Ethnopharmacological relevance

Dregea volubilis is an important folk medicinal plant used as an ingredient in Ayurvedic formulations to treat asthma, piles, urinary tract infections, tumours, leucoderma, piles, inflammations, rheumatic pain, cough, severe cold and fever.

Aim of the study

The phytochemicals, percentage of extract yield, total phenolics and flavonoids, in vitro antioxidant, antidiabetic and antibacterial activities of six solvent extracts obtained from the leaves of D. volubilis (DVL) were investigated.

Material ad Methods

Chemical composition of DVL extract was analysed using GC-MS, total phenolics and flavonoids by spectrophotometric methods. Antioxidant activity was performed using eight in vitro assays and antidiabetic activity was evaluated by α-amylase and α-glucosidase inhibitory assays. Antibacterial activity was studied against 10 pathogenic bacteria by agar disc diffusion and microdilution method.

Results

The extract yield was higher in hydroalcoholic (9.15%) and methanolic extracts (6.8%). A total of 67 compounds were identified from six extracts, of which 17 compounds especially squalene, oleic acid and palmitic acid were prominent constituents. Maximum amount of total phenolics (48.66 ± 4.19 mg GAE/g) and flavonoids (29.58 ± 0.47 mg QE/g) were recorded in methanolic and hydroalcoholic extracts respectively. Hydroalcoholic and methanolic extracts displayed strong inhibition of α-amylase and α-glucosidase with an IC₅₀ of 60.51 ± 2.78 and 38.58 ± 0.56 µg/mL respectively. Methanol extract showed highest DPPH, nitric oxide and superoxide radical activities with the IC₅₀ of 39.24 ± 2.56, 13.06 ± 1.40 and 13.71 ± 6.99 µg/mL respectively. While, hydroalcoholic extract exhibited better free radical scavenging ability for ABTS (51.23 ± 8.36 µg/mL), hydroxyl radical scavenging (46.92 ± 14.30 µg/mL), total antioxidant (16.81 ± 1.60 AAE mg/g) and metal chelating ability (49.61 ± 0.96 EDTA E mg/g). The FRAP assay showed better activity in aqueous extract with a value of 258.25 ± 3.31 mM Fe (II) E mg/g. Hydroalcoholic, ethyl acetate and aqueous extracts showed significant antibacterial activity at higher concentrations against P. vulgaris (21.0 ± 1.01 mm), B. subtilis (22.6 ± 0.54 mm) and E. coli (27.8 ± 0.83 mm) respectively. The correlation analysis revealed a strong positive relationship between the amount of total phenolics and flavonoids with antioxidant and antidiabetic activities in a concentration dependent way.

Conclusion

The results of present investigation proved that hydroalcoholic extract of DVL could be used as a promising natural antioxidant with potential enzyme inhibitory and antibacterial properties and might be used as a therapeutic agent in pharmaceutical and nutraceutical industries.

中文翻译：

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苦竹叶各种溶剂提取物的化学成分，体外抗氧化剂，抗糖尿病和抗菌活性的比较评价

民族药理学意义

Dregea volubilis是一种重要的民间药用植物，用作印度草药制剂中的成分，可治疗哮喘，桩，尿路感染，肿瘤，白带，桩，炎症，风湿性疼痛，咳嗽，严重感冒和发烧。

研究目的

研究了从伏地黄（DVL）叶片中获得的六种溶剂提取物的植物化学成分，提取物百分比，总酚和类黄酮，体外抗氧化剂，抗糖尿病和抗菌活性。

实质广告方法

通过分光光度法使用GC-MS，总酚和类黄酮分析了DVL提取物的化学组成。使用八种体外测定法进行抗氧化活性，并通过α-淀粉酶和α-葡萄糖苷酶抑制测定法评估抗糖尿病活性。通过琼脂圆盘扩散和微稀释法研究了对10种病原菌的抗菌活性。

结果

在水醇提取物（9.15％）和甲醇提取物（6.8％）中，提取物产率较高。从六种提取物中共鉴定出67种化合物，其中17种化合物，特别是角鲨烯，油酸和棕榈酸是主要成分。分别在甲醇和水醇提取物中记录了最大总酚含量（48.66±4.19 mg GAE / g）和类黄酮（29.58±0.47 mg QE / g）。水醇和甲醇提取物显示出对α-淀粉酶和α-葡萄糖苷酶的强烈抑制作用，IC _50分别为60.51±2.78和38.58±0.56 µg / mL。使用IC _50时，甲醇提取物显示出最高的DPPH，一氧化氮和超氧自由基活性分别为39.24±2.56、13.06±1.40和13.71±6.99 µg / mL。同时，水醇提取物对ABTS的自由基清除能力（51.23±8.36 µg / mL），对羟基自由基的清除能力（46.92±14.30 µg / mL），总抗氧化剂（16.81±1.60 AAE mg / g）和金属螯合能力（49.61） ±0.96 EDTA E毫克/克）。FRAP分析在水提取物中显示出更好的活性，值为258.25±3.31 mM Fe（II）E mg / g。水乙醇，乙酸乙酯和水提取物在较高浓度下对寻常型毕赤酵母（21.0±1.01 mm），枯草芽孢杆菌（22.6±0.54 mm）和大肠杆菌具有明显的抗菌活性。（27.8±0.83毫米）。相关性分析显示，总酚和类黄酮的含量与抗氧化剂和抗糖尿病活性之间呈强烈的正相关关系，且呈浓度依赖性。

结论

本研究的结果证明，DVL的水醇提取物可以用作具有前景的天然抗氧化剂，具有潜在的酶抑制和抗菌特性，并且可以用作药物和营养保健行业的治疗剂。