Department of Pharmacy, Rajshahi University, Rajshahi 6205, Bangladesh.
BMC Complement Altern Med. 2014 Feb 4;14:45. doi: 10.1186/1472-6882-14-45.
Antioxidant compounds like phenols and flavonoids scavenge free radicals and thus inhibit the oxidative mechanisms that lead to control degenerative and other diseases. The aim of this study was to investigate the antioxidant activity in vitro, total phenolic and flavonoid contents in ethanol extracts and fractions of Crescentia cujete leaves and stem bark.
Crescentia cujete leaves and bark crude ethanol extract (CEE) and their partitionates petroleum ether (PEF), chloroform (CHF), ethyl acetate (EAF) and aqueous (AQF) were firstly prepared. Different established testing methods, such as 1, 1-diphenyl-2-picryl hydrazyl (DPPH) radical, ferric reducing power (FRP), and total antioxidant capacity (TAC) assays were used to detect the antioxidant activity. Further, the total yield, total phenolic (TPC) and total flavonoid contents (TFC) of CEE and all the fractions were determined. Ethanol extracts of both leaves and stem bark were also subjected to preliminary phytochemical screening to detect the presence of secondary metabolites, using standard phytochemical methods (Thin layer chromatography and spray reagents).
Phytochemical screening of crude ethanol extract of both leaves and stem bark revealed the presence of steroids, flavonoids, saponins, tannins, glycosides and terpenoids. All the fractions and CEE of leaves and bark exhibited antioxidant activities, however, EAF of leaves showing the highest antioxidant activity based on the results of DPPH, FRP and TAC assay tests. The above fraction has shown the significant DPPH scavenging activity (IC50 = 8.78 μg/ml) when compared with standard ascorbic acid (IC50 =7.68 μg/ml). The TAC and FRP activities increased with increasing crude extract/fractions content. The TPC (371.23 ± 15.77 mg GAE/g extract) and TFC (144.64 ± 5.82 mg QE/g extract) of EAF of leaves were found significantly higher as compared to other solvent fractions for both leaves and bark. TPC were highly correlated with the antioxidant activity (R2 = 0.9268 and 0.8515 in DPPH test for leaves and bark, respectively).
The results of the study show that leaves of C. cujete possesses significant free radical scavenging properties compared with stem bark and a clear correlation exists between the antioxidant activity and phenolic content.
抗氧化化合物，如酚类和类黄酮，可清除自由基，从而抑制导致控制退行性和其他疾病的氧化机制。本研究的目的是研究 Crescentia cujete 叶和茎皮乙醇提取物及其馏分的体外抗氧化活性、总酚和类黄酮含量。
首先制备 Crescentia cujete 叶和树皮粗乙醇提取物（CEE）及其石油醚（PEF）、氯仿（CHF）、乙酸乙酯（EAF）和水（AQF）馏分。使用 1,1-二苯基-2-苦基肼基（DPPH）自由基、铁还原能力（FRP）和总抗氧化能力（TAC）测定等多种已建立的测试方法来检测抗氧化活性。此外，还测定了 CEE 和所有馏分的总产率、总酚（TPC）和总类黄酮含量（TFC）。还对叶和茎的乙醇提取物进行了初步的植物化学成分筛选，以使用标准植物化学方法（薄层色谱和喷雾试剂）检测次生代谢物的存在。
叶和茎树皮粗乙醇提取物的植物化学成分筛选表明存在甾体、黄酮类、皂苷、单宁、糖苷和萜类化合物。所有馏分和叶和树皮的 CEE 均表现出抗氧化活性，然而，根据 DPPH、FRP 和 TAC 测定结果，叶的 EAF 显示出最高的抗氧化活性。该馏分显示出显著的 DPPH 清除活性（IC50 = 8.78μg/ml），与标准抗坏血酸（IC50 = 7.68μg/ml）相比。随着粗提取物/馏分含量的增加，TAC 和 FRP 活性增加。叶的 EAF 的 TPC（371.23±15.77mg GAE/g 提取物）和 TFC（144.64±5.82mg QE/g 提取物）明显高于其他溶剂馏分。TPC 与抗氧化活性高度相关（叶的 DPPH 测试中 R2分别为 0.9268 和 0.8515）。
研究结果表明，与茎皮相比，C. cujete 的叶具有显著的自由基清除特性，并且抗氧化活性与酚含量之间存在明显的相关性。
