Adipogenic Activity of Wild Populations ofRhododendron groenlandicum, a Medicinal Shrub from the James Bay Cree Traditional Pharmacopeia

Abstract

The traditional medicinal plant, Labrador tea (Rhododendron groenlandicum (Oeder) Kron & Judd; Ericaceae), present in the pharmacopoeia of the Cree of Eeyou Istchee, has shown glitazone-like activity in the 3T3-L1 adipogenesis bioassay. This activity has been attributed to phenolic compounds, which have been shown to vary in this plant as a function of insolation parameters. The goal of this study was to determine if these changes in phenolic content were pharmacologically significant. Leaves were harvested in 2006 throughout the James Bay region of Northern Quebec and ethanol extracts were tested in vitro using the 3T3-L1 murine cell line adipogenesis bioassay. This traditional medicinal plant was found active in the assay. However, there was no detectable spatial pattern in the accumulation of intracellular triglycerides, suggesting that such patterns previously observed in the phenolic profile of Labrador tea were not pharmacologically significant. Nonetheless, a reduction in the adipogenic activity was observed and associated with higher concentrations of quercetin for which selected environmental variables did not appropriately explain its variation.

Phytogeographic and genetic variation inSorbus, a traditional antidiabetic medicine—adaptation in action in both a plant and a discipline

“…Both the increase at higher latitudes of the expression of genes involved in the production of secondary metabolites in bark and leaf tissue, and the increase in antioxidant activities and phenolic content for bark tissue at higher latitudes are supported by previous findings (Fraser et al, 2007; McCune & Johns, 2007; Rapinski et al, 2014; Rapinski et al, 2015). Plants growing at higher latitudes are theorized to cope with a greater stress such as UV radiation, a shorter growing season and other harsher environmental conditions, including a decrease in soil moisture and an increase in cold (McCune & Johns, 2007; Rozema et al, 1997).…”

“…Indeed, the general trend of greater gene expression in samples collected from higher latitude and to some extent coastal locations is consistent with divergent metabolic responses stimulated by the environment (Hartmann et al, 2005; Rapinski et al, 2014; Rapinski et al, 2015). Both the increase at higher latitudes of the expression of genes involved in the production of secondary metabolites in bark and leaf tissue, and the increase in antioxidant activities and phenolic content for bark tissue at higher latitudes are supported by previous findings (Fraser et al, 2007; McCune & Johns, 2007; Rapinski et al, 2014; Rapinski et al, 2015).…”

“…They also have developed a number of non-technological approaches to identify plants and locations that will have the greatest concentration of medicinal active compounds (De Almeida, De Amorim & De Albuquerque, 2011). Modern experimental methods have confirmed these traditional approaches (Haddad et al, 2012; Rapinski et al, 2014; Rapinski et al, 2015) and have helped to identify useful phytochemicals compounds (Shang et al, 2012). Nevertheless, there remains a great divide between medicinal plant information held by indigenous groups and what is known from modern scientific inquiry.…”

Growth environment and organ specific variation in in-vitro cytoprotective activities of Picea mariana in PC12 cells exposed to glucose toxicity: a plant used for treatment of diabetes symptoms by the Cree of Eeyou Istchee (Quebec, Canada)

“…We have also shown that harvest location can impact the cytoprotective activities of P. mariana , particularly for bark extracts, which tended to be more effective when obtained from inland forest populations than from coastal and inland bog populations. In a similar fashion, [28, 29] showed a latitudinal trend in key phenolic concentration but failed to find a correlation with bioactivity. In general, the strength of the observed activity of needle, bark and cone is correlated with the total phenolic concentration of the extracts.…”

Anti-apoptotic potential of several antidiabetic medicinal plants of the eastern James Bay Cree pharmacopeia in cultured kidney cells

“…Another of the weaker nephroprotective plants in our Ann V/PI assay, namely R. groenlandicum , appeared to increase the activation of caspase 8 compared to hypertonic stress whereas it had no apparent effect on cleaved caspase 3 and caspase 9 activities. This result is surprising since Labrador tea ( R. groenlandicum ) was previously observed by our group to exhibit several beneficial antidiabetic activities when tested in both in vitro bioassays [ 36 , 94 ] and in vivo animal models of obesity and mild diabetes [ 95 , 96 ]. Such antidiabetic activities would be expected to improve renal function (for instance, through reduction of glycemia and improvement of insulin resistance).…”