RESUMO
The Korean prostrate spurge Euphorbia supina is a weed that has been used in folk medicine in Korea against a variety of diseases. Nine polyphenols were characterized for this plant by using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and the results were compared with the literature data. The individual components were validated using the calibration curves of structurally related external standards and quantified for the first time by using the validated method. Correlation coefficients (r (2)) were >0.9907. The limit of detection and limit of quantification of the method were >0.028 mg/L and 0.094 mg/L, respectively. Recoveries measured at 50 mg/L and 100 mg/L were 76.1-102.8% and 85.2-98.6%, respectively. The total amount of the identified polyphenols was 3352.9 ± 2.8 mg/kg fresh plant. Quercetin and kaempferol derivatives formed 84.8% of the total polyphenols. The antioxidant activities of the flavonoids were evaluated in terms of 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation-scavenging activity, and the reducing power showed a dose-dependent increase. Cell viability was effectively suppressed at polyphenol mixture concentrations >250 mg/L.
RESUMO
AIM OF THE STUDY: Phototoxicity can be either harmful or beneficial. Yet the phototoxicity of oriental medicinal plants is an understudied area. The purpose of this study is to fill in this gap. MATERIALS AND METHODS: The phototoxic potential of oriental medicinal plants was examined in vitro using photohemolysis and the Candida albicans test. Seventeen medicinal plants [Acorus gramineus (ACG), Panax ginseng C.A. (PAG), Platycodon grandiflorum (PLG), Aractylodes japonica (ATJ), Xanthium strumarium (XAS), Dioscorea batatas (DIB), Anemarrhena asphodeloides (ANA), Polygonatum sibiricum Red (PSR), Cocculus trilobus (COT), Ficus carica (FIC), Chelidonium majus var. asiaticum (CMA), Pulsatilla koreana (PUK), Agrimonia pilosa (AGP), Zanthoxylum schinifolium (ZAS), Angelica gigas (ANG), Ledebouriella seseloides (LES), and Cnidium officinale (CNO)] were selected because they showed strong fluorescence in one of our previous studies of 62 plants. We further evaluated in vivo phototoxicity in mice. 0.75 mL/kg of seed oil for Xanthium strumarium (XAS, ), or 1.25 mL/kg of extracted solutions of Atractylodes japonica (ATJ, ), Chelidonium majus var. asiaticum (CMA, ), Zanthoxylum schinifolium (ZAS, ), and Ledebouriella seseloides (LES, ) were given once, and evaluated for sunburn edema, formation of sunburn cell, decrease of epidermal Langerhans cells and local suppression of contact hypersensitivity by UVA irradiation. RESULTS: Sixteen out of the 17 plants tested except COT showed significant photohemolysis, and 5 of those exhibited phototoxic killing of Candida albicans. The phototoxicity of oriental medicines using those 5 plants was then studied in mice. The 5 plants increased sunburn edema and formation of sunburn cell, and suppressed immune responses locally by decreasing epidermal Langerhans cells and contact hypersensitivity by UVA irradiation. CONCLUSIONS: More than a quarter of oriental medicinal plants can be phototoxic, and strong fluorescence measured by absorption and fluorescence spectra can be an easier way to screen for phototoxicity. On the other hand, the phototoxicity of the plants may also be used therapeutically. Further studies regarding the phototoxicity of active components extracted from both live and dried oriental medicinal plants are necessary.