Structure and ecological features of the Yeravninsky steppes flora (Western Transbaikalia)

The paper is devoted to the characteristics of the floristic diversity of steppe vegetation in the southern part of the Vitim plateau in Yeravninskaya and Uldurginskaya basins. There is a southern border of the permafrost. The flora of the steppes is characterized by a depleted composition in comparison with the steppes of the Selenga middle mountains. Some widespread plant species of the true steppes of the Central Asia are absent here. The basis of the ecological and phytocoenotic structure is the steppe group, which is dominated by mountain and forest-steppe plant species. There is less participation of the true steppe species; this fact indicates an insular nature of these steppes. A group of light-coniferous species is significant; they are the part of the cryoarid forest-steppe complexes of the Vitim plateau. In the ecological structure of the flora xeromesophyte and gemixerophyte species dominate. They have the most important coenotic role in the formation of the vegetation cover of these steppes. The cereals species are of high coenotic significance, there are indicators of the dry bunchgrass steppes of Southern Siberia (Poa botryoides (Trin. ex Griseb.) Roshev., Agropyron cristatum (L.) Gaertn., Koeleria cristata (L.) Pers.). The role of mesoxerophytic of East Asian and Daurian-Manchurian species is also high (Filifolium sibiricum (L.) Kitam., Stellera chamaejasme L., Bupleurum scorzonerifolium Willd.). They are typical for meadow steppes of the Central Asian sector of the Palearctic.

DYNAMIC CHANGES IN THE COMPOSITION OF BIOLOGICALLY ACTIVE COMPOUNDS OF BUPLEURUM SCORZONERIFOLIUM WILLD. AERIAL PART IN DIFFERENT PHENOLOGICAL PHASES

The article is devoted to investigate the changes in the composition of biologically active substances (essential oils, lipid fraction, phenolic compounds) of the aerial part of the Bupleurum scorzonerifolium Willd. in depending on the phase of plant development. The greatest variety of compounds included in the composition of essential oils is characterized by a flowering phase. Fifteen terpene compounds – p-cymol, β-myrcene, trans-β-ocymene, limonene, (E,E)-α-farnesene, α-copaene, β-elemene, humulene, germacrene D, caryophyllene, γ-muurolene, bicyclogermacrene, Δ-cadinene, t-muurolol, spatulenol – are constant components of essential oils, regardless of phenophase. The quantitative content of these components varies from trace to major at different phenological phases. The coincidence of the main components of the lipid fraction was established. The main saturated acid is 16:0. Its content changes depending on the phase of vegetation – it is approximately at the same level determined in the phases of vegetation and flowering phases (26.78% and 27.26%, respectively) and there is a decrease in the fruit phase (18.17%). The main monounsaturated fatty acid is 18:1n9. Its greatest content was found in the fruiting phase, the smallest – flowering. The predominant polyunsaturated fatty acid is 18:2n9,12. Its greatest content was found in the vegetation phase (26.78%), the lowest - flowering (24.23%). However, the total content of unsaturated fatty acids exceeds the total content of saturated fatty acids in all phases of plant development. Although, their ratio varies from phenophase. There is a general pattern of highest content of phenolic compounds in the flowering phase for all studied samples. It was shown that during the flowering phase, the maximum accumulation of essential oils, lipids and phenolic compounds is observed.

Effect of polysaccharide from the root of Bupleurum Chinese DC and Bupleurum scorzonerifolium Willd on hydrogen peroxide-induced myocardial apoptosis

Purpose: To investigate the protective effect of polysaccharide (BRP) from the root of Bupleurum Chinese DC. and Bupleurum scorzonerifolium Willd. on cardiomyocyte cells. Methods: Response surface methodology (RSM) based on Box-Behnken Design (BBD) was performed to optimize the extraction conditions for BRP. The effect of BRP on cardiomyocyte cell apoptosis was evaluated in H9c2 cells treated with hydrogen peroxide (H2O2). Cell viability was determined by CCK-8 assay, while oxidative stress levels in H9c2 cells, including lactate dehydrogenase (LDH), superoxide dismutase (SOD), catalase (CAT) and creatine kinase (CK) were determined using commercial kits following the manufacture’s instruction. mRNA expressions (caspase-3, caspase-8, caspase-9 and Fas) were determined by quantitative real time-polymerase chain reaction (RT-qPCR). Results: The obtained optimal extraction conditions for BRP was as follows: extraction time (1.43 h), ratio of water to the raw material (30 mL/g) and extraction times (2 times). BRP (200, 400, 600 and 800 μg/mL) significantly increased the cell viability of H2O2 induced H9c2 cells (p < 0.05, p < 0.01, p < 0.01, p < 0.01, respectively). BRP (200, 400 and 800 μg/mL) significantly decreased LDH and CK levels (p < 0.01, p < 0.01, p < 0.01, respectively). However, BRP increased levels of SOD (200, 400 and 800 μg/mL, p < 0.05) and CAT (400 and 800 μg/mL, p < 0.05) in H9c2 cells. BRP significantly downregulated mRNA expressions of Caspase-3, Caspase-8, Caspase-9 and Fas (200, 400 and 800 μg/mL, p < 0.01) in H9c2 cells induced by H2O2. Conclusion: BRP protects cardiomyocyte against apoptosis via inhibition of oxidative stress and mitochondria-mediated intrinsic apoptosis, and thus, may be potential therapeutic agent for the management of cardiovascular diseases. Keywords: Bupleurum Chinese, Bupleurum scorzonerifolium Willd., Polysaccharide, Cardiomyocyte, Apoptosis, H9c2 cell, Biochemical parameters

TRITERPENE COMPOUNDS OF THE ABOVE GROUND ORGANS OF THE BUPLEURUM SCORZONERIFOLIUM WILLD. OF THE BAIKAL REGION FLORA

Representatives of the genus Bupleurum L. in the composition of biologically active substances accumulate triterpene compounds (derivatives of α-amyrin and β-amyrin). Triterpene glycosides isolated from plants of the genus Bupleurum are called saikosaponinov, buplevrozidy, skorzonerozidy. Plants of the genus Bupleurum in the underground organs accumulate triterpene compounds in an amount of from 1 to 7%. Triterpene compounds of plants of the genus Bupleurum possess a hepatoprotective, antiviral, cytostatic effect. We have studied the triterpene compounds of the aerial organs of Bupleurum scorzonerifolium Willd. The material for the study was collected on the territory of the Irkutsk region (Russia). Isolation of triterpene compounds was performed with 70% ethyl alcohol. The compounds were identified by liquid chromatography with mass spectrometry and diode-matrix detection (UPLC-DAD-ESI-MS/MS). According to the results of the analysis, the content of 5 triterpene compounds was established: saikosaponinov A, B2, C, D, F. The isolated compounds are structurally derived from oleanan, in which glycosidation is observed at the C-3 position with α-L-rhinose, β-D-glucose and β-D-fucose. The spectrophotometric method determined the quantitative content of the amount of triterpene compounds in the above-ground organs of B. scorzonerifolium at different phases of the vegetation of the plant, by organs (in flowers, leaves, stalks), and also depending on the place of growth. It has been established that the maximum amount of the amount of triterpene compounds accumulates in the aboveground organs of B. scorzonerifolium during the flowering phase – 1.54±0.05%; the highest content of this group of compounds is noted in flowers – 1.70±0.06%; most of all, this group of compounds is collected by samples collected in the Ust-Horde Buryat District (1.96±0.06%). The aboveground organs of B. scorzonerifolium can be used as a source of triterpene compounds, the highest content of which is noted in the flowering phase. The study of triterpene compounds in the aboveground organs of B. scorzonerifolium was carried out for the first time.

In Vitro Anti-Inflammatory and Immunomodulatory Activities of an Extract from the Roots of Bupleurum rotundifolium

Background: Some Bupleurum species, such as the Bupleurum chinense DC. or the Bupleurum scorzonerifolium Willd have been extensively studied (especially their roots) for the treatment of inflammation. In contrast, only compounds extracted from the aerial parts of Bupleurum rotundifolium have been studied and showed anti-inflammatory or antiproliferative activities. This study was conducted to investigate the antioxidant, anti-inflammatory, and immunomodulatory effects of Bupleurum rotundifolium roots. Methods: To tackle the various aspects of inflammation, we studied in vitro a methanolic extract from the roots of Bupleurum rotundifolium on peripheral blood mononuclear cells (PBMCs), polymorphonuclear neutrophils (PMNs), and the monocytic cells THP-1. Its antioxidant capacities and iron-chelating activity were assessed. The extract was tested on THP-1 differentiation, reactive oxygen species (ROS) production by leukocytes, neutrophils chemotaxis, cytokines, PGE2 production, and NF-κB activation in PBMCs. Results: The extract showed a decreased ROS production in stimulated cells. It increased PBMC chemokine secretion and up-regulated the differentiation of THP-1 monocytes into macrophage-like cells, indicating a potential interest of the extract in the resolution of acute inflammation. In addition, the analysis of cytokine production suggests that Bupleurum rotundifolium has immunomodulatory properties. Conclusions: Cytokines secretion, especially IL-1β and IL-12p70, provided us with a set of indicators suggesting that the extract might be able to drive the polarization of macrophages and lymphocytes toward a Th2 anti-inflammatory profile in excessive inflammation.

METABOLOMIC PROFILE BUPLEURUM SCORZONERIFOLIUM WILLD., GROWING IN THE BAIKAL REGION

In folk medicine in the Baikal region, an infusion from the aerial part of the plant Bupleurum scorzonerifolium (Willd) is widely used as a choleretic and anti-inflammatory agent. The choleretic effect of herbal remedies is mainly due to the content of phenylpropanoids and flavonoids. Using high performance liquid chromatography with a diode-matrix detector and 3Q electrospray ionization detector, we studied the metabolic profile of the phenylpropanoids and flavonoids of the aboveground organs of B. scorzonerifolium (Willd.), which grows in the Baikal region. In the aboveground organs of B. scorzonerifolium, 7 phenylpropanoids and 17 flavonoids were identified, of which 15 compounds for the species were identified for the first time. Quantitative determination of individual components was carried out in the aboveground organs of B. scorzonerifolium and dry extract by microcolumn HPLC with UV detection. The predominant components in the aerial part of the plant are 5-O-caffeic quinic acid, 3,5-di-O-caffeic quinic acid, isoquercitrin, isorhamnetin-3-O-glucoside, kaempferol-3-O-rhamnoside and rutin. The dry extract obtained from the aerial part of B. scorzonerifolium contains the entire complex of phenylpropanoids and flavonoids, which are identified in the plant. The content of active ingredients in the extract is 2.5–3.0 times higher than in the aboveground organs. The aboveground organs and dry extract of B. scorzonerifolium can be used as a source of phenylpropanoids and flavonoids.