Research and Biotechnology, St. Luke's Medical Center, E. Rodriguez Avenue, Quezon City, Philippines 1112.
Kobe J Med Sci. 2021 Dec 21;67(3):E98-E111.
In this study, we investigated the antiviral activity of lyophilized crude leaf extracts of the Philippine marshmint (Mentha arvensis L., commonly called yerba buena) against DENV-2 in vitro. The plant specimen was authenticated by DNA barcoding analysis using standard primers for amplification of rbcL, matK, ITS1, ITS2 and trnH-psbA. Aqueous, methanol and ethanol leaf extracts were prepared, and lyophilized prior to testing for its cytotoxicity and antiviral activities. All extracts presented cytotoxic activities against Vero cells in a dose-dependent manner. Half maximal cytotoxicity concentration (CC50) was calculated at 2,889.60 µg/mL for the aqueous extract, 1,928.62 µg/mL for the methanol extract, and 3,380.30 µg/mL for the ethanol extract. Antiviral activities assessed by plaque reduction assay revealed reduced DENV-2 viral infectivity, with the ethanol extract observed to have the strongest activity decreasing plaque numbers by 62% relative to the control. The methanol extract was observed to be most effective when added before infection causing 72% reduction in plaque numbers, whereas none of the extracts inhibited plaque formation by more than 40% when added after infection. DENV-2 NS1 antigen production was significantly reduced by the methanol extract, while viral RNA levels were also decreased as determined by real time RT-PCR. Phytochemical analysis revealed the presence of flavonoids, phenolics, tannins, proteins, reducing sugars and saponins. Our preliminary results are promising, however, it should be interpreted with caution as further studies are needed to establish its potential therapeutic application against dengue infection.
在这项研究中，我们研究了冻干菲律宾薄荷（Mentha arvensis L.，通常称为 yerba buena）叶提取物对 DENV-2 的体外抗病毒活性。通过使用 rbcL、matK、ITS1、ITS2 和 trnH-psbA 标准引物扩增的 DNA 条形码分析对植物标本进行了鉴定。制备了水提物、甲醇提物和乙醇提物，并在测试其细胞毒性和抗病毒活性之前将其冻干。所有提取物均以剂量依赖的方式对 Vero 细胞表现出细胞毒性。水提物的半最大细胞毒性浓度 (CC50) 为 2,889.60 µg/mL，甲醇提物为 1,928.62 µg/mL，乙醇提物为 3,380.30 µg/mL。通过蚀斑减少测定评估的抗病毒活性显示出降低的 DENV-2 病毒感染力，乙醇提取物观察到具有最强的活性，相对于对照减少了 62%的蚀斑数量。甲醇提取物在感染前添加时观察到最有效，导致蚀斑数量减少 72%，而当在感染后添加时，没有任何提取物抑制超过 40%的蚀斑形成。甲醇提取物显著减少 DENV-2 NS1 抗原的产生，同时通过实时 RT-PCR 也降低了病毒 RNA 水平。植物化学分析显示存在类黄酮、酚类、单宁、蛋白质、还原糖和皂苷。我们的初步结果很有希望，但是应该谨慎解释，因为需要进一步的研究来确定其对登革热感染的潜在治疗应用。
