Uddin Riaz, Saha Moni Rani, Subhan Nusrat, Hossain Hemayet, Jahan Ismet Ara, Akter Raushanara, Alam Ashraful
Department of Pharmacy, Stamford University Bangladesh, Dhaka-1217, Bangladesh.
School of Biomedical Sciences, Charles Sturt University, Wagga Wagga (NSW), Australia.
Adv Pharm Bull. 2014;4(3):273-81. doi: 10.5681/apb.2014.040. Epub 2014 Feb 7.
Gardenia jasminoides is a traditional medicinal plant rich in anti-inflammatory flavonoids and phenolic compounds and used for the treatment of inflammatory diseases and pain. In this present study, antioxidant potential of Gardenia jasminoides leaves extract was evaluated by using various antioxidant assays.
Various antioxidant assays such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, reducing power and total antioxidant capacity expressed as equivalent to ascorbic acid were employed. Moreover, phenolic compounds were detected by high-performance liquid chromatography (HPLC) coupled with diode-array detection.
The methanol extract showed significant free radical scavenging activities in DPPH radical scavenging antioxidant assays compared to the reference antioxidant ascorbic acid. Total antioxidant activity was increased in a dose dependent manner. The extract also showed strong reducing power. The total phenolic content was determined as 190.97 mg/g of gallic acid equivalent. HPLC coupled with diode-array detection was used to identify and quantify the phenolic compounds in the extracts. Gallic acid, (+)-catechin, rutin hydrate and quercetin have been identified in the plant extracts. Among the phenolic compounds, catechin and rutin hydrate are present predominantly in the extract. The accuracy and precision of the presented method were corroborated by low intra- and inter-day variations in quantitative results in leaves extract.
These results suggest that phenolic compounds and flavonoids might contribute to high antioxidant activities of Gardenia jasminoides leaves.
栀子是一种富含抗炎黄酮类化合物和酚类化合物的传统药用植物，用于治疗炎症性疾病和疼痛。在本研究中，通过各种抗氧化测定法评估了栀子叶提取物的抗氧化潜力。
采用了各种抗氧化测定法，如1,1-二苯基-2-苦基肼（DPPH）自由基清除测定法、还原能力以及以抗坏血酸当量表示的总抗氧化能力。此外，通过高效液相色谱（HPLC）结合二极管阵列检测来检测酚类化合物。
与参考抗氧化剂抗坏血酸相比，甲醇提取物在DPPH自由基清除抗氧化测定中表现出显著的自由基清除活性。总抗氧化活性呈剂量依赖性增加。该提取物还表现出很强的还原能力。总酚含量测定为190.97毫克/克没食子酸当量。采用HPLC结合二极管阵列检测来鉴定和定量提取物中的酚类化合物。在植物提取物中已鉴定出没食子酸、（+）-儿茶素、芦丁水合物和槲皮素。在酚类化合物中，儿茶素和芦丁水合物在提取物中含量较高。叶提取物定量结果的日内和日间变化较小，证实了所提出方法的准确性和精密度。
这些结果表明，酚类化合物和黄酮类化合物可能是栀子叶具有高抗氧化活性的原因。
