Antibacterial and antioxidant properties of three Chinese herbs of Clematis species

• Main Authors: E-En Tsai, 蔡宜恩
• Other Authors: Li-Yeh Chuang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/98357538094436942261

碩士 === 義守大學 === 生物技術與化學工程研究所碩士班 === 98 === Since the British scientist Fleming discovered Penicillin back in 1928, people enjoyed over 40 years of their lives without the fear of complications caused by bacteria infections during therapy processes that may lead to death. However, these good old times has come to an end due to excessive dependence and abuse of antibiotics. The excessive use of antibiotics resulted in drug-resistant bacteria, so hospitals had to increase the dosage of antibiotics or change to other antibiotics. In the light of increasing in multiple drug-resistant bacteria, which causes many current antibiotics to become invalid, we aim to look for possible valid ingredients in the Chinese herbs that may replace current antibiotics. In this study, we have chosen three herbs of Ranunculaceous Clematis plants: Clematidis Radix, Caulis Clematidis armandii and herba Clematidis intricatae as the media of research. There had been only few published reports that pointed out Clematidis Radix as having antibacterial effects, but none for Caulis Clematidis armandii and herba Clematidis intricatae. In order to characterize the active components of these Chinese herbs, the three kinds of herbs were extracted by ethanol extraction. Through the disc diffusion test, the herbs revealed good antibacterial activity against the following clinical antibiotic resistant pathogens：Staphyloccocus aureus, Acinetobacter baumannii and Pseudomonas aeruginosa. The ethanol extracts then were partitionated into different organic solvents based on their polarity for distribution extraction. Following the bioassay, the active fraction were found in ethyl acetate fraction. We have also found that all of the clinical pathogens in our test were sensitive for the extracts. The results obtained from minimum inhibitory concentration ( MIC ) and minimum bactericidal concentration ( MBC ) tests, showed that three kinds of herbs'' MIC and MBC were: herba Clematidis intricatae''s MIC was about 1.8～5.5 mg / mL and the MBC was about 3.0～5.5 mg / mL; Clematidis Radix''s MIC was about 6.0～14.0 mg / mL and MBC was about 2.0～16.0 mg / mL; Caulis Clematidis armandii''s MIC was greater than 10.0 mg / mL. Moreover, the time killing curve test, indicated that Caulis Clematidis armandii did not have bactericidal affects, although the other two herbs could kill bacteria within half an hour and maintained no bacterial growth within 24-hours. According to the results of GC-MS identification, the active components of herba Clematidis intricatae fraction collected from column chromatography had no structural information match in the GC-MS database and related documents; therefore it is suggested to be unknown substances. Through the thin layer chromatography test, the results showed that the active substances might be phenolic compounds. In addition, the antioxidant activities were determined for the three herbs in response to people’s pursuit of anti-aging material and cancer cures in recent years. According to the results of the antioxidation analysis, herba Clematidis intricatae presented a higher antioxidant activity with the IC50 of DPPH at 134.00 μg/mL；the value of TEAC is 247.66 mg Trolox/g; and the slope of reducing power is 0.40; the total phenolic content is 133.45 mg Gallic acid/g dw and the total flavonoid content is 76.762 mg Quercetin/g dw. According to the results of this study, the antimicrobial activity of herba Clematidis intricatae is the best among the three herbs, and it has a broad-spectrum of antibacterial activity. Moreover, herba Clematidis intricatae also showed the best antioxidant activity. Overall, herba Clematidis intricatae, of the three herbs in this study, has the most potential in becoming an alternative antibiotic.