抗發炎物對急性衰竭運動後生理功能及發炎反應之研究

Abstract

適度且規律的運動有助於健康促進，過度激烈運動則對身體生理功能產生有害之影響。研究證實，急性衰竭運動會造成肌肉損傷，使肌肉容易出現疲勞現象，並引起炎症反應，進而降低運動表現。目前許多研究以增補具抗發炎物質的方式，改善組織損傷及發炎反應的情況，並藉此提升運動表現。本研究旨在以阿斯匹靈(aspirin, ASA)及蜆萃取物(freshwater clam extract, FCE)等抗發炎物補充對於大鼠在急性衰竭運動後生理功能、肌肉損傷及發炎反應之影響。實驗共分為兩個部分，第一部分以阿斯匹靈補充: 將48隻WKY大鼠隨機分組:控制組（C）、阿斯匹靈20mg/kg組（C+ASA 20mg）、阿斯匹靈100 mg/kg組（C+ASA 100mg）、運動組（E）、阿斯匹靈20mg/kg運動組（E+ASA 20mg）及阿斯匹靈100 mg/kg運動組（E+ASA 100mg），共計6組。服用阿斯匹靈各組均在急性運動模式前1小時餵食不同的劑量。運動組之大鼠在跑步機從事單次激烈運動至衰竭，耐力運動最後速度為 30m/min，跑步機坡度為10％，其最大攝氧量約為70-75％。所有控制組及運動鼠於衰竭運動完成後，以清醒鼠模式將導管植入股動脈後，在運動後1 (post)、6、12、18、24小時採集動脈血進行血液生化檢測，炎症反應相關的細胞激素IL-6、TNF-α與IL-10的濃度則在運動完成後第1(post)、12、24 小時檢驗，並於運動後24小時犧牲所有大鼠，摘取肝臟做病理切片分析。 第一部分實驗結果顯示：急性衰竭運動後，運動組與阿斯匹靈20mg/kg運動組及阿斯匹靈100 mg/kg運動組比較，各組的平均跑步時間並未達到顯著差異。與運動組相較下，服用阿斯匹靈會顯著地降低前發炎激素IL-6及TNF-α的水準。而阿斯匹靈100 mg/kg運動組則會顯著增加IL-10的濃度，但是會使運動後血漿中肌酸激酶 (CK)、乳酸脫氫酶(LDH)、天冬氨酸氨基轉移酶 (AST) 和丙氨酸基轉移酶 (ALT) 的濃度和肝臟中白血球浸潤之嚴重度升高。餵食100mg/kg劑量之阿斯匹靈運動組的總膽固醇 (TCHOL)、三酸甘油脂 (TG) 及高密度脂蛋白 (HDL-C) 數值則顯著低於運動組。此外，劑量較高的阿斯匹靈在急性衰竭運動後亦會造成肝臟中白血球浸潤情形嚴重。結論:阿斯匹靈並無法提升運動表現，而服用高劑量阿斯匹靈則會加重大鼠急性衰竭運動後肌肉和肝臟損傷的狀況，但仍具有顯著的抗發炎效果。 第二部分為增補蜆萃取物: 將32隻WKY大鼠隨機分為4組:控制組 (SC)，控制組+蜆萃取物 (SC+FCE)，運動組 (E)，運動+蜆萃取物組 (E+FCE)。餵食蜆萃取物組，以每天20mg/kg之劑量，連續餵食7天。運動組的運動流程與處方與第一部分相同，於單次激烈運動至衰竭。利用清醒鼠模式收集血液的方法則和第一部分相同。在運動後1 (post)、3、6、12、24小時採集動脈血進行等血液生化檢測，以及分析血漿中TNF-α與IL-10的濃度，並於運動後24小時予以犧牲大鼠，摘取肝臟做病理切片分析。第二部分結果顯示:蜆萃取物增補不僅可延長運動鼠衰竭時間，而且還能顯著降低運動大鼠血漿中肌酸磷酸激酶 (CPK)、LDH、AST、ALT、乳酸 (lactate)、前發炎激素TNF-α的水準及肝損傷病理程度。與運動組比較下，服用蜆萃取物可以顯著提升運動大鼠血中葡萄糖及抗發炎激素IL-10的濃度。 綜合上述結論，大鼠於急性衰竭運動前服用高劑量阿斯匹靈100mg/kg，在運動後則有抗發炎的效果。除無法提升耐力運動表現外，反而會使激烈運動後所引發的肌肉傷害及肝臟功能受損情形加劇。另外，在急性衰竭運動前以蜆萃取物增補，不僅可提升運動表現外，同時也會降低因急性激烈運動所產生的肌肉損傷及炎症反應，並可保護運動所誘發的肝功能異常及組織損傷。

Moderate and regular exercise could promote human health, but overtraining and exhaustive exercise will be detrimental to physiological functions. Many studies have shown that acute exhaustive exercise could provoke muscle damage leading to the muscular fatigue and inflammation. Therefore, the acute inflammatory response had been associated with limited exercise performance. Currently, numerous studies have been identified as potential sources of anti-inflammatory material supplements to improve tissue damage and inflammation. The aim of this study was to investigate the effects of aspirin and freshwater clam extract (FCE) administration on endurance performance, biochemical parameters, inflammatory response and liver injury induced by an acute bout of exhaustive exercise in rats. There were two-part experiments in this study. In first part experiment , forty-eight rats were randomly divided into six subgroups: control (C), exercise (E) , 20mg/kg/day aspirin-control (C+ASA20), 20mg/kg/day aspirin-exercise (E+ASA20), 100mg/kg/day aspirin-control (C+ASA100), and 100mg/kg/day aspirin-exercise(E+ASA100). Aspirin or vehicle was given by gastric gavage 1 h prior to the treadmill test. Rats in groups E and E+ASA underwent a single bout of the strenuous exercise to exhaustion on a motorized treadmill at a final speed of 30m/min, 10% grade, approximately 70-75% VO2 max. Blood was drawn at 1h (post), 6 h, 12 h, 18 h, and 24 h after acute exhaustive exercise for biochemical analyses. Rats were sacrificed at 24 h following the heavy exertion and the liver was removed for histological assessment. The results shown that mean exercise time to exhaustion was not significant difference among E, E+ASA20 and E+ASA100 rats. Aspirin markedly reduced the production of the pro-inflammatory cytokines, IL-6 and TNF-alpha. Aspirin (100 mg/kg) also significantly raised IL-10 production in trained rats, but worsened the level of exercise-induced plasma CK, LDH, AST, ALT and liver infiltrating leukocytes. High dose aspirin can further diminish the levels of total cholesterol, triglycerides and high-density in trained rats. Our results suggest that prophylactic administration of high dose of aspirin can cause greater severity of liver dysfunction after exhaustive exercise. Prophylactic aspirin can’t extend endurance time due to increasing muscle damage but attenuating inflammation during exhaustive exercise in rats. In second experiment, thirty-two rats were divided into four groups: sedentary control (SC); SC group with FCE supplementation (SC+FCE); exhaustive exercise (E); and E group with FCE supplementation (E+FCE). The SC+FCE and E+FCE groups were treated with gavage administration of 20 mg/kg for seven consecutive days. The exercise protocol was the same in first part experiment. Blood samples were collected for the evaluation of biochemical parameters. The cytokine levels of TNF-α and IL-10 were also examined. Twenty-four hours after exhaustive exercise, the rat livers were removed for H & E stain. The result shown that FCE supplementation could extend the time to exhaustion in exercised rats. The levels of CPK, LDH, AST, ALT, lactate, TNF-α and H & E stains of the liver injury were significantly decreased in the E+FCE group, but the blood glucose and IL-10 were significantly higher in comparison with the E group. This study suggests that FCE supplementation may improve endurance performance and reduce exercise-induced muscle damage, inflammatory stress and liver injury. To sum up, the present data would suggest the high dose (100mg/kg) aspirin administration could not only improve endurance performance but deteriorate the damage induced by exercise in muscle and liver functions in rats. Besides, FCE supplement might promote exercise performance, reduce exercise-induced muscle damage and inflammatory response, as well as protect against liver injury induced by acute exhaustive exercise.