ABSTRACT
BACKGROUND: In our previous studies conducted on Ardisia crispa roots, it was shown that Ardisia crispa root inhibited inflammation-induced angiogenesis in vivo. The present study was conducted to identify whether the anti-angiogenic properties of Ardisia crispa roots was partly due to either cyclooxygenase (COX) or/and lipoxygenase (LOX) activity inhibition in separate in vitro studies. METHODS: Benzoquinonoid fraction (BQ) was isolated from hexane extract by column chromatography, and later analyzed by using gas chromatography-mass spectrometry (GC-MS). Anti-angiogenic effect was studied on mouse sponge implantation assay. Ardisia crispa ethanolic rich fraction (ACRH), quinone-rich fraction (QRF) and BQ were screened for COX assay to evaluate their selectivity towards two isoforms (COX-1 and COX-2), The experiment on soy lipoxygenase (LOX) inhibitory assay was also performed to determine the inhibitory effect of ACRH, QRF and BQ on soy LOX. RESULTS: BQ was confirmed to consist of 2-methoxy-6-undecyl-1,4-benzoquinone, when compared with previous data. Antiangiogenesis study exhibited a reduction of mean vascular density (MVD) in both ACRH and QRF, compared to control. In vitro study showed that both ACRH and QRF inhibited both COX-1 and COX-2, despite COX-2 inhibition being slightly higher than COX-1 in BQ. On the other hand, both ACRH and QRF were shown to have poor LOX inhibitory activity, but not BQ. CONCLUSIONS: In conclusion, ACRH and QRF might possibly exhibit its anti-angiogenic effect by inhibiting cyclooxygenase. However, both of them were shown to possess poor LOX inhibitory activity. On the other hand, BQ displayed selectivity to COX-2 inhibitory property as well as LOX inhibitory effect.
Subject(s)
Angiogenesis Inhibitors/therapeutic use , Ardisia/chemistry , Cyclooxygenase 2 Inhibitors/pharmacology , Cyclooxygenase Inhibitors/therapeutic use , Inflammation/drug therapy , Neovascularization, Pathologic/prevention & control , Phytotherapy , Angiogenesis Inhibitors/analysis , Angiogenesis Inhibitors/pharmacology , Animals , Benzoquinones/analysis , Benzoquinones/pharmacology , Benzoquinones/therapeutic use , Cyclooxygenase 1/metabolism , Cyclooxygenase 2/metabolism , Cyclooxygenase Inhibitors/analysis , Cyclooxygenase Inhibitors/pharmacology , Gas Chromatography-Mass Spectrometry , Inflammation/metabolism , Lipoxygenase/metabolism , Male , Mice, Inbred ICR , Neovascularization, Pathologic/metabolism , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Plant Roots/chemistry , Prostaglandin-Endoperoxide Synthases/metabolismABSTRACT
BACKGROUND: Ardisia crispa (Myrsinaceae) is used in traditional Malay medicine to treat various ailments associated with inflammation, including rheumatism. The plant's hexane fraction was previously shown to inhibit several diseases associated with inflammation. As there is a strong correlation between inflammation and angiogenesis, we conducted the present study to investigate the anti-angiogenic effects of the plant's roots in animal models of inflammation-induced angiogenesis. METHODS: We first performed phytochemical screening and high-performance liquid chromatography (HPLC) fingerprinting of the hexane fraction of Ardisia crispa roots ethanolic extract (ACRH) and its quinone-rich fraction (QRF). The anti-inflammatory properties of ACRH and QRF were tested using the Miles vascular permeability assay and the murine air pouch granuloma model following oral administration at various doses. RESULTS: Preliminary phytochemical screening of ACRH revealed the presence of flavonoids, triterpenes, and tannins. The QRF was separated from ACRH (38.38% w/w) by column chromatography, and was isolated to yield a benzoquinonoid compound. The ACRH and QRF were quantified by HPLC. The LD(50) value of ACRH was 617.02 mg/kg. In the Miles vascular permeability assay, the lowest dose of ACRH (10 mg/kg) and all doses of QRF significantly reduced vascular endothelial growth factor (VEGF)-induced hyperpermeability, when compared with the vehicle control. In the murine air pouch granuloma model, ACRH and QRF both displayed significant and dose-dependent anti-inflammatory effects, without granuloma weight. ACRH and QRF significantly reduced the vascular index, but not granuloma tissue weight. CONCLUSIONS: In conclusion, both ACRH and QRF showed potential anti-inflammatory properties in a model of inflammation-induced angiogenesis model, demonstrating their potential anti-angiogenic properties.