pancakes的部落格

月桂葉(Bay leaf，Laurus nobilis)

樟科(Lauraceae)月桂屬(Laurus)

學名：Laurus nobilis

中文名：月桂葉

圖1：月桂(Laurus nobilis)#1

【生理活性】

整株地上部分來源的伊朗月桂精油，主要成分有桉葉油醇(1,8-Cineole，55.8%)、α-乙酸萜品酯(α-terpinyl acetate，15.14%)、品烯四醇(terpinen-4-ol，5.27%)、α-蒎烯(α-pinene，5.26%)、β-蒎烯(β-pinene，4.06%)、異丙基甲苯(p-cymene，2.7%)和芳樟醇(linalool，1.4%)#2。若再比較月桂生長、開花前、開花和結果期4種階段採收所製精油彼此間差異，發現主成分含量僅稍有不同，差異並不明顯#3。賽普勒斯北方的月桂葉精油也有相似的成分組成，主要是桉葉油醇(58.59%)、α-乙酸萜品酯(8.82%)和品烯四醇  (4.25%) #4。

除了桉葉油醇和蒎烯類，花朵含量較高的揮發性成分有α-桉葉油醇(α-eudesmol)、β-欖烯(β-elemene)和β-石竹烯(β-caryophyllene)，果實有(E)-β-羅勒烯((E)-β-ocimene)和雙環大牻牛兒烯(bicyclogermacrene)，花苞則是(E)-β-羅勒烯和大根香葉烯(germacrene D)#5。

其他在月桂葉有機溶劑萃取物中也發現多種黃酮糖苷和megastigmane糖苷類成分#6-7，例如：山奈酚-3-吡喃鼠李糖苷(kaempferol-3-rhamnopyranoside)、山奈酚-3,7-二吡喃鼠李糖苷(kaempferol-3,7-dirhamnopyranoside)和laurosides A-E等物質。

民俗療法

傳統上使用月桂治療風濕、皮膚和腸胃疾病，例如：脹氣、消化不良、打嗝，在伊朗則用於癲癇治療。土耳其人認為有緩解痔瘡、風濕療效，並可作為蛇毒解毒劑，因它能幫助利尿及舒緩腹痛。近期另外發現可能也有治療糖尿病和預防偏頭痛效果。#8-9

抗氧化

實驗顯示，月桂葉乙酸乙酯萃取物有最佳的清除自由基功效，除了對多種自由基來源見效外，也可有效減少油脂過氧化。另在小鼠試驗，月桂葉萃取物可減少肝臟和血液內油脂的過氧化，達到保護作用，儘管有化學毒物存在，也同樣有效。#10

抗菌

月桂的20%酒精萃取物，能抑制金黃色葡萄球菌，效力和四環黴素(tetracycline)相似#11。月桂葉精油於濃度3.185 µL/cm²暴露168小時下可完全殺死玉米害蟲(玉米象，Sitophilus zeamais)並使蟲卵滅絕#12。有研究比較生鮮和乾燥月桂葉製成精油的抑菌差異，結果顯示乾燥來源精油表現較佳，能抑制大腸桿菌、綠膿桿菌、金黃色葡萄球菌、指狀青黴和鏈格孢菌屬，不過若和常用抗生素的抑菌力相比，仍是遠遠不及#13。

鎮痛和抗發炎

小鼠和大鼠研究證明，月桂葉精油可鎮痛且能抑制發炎引起的腫脹，另還有溫和鎮靜功效。其鎮痛和抗發炎表現與治療用藥嗎啡(morphine)和匹洛西卡(piroxicam)效果相近#14。

抗癲癇

因藥物(Pentylenetetrazol)誘發癲癇的小鼠，若於給予藥物前先腹腔注射0.75-1 ml/kg的月桂葉精油，則可完全抑制癲癇的誘發#9。根據過去研究，月桂葉精油抗癲癇功效可能是多種成分合作發揮產生的結果，這些成分包含桉葉油醇、蒎烯、丁香酚(eugenol)、甲基丁香酚(methyl eugenol)和芳樟醇。

神經保護

在大鼠的帕金森氏症實驗模型，多巴胺(dopamine)誘發神經細胞產生自由基並凋亡，6-羥基多巴胺(6-hydroxydopamine)同樣能導致神經細胞死亡。月桂葉己烷萃取物在實驗中，於濃度1.0μg/ml即能有效抑制多巴胺誘發的自由基，並減少細胞凋亡，保護神經細胞。萃取物主要的兩種成分，木香烯內脂(costunolide)和去氫木香內酯(dehydrocostus lactone)，與治療巴金森氏症藥物阿撲嗎啡(apomorphine)的保護效果相比，似乎更為優異(IC₅₀=7.3、3.6，18.1μM)。#15

改善阿茲海默症

過去研究認為乙醯膽鹼(acetylcholine)參與我們的認知和學習過程，乙醯膽鹼酯酵素(acetylcholinesterase)負責水解完成工作的乙醯膽鹼，因此抑制乙醯膽鹼酵素有助保留更多乙醯膽鹼，改善輕微或中度阿茲海默症。體外研究發現#16，月桂葉水萃物、酒萃物和精油皆有抑制乙醯膽鹼酯酵素活性功效，其中以精油和酒萃物較明顯。

改善糖尿病

α-澱粉酵素(α-amylase)和α-葡萄糖苷酵素(α-glucosidase)能將人體內碳水化合物分解成小分子糖，促進人體吸收，抑制這些酵素能減緩小分子糖進入血液造成餐後血糖上升，有助於改善第二型糖尿病。月桂葉精油經體外研究顯示#17，具有抑制α-葡萄糖苷酵素活性功效，若能進一步純化主要成分桉葉油醇(1,8-cineole)和R-(+)-檸烯(R-(+)-limonene)，效果會更好。

護肝

月桂葉酒萃物在大鼠研究展現護肝功效。腹腔注射毒物的大鼠在36小時內會全數死亡，但在注射毒物和月桂葉酒萃物混合物的實驗組，全數活過36小時，且肝損傷程度顯著改善，在20天的觀察期間，肝指數逐漸回復至未中毒前狀態#18。

可能風險

豐年蝦的毒性研究表示#19，月桂葉水萃物和酒萃物低毒性，但己烷萃取物高毒性，662.71 ppm即可使半數豐年蝦致死。

【料理應用】

月桂原生於南歐地中海流域，是北美、歐洲和經典法式料理頻繁使用的香草#8, 15。將生鮮月桂葉乾燥能提升香氣，它耐煮，適合添加在蒸煮、燉肉、燉菜和湯品增添風味及去腥，但烹調後食用前應將月桂葉取出，因葉片似皮革、味如蠟、邊緣尖銳、久煮生苦，不好吃也可能劃傷喉嚨或腸胃，這也是為什麼要使用整片月桂葉的原因，為了方便取出#20-22。乾燥月桂葉精油和壓榨油常用於魚、肉類和湯品料理調味，果實來源的油脂則可製皂#8, 23。

月桂葉精油有助於托斯卡尼香腸的保存和安全，研究表示製造配方中添加濃度0.05-0.1 g/100 g精油可有效降低大腸桿菌群孳生、延長保存期限、減少油脂過氧化#24。飼料中添加月桂葉可影響肉質，虹鱒吃含有月桂葉的飼料後，重量降低，但蛋白質增加且帶月桂香，感官評測上明顯優於吃一般飼料的虹鱒#25。北非鬍鯰(Clarias gariepinus)食用含月桂葉氯仿萃取物的飼料，可提高存活率、增加蛋白質和體重，有促進生長功能#26。

參考文獻：

(1)Ghadiri, E., Ahmadi, R., Moridikyia, A., Mahdavi, E., & Tavakoli, P. (2014). Laurus nobilis has Antibacterial Activity against Staphylococcus aureus. In International Conference on Food, Biological and Medical Sciences, Jan (pp. 28-29).

(2)Verdian-Rizi, M. (2009). Chemical composition and larvicidal activity of the essential oil of Laurus nobilis L. from Iran. Iranian Journal of Pharmaceutical Sciences, 5(1), 47-50.

(3)Verdian-rizi, M. (2009). Variation in the essential oil composition of Laurus nobilis L. of different growth stages cultivated in Iran. Journal of Basic and Applied Sciences, 5(1), 33-36.

(4)Yalçın, H., Anık, M., Şanda, M. A., & Çakır, A. (2007). Gas chromatography/mass spectrometry analysis of Laurus nobilis essential oil composition of northern Cyprus. Journal of medicinal food, 10(4), 715-719.

(5)Kilic, A., Hafizoglu, H., Kollmannsberger, H., & Nitz, S. (2004). Volatile constituents and key odorants in leaves, buds, flowers, and fruits of Laurus nobilis L. Journal of agricultural and food chemistry, 52(6), 1601-1606.

(6)De Marino, S., Borbone, N., Zollo, F., Ianaro, A., Di Meglio, P., & Iorizzi, M. (2004). Megastigmane and phenolic components from Laurus nobilis L. leaves and their inhibitory effects on nitric oxide production. Journal of Agricultural and Food Chemistry, 52(25), 7525-7531.

(7)Emam, A. M., Mohamed, M. A., Diab, Y. M., & Megally, N. Y. (2010). Isolation and structure elucidation of antioxidant compounds from leaves of Laurus nobilis and Emex spinosus. Drug Discov Ther, 4(3), 202-207.

(8)Mansour, Oussama, and Ghenwa Ismail. (2018). Review Study on the Physiological Properties and Chemical Composition of the Laurus nobilis. The Pharmaceutical and Chemical Journal, 5(1):225-231

(9)Sayyah, M., Valizadeh, J., & Kamalinejad, M. (2002). Anticonvulsant activity of the leaf essential oil of Laurus nobilis against pentylenetetrazole and maximal electroshock-induced seizures. Phytomedicine, 9, 212–216.

(10)Kaurinovic, B., Popovic, M., & Vlaisavljevic, S. (2010). In vitro and in vivo effects of Laurus nobilis L. leaf extracts. Molecules, 15(5), 3378-3

(11)Ghadiri, E., Ahmadi, R., Moridikyia, A., Mahdavi, E., & Tavakoli, P. (2014). Laurus nobilis has Antibacterial Activity against Staphylococcus aureus. In International Conference on Food, Biological and Medical Sciences, Jan (pp. 28-29).

(12)Barros, G., Magro, A., Conceição, C., Matos, O., Barbosa, A., Bastos, M. M., & Mexia, A. (2015). The use of Laurus nobilis and Mentha pulegium essential oils against Sitophilus zeamais (Coleoptera: Curculionidae) on stored maize. Revista de Ciências Agrárias.

(13)Dahak, K., Bouamama, H., Benkhalti, F., & Taourirte, M. (2014). Drying methods and their implication on quality, quantity and antimicrobial activity of the essential oil of Laurus nobilis L. From morocco. OnLine Journal of Biological Sciences, 14(2), 94-101.

(14)Sayyah, M., Saroukhani, G., Peirovi, A., & Kamalinejad, M. (2003). Analgesic and anti-inflammatory activity of the leaf essential oil of Laurus nobilis Linn. Phytotheraphy Research, 17, 733–736.

(15)Ham, A.-R., Shin, J.-H., Oh, K.-B., Lee, S.-J., Nam, K.-W., Koo, U., … Mar, W.-C. (2011). Neuroprotective Effect of the n-Hexane Extracts of Laurus nobilis L. in Models of Parkinson’s Disease. Biomolecules and Therapeutics, 19(1), 118–125.

(16)Ferreira, A., Proença, C., Serralheiro, M. L. M., & Araujo, M. E. M. (2006). The in vitro screening for acetylcholinesterase inhibition and antioxidant activity of medicinal plants from Portugal. Journal of ethnopharmacology, 108(1), 31-37.

(17)Basak, S. S., & Candan, F. (2013). Effect of Laurus nobilis L. essential oil and its main components on α-glucosidase and reactive oxygen species scavenging activity. Iranian journal of pharmaceutical research: IJPR, 12(2), 367.

(18)Gasparyan, G., Tiratsuyan, S., Kazaryan, S., & Vardapetyan, H. (2015). Effect of Laurus nobilis extract on the functioning of liver against CCl4 induced toxicity. Journal of Experimental Biology and Agricultural Sciences, 3(2), 174-183.

(19)Kivc[1]ak, B., & Mert, T. (2002). Preliminary evaluation of cytotoxic properties of Laurus nobilis leaf extracts. Fitoterapia, 73, 242–243.

(20)https://www.wikihow.com/Use-Bay-Leaves

(21)https://www.home-ec101.com/the-misunderstood-herb-how-to-use-bay-leaves/

(22)http://galainthekitchen.com/bay-leaves-culinary-uses/

(23)Bozan, B., & Karakaplan, U. (2007). Antioxidants from laurel (Laurus nobilis L.) berries: influences of extraction procedure on yield and antioxidant activity of extracts. Acta Alim. 36, 321-328.

(24)Mello da Silveira, S.; Bittencourt Luciano, F.; Fronza, N.; Cunha, A., Jr.; Neudí Scheuermann, G.; Werneck Vieirad, C.R. Chemical composition and antibacterial activity of Laurus nobilis essential oil towards foodborne pathogens and its application in fresh Tuscan sausage stored at 7 ◦C. LWT-Food Sci. Technol. 2014, 59, 86–93.

(25)Cagiltay, F., Diler, İ., Varlik, C. (2011). The effects of Bay Leaf on rainbow trouts growth, aromatic and meat composition. Journal of Animal and Veterinary Advances, 10, 1914-1915.

(26)Turan, F., Ganpolat, E., & Aygen, U. (2016). Effect of Bay Laurel (Laurus nobilis) Extract on Growth of the African Catfish, Clarias gariepinus (Burchell, 1822). Pakistan Journal of Zoology, 48(2), 489-489.