当前位置： SCI文献检索 > PLANTA MEDICA期刊下所有文献 > Seasonal variation of phenolic constituents and medicinal activities of Northern Labrador tea, Rhododendron tomentosum ssp. subarcticum, an Inuit and cree First Nations traditional medicine.

Seasonal variation of phenolic constituents and medicinal activities of Northern Labrador tea, Rhododendron tomentosum ssp. subarcticum, an Inuit and cree First Nations traditional medicine.

Abstract：

:Northern Labrador tea, Rhododendron tomentosum ssp. subarcticum, is one of the most commonly used medicinal plants by Inuit and other First Nations peoples of Canada. The phenolic profile and seasonal variation of this commonly used medicinal plant remains largely unknown. To assess optimal harvesting time, R. tomentosum was collected in accordance with traditional knowledge practices bimonthly throughout the snow-free summer in Iqaluit, Nunavut. The antioxidant potency was measured in a DPPH radical scavenging assay, and the anti-inflammatory activity was determined with a TNF-α production assay. The seasonal variation of phenolic content was assessed with HPLC-DAD for fifteen of the most abundant phenolic compounds; (+)-catechin, chlorogenic acid, PARA-coumaric acid, quercetin 3-O-galactoside (hyperoside), quercetin 3-O-glucoside (isoquercitrin), quercetin 3-O-rhamnoside (quercitrin), quercetin pentoside, myricetin, quercetin, 3 procyanidins, and 3 caffeic acid derivatives. The most abundant constituent was (+)-catechin, which made up 19 % of the total weight of characterized phenolics. There was significant seasonal variation in the quantity of all fifteen constituents assessed, whereas there was no seasonal variation of their total sum. The antioxidant activity was positively correlated with phenolic content and negatively correlated with daylight hours. The anti-inflammatory activity was negatively correlated with caffeic acid derivative 1 and daylight hours. Together these results demonstrate that the timing of harvest of R. tomentosum impacts the plant's phenolic content and its antioxidant and anti-inflammatory activities.

journal_name

Planta Med

journal_title

Planta medica

authors

Black P,Saleem A,Dunford A,Guerrero-Analco J,Walshe-Roussel B,Haddad P,Cuerrier A,Arnason JT

doi

10.1055/s-0030-1270968

subject

Has Abstract

pub_date

2011-09-01 00:00:00

pages

1655-62

issue

eissn

0032-0943

issn

1439-0221

journal_volume

pub_type

杂志文章

在线工具

Seasonal variation of phenolic constituents and medicinal activities of Northern Labrador tea, Rhododendron tomentosum ssp. subarcticum, an Inuit and cree First Nations traditional medicine.