title: Polyphenols from aerial parts of Polygonum bellardii and their biological activities.
abstract: BACKGROUND
  Polygonum species have been used in the treatment of several types of inflammatory disorders and cancer. Nevertheless, there are no reports related to the anti-inflammatory and anti-proliferative activities of Polygonum bellardii All. (Polygonaceae).
  
  
  OBJECTIVE
  This study investigated the chemical composition of the methanol extract of P. bellardii. The anti-inflammatory and cytotoxic activities of methanol, n-butanol, ethyl acetate extracts and isolated polyphenols were determined.
  
  
  METHODS
  The chemical structure of the isolated compounds was elucidated using different spectral techniques. MTT assay was used to evaluate the anti-proliferative activity in HeLa, MCF-7 and HepG-2 cells. Inhibition of 5-lipoxygenase (5-LOX) activity and prostaglandin E2 (PGE2) production in stimulated HepG-2 cells were used to assess the anti-inflammatory activity.
  
  
  RESULTS
  The present study resulted in isolation of five compounds (new for the species). They were identified as gallic acid (1), quercetin (2), myricetin (3), quercetin-3-O-β-D-glucopyranoside (5) and myricetin-3-O-α-arabinofuranoside (7). Additionally, a couple of previously isolated compounds such as quercetin-3-O-(5″-acetyl-α-arabinofuranoside) (4) and myricetin-3-O-(5″-acetyl-α-arabinofuranoside) (6) were detected. The n-butanol extract has the highest cytotoxicity in HeLa, MCF-7 and HepG-2 cells, with IC₅₀ values of 15.26, 50.66 and 30.09 µg/ml, respectively. Compound 6 exhibited a marked cytotoxicity in HeLa (IC₅₀ 75.04 µg/ml) and HepG-2 (IC₅₀ 41.03 µg/ml) cells. Crude extracts and pure compounds inhibited the 5-LOX activity and PGE2 production in a dose-dependent manner (0.1-250 µg/ml).
  
  
  CONCLUSIONS
  These results explain the traditional uses of P. bellardii and indicate that polyphenols, despite structural similarity, have different cytotoxic and anti-inflammatory effects.
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University, Assiut, Egypt.
authors.forename: Adel Mohamed
authors.initials: AM
authors.lastname: Abd El-Kader
authors.forename: Mahmoud Zaki
authors.initials: MZ
authors.lastname: El-Readi
authors.forename: Amany Sayed
authors.initials: AS
authors.lastname: Ahmed
authors.forename: Alaa Mohamed
authors.initials: AM
authors.lastname: Nafady
authors.forename: Michael
authors.initials: M
authors.lastname: Wink
authors.forename: Zedan Zeid
authors.initials: ZZ
authors.lastname: Ibraheim
mesh_terms: D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D001094:Arachidonate 5-Lipoxygenase / Q000187:drug effects / Q000378:metabolism; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000473:pathology; D015232:Dinoprostone / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D016859:Lipoxygenase Inhibitors / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D008113:Liver Neoplasms / Q000188:drug therapy / Q000473:pathology; D061986:MCF-7 Cells; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D028502:Polygonum / Q000737:chemistry*; D059808:Polyphenols / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D012997:Solvents / Q000737:chemistry; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy / Q000473:pathology
chemical_list: D000893:Anti-Inflammatory Agents; D000972:Antineoplastic Agents, Phytogenic; D016859:Lipoxygenase Inhibitors; D010936:Plant Extracts; D059808:Polyphenols; D012997:Solvents; D001094:Arachidonate 5-Lipoxygenase; D015232:Dinoprostone