Palaniyappan Sivagaami, Sridhar Arun, Arumugam Manikandan, Ramasamy Thirumurugan
Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India.
Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals & Health (FARAH), Faculty of Veterinary Medicine, University of Liège, 4000, Liège, Belgium.
Appl Biochem Biotechnol. 2024 Feb;196(2):729-773. doi: 10.1007/s12010-023-04565-z. Epub 2023 May 15.
Aloe barbadensis Miller (ABM) is a traditional medicinal plant all over the world. Numerous studies were conducted to exhibit its medicinal properties and most of them were concentrated on its metabolites against human pathogens. The current research work evaluates the attributes of different polar-based extracts (ethanol, methanol, ethyl acetate, acetone, hexane, and petroleum ether) of dried Aloe barbadensis leaf (ABL) to investigate its phytochemical constituents, antioxidant potential (DPPH, ABTS), phenolic, tannin, flavonoid contents, identification of bioactive compounds, and functional groups by gas chromatography-mass spectrometry (GC-MS) and fourier transform infrared spectroscopy (FT-IR) respectively, and comparing antibacterial efficacy against human pathogens, aquatic bacterial pathogens, and zoonotic bacteria associated with fish and human. The present results showed that the methanolic extract of ABL showed higher antioxidant activity (DPPH-59.73 ± 2.01%; ABTS-74.1 ± 1.29%), total phenolic (10.660 ± 1.242 mg GAE/g), tannin (7.158 ± 0.668 mg TAE/g), and flavonoid content (49.545 ± 1.928 µg QE/g) than that of other solvent extracts. Non-polar solvents hexane and petroleum ether exhibited lesser activity among the extracts. In the case of antibacterial activity, higher inhibition zone was recorded in methanol extract of ABL (25.00 ± 0.70 mm) against Aeromonas salmonicida. Variations in antibacterial activity were observed depending on solvents and extracts. In the current study, polar solvents revealed higher antibacterial activity when compared to the non-polar and the mid-polar solvents. Diverse crucial bioactive compounds were detected in GC-MS analysis. The vital compounds were hexadecanoic acid (30.69%) and 2-pentanone, 4-hydroxy-4-methyl (23.77%) which are responsible for higher antioxidant and antibacterial activity. Similar functional groups were identified in all the solvent extracts of ABL with slight variations in the FT-IR analysis. Polar-based solvent extraction influenced the elution of phytocompounds more than that of the other solvents used in this study. The obtained results suggested that the ABM could be an excellent source for antioxidant and antibacterial activities and can also serve as a potential source of effective bioactive compounds to combat human as well as aquatic pathogens.
库拉索芦荟是一种全球范围内的传统药用植物。人们进行了大量研究以展现其药用特性，其中大部分研究集中于其针对人类病原体的代谢产物。当前的研究工作评估了干燥库拉索芦荟叶（ABL）不同极性提取物（乙醇、甲醇、乙酸乙酯、丙酮、己烷和石油醚）的特性，以分别通过气相色谱 - 质谱联用仪（GC - MS）和傅里叶变换红外光谱仪（FT - IR）研究其植物化学成分、抗氧化潜力（DPPH、ABTS）、酚类、单宁、黄酮含量、生物活性化合物鉴定及官能团，同时比较其对人类病原体、水生细菌病原体以及与鱼类和人类相关的人畜共患病菌的抗菌效果。目前的结果表明，ABL的甲醇提取物显示出比其他溶剂提取物更高的抗氧化活性（DPPH - 59.73 ± 2.01%；ABTS - 74.1 ± 1.29%）、总酚含量（10.660 ± 1.242毫克没食子酸当量/克）、单宁含量（7.158 ± 0.668毫克单宁酸当量/克）和黄酮含量（49.545 ± 1.928微克槲皮素当量/克）。非极性溶剂己烷和石油醚在提取物中表现出较低的活性。在抗菌活性方面，ABL的甲醇提取物对杀鲑气单胞菌的抑菌圈较大（25.00 ± 0.70毫米）。观察到抗菌活性因溶剂和提取物的不同而有所变化。在本研究中，极性溶剂与非极性和中极性溶剂相比显示出更高的抗菌活性。在GC - MS分析中检测到了多种关键生物活性化合物。主要化合物为十六烷酸（30.69%）和4 - 羟基 - 4 - 甲基 - 2 - 戊酮（23.77%），它们具有较高的抗氧化和抗菌活性。在ABL的所有溶剂提取物中鉴定出了相似的官能团，FT - IR分析中略有差异。基于极性的溶剂萃取对植物化合物洗脱的影响比本研究中使用的其他溶剂更大。所得结果表明，库拉索芦荟可能是抗氧化和抗菌活性的优质来源，也可作为对抗人类及水生病原体的有效生物活性化合物的潜在来源。
