| Echinacea purpurea L., as a perennial herbaceous plant, is widely grown in variousparts of world for commercial purpose, and is attributed to its immunostimulatory,antioxidant, antiviral and antifungal properties. Cichoric acid, belongs to caffeic acidderivatives, is one of the most abundant phenolic compounds and one of the maincharacteristic components in E. purpurea, and is also an important immune activeconstituent. Extraction, purifcation and quantitative HPLC of cichoric acid from E.purpurea were investigated. Tyrosinase inhibition properties, antioxidative andanti-inflammatory activity of cichoric acid extract were tested. The specific findings wereas follows:1. Extraction conditions of cichoric acid from the flowers of E. purpurea L. wereinvestigated through an orthogonal design of L9(34) assay. The extraction wasoptimized by adding40%ethanol at a ratio of1:15(g/mL) to extract threetimes at70℃for1h. For purifcation, the extraction was concentrated to1/10volume,then the extraction was passed through an AB-8macroporous resin column to be absorbed,purified and eluted with50%ethanol. The eluant was concentrated to1/10volume,adjusted to pH3.0, then extracted with ethyl acetate four times. The final solution wascarefully evaporated just to dryness with a vacuum evaporator (60oC). The purity,determined by HPLC, was60.23%.2. The cichoric acid extract (CAE) from E. purpurea was found to have significanttyrosinase inhibition activity in broad range of concentration (≥10mg/mL). Aconcentration-dependent response of the extract was evident at tested concentrations.These concentrations almost perfectly inhibited tyrosinase activity:20mg/mL-78.25%(monophenol enzyme);10mg/mL-100%(bisphenol enzyme).3. In order to study antioxidative of cichoric acid extract from E. purpurea, the abilityof scavenging free radical was tested by the elimination of the1,1-diphenyl-2-picryl-hydrazyl (DPPH·), hydroxyl radical (OH·) and lipid peroxidation.Meanwhile, the cichoric acid extract was added to lard oil and colza oil respectively for thedetermination of its antioxidant effect. The inhibition of the DPPH·, OH·and lipidperoxidation were strengthened along with cichoric acid extract density increasing. Thecichoric acid extract can keep the oxidative stability of oils significantly and theantioxidant of the extract to lard oil is stronger than colza oil. The antioxidant of5g/kgcichoric acid extract to lard oil and colza oil are stronger than the0.2g/kg butylatedhydroxytoluene (BHT) and butylated hydroxyanisole (BHA). 4. Cichoric acid extract from E. purpurea was tested against paw swelling model,abdominal capillary permeability model in mice and collagen-induced arthritis (CIA)model in rats. Administration with all doses of CAE obviously decreased the paw swellingand abdominal capillary permeability in mice, and a dose-dependent response of theextract was evident at the tested doses. Administration with all doses of CAE (8,16and32mg/kg) obviously decreased the paw swelling, restored body weight and decreased theweight of thymus and of spleen in CIA rats. All doses of CAE significantly (P <0.05)reduced the levels of TNFα, IL-1β and PGE-2in serum of CIA rats. CAE (32mg/kg)significantly decreased the levels of nuclear factor-κB (NF-κB), TNFα andcyclooxygenase2(Cox-2) in synovium tissues of ankle joint of CIA rats. It alsosignificantly decreased the NF-κB and Cox-2levels in synovium tissues of knee joint ofCIA rats. On the basis of these results obtained it can be concluded that CAE is a potentanti-arthritic agent, the mode of action of which is associated with the significant inhibitionof the levels of inflammatory and destructive proteins.These laid the foundation for further studying of cichoric acid and having certainpracticability and reference for the development of this plant resource. |
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