Rhamnus crenata leaf extracts exhibit anti-inflammatory activity via modulating the Nrf2/HO-1 and NF-κB/MAPK signaling pathways

Objective:To elucidate the potential anti-inflammatory mechanisms of Rhamnus crenata leaf extracts using RAW264.7 cells.Methods:We used 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay to measure cell viability.Nitric oxide(NO)production was measured using Griess reagent.Western blotting and RT-PCR assays were carried out for analyzing the protein and gene expressions of pro-inflammatory mediators,respectively.Moreover,PD98059(ERK1/2 inhibitor),SB203580(p38 inhibitor),SP600125(JNK inhibitor),and BAY11-7082(NF-κB inhibitor)were used to evaluate the anti-inflammatory mechanism of Rhamnus crenata leaf extract.Results:Rhamnus crenata leaf extracts significantly inhibited the production of the pro-inflammatory mediators such as NO,iNOS,COX-2,IL-1β,and TNF-αin lipopolysaccharide(LPS)-stimulated RAW264.7 cells.Rhamnus crenata leaf extracts also suppressed LPS-induced degradation of IκB-αand nuclear accumulation of p65,which resulted in the inhibition of NF-κB activation in RAW264.7 cells.Additionally,the extracts attenuated the phosphorylation of p38,ERK1/2,and JNK in LPS-stimulated RAW264.7 cells.Moreover,HO-1 expression induced by Rhamnus crenata leaf extracts was significantly downregulated by SB230580,PD98059,SP600125 and BAY11-7082.Conclusions:Rhamnus crenata leaf extract may upregulate HO-1 expression through inhibition of p38,ERK1/2,and NF-κB activation,which may contribute to the anti-inflammatory activity of the extracts.Rhamnus crenata leaf extracts may have great potential for the development of anti-inflammatory drugs to treat acute and chronic inflammatory diseases.

Proximate and mineral components of Viscum album var. coloratum grown on eight different host tree species

Mistletoes are parasite plants growing on various tree species,taking nutrients from the host.Beneficial compounds of mistletoe were used in medicine and these mistletoes were commonly collected from oak species that were not well identified.We analyzed the nutritional value by measuring proximate and mineral components of Korean mistletoe(Viscum album var.coloratum)from various host trees.Carbohydrate was the most proximate component in both leaves and twigs followed crude protein,crude fiber,crude ash and crude fat.While the contents of the proximate components and minerals varied among hosts and between plant parts,leaves contained higher crude protein and ash,and more minerals except for magnesium than twigs,although no significant difference was found inmistletoe grown on Prunus mandshurica.There were significant differences of proximate and mineral contents depending on the host species.Mistletoe grown on Chaenomeles sinensis contained higher levels of carbohydrates,crude fat,crude ash,magnesium,calcium,sodium,iron,and zinc than mistletoe grown on other species.Mistletoe grown on P.mandshurica contained high mineral levels of potassium,copper and phosphorous.The nutritional value of mistletoes were greatly influenced by the host species but among the hosts,specific nutrients accumulated in leaves more than in twigs,and vice versa.Based on the analysis,Korean mistletoe contains relatively good quality of nutrients and has high potential for dietary supplements as well as for medicinal compounds.