新型抗生素研究实验-医学essay短文
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12-22, 2015
由于病原菌对常用抗生素的耐药性,当前抗菌药物的疗效十分有限,因此有必要寻找新的替代化合物。在这项研究中,主要目的是研究金银花的抗菌活性粳稻化合物粗提取液和不同乙酸乙酯和丁醇提取并与抗生素(氨苄青霉素)的合作活动。
麦克风值确定(表4.7)表明,金银花的提取粳稻花具有抗菌活性。甲醇和丁醇提取物表现出温和的抗菌活性与大肠杆菌,k .肺炎和沙雷氏菌属的种虫害MIC值介于12.5毫克/毫升之间和25毫克/毫升,而乙酸乙酯提取获得的MIC值相对较低, 对提到的细菌范围从6.25毫克/毫升至12.5毫克/毫升,从而显示有效的抗菌活性。
Resistance to antibiotics by major bacterial pathogens has limited the efficacy of current antibacterial drugs, and thus it is necessary to search for new alternative compounds. In this study, the main objective was aimed to investigate the antimicrobial activity of Lonicera japonica methanolic crude extract and different sub-fraction (ethyl-acetate and butanol) extracts and its synergism activity with antibiotic (ampicillin).
The MIC values determined (Table 4.7) had demonstrated that the extracts of the Lonicera japonica flower possess antimicrobial activity. Methanol and butanol extracts exhibit moderate antimicrobial activity against S. epidermidis, E. coli, K. pneumonia and Serratia spp. with MIC values ranged between 12.5mg/mL and 25mg/mL; while ethyl acetate extract obtained relatively low MIC values, ranged from 6.25mg/mL to 12.5mg/mL against mentioned bacteria and thus displaying promising antimicrobial activity. In MBC test conducted, K. pneumonia was the most sensitive bacteria to ethyl-acetate extract with MBC value of 25mg/mL.
The TLC separation of the plant extracts showed good separation of the compounds and hence the antimicrobial activity of the separated compounds can be determined by TLC bioautography agar overlay method. The bioautography assay proved that plant extracts do contain active compounds that have antimicrobial activity as clear zone of inhibition was observed. In bioautography, clear zones of inhibition were recorded in ethyl-acetate extract on all of the tested bacteria; while for methanol extract, clear zone was only observed in the control spot on S. epidermidis, indicating the possibility that the bioactive compounds within methanol extract have synergistic activity among each other. It is recommended that further investigation into the compounds where clear zones of inhibition were recorded, to be conducted to determine the bioactive properties of that particular compound.
In synergism test, synergistic interactions of plant extracts with ampicillin were observed and results showed that, the combination of ampicilin with different plant extracts exhibited positive results. Such combination had significantly lowered both the MIC values of ampicilin and plant extracts against tested bacteria, including E. coli, K. pneumonia and Serratia spp. The strong synergism activity between the plant extracts and ampicillin proved the therapeutic potential of this plant. Since K. pneumonia was resistant to ampicilin (Table 4.3), results of this study may suggest that the Lonicera japonica extracts possess compounds with antimicrobial properties which can be used as antimicrobial agents in new drugs against drug-resistant bacteria.
It is thus concluded that Lonicera japonica do possess antimicrobial properties for at least certain type of potent microbes and this activity is largely dependent on the extracts used. The objectives of this study which were to determine the MIC and MBC value of Lonicera japonica plant extracts; test the antimicrobial properties of separated active compounds from plant extracts using TLC bioautography assay and investigate the synergism activity of the plant extracts with antibiotic were successfully achieved.
From the finding of antimicrobial activities of the plant under study, further work need to be done on the isolation, purification and structural elucidation of the bioactive compounds in these plants. Besides, there is a need to widen the extraction solvents choice of the plant, since the activity of the plant depend on the properties of the solvent used. Further study can be carried out to identify the compounds responsible for the enhancement of antibiotic activity. An elucidation of the mechanisms of action of these compounds must be followed by toxicity and in vivo tests to determine the therapeutic application of such compounds in combination. Based on the plant species traditional uses, additional pharmacological studies, such as anti-inflammatory activity could also be conducted.
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