Sai Kusum, Thapa Rashmi, Devkota Hari Prasad, Joshi Khem Raj
School of Health and Allied Sciences, Faculty of Health Sciences, Pokhara University, Pokhara 33700, Nepal.
Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oehonmachi, Chuo-ku, Kumamoto 862-0973, Japan.
Medicines (Basel). 2019 Jun 25;6(2):70. doi: 10.3390/medicines6020070.
More than 700 plants are reported to be used for medicinal purposes in Nepal; however, many of them are not studied for their scientific evidences. The aims of the present study were the estimation of the total phenolic and flavonoid contents, and the evaluation of the free radical scavenging and α-amylase inhibitory activities of five selected medicinal plants from western Nepal: Wall. (Gesneriaceae), Lour. (Loganiaceae), L. (Caricaceae), (Nees) Keng f. (Gramineae) and (L. f.) Kurz (Anacardiaceae). The total phenolic content (TPC) and total flavonoid content (TFC) were measured using Folin-Ciocalteu's phenol reagent and aluminium chloride methods, respectively. A 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay was used to evaluate the free radical scavenging activity and an α-amylase inhibitory assay was carried out to determine the in vitro antidiabetic activity. The phytochemical screening of five hydroalcoholic plant extracts revealed the presence of various secondary metabolites, including alkaloids, flavonoids, reducing sugars, saponins, terpenoids and tannins. The amounts of total phenolics and flavonoids were found to be the highest in leaf extract, which also showed the most potent free radical scavenging activity. Extract of fruits showed the highest α-amylase inhibitory activity, whereas the extracts of leaves and leaves exhibited moderate activity. Some of the medicinal plants selected in this study showed high TPC and TFC values and potent bioactivities. These results may provide the scientific evidences of the traditional uses of these plants. However, further detailed studies on bioactive compounds isolation and identification and evaluation of in vivo pharmacological activities should be performed in future.
据报道，尼泊尔有700多种植物被用于药用；然而，其中许多植物尚未进行科学证据研究。本研究的目的是估计五种选自尼泊尔西部的药用植物的总酚和黄酮含量，并评估其自由基清除和α-淀粉酶抑制活性： （苦苣苔科）、 （马钱科）、 （番木瓜科）、 （禾本科）和 （漆树科）。分别使用福林-西奥尔特试剂法和氯化铝法测定总酚含量（TPC）和总黄酮含量（TFC）。采用1,1-二苯基-2-苦基肼（DPPH）自由基清除试验评估自由基清除活性，并进行α-淀粉酶抑制试验以测定体外抗糖尿病活性。对五种植物水醇提取物的植物化学筛选显示存在各种次生代谢物，包括生物碱、黄酮类、还原糖、皂苷、萜类和单宁。发现 叶提取物中的总酚和黄酮含量最高，其自由基清除活性也最强。 果实提取物显示出最高的α-淀粉酶抑制活性，而 叶和 叶提取物表现出中等活性。本研究中选择的一些药用植物显示出高TPC和TFC值以及强大的生物活性。这些结果可能为这些植物的传统用途提供科学证据。然而，未来应进一步详细研究生物活性化合物的分离和鉴定以及体内药理活性的评估。
