pancakes的部落格

阿拉伯乳香(Frankincense，Boswellia Sacra)

橄欖科(Burseraceae)乳香屬(Boswellia)

學名：Boswellia Sacra (據說和索馬利亞的Boswellia Carteri同種[1])

別名：Olibanum

圖1：Boswellia Sacra [1]

乳香樹生長在中非、阿拉伯半島南方和印度。Frankincense名字起源於古法文，表示quality incense；別名Olibanum來自阿拉伯語al-lub-n，意謂乳品來源，但也有人猜測出處是阿拉伯語的”黎巴嫩之油”，因為黎巴嫩是販售給歐洲人乳香的地方，或是阿拉伯語的“Laben”和“Luban”，意指樹脂、奶油。[2-3]

Silver 和 Hojari是公認品質最高的乳香[2]，阿曼當地人認為Silver又略勝一籌，可是西方買家不這麼認為。原因或許來自於Hojari在相對低溫、潮濕的歐美國家能釋放較佳的香氣，而Silver則比較適宜阿拉伯國家的乾、熱氣候。乳香評鑑不僅和香氣有關，還需檢視顏色和凝塊大小，色澤越淡且大塊的價值最高。

乳香貿易在阿拉伯半島和北非地區已有超過5000年歷史，自西元前即用於宗教或儀式慶典等重要場合，所以乳香一直有其珍貴象徵，死於西元前1323年的埃及法老–圖坦卡門(Tutankhamun)，在其出土的陵墓中也發現乳香是陪葬品之一。乳香傳統主要應用在薰香、香水定香劑和抗發炎治療；現代科學則藉由樹脂的疏水和成膜特性，發展製成具緩釋輸送需求的藥錠或微粒膠囊劑型。[1-2]

【生理活性】

未純化的乳香樹脂約含有5-9%精油、65-85%酒精可溶解樹脂以及殘餘的水溶性樹脂[4]。阿曼的乳香經水蒸餾而得的精油產率5.5%，組成為97.3% 單萜類(monoterpenes)和2.7%倍半萜類(sesquiterpene)，沒有任何的雙萜類(diterpene)。單萜類主要含檸烯(limonene，33.5%)、E-β-羅勒烯(E-β-ocimene，32.3%)和香葉烯(myrcene，6.9%)，倍半萜類以E-石竹烯(E-caryophyllene，0.9%)濃度最高[5]。先前的其他研究則反而是α-蒎烯(α-pinene)含量最多，範圍從6.3-23.2%[6]，若蒸餾溫度升高，α-蒎烯比率下降，乳香酸(boswellic acids：11-keto-β-boswellic acid (KBA)、acetyl-11-keto-β boswellic acid (AKBA)、α-boswellic acid、3-O-acetyl-α-boswellic acid、acetyl-β-boswellic acid).總量增加 [7-8]。

另篇研究使用當地分級4種等級的阿曼乳香商品[1]，結果發現第1級的Hoojri和第4級的Shaabi，雖然價格落差非常大(83 $/kg-15 $/kg)，顏色和質地也不相近，但精油組成、產率和旋光性卻很類似。第2級的Najdi (67 $/kg)和第3級的Shathari (31 $/kg)，雖和Hoojri、Shaabi不同，不過它們的檸烯濃度都明顯較高。Najdi的香葉烯含量，和其他3者相比又更為突出。Hoojri精油則有最高的單萜類(91.5%)，α-蒎烯濃度也最高(76.0%)。綜合觀之，這4種商品有相似的精油組成，但各別成分含量除了有相似性，也表現出程度不等的相異性。

民俗療法

乳香可食，但需處理經過純化，呈色半透明且未見黑或褐色不純物，通常是淡黃帶淺綠色，口感如口香糖[2]。在傳統醫學領域，它的應用極為廣泛，從牙周、皮膚、消化道到呼吸道的不適，都能適用；自古時的埃及、中國、羅馬和印度，乳香樹全株各部位便被充分利用在多種需求[9]。阿育吠陀醫學上，含乳香樹脂或萃取物的用藥可治多發性關節炎(polyarthritis)和風濕[10-11]，印度的乳香樹脂也常用於治氣喘[12]。薰燒乳香可驅逐蚊子，避免蚊媒傳染疾病，例如：瘧疾、登革熱或西尼羅河病毒(West Nile virus)[2]。

抗菌

4種等級的阿曼乳香：Hoojri、Najdi、Shathari和Shaabi。整體來說，4種精油抑制格蘭氏陽性菌效果優於革蘭氏陰性菌；最廉價的Shaabi表現最好，實驗中所測試的菌種皆能有效抑制，最小抑菌濃度在5-80 μl/ml (10⁶ cells/ml)，抑菌圈對比其他3者也普遍更廣[1]。

乳香樹枝精油也有抑菌力[13]，對糞腸球菌 (Enterococcus faecalis)、痢疾志賀氏桿菌(Shigella dysenteriae)、腸道沙門氏菌(Salmonella enterica)、仙人掌桿菌 (Bacillus cereus)和非致病性李斯特菌(Listeria innocua)顯著有效；乳香樹枝甲醇萃取物則能有效抑制腸道沙門氏菌和非致病性李斯特菌。比較樹枝精油和甲醇萃取物在真菌白色念珠菌(Candida albicans)和麴菌屬(Aspergillus spp.)的抑制效果，精油的抑制能力相對出色。

治療腸胃發炎

臨床試驗顯示，乳香樹脂對潰瘍性結腸炎(ulcerative colitis)有效[14-15]，可改善腹瀉；齧齒目動物試驗結果，除減少腹瀉也能緩和腸蠕動，且沒有便秘副作用[16]。另乳香萃取物在克隆氏症(Crohn’s disease)[17]、膝關節炎[18]和膠原性結腸炎(collagenous colitis)[19]的治療上也表現出高度潛力。

抗癌

經100℃12小時水蒸餾所製的阿曼乳香精油，體外研究[7]在600-1200倍稀釋下，可抑制多種乳癌細胞且不會造成正常細胞明顯死亡；但若在78℃水蒸餾所得精油，於200-800倍稀釋時雖能使乳癌細胞致死，但也導致大量正常細胞死亡。所有乳癌細胞中，乳香精油對MCF7細胞株的抗癌效果最好。

雖然乳香酸過往研究曾證明具抗神經癌細胞功能[20-21]，不過殺死乳癌細胞的可能不是乳香酸。原因有二：1.乳香酸在因儲存過程中發生降解時，精油的抗癌效果依舊維持原樣；2.含15.5%乳香酸的純露，僅經5倍稀釋竟無法殺死乳癌細胞。雖然作者難以找出抗乳癌的活性分子[7]，但仍根據後續實驗解釋可能原因：Akt 和ERK1/2訊息路徑的活化被認為會加速乳癌發展以及提早產生抗藥性[22-24]，乳香酸能活化Akt 和ERK1/2訊息傳遞路徑，而乳香精油反而會抑制，或許兩者之間的差異便是造成結果相異的主因。

一名52歲患有侵襲性泌尿上皮癌pT1/pT2期的西班牙男性患者[25]，手術切除腫瘤後他每日口服阿拉伯乳香精油3ml持續25個月，結果第一年經歷2次復發，但腫瘤大小遠比初時小，再經手術切除後觀察，第14個月之後即未再復發，肝腎功能透過血液檢測也未有任何異常，這可能表示阿拉伯乳香精油有預防罹患侵襲性泌尿上皮癌的潛力。所用精油是以樹脂1：水2.5 (w/v)於100℃水蒸餾在11-12小時區間所收集而得[26]，療程期間同時也轉變飲食：盡量白肉取代紅肉、吃維他命C、綜合維他命、花椰菜芽萃取物、蔬果汁(羽衣甘藍、胡蘿蔔、薑、巴西里、蘋果、黃瓜、哈瓦那辣椒)。

減少神經退化

12周公大鼠連續21天暴露於每天一次每次60分鐘由手機釋出的900-MHz電磁輻射[27]，結果控制組大鼠海馬迴內的椎體細胞、小腦的普金斯細胞(Purkinje cell)和齒狀迴的顆粒細胞數都顯著降低，導致神經退化。以胃管灌食500 mg/kg/day阿拉伯乳香持續21天的大鼠可有效維持神經細胞存活，延緩神經退化。

鎮痛

口服阿拉伯乳香精油或萃取物300 mg/kg of the body weight劑量的小鼠能顯著鎮痛[28]，有時效果更優於同劑量的阿斯匹靈(aspirin)。Shabi乳香精油(正己烷溶劑萃取)在疼痛早期(0-5 min)和晚期(20-30 min)分別能鎮痛57.5%和55.6%；[甲醇→60% chloroform/n-hexane]萃取物早期有55.3%、晚期66.7%；而阿斯匹靈分別僅36.2%和29.6%。

可能風險

精油氧化可能導致皮膚過敏，應儲存在避光、少氧和低溫環境。由於主要成分α-蒎烯和檸烯的低生育毒性，因此懷孕期間仍可使用。[29]

【芳療功效】

相較於印度乳香的清香，由乾燥樹脂水蒸氣蒸餾製成的阿拉伯乳香精油有宜人的巴薩米可醋(balsamic)香氣和甜味；乳香精油能改善呼吸，使呼吸暢通，所以對氣喘病人非常有幫助。芳療除能透過精油，另也能選擇嗅聞薰燒乳香等其他方式。[2、10]

傳統使用乳香治療呼吸道不適[30]會透過蒸氣吸入、沐浴或按摩等途徑，對咳嗽、黏膜炎、支氣管炎和氣喘皆有助益。在動物實驗[31]，小鼠吸嗅過阿拉伯乳香精油，能有效抑制呼吸道過敏和過度反應(airway hyperresponsiveness)，適時調控免疫回應，減少發炎發生，可當作一個簡單且便宜的氣喘輔助治療選擇。

參考資料：

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(2)JS, P., Marapur, S. C., Kadam, D. V., & Kamalapur, M. V. (2010). Pharmaceutical and medicinal applications of Olibanum gum and its constituents: A review. Journal of Pharmacy Research, 3(3), 587-589.

(3)Alam, Dr. Tanveer & NAJAM, DR. LUBNA. (2018). Frankincense: Essential Oils and its Applications.

(4)Tauchnitz, L. Tucker, AO 1986. Frankincense and myrrh. Econ. Bot. 40: 425-433. Vaughan, J. 1852. Notes upon the drugs observed at Aden, Arabia. Pharmaceut. Journ. Trans. 12: 226-229.

(5)Al-Harrasi, A., & Al-Saidi, S. (2008). Phytochemical analysis of the essential oil from botanically certified oleogum resin of Boswellia sacra (Omani Luban). Molecules, 13(9), 2181-2189.

(6)Mertens, M., Buettner, A., & Kirchhoff, E. (2009). The volatile constituents of frankincense–a review. Flavour and Fragrance Journal, 24(6), 279-300.

(7)Suhail, M. M., Wu, W., Cao, A., Mondalek, F. G., Fung, K. M., Shih, P. T., ... & Lin, H. K. (2011). Boswellia sacra essential oil induces tumor cell-specific apoptosis and suppresses tumor aggressiveness in cultured human breast cancer cells. BMC complementary and alternative medicine, 11(1), 129.

(8)Rashan, L., Hakkim, F. L., Idrees, M., Essa, M. M., Velusamy, T., Al-Baloshi, M., ... & Hasson, S. S. A. A. (2019). Boswellia Gum Resin and Essential Oils: Potential Health Benefits− An Evidence Based Review. International Journal of Nutrition, Pharmacology, Neurological Diseases, 9(2), 53.

(9)Murthy, K. S. R., Reddy, M. C., Rani, S. S., & Pullaiah, T. (2016). Bioactive principles and biological properties of essential oils of Burseraceae: A review. Journal of Pharmacognosy and Phytochemistry, 5(2), 247.

(10)Mikhaeil, B. R., Maatooq, G. T., Badria, F. A., & Amer, M. M. (2003). Chemistry and immunomodulatory activity of frankincense oil. Zeitschrift für Naturforschung C, 58(3-4), 230-238.

(11)Chevrier, M. R., Ryan, A. E., Lee, D. Y. W., Zhongze, M., Wu-Yan, Z., & Via, C. S. (2005). Boswellia carterii extract inhibits TH1 cytokines and promotes TH2 cytokines in vitro. Clinical and diagnostic laboratory immunology, 12(5), 575-580.

(12)Gupta, I., Gupta, V., Parihar, A., Gupta, S., Lüdtke, R., Safayhi, H., & Ammon, H. P. (1998). Effects of Boswellia serrata gum resin in patients with bronchial asthma: results of a double-blind, placebo-controlled, 6-week clinical study. European journal of medical research, 3(11), 511.

(13)Abdoul-latif, F. M., Obame, L. C., Bassolé, I. H., & Dicko, M. H. (2012). Antimicrobial activities of essential oil and methanol extract of Boswellia sacra Flueck. and Boswellia papyrifera (Del.) Hochst from Djibouti. International Journal of Management, Modern Sciences and Technologies, 1, 1-10.

(14)Gupta, I., Parihar, A., Malhotra, P., Singh, G. B., Lüdtke, R., Safayhi, H., & Ammon, H. P. (1997). Effects of Boswellia serrata gum resin in patients with ulcerative colitis. European journal of medical research, 2(1), 37-43.

(15)Gupta, I., Parihar, A., Malhotra, P., Gupta, S., Lüdtke, R., Safayhi, H., & Ammon, H. P. (2001). Effects of gum resin of Boswellia serrata in patients with chronic colitis. Planta medica, 67(05), 391-395.

(16)Borrelli, F., Capasso, F., Capasso, R., Ascione, V., Aviello, G., Longo, R., & Izzo, A. A. (2006). Effect of Boswellia serrata on intestinal motility in rodents: inhibition of diarrhoea without constipation. British journal of pharmacology, 148(4), 553.

(17)Gerhardt, H., Seifert, F., Buvari, P., Vogelsang, H., & Repges, R. (2001). Therapy of active Crohn disease with Boswellia serrata extract H 15. Zeitschrift fur Gastroenterologie, 39(1), 11-17.

(18)Kimmatkar, N., Thawani, V., Hingorani, L., & Khiyani, R. (2003). Efficacy and tolerability of Boswellia serrata extract in treatment of osteoarthritis of knee–a randomized double blind placebo controlled trial. Phytomedicine, 10(1), 3-7.

(19)Madisch, A., Miehlke, S., Eichele, O., Mrwa, J., Bethke, B., Kuhlisch, E., ... & Stolte, M. (2007). Boswellia serrata extract for the treatment of collagenous colitis. A double-blind, randomized, placebo-controlled, multicenter trial. International journal of colorectal disease, 22(12), 1445-1451.

(20)Winking, M., Sarikaya, S., Rahmanian, A., Jödicke, A., & Böker, D. K. (2000). Boswellic acids inhibit glioma growth: a new treatment option?. Journal of Neuro-oncology, 46(2), 97-103.

(21)Akihisa, T., Tabata, K., Banno, N., Tokuda, H., Nishihara, R., Nakamura, Y., ... & Suzuki, T. (2006). Cancer chemopreventive effects and cytotoxic activities of the triterpene acids from the resin of Boswellia carteri. Biological and Pharmaceutical Bulletin, 29(9), 1976-1979.

(22)Lin, H. J., Hsieh, F. C., Song, H., & Lin, J. (2005). Elevated phosphorylation and activation of PDK-1/AKT pathway in human breast cancer. British journal of cancer, 93(12), 1372-1381.

(23)Svensson, S., Jirström, K., Rydén, L., Roos, G., Emdin, S., Ostrowski, M. C., & Landberg, G. (2005). ERK phosphorylation is linked to VEGFR2 expression and Ets-2 phosphorylation in breast cancer and is associated with tamoxifen treatment resistance and small tumours with good prognosis. Oncogene, 24(27), 4370-4379.

(24)Gee, J. M., Robertson, J. F., Ellis, I. O., & Nicholson, R. I. (2001). Phosphorylation of ERK1/2 mitogen‐activated protein kinase is associated with poor response to anti‐hormonal therapy and decreased patient survival in clinical breast cancer. International journal of cancer, 95(4), 247-254.

(25)Xia, D., Lou, W., Fung, K. M., Wolley, C. L., Suhail, M. M., & Lin, H. K. (2017). Cancer chemopreventive effects of Boswellia sacra gum resin hydrodistillates on invasive urothelial cell carcinoma: report of a case. Integrative cancer therapies, 16(4), 605-611.

(26)Ni, X., Suhail, M. M., Yang, Q., Cao, A., Fung, K. M., Postier, R. G., ... & Lin, H. K. (2012). Frankincense essential oil prepared from hydrodistillation of Boswellia sacra gum resins induces human pancreatic cancer cell death in cultures and in a xenograft murine model. BMC Complementary and Alternative Medicine, 12(1), 253.

(27)Kivrak, E. G., Altunkaynak, B. Z., Alkan, I., Yurt, K. K., Kocaman, A., & Onger, M. E. (2017). Effects of 900-MHz radiation on the hippocampus and cerebellum of adult rats and attenuation of such effects by folic acid and Boswellia sacra. Journal of microscopy and ultrastructure, 5(4), 216-224.

(28)Al-Harrasi, A., Ali, L., Hussain, J., Rehman, N. U., Ahmed, M., & Al-Rawahi, A. (2014). Analgesic effects of crude extracts and fractions of Omani frankincense obtained from traditional medicinal plant Boswellia sacra on animal models. Asian Pacific Journal of Tropical Medicine, 7, S485-S490.

(29)Tisserand, R., & Young, R. (2013). Essential oil safety-e-book: A guide for health care professionals. Elsevier Health Sciences.

(30)Hamidpour, R., Hamidpour, S., Hamidpour, M., & Shahlari, M. (2013). Frankincense (乳香 Rǔ Xiāng; Boswellia species): from the selection of traditional applications to the novel phytotherapy for the prevention and treatment of serious diseases. Journal of traditional and complementary medicine, 3(4), 221-226.

(31)Lee, H. Y., Yun, M. Y., & Kang, S. M. (2008). Anti-inflammatory effect of Boswellia sacra (Franckincense) essential oil in a mouse model of allergic asthma. Microbiology and Biotechnology Letters, 36(4), 343-352.