探討薑黃素製劑對金黃色葡萄球菌和白色念珠菌的抗微生物活性

Abstract

白色念珠菌(Candida albicans)及金黃色葡萄球菌(Staphylococcus aureus)為造成院內感染的常見菌株，且其在臨床上的治療也面臨抗藥性的問題。開發天然化合物或其衍生物來作為抗菌藥物，被認為是一種可行的研究方向。其中，從薑黃（Curcuma longa）的有效成分中萃取出的薑黃素(Curcumin)具安全有效的生物活性，如抗發炎，抗氧化等等；另外，薑黃素具廣泛的抗微生物活性，包括抗菌和抗真菌特性以及影響其生物膜形成的能力，且目前已有文獻發現，高濃度的薑黃素對白色念珠菌及金黃色葡萄球菌的懸浮細胞皆具有抗菌活性。本研究工作主要是利用實驗室既有配方所製備而成的Curcumin對白色念珠菌及金黃色葡萄球菌的抗菌能力進行測試。實驗結果發現相較溶解於DMSO的Curcumin，實驗室製備的Curcumin配方對白色念珠菌具較高的抑菌效果；而雖然針對金黃色葡萄球菌須採用較高濃度的劑量才具明顯抑菌能力，但在低劑量的情形下尚可嘗試結合臨床常用抗菌藥物的方式增強其抑菌效果。因此，本研究之目的除了利用實驗室製備的Curcumin配方測試對白色念珠菌及金黃色葡萄球菌的抗菌能力外，也進一步比較其結合臨床常用抗菌藥物(Ampicillin、Gentamicin及Fluconazole)對這兩種菌株之抑菌效果外，也比較這一配方在具抗藥性的菌株(Methicillin-resistant Staphylococcus aureus, MRSA)的殺菌能力。結果發現在結合臨床藥物及Curcumin配方後，發現可有效降低所需劑量或能達到全殺之抗菌效果。另外，為瞭解這一與臨床藥物的增強效果是否僅針對單一菌株具專一性，故同時測試同為革蘭氏陽性菌的表皮葡萄球菌(Staphylococcus epidermidis )之抗菌能力，而實驗結果也發現具有相同的效力。

Candida albicans and Staphylococcus aureus are common strains in nosocomial infections, and both of them have developed drug resistance to antibiotics. Curcumin, the active ingredients of Curcuma longa, has been demonstrated its biological activities, such as anti-inflammatory and antioxidant, etc. Besides, Curcumin also has a wide range of antimicrobial activities, including antibacterial, antifungal properties, and the stability of microbial biofilm. It has been shown that high dose of Curcumin has antimicrobial activities against the planktonic cells of Candida albicans and Staphylococcus aureus. The purpose of this study was to investigate the antimicrobial activities of a formulated curcumin against Candida albicans and Staphylococcus aureus. We found that formulated curcumin has higher antifungal activities than curcumin dissolved in DMSO against Candida albicans. Although higher dose of formulated curcumin was required for Staphylococcus aureus planktonic cells, we found that the combination of formulated curcumin and ampicillin has additive antibacterial activities. This formulated curcumin combined with fluconazole has simialr additive cytotoxicity against Candida albicans. Finally, we showed that this additive bactericidal activity could also be verified in other clinical drugs such as gentamicin as well as against Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis.