Evaluation of the Antioxidant Activity of Coreopsis Tinctoria Nuff. and Optimisation of Isolation by Response Surface Methodology

Abstract

Evaluation of the antioxidant activity of Coreopsis tinctoria Nuff. and optimisation of isolation by response surface methodologyThe aim of the present study was to determine the antioxidant activity of Coreopsis tinctoria flowering tops (CTFT). Studies were conducted to obtain suitable extraction conditions for chlorogenic acid, quercetin, luteolin, apigenin and kaempferol, which were identified and quantified by HPLC. Response surface methodology was employed to optimise the ultrasound-assisted extraction conditions including extraction time, ethanol concentration and liquid-solid ratio. The antioxidant activity of the extracts was analysed using various antioxidant models, such as DPPH, ABTS and hydroxyl radical scavenging assay. CTFT extracted for 15.0 min with ethanol at a concentration of 60.4 % and with liquidsolid ratio 27.5:1 possessed a considerable amounts of total flavonoids and polyphenols (18.9 %). This extract showed higher scavenging activity of ABTS and hydroxyl radical activity than rutin, however not in the DPPH test. We may assume that CTFT possess antioxidant and free radical scavenging potentials.

Extracts ofCoreopsis tinctoriaNutt. Flower Exhibit Antidiabetic Effects via the Inhibition ofα-Glucosidase Activity

“…The interpretations are summarized in Table 1 and showed that both EEC and WEC were rich in flavonoid compounds, and EEC contained more constituents. These data are in agreement with the previous reports [ 13 , 18 ].…”

“…Previous studies have shown that CTF is rich in flavonoids and polyphenols [ 13 , 18 ]. Similarly, we found that EEC and WEC contain 27.28% and 36.2% total flavonoids, respectively.…”

Hepatoprotective effect of Coreopsis tinctoria flowers against carbon tetrachloride-induced liver damage in mice

“…Flower infusion tea is used as a beverage to treat hypertension and hyperlipidemia [2]. Pharmacological studies have indicated that C. tinctoria exhibits some biological effects including antioxidant [3], antidiabetic [4], antihypertensive [5], and cytoprotective [1] activities. Although C. tinctoria is used for liver diseases, studies have yet to report on its hepatoprotective effect.…”

The Flower Tea Coreopsis tinctoria Increases Insulin Sensitivity and Regulates Hepatic Metabolism in Rats Fed a High-Fat Diet

“…Additionally, in Portugal, two cups per day of an infusion of CT flowering tops has been traditionally used to control diabetes (15). Pharmacological studies have shown that CT exhibits many beneficial biological activities, including antihyperlipidemic (16), antioxidative (17), antidiabetic (18), and antihypertensive (19) effects. The effects of CT are mainly attributed to its flavonoid-like polyphenols (20); however, the effects of drinking CT tea on insulin sensitivity and hepatic glucose metabolism are still unknown.…”