Spirodela polyrhiza (L.) Sch. ethanolic extract inhibits LPS-induced inflammation in RAW264.7 cells.
OBJECTIVE
Spirodela polyrhiza (L.) Sch. is widely used in Korean traditional medicine. No previous work has investigated in detail the anti-inflammatory activities of S. polyrhiza or assessed in vitro their potential underlying mechanism(s). We assessed the effects of S. polyrhiza ethanolic extract (SPEE) on the production of inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and investigated some potential underlying mechanisms. Additionally, we performed simultaneous determination of seven flavonoids in S. polyrhiza by high-performance liquid chromatography (HPLC)-photodiode array (PDA).


METHODS
RAW264.7 cells were subjected to 5, 10, 20, and 50 μg/mL of SPEE for 1 h then treated with LPS for 24 h. Production of namely nitric oxide (NO), prostaglandin E(2) and cytokine levels were measured by the Griess reagent and ELISA, respectively. To investigate the underlying mechanisms of the anti-inflammatory activities of SPEE, expression of NO synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-kappa B (NF-κB) proteins were evaluated by western blot analysis. HPLC analysis was performed using a Gemini C(18) column at 40°C and PDA detection at 340 nm.


RESULTS
SPEE treatment significantly inhibited the LPS-induced production of NO, prostaglandin E(2), interleukin-6, and tumor necrosis factor-α and inhibited the expression of iNOS and COX-2 via attenuation of NF-κB p65 expression. The contents of the seven flavonoids in S. polyrhiza range from 0.25 to 8.77 mg/g.


CONCLUSIONS
These results indicate that the anti-inflammatory activity of SPEE may be NF-κB p65 signaling. Also, the method will help to improve quality control of S. polyrhiza.
Basic Herbal Medicine Research Group, Korea Institute of Oriental Medicine, Yuseong-gu, Daejeon, Republic of Korea.
Chang-Seob
CS
Seo
Mee-Young
MY
Lee
In-Sik
IS
Shin
Jin-Ah
JA
Lee
Hyekyung
H
Ha
Hyeun-Kyoo
HK
Shin
D000818:Animals; D029064:Araceae / Q000737:chemistry*; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000378:metabolism; D007249:Inflammation / Q000139:chemically induced* / Q000188:drug therapy* / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000633:toxicity*; D055670:Medicine, Korean Traditional; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D051996:Transcription Factor RelA / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D015850:Interleukin-6; D008070:Lipopolysaccharides; D010936:Plant Extracts; C498144:Rela protein, mouse; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2