Anti-oxidant and Antiproliferative Activities of Mongolian Medicinal Plant Extracts and Structure Isolation of Gnetin-H Compound.

BACKGROUND: Reactive oxygen species are involved in the etiology and progress of many kinds of diseases such as cancer, cardiovascular diseases, inflammatory and neurodegenerative disorders. Epidemiological studies reported that fruits, vegetables, and wines containing a high percentage of phenolics and flavonoids showed a positive impact in treating inflammatory diseases, reducing cancer risk, and increasing life expectancy. OBJECTIVE: Some Mongolian medicinal plants were studied for their antioxidant activity and anticancer effects. METHODS: Selected Mongolian medicinal plant extracts were examined for their antioxidant activity by the DPPH-radical scavenging assay, the content of phenolics and flavonoids by Folin-Ciocalteu and the Dowd method, respectively, and anti-cancer activities in human hepatoma cell line HepG2 cells by MTT assay. RESULTS: Methanol extract from Hippophae rhamnoides L. leaf and ethanol extract from Artemisia macrocephala Jacq. ex Bess. showed the highest efficiency to scavenge free radicals. Ethanol extracts from Hippophae rhamnoides L. grain and Paeonio anomala L. leaf showed the highest total phenolics content, whereas Hippophae rhamnoides L. fruit methanol extract and ethanol extract from Caragana leucophloea pojark. mentioned the highest flavonoids content. The Artemisia macrocephala Jacq. ex Bess seed wallet and Paeonia anomala L. seed wallet showed the most potent antiproliferative effects against human liver cancer HepG2 cell line. Gnetin-H compound was isolated from the Paeonio anomala L. seed wallet extract, and its molecular structure was determined by 1H and 13C NMR spectrum and IR spectroscopy methods. CONCLUSION: The screening study on anti-oxidative effects of 21 extracts from 15 Mongolian medicinal plants showed anti-oxidative activities and was rich in phenolics and flavonoids. Among these, methanol extract of the Hippophae rhamnoides L. leaf showed a better anti-oxidative effect than the ethanol extract. Artemisia macrocephala Jacq. ex Bess and Paeonia anomala L. seed wallet mentioned the best anti-cancer effects. Gnetin-H, methyl gallate, ethylgallate were the major components in the extract from the Paeonio anomala L. seed wallet. Finally, the molecular structure of gnetin-H was determined by NMR and IR spectroscopy. Further investigation, especially in vivo antioxidant activity, is needed to justify the use of a natural source of antioxidants to prevent the progression of diseases such as cancer.

Shade effects on growth, photosynthesis and chlorophyll fluorescence parameters of three Paeonia species.

Insufficient light intensity inhibits the growth of cultivated herbaceous peony and decreases its economic value. Owing to the increased demand for shade-tolerant herbaceous peony, the selection of appropriate parents for hybridization is essential. Paeonia anomala, Paeonia intermedia and Paeonia veitchii can grow under shade conditions in their natural habitats; however, their photosynthetic capacities under shade have not been studied. In this study, we simulated low light intensity (30% sunlight) and evaluated the morphological, photosynthetic and chlorophyll fluorescence parameters of these three species. Moreover, the shade tolerance of these species as well as two common cultivars (Paeonia lactiflora 'Da Fugui', which is suitable for solar greenhouse cultivation, and P. lactiflora 'Qiao Ling', which is not suitable for solar greenhouse cultivation) was evaluated. The results showed that under shade, the leaf area of P. anomala and P. intermedia increased, the single flowering period of P. intermedia and P. veitchii was prolonged, and the flower color of P. veitchii faded. With respect to P. anomala, P. intermedia and P. veitchii, shade eliminated the photosynthetic 'lunch break' phenomenon and decreased photoinhibition at midday. Furthermore, the maximum photochemical efficiency (Fv/Fm) and maximum primary photochemical yield (Fv/Fo) of photosystem II (PSII) in the three species improved significantly, and their changes in light dissipation were different. The shade tolerance of the tested accessions was in the order P. veitchii > P. intermedia > P. anomala > 'Da Fugui' > 'Qiao Ling', showing that the three wild species were better adapted to low light intensity than the cultivars. Thus, P. anomala, P. intermedia and P. veitchii could potentially be used in the development of shade-tolerant herbaceous peony cultivars.

The complete chloroplast genome of Paeonia anomala subsp. veitchii.

The complete chloroplast genome of Paeonia anomala subsp. veitchii., an important traditional Chinese herbal medicine, was sequenced and characterized in this study. The genome size is 152 682 bp in length with 38.42% GC content. Two inverted repeats (25 653 bp) are separated by a large single copy (84 398 bp) and a short single copy (16 978 bp). The genome contains 130 individual genes, including 85 protein-coding genes, 37 tRNA genes and 8 rRNA genes. Twenty-one genes contain one or two introns. Phylogenetic tree analysis of P. anomala subsp. veitchii and other 12 species belonging to Pentapetalae using MEGA6 with the neighbour-joining algorithm revealed that the chloroplast genome was clustered in subfamily Paeoniaceae.

Gnetin H isolated from Paeonia anomala inhibits FcεRI-mediated mast cell signaling and degranulation.

ETHNOPHARMACOLOGICAL RELEVANCE: Paeonia anomala L. is used in Mongolian traditional medicine to treat various diseases including indigestion, abdominal pain, kidney disorders, inflammation, and female diseases. In this study we examined the effects of Paeonia anomala extract (PAE) and compounds derived from Paeonia anomala on immunoglobulin E (IgE)-mediated type I hypersensitivity responses in vitro. MATERIALS AND METHODS: Degranulation assay, reverse transcription PCR, enzyme-lined immunosorbent assays, western blot analyses were performed to measure allergic and proinflammatory mediators in IgE-stimulated rat basophilic leukemia (RBL)-2H3 mast cells treated with or without PAE or gnetin H. RESULTS: Seventeen compounds were isolated, and ß-hexosaminidase release from IgE-stimulated RBL-2H3 mast cells was measured. Of the seventeen isolated compounds, gnetin H, a resveratrol derivative, significantly inhibited ß-hexosaminidase release from RBL-2H3 cells with an IC50 value of 0.3 µM. Notably, Gnetin H reduced ß-hexosaminidase release at lower concentrations than resveratrol. Furthermore, PAE and gnetin H inhibited histamine secretion, decreased the production and mRNA expression of tumor necrosis factor-α and interleukin-4 and suppressed translocation of nuclear factor κB. PAE and gnetin H also reduced the expression of cyclooxygenase-2 and production of prostaglandin E2. PAE and gnetin H suppressed the phosphorylation of Syk, protein kinase C (PKC)µ, phospholipase Cγ, and the mitogen-activated protein kinases, c-Jun N-terminal kinase, p38, and extracellular signal-regulated kinase. CONCLUSIONS: These results suggest that PAE and its active compound gnetin H could be promising therapeutic agents for allergic disorders.