| 摘要: | 構樹（Brossonetia papyrifera (L.) L’Herit. ex Vent）為桑科構屬植物，始載於名醫别錄以成熟果實入藥，主要功效有補虛勞、治跌打損傷、改善學習記憶等功能。而該植物之其他部分如葉、莖、根皮等亦於歷代本草中有入藥之記載，但現代之研究主要著重其根及果實之藥理活性，因此本研究針對其主要四個用部根、莖、葉及果實進行主要傳統功效與藥理活性（抑制 AChE、抗氧化暨神經保護、鎮痛發炎）之比較。
首先進行離體 AChE 抑制活性之比較，結果發現以莖之抑制乙醯膽鹼酯酶活性最佳、其次為根及果實。其次，針對構樹各部位之抗氧化成分含量及抗氧化活性進行比較，結果發現，以根含較豐富之總酚類及 phenylpropanoid glycoside 成分，且亦以根具有較佳之清除 ROS 自由基及抗氧化活性；而在迴歸分析中亦發現根之抗氧化活性與 phenylpropanoid glycoside 成分之含量有密切關係。最後，選用抗氧化活性較佳之根及葉進行對 H2O2 誘發神經細胞損傷保護作用之評估，結果發現根對 H2O2 誘發神經細胞損傷具較佳之保護作用，其作用機轉可能與其抗氧化活性以致減少細胞內外氧化壓力、及降低細胞內之GSH 消耗，以增加細胞本身之抗氧化機制有關。
最後，針對構樹各部位之鎮痛抗發炎活性（醋酸誘發扭體反應、福馬林誘發舔足試驗、角叉菜膠誘發大鼠足蹠腫脹和微血管滲透性）進行比較，結果發現各部位中以根具有較佳之鎮痛抗炎活性，其次為果實；其結果發現可能抗炎機轉主要與抑制前 2 小時致炎物質 serotonin 及 NO 所致之微血管滲透增加有關，而與後期 COX-2 所產生之發炎較無關連。
總結上述結果，針對構樹其主要四個用部進行抗氧化暨神經保護、鎮痛發炎等三項藥理活性之比較，皆以根部較果最佳，其對神經保護作用可能與其抗氧化活性以致減少細胞內外氧化壓力、及降低細胞內之GSH 消耗，以增加細胞本身之抗氧化機制有關。而於抗發炎機轉主要與抑制前 2 小時致炎物質 serotonin 及 NO 所致之微血管滲透增加有關，故構樹根為構樹各部位中最值得開發研究之部位。
Each parts of Brossonetia papyrifera (L.) L’Herit. ex Vent, including leaf, fruit, stem et al., are used to cure edema, itch and pain as described in the traditional Pent’sao. Modern pharmacological reports pointed out that the fruit and radix of B. papyrifera possessed memory-improving and lipid peroxidation inhibiting activities. However, the antinociceptive and anti-inflammatory activities of B. papyrifera are not investigate a untill recently. This study aim to compare the acetylcholinesterase inhibiting, antioxidant, neuroprotective, antinociceptive and anti-inflammatory activities of various parts from B. papyrifera.
First, the result showed that the stem of B. papyrifera had the best AChE inhibiting activity in vitro. Second, the radix and leaf, enriched antioxidant components including total phenolic and phenylpropranoid glycoside, possessed the best ROS scavenging and antioxidant activities than the other patrs of B. papyrifera. The radix had the better protective effect on hydrogen peroxide-induced oxidative damage in SH-SY5Y cells than the leaf of B. papyrifera. The radix reversed the decrease in the cell viability and intracellular GSH contents, and the increase in the intracellular and extracellular oxidative stress caused by hydrogen peroxide.
Finally, the analgesic and antiinflammatory effects of various part of B. papyrifera were compared by chemical-induced pain and inflammation in rodents. The results showed that the radix significantly decreased the nociception induced by acetic acid and formalin, and paw edema caused by carrageenan. We further found the radix decrease vascular permeability increased by serotonin and sodium nitroprusside in rats.
In conclusion, the radix is a potential used part of B. papyrifera on the antioxidant, neuroprotective, analgesic and antiinflammatory activities. The neuroprotective mechanisms of the radix were related to the decreases in the intracellular ROS contents and GSH consumption via its antioxidant properties. The antiinflammatory mechanism of the radix was related to inhibiting the increase in vascular permeability via serotonin and NO. |
