Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh, 11451, Saudi Arabia.
Departments of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
BMC Complement Altern Med. 2018 Aug 10;18(1):237. doi: 10.1186/s12906-018-2302-x.
Cancers and microbial infections are still a major health problem, therefore research on new anticancer and antimicrobial agents ought to be continued. Natural products including essential oils from medicinal plants continue to be an important resource to manage various diseases. Thus, the particular objectives of this study are to investigate the chemical composition, cytotoxic, antimicrobial and antioxidant activities of three Plectranthus species namely P. cylindraceus Hocst. ex Benth., P. asirensis JRI Wood and P. barbatus Andrews grown in Saudi Arabia.
The essential oils of the three Plectranthus species were obtained by hydrodistllation and analyzed using GC/FID and GC-MS. The essential oils were further assessed for their cytotoxic, antimicrobial and antioxidant activities. Determination of the cytotoxic activity was carried out against Hela, HepG2 and HT-29 cancer cell lines by utilizing MTT-assay. The antimicrobial activity was assessed against six bacterial and fungal strains by using broth micro-dilution assay. In addition, the antioxidant activity was evaluated utilizing the DPPH and β-Carotene-linoleic acid assays.
The GC/FID and GC-MS analysis led to the identification of 59, 60 and 42 compounds representing 89.0% 95.0 and 97.1% of the total essential oils of P. cylindraceus, P. asirensis and P. barbatus, respectively. The essential oils were characterized by a high content of oxygenated sesquiterpenes in P. cylindraceus, sesquiterpene hydrocarbons in P. asirensis and monoterpene hydrocarbons in P. barbatus where maaliol (42.8%), β-caryophyllene (13.3%) and α-pinene, (46.2%) were the predominant compounds. Additionally, the oils particularly of P. cylindraceus and P. barbatus exhibited remarkable cytotoxic and antimicrobial activities with IC-values between 3.8 and 7.5 μg/mL and MIC-values ranging from 0.137 to 4.40 mg/mL. Moreover, the oils showed moderate to high radical scavenging and antioxidative activities ranging from 52 to 75% at the highest concentration of 1 mg/mL.
The observed results back the suggestion that these three Plectranthus species represent a promising source of cytotoxic and antimicrobial agents.
癌症和微生物感染仍然是一个主要的健康问题，因此应该继续研究新的抗癌和抗菌药物。包括药用植物精油在内的天然产物仍然是治疗各种疾病的重要资源。因此，本研究的具体目标是研究三种沙特阿拉伯产的假糙苏属植物，即圆柱状假糙苏（Plectranthus cylindraceus Hocst. ex Benth.）、阿西尔假糙苏（P. asirensis JRI Wood）和多毛假糙苏（P. barbatus Andrews）的化学成分、细胞毒性、抗菌和抗氧化活性。
通过水蒸馏法从三种假糙苏属植物中提取精油，并使用 GC/FID 和 GC-MS 进行分析。进一步评估精油的细胞毒性、抗菌和抗氧化活性。通过 MTT 测定法在 Hela、HepG2 和 HT-29 癌细胞系中测定细胞毒性活性。通过肉汤微量稀释法评估抗菌活性。此外，利用 DPPH 和β-胡萝卜素-亚油酸法评估抗氧化活性。
GC/FID 和 GC-MS 分析导致鉴定出 59、60 和 42 种化合物，分别代表 P. cylindraceus、P. asirensis 和 P. barbatus 总精油的 89.0%、95.0%和 97.1%。这些精油的特点是 P. cylindraceus 中含有高含量的含氧倍半萜，P. asirensis 中含有萜类化合物，P. barbatus 中含有单萜化合物，其中马罗醇（42.8%）、β-石竹烯（13.3%）和α-蒎烯（46.2%）是主要化合物。此外，这些油，特别是 P. cylindraceus 和 P. barbatus 的油，表现出显著的细胞毒性和抗菌活性，IC 值在 3.8 至 7.5μg/mL 之间，MIC 值范围从 0.137 至 4.40mg/mL。此外，这些油在最高浓度为 1mg/mL 时表现出中等至高的自由基清除和抗氧化活性，范围为 52%至 75%。
观察到的结果支持以下观点，即这三种假糙苏属植物是具有细胞毒性和抗菌活性的有前途的药物来源。
