA) and paired t-test with Holm’s method were performed, and the incremental area under the curve (iAUC) from before to 60 min after exercise was calculated. No significant differ­ences in the pre-exercise levels of biochemical indices were observed between the CON-Ex and OG-Ex assessments. No significant interaction effects were observed in exercise-induced changes in leukocytes, neutrophils, lymphocytes, NKCA, IL-10, or cortisol. A significant interaction effect was observed in exercise-induced changes in IL-6 (p＝0.011). OG consumption also significantly decreased the iAUC of IL-6 (CON-Ex, 82.5±12.2 min･pg/mL ; OG-Ex, 55.5±14.2 min･pg/mL ; p＝0.018). Our findings support the hypothesis that two months of OG supplementation attenuates exercise-induced increases in IL-6 levels among untrained men. However, OG did not exert a similar effect on other immunological parameters. Further study is required to clarify the effect of OG on exercise-induced activation of the immune system

THE PROTECTIVE EFFECT OF PROPRANOLOL ON ISCHEMIC MYOCARDIUM: AN ELECTRON MICROSCOPIC STUDY

The protective effect of propranolol on ischemic myocardium was studied experimentally and clinically by electron microscope. In an animal experiment, ischemic changes were produced in the posterior papillary muscle of the rabbit following 3, 15, and 30 minutes of occlusion of the circumflex coronary artery. Propranolol (0.25 mg/kg) was injected into the left atrial cavity before occlusion of the artery. The posterior papillary muscle was excised and examined by electron microscope. In clinical experience, propranolol (20 µg/kg) was given intravenously to 6 patients who underwent open heart surgery. Transmural left ventricular myocardial biopsy was performed after the anoxic cardiac arrest and the material, particularly the subendocardium, was examined by electron microscope. It was shown that propranolol was effective, both in the experiment and in the clinical experience, in preserving ischemic myocardium. The possible mechanisms through which propranolol might act were considered to be (1) indirect effect of altered oxygen supply vs. demand, effected by reducing heart rate and reducing cardiac output due to the drug’s function as a beta blocker, (2) direct cellular effect, i.e., reducing myocardial substrate metabolism along with stabilization of cellular structure, and (3) increase collateral circulation to the subendocardium