Metabolomic Profiling, Antioxidant and Anti-inflammatory Activities of Hypericum Species Growing in South Korea

Although Hypericum species are best known as plants that produce hypericin and are used in folk medicine, their other chemical constituents are poorly understood. Polyphenolic secondary metabolites from whole plants of representative Korean Hypericum species ( H. laxum Koidz., H. erectum Thunb., and H. ascyron L.) were analyzed using a ultra performance liquid chromatography-quadrupole time-of-flight/mass spectrometry (UPLC-Q-TOF/MS)-based approach combined with unsupervised principal component analysis (PCA) multivariate analysis. On the loading scatter plot, significant changes in metabolites were found between species, and three flavonol glycosides (8: quercetin-3- O-galactoside, 12: kaempferol-3- O-glucoside, and 13: quercetin-3- O-rhamnoside) were evaluated as key markers among 17 isolated metabolites. The extracts of H. laxum Koidz. exhibited significant quenching effects on DPPH and ABTS radicals, with IC50 values of 10–20 μg/mL, and were slightly higher in total phenol (TP) and total flavonoid (TF) contents than other species. Additionally, anti-inflammatory activity was observed by reduced nitric oxide (NO) and interleukin-6 (IL-6) production from lipopolysaccharide (LPS)-stimulated macrophages (RAW 264.7 cells). This is the first study to report the presence of bioactive metabolites and their correlating biological activities in H. laxum Koidz.

Total Polyphenol Content,in vitroAntifungal and Antioxidant Activities of Callus Cultures fromInula crithmoides

This is the first report on the antioxidant and antifungal activities of callus cultures from Inula crithmoides L. (Asteraceae). Callus cultures were initiated from leaf sections, on initial culture MS basal medium supplemented with various concentrations of 2,4-D (2,4-dichlorophenoxyacetic acid), NAA (1-naphthaleneacetic acid) and IBA (indole-3-butyric acid) and a 72% survival was achieved. Significant differences between the various auxins used as phytohormones on callus growth were found. Maximum callusing was noticed on the leaf explants grown on MS basal medium supplemented with 1 mgL–12,4-D. Subsequently the antioxidant and antimicrobial activities of the methanol extract from calli were investigated. Antioxidant studies suggested that the methanol extracts of dark-grown and light-grown callus were able to reduce the stable free radical 2,2-diphenyl-1-picrilhydrazyl (DPPH). In the inhibition against lipid peroxidation, extracts of dark-grown callus showed the strongest effect with IC50values better than those of the standards. The methanol extract of callus cultures had significant antifungal activity only against two of the fungi tested: Alternaria solani and Phytophthora cryptogea. Against all the other tested fungi, the I. crithmoides calli extracts showed fungistatic activity.

Volatile Constituents of Two Hypericum Species from Tunisia

The chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of the Tunisian Hypericum perforatum and H. ericoides ssp. roberti was elucidated by a combination of GC and GC-MS analyses. The main constituents of the oil of H. perforatum were α-pinene (11.8%), α-ylangene (10.4%), germacrene-D (9.5%), n-octane (6.5%) and α-selinene (5.9%). The oil of H. ericoides ssp. roberti exhibited a higher amount of aliphatic and branched hydrocarbons and the main constituents were n-octane (29.1%), α-pinene (10.9%), pulegone (7.7%) and acetophenone (7%). Both qualitative and quantitative differences were observed between the studied oils. This chemical variability seems likely to result from the genetic variability, since samples of both species were collected at the same location and processed under the same conditions.