In vitro anti-inflammatory and wound-healing potential of a Phyllostachys edulis leaf extract--identification of isoorientin as an active compound

• Published in: Planta medica Vol. 80; no. 18; p. 1678
• Main Authors: Wedler, Jonas, Daubitz, Tony, Schlotterbeck, Götz, Butterweck, Veronika
• Format: Journal Article
• Language: English
• Published: Germany 01-12-2014
• Subjects: 3T3 Cells - drug effects; Animals; Anti-Inflammatory Agents, Non-Steroidal - chemistry; Anti-Inflammatory Agents, Non-Steroidal - pharmacology; Cell Line - drug effects; Dose-Response Relationship, Drug; Humans; Interleukin-6 - metabolism; Interleukin-8 - metabolism; Luteolin - isolation & purification; Luteolin - pharmacology; Mice; Plant Extracts - chemistry; Plant Extracts - pharmacology; Plant Leaves - chemistry; Poaceae - chemistry; Tumor Necrosis Factor-alpha - pharmacology; Vascular Endothelial Growth Factor A - metabolism; Wound Healing - drug effects
• ISSN: 1439-0221
• DOI: 10.1055/s-0034-1383195

Extracts prepared from the leaves of Phyllostachys edulis (bamboo) have received attention in pharmacological research due to their potent antitumor, anti-inflammatory, antimicrobial, and anti-ulcerogenic activities. In this study, anti-inflammatory effects of a bamboo leaf extract on tumor necrosis factor alpha-induced overproduction of interleukin 8, vascular endothelial growth factor, and interleukin 6 in immortalized human keratinocytes were investigated for the first time. In addition, wound-healing effects were evaluated in 3T3-swiss albino mouse fibroblasts. Bamboo leaf extract and isoorientin inhibited the tumor necrosis factor alpha-induced release of interleukin 8 and vascular endothelial growth factor. Furthermore, isoorientin dose-dependently reduced levels of interleukin 6 in tumor necrosis factor alpha-α-treated immortalized human keratinocytes cells. Wound healing was evaluated using a modification of the classical scratch assay. For evaluation of the wound gap, a new computerized method based on time-lapse microscopy was developed. It was shown that bamboo leaf extract (10 µg/mL) improved wound closure by 28 % (12 h) and 54 % (24 h), respectively. In concentrations of 50 µg/mL and above, bamboo leaf extract inhibited cell migration without affecting cell viability. Isoorientin (10 µM) improved wound closure by 29 % (12 h) and 56 % (24 h), respectively. Comparable to bamboo leaf extract, higher concentrations of isoorientin prevented cell migration. It is suggested that bamboo leaf extract as well as isoorientin have a dual activity - in higher doses, they show anti-inflammatory effects, and in lower concentrations, they exert anti-angiogenic activities.