Abstract：
BACKGROUND: For many centuries, medicinal herbs and their derivatives have been used to treat or prevent various diseases. However, environmental factors such as the season for collection of plant may change the therapeutic efficacy. The present work investigates seasonal variations of phenolic, flavonoid content, antioxidant, antibacterial, and cytotoxic potential of hydroalcoholic extract of Rheum khorasanicum (HER).
METHODS: R. khorasanicum was collected in three different months: December, February, and April. The Folin-Ciocalteu assay was applied to measure the total phenolic content of HER. Antioxidant activities (DPPH and FRAP) were also determined. Next, the extracts were evaluated for antibacterial potential against some Gram-positive and Gram-negative strains. The minimal inhibitory concentration (MIC) was determined by the microdilution method. Finally, the effect of extracts on the viability of C6, A549, and HT-29 cells was evaluated via the MTT assay.
RESULTS: All three extracts contained considerable phenolic and flavonoid contents and showed desirable antioxidant activity. The April sample exhibited the greatest phenolic and flavonoid content and significant antioxidant activity potential in the FRAP test. In addition, the April sample had the highest antibacterial activity and cytotoxic effect on the cancerous cell lines.
CONCLUSIONS: The April extract showed more antioxidant, antibacterial and cytotoxic effect, probably because of its higher phenolic and flavonoid contents than other samples. These results demonstrate that the harvest timing of R. khorasanicum affects the plant\'s phenolic content and its antioxidant and cytotoxicity activities.
METHODS: R. khorasanicum was collected in three different months: December, February, and April. The Folin-Ciocalteu assay was applied to measure the total phenolic content of HER. Antioxidant activities (DPPH and FRAP) were also determined. Next, the extracts were evaluated for antibacterial potential against some Gram-positive and Gram-negative strains. The minimal inhibitory concentration (MIC) was determined by the microdilution method. Finally, the effect of extracts on the viability of C6, A549, and HT-29 cells was evaluated via the MTT assay.
RESULTS: All three extracts contained considerable phenolic and flavonoid contents and showed desirable antioxidant activity. The April sample exhibited the greatest phenolic and flavonoid content and significant antioxidant activity potential in the FRAP test. In addition, the April sample had the highest antibacterial activity and cytotoxic effect on the cancerous cell lines.
CONCLUSIONS: The April extract showed more antioxidant, antibacterial and cytotoxic effect, probably because of its higher phenolic and flavonoid contents than other samples. These results demonstrate that the harvest timing of R. khorasanicum affects the plant\'s phenolic content and its antioxidant and cytotoxicity activities.
摘要：
背景：几个世纪以来，草药及其衍生物已被用于治疗或预防各种疾病。然而,环境因素如植物采集季节可能会改变治疗效果。目前的工作调查了酚类物质的季节性变化，类黄酮含量，抗氧化剂，抗菌，和大黄水醇提取物（HER）的细胞毒性潜力。
方法：Rhorasanicum是在三个不同的月份收集的：12月，二月,和四月。Folin-Ciocalteu测定法用于测量HER的总酚含量。还测定了抗氧化活性(DPPH和FRAP)。接下来,评估提取物对一些革兰氏阳性和革兰氏阴性菌株的抗菌潜力。通过微量稀释法测定最小抑制浓度(MIC)。最后,通过MTT分析评估提取物对C6，A549和HT-29细胞活力的影响。
结果：所有三种提取物均含有可观的酚类和类黄酮含量，并显示出理想的抗氧化活性。4月份的样品在FRAP测试中表现出最大的酚类和类黄酮含量和显着的抗氧化活性潜力。此外,4月样本对癌细胞系具有最高的抗菌活性和细胞毒性作用。
结论：四月提取物显示出更多的抗氧化剂，抗菌和细胞毒性作用，可能是因为它的酚类和类黄酮含量比其他样品高。这些结果表明R的收获时间。刺槐影响植物的酚类含量及其抗氧化和细胞毒性活性。
方法：Rhorasanicum是在三个不同的月份收集的：12月，二月,和四月。Folin-Ciocalteu测定法用于测量HER的总酚含量。还测定了抗氧化活性(DPPH和FRAP)。接下来,评估提取物对一些革兰氏阳性和革兰氏阴性菌株的抗菌潜力。通过微量稀释法测定最小抑制浓度(MIC)。最后,通过MTT分析评估提取物对C6，A549和HT-29细胞活力的影响。
结果：所有三种提取物均含有可观的酚类和类黄酮含量，并显示出理想的抗氧化活性。4月份的样品在FRAP测试中表现出最大的酚类和类黄酮含量和显着的抗氧化活性潜力。此外,4月样本对癌细胞系具有最高的抗菌活性和细胞毒性作用。
结论：四月提取物显示出更多的抗氧化剂，抗菌和细胞毒性作用，可能是因为它的酚类和类黄酮含量比其他样品高。这些结果表明R的收获时间。刺槐影响植物的酚类含量及其抗氧化和细胞毒性活性。
