title: Effect of honghua (Flos Carthami) on nitric oxide production in RAW 264.7 cells and alpha-glucosidase activity.
abstract: OBJECTIVE
  To study the effects of extracts from Honghua (Flos Carthami) on lipopolysaccharide induced nitric oxide (NO) production in RAW 264.7 cells and the influence of the extracts on yeast a-glucosidase activity. The total flavonoid content of the extracts was also determined.
  
  
  METHODS
  Cytotoxicity of the extracts to RAW 264.7 cells was evaluated by the ATPlite method. Inhibitory effects of the extracts on NO production were evaluated by Griess assay. Curcumin was used as a positive control. Screening of extracts for potential a-glucosidase inhibitors was done by a fluorometric assay. The assay was based on the hydrolysis of 4-methylumbelliferyl-a-D-glucopyranoside to form the fluorescent product, 4-methylumbelliferone. Acarbose was used as a positive control. The total flavonoid content was tested using kaempferol as the standard.
  
  
  RESULTS
  There were significant inhibitory effects on NO production when the extracts were 25-100 microg/ mL (P < 0.05) and curcumin was 2-4 microg/mL (P < 0.001). The extracts showed an inhibitory effect on alpha-glucosidase activity at the concentrations of 15.6-125 microg/mL with a half maximal (50%) inhibitory concentration (IC50) of (32.8 +/- 5.7) microg/mL, compared with the IC50 of acarbose at (1.8 +/- 0.4) microg/mL. There was a significant difference between the two IC50 values (P < 0.001). The total content of flavonoids per gram of dried herb was 1.14 mg.
  
  
  CONCLUSIONS
  Honghua (Flos Carthami) showed inhibitory effects on NO production in activated RAW 264.7 macrophage cells and an inhibitory effect on yeast alpha-glucosidase. There might be a relationship between these pharmacological effects and its flavonoid content.
authors.forename: Hui
authors.initials: H
authors.lastname: Liao
authors.forename: Linda
authors.initials: L
authors.lastname: Banbury
authors.forename: Hongping
authors.initials: H
authors.lastname: Liang
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Wang
authors.forename: Xiaokai
authors.initials: X
authors.lastname: Lü
authors.forename: Ling
authors.initials: L
authors.lastname: Hu
authors.forename: Jin
authors.initials: J
authors.lastname: Wu
mesh_terms: D000818:Animals; D031178:Carthamus / Q000737:chemistry*; D031187:Carthamus tinctorius; D002460:Cell Line; D004365:Drugs, Chinese Herbal / Q000032:analysis / Q000494:pharmacology*; D005419:Flavonoids / Q000032:analysis / Q000494:pharmacology; D035264:Flowers / Q000737:chemistry; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D000520:alpha-Glucosidases / Q000378:metabolism*
chemical_list: D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D009569:Nitric Oxide; C079426:Honghua extract, Carthamus tinctorius; D000520:alpha-Glucosidases