Garden Rhubarb Research Articles

Anti-inflammatory and antioxidant actions of extracts from Rheum rhaponticum and Rheum rhabarbarum in human blood plasma and cells in vitro

Rheum rhaponticum L. (rhapontic rhubarb) and Rheum rhabarbarum L. (garden rhubarb) are edible and medicinal rhubarb species used for many centuries in traditional medicine. This work is focused on the biological activity of extracts from petioles and roots of R. rhaponticum and R. rhabarbarum as well as rhapontigenin and rhaponticin, typical stilbenes present in these rhubarbs, in a context of their effects on blood physiology and cardiovascular health. Anti-inflammatory properties of the examined substances were evaluated in human peripheral blood mononuclear cells (PBMCs) and THP1-ASC-GFP inflammasome reporter cells. Due to the coexistence of inflammation and oxidative stress in cardiovascular diseases, the study design included also antioxidant assays. This part of the work involved the assessment of the protective efficiency of the examined substances against the peroxynitrite-triggered damage to human blood plasma components, including fibrinogen, a protein of critical importance for blood clotting and maintaining the haemostatic balance. Pre-incubation of PBMCs with the examined substances (1–50 μg/mL) considerably decreased the synthesis of prostaglandin E2 as well as the release of pro-inflammatory cytokines (IL-2 and TNF-α) and metalloproteinase-9. A reduced level of secreted apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) specks in the THP-1-ASC-GFP cells was also observed. The examined substances significantly diminished the extent of ONOO‾induced oxidative modifications of blood plasma proteins and lipids and normalized, or even strengthened blood plasma antioxidant capacity. Furthermore, a reduction of oxidative damage to fibrinogen, including modifications of tyrosine and tryptophan residues along with the formation of protein aggregates was found.

Prospects of Rhubarb Juice Production and Utilization

The review is devoted to the nutritional significance and prospects of garden rhubarb (Rheum rhabarbarum L.) utilization in food industry. High yield of juice reaching 90% and the ability to complex rhubarb stems processing for juice production and pectin extraction from rhubarb stem pomace are empathized. Rhubarb stems pomace recorded up to 21-23 % of pectin, which is significantly higher than in natural industrial sources of pectin. Medicinal value of rhubarb juice is discussed: antioxidant, anti-inflammatory, anti-carcinogenic, cardioprotective and anti-diabetic properties are indicated. Examples of high antioxidant content and unique organic acids composition of rhubarb juice are highlighted. Sorbic and benzoic acids are indicated as important components of juice widely used in food industry as food preservatives. Citric acid is shown to be the main component of rhubarb organic acids in spring. Special attention is paid to the non-waste production of juice thanks to the possibility of pomace processing for pectin recovery. Juice biochemical characteristics of four garden rhubarb cultivars (selection of Federal Scientific Center of Vegetable Production) are described: Udalets, Malakhit, Zaryanka and Krupnochereshkovy). Expediency of further selection on high anthocyanin content in rhubarb stems are empathized.

Rheum rhaponticum and Rheum rhabarbarum Extracts as Modulators of Endothelial Cell Inflammatory Response.

Inflammation, endothelial dysfunction, and alterations in blood physiology are key factors contributing to atherosclerosis and other cardiovascular disorders. Hence, modulation of endothelial function and reducing its pro-inflammatory and pro-thrombotic activity is considered one of the most important cardioprotective strategies. This study aimed to evaluate the anti-inflammatory potential of rhubarb extracts isolated from petioles and underground organs of Rheum rhabarbarum L. (garden rhubarb) and R. rhaponticum L. (rhapontic rhubarb) as well as two stilbenoids, typically found in these plants, i.e., rhapontigenin (RHPG) and its glycoside, rhaponticin (RHPT). Analysis of the anti-inflammatory effects of the indicated rhubarb-derived substances involved different aspects of the endothelial cells' (HUVECs) response: release of the inflammatory mediators; cyclooxygenase (COX-2) and 5-lipoxygenase (5-LOX) expression as well as the recruitment of leukocytes to the activated HUVECs. The ability of the rhubarb-derived extracts to inhibit COX-2 and 5-LOX activities was examined as well. The study was supplemented with the in silico analysis of major components of the analyzed extracts' interactions with COX-2 and 5-LOX. The obtained results indicated that the examined plant extracts and stilbenes possess anti-inflammatory properties and influence the inflammatory response of endothelial cells. Biochemical and in silico tests revealed significant inhibition of COX-2, with special importance of rhaponticin, as a compound abundant in both plant species. In addition to the reduction in COX-2 gene expression and enzyme activity, a decrease in the cytokine level and leukocyte influx was observed. Biochemical tests and computational analyses indicate that some components of rhubarb extracts may act as COX-2 inhibitors, with marginal inhibitory effect on 5-LOX.

Biochemical Characteristics and Elemental Composition Peculiarities of Rheum tataricum L. in Semi-Desert Conditions and of European Garden Rhubarb

Biochemical and mineral peculiarities of plants inhabiting desert and semi-desert areas may provide important information about the mechanism of their adaptability and reveal the prospects of their utilization. Rheum tataricum L., known for its high tolerance to drought, salinity, and nutritional deficiency, is the least studied species of wild rhubarb. Using biochemical and ICP-MS analysis, the antioxidant status and mineral composition of R. tataricum were determined. Extremely high levels of antioxidant activity (148–155 mg GAE g−1 d.w.), polyphenols (24.6–25.1 mg GAE g−1 d.w.) and carotenoids (1.94 mg-eq β-carotene g−1 d.w.) were revealed in roots, proline in leaves (71.1 ± 6.2 mg kg−1 d.w.) and malic acid in stems (3.40 ± 0.50 mg g−1 d.w.). Compared to garden rhubarb, R. tataricum demonstrated significant root–leaves translocation of Li, Se, Si, and Mo, known to participate in plant antioxidant defense. Under high levels of Ca, Na, Mg, Fe, Cr and Si in soil, R. tataricum demonstrated the ability to significantly increase the accumulation of these elements in roots, showing a hyperaccumulation ability for Sr. The first broad picture of R. tataricum biochemical and mineral characteristics in semi-desert habitat and its nutritional value indicate the prospects of R. tataricum utilization in plant breeding, medicine, and nutrition.

A Review on Rhubarb-Derived Substances as Modulators of Cardiovascular Risk Factors-A Special Emphasis on Anti-Obesity Action.

The currently available anti-obesity therapies encounter many associated risks and side effects often causing the ineffectiveness of treatment. Therefore, various plant-derived substances have been extensively studied as a promising support or even an alternative for existing anti-obesity therapies. This review is dealing with the anti-obesity potential of edible and ethnomedicinal rhubarb species and emerging possible role of the rhubarb-derived extracts or individual compounds in the prevention of obesity and perspectives for their use in an anti-obesity treatment. A special emphasis is put on the most popular edible specimens, i.e., Rheum rhabarbarum L. (garden rhubarb) and Rheum rhaponticum L. (rhapontic rhubarb, Siberian rhubarb); however, the anti-obesity potential of other rhubarb species (e.g., R. officinale, R. palmatum, and R. emodi) is presented as well. The significance of rhubarb-derived extracts and low-molecular specialized rhubarb metabolites of diversified chemical background, e.g., anthraquinones and stilbenes, as potential modulators of human metabolism is highlighted, including the context of cardiovascular disease prevention. The available reports present multiple encouraging rhubarb properties starting from the anti-lipidemic action of rhubarb fibre or its use as purgative medicines, through various actions of rhubarb-derived extracts and their individual compounds: inhibition of enzymes of cholesterol and lipid metabolism, targeting of key molecular regulators of adipogenesis, regulators of cell energy metabolism, the ability to inhibit pro-inflammatory signalling pathways and to regulate glucose and lipid homeostasis contributing to overall in vivo and clinical anti-obesity effects.

Antibacterial and antioxidative properties ofdifferent parts of garden rhubarb, blackcurrant, chokeberry and blue honeysuckle.

It is important to find plant materials that can inhibit the growth of Listeria monocytogenes and other food-spoiling bacteria both in vitro and in situ. The aim of the study was to compare antibacterial and antioxidative activity of selected plant-ethanol infusions: leaves and berries of blackcurrant (Ribes nigrum L.), berries of chokeberry (Aronia melanocarpa (Michx.) Elliott) and blue honeysuckle (Lonicera caerulea L. var. edulis); petioles and dark and light roots of garden rhubarb (Rheum rhaponticum L.) for potential use in food matrices as antibacterial and antioxidative additives. The strongest bacterial growth inhibition was observed in 96% ethanol infusions of the dark roots of rhubarbs. In 96% ethanol, nine out of ten studied plant infusions had antibacterial effect against L. monocytogenes, but in 20% ethanol only the infusions of dark rhubarb roots had a similar effect. Chokeberry and other berries had the highest antioxidative activity, both in 20% and 96% ethanol infusions. The combination of dark rhubarb roots or petioles and berries of black chokeberry, blackcurrant or some other anthocyanin-rich berries would have potential as both antibacterial and antioxidative additives in food. © 2018 Society of Chemical Industry.

Corrigendum to “Ecofriendly Synthesis of Silver Nanoparticles from Garden Rhubarb (Rheum rhabarbarum)”

Corrigendum to “Ecofriendly Synthesis of Silver Nanoparticles from Garden Rhubarb (<i>Rheum rhabarbarum</i>)”

The inhibitory effect of plant infusions on selected bacteria

The present study determined the inhibitory patterns of the water and ethanol infusions of garden rhubarb, sea buckthorn, bilberry, blue-berried honeysuckle, black currant and tomato on targeted bacterial species. The larger inhibition zones against more than four different bacterial species were measured in case of ethanol infusions of garden rhubarb root, blue-berried honeysuckle and sea buckthorn. In case of water infusions the stronger inhibitory effect was found for garden rhubarb root, black currant and blue-berried honeysuckle. It was found that L. acidophilus, K. rhizophila and B. subtilis were the most susceptible bacteria in relation of ethanol infusions of studied plants, whereas the growth of K. rhizophila, B. subtilis and C. jejuni were most inhibited by water infusions. In accordance with present in vitro study, we conclude that the garden rhubarb and blue-berried honeysuckle are attractive candidates for food industries as natural antimicrobial additives in foods.DOI: http://dx.doi.org/10.5755/j01.ct.61.3.2662

Effect of different cooking regimes on rhubarb polyphenols

Polyphenolic components, such as anthraquinones and stilbenes, from species of the genus Rheum have been shown to have a range of bioactivities relevant to human health. This paper outlines the polyphenolic composition of edible petioles of garden rhubarb (Rheum rhapontigen) and describes the effects of common cooking methods on total polyphenolic content, anthocyanin content and total antioxidant capacity. Most cooking regimes (fast stewing, slow stewing and baking) except blanching increased total polyphenol content and overall antioxidant capacity, compared to the raw material. The patterns of anthocyanin content and total polyphenol content between the different cooking regimes suggested a balance between two processes; cooking facilitated the release of polyphenol compounds from the rhubarb but also caused breakdown of the released compounds. Baking and slow stewing offered the best maintenance of colour through preservation of anthocyanin and the highest antioxidant capacity. Baking for 20 min provided well-cooked rhubarb with the highest antioxidant capacity and the highest anthocyanin content, which is important for the aesthetic quality of the dish. Liquid chromatography–mass spectrometric (LC–MS) analysis putatively identified over 40 polyphenol components in raw rhubarb, including anthraquinone, stilbene, anthocyanin and flavonol derivatives. Baking caused selective effects on the stability of the different polyphenol components. Initially, the yield of all components increased but there was a drastic decline in the relative stability of anthraquinone aglycones with increasing cooking time and initial evidence for the turnover of other anthraquinone derivatives was obtained.

Trans‐resveratrol alone and hydroxystilbenes of rhubarb (Rheum rhaponticum L.) root reduce liver damage induced by chronic ethanol administration: a comparative study in mice

The hepatoprotective effects and pharmacokinetics of trans-resveratrol and hydroxystilbenes of the garden rhubarb (Rheum rhaponticum L., R. rhaponticum) root ethanol extract were studied. Ethanol was administered to male BALB/c mice for 35 days in an inhalation chamber. During this time vehicle, trans-resveratrol (20 mg/kg per day) or R. rhaponticum extract was intraperitoneally (i.p.) administered and mice were sacrificed for the collection of liver and blood. In an additional experiment, the level of parent compounds and metabolites was estimated in the blood after acute i.p. administration of trans-resveratrol or R. rhaponticum extract. The levels of hydroxystilbenes, their metabolites and fatty acid oxy-metabolites (oxylipins) were studied by LC-tandem DAD-MS/MS. Ethanol induced hepatotoxicity, as evidenced by histological changes and accumulation of oxylipins in the blood. Both trans-resveratrol and R. rhaponticum extract reduced the extent of these changes. The pharmacokinetics of trans-resveratrol was characterized by a rapid removal from the blood and metabolism to sulfates and glucuronides. After the administration of R. rhaponticum extract, in addition to trans-resveratrol glucoside and its metabolites, several other hydroxystilbenes were found. Inhibition of oxidation of polyunsaturated fatty acids is proposed as a basis of the hepatoprotective effect of both trans-resveratrol and R. rhaponticum extract.

Phenolic composition of rhubarb

Extracts of different parts (leaves, petioles and rhizomes) of domestic garden rhubarb (hybrids of Rheum rhabarbarum L. and Rheum rhaponticum L.) were investigated for their content of phenolic ingredients. Two stilbenes (trans-rhapontigenin, trans-desoxyrhapontigenin), five stilbene glycosides (trans-rhaponticin, cis- and trans-desoxyrhaponticin, trans-resveratrol-4′-O-β-d-glucopyranoside, trans-piceatannol-3′-O-β-d-glucopyranoside) and seven flavonoids [rutin, quercetin-3-O-glucuronide, isovitexin, 6,8-di-C-β-d-glucosylapigenin, 6-C-β-d-glucosyl-8-C-β-d-arabinosylapigenin (schaftoside), 6-C-β-d-arabinosyl-8-C-β-d-glycosylapigenin (isoschaftoside), (+)-catechin] were unequivocally established. Separation was done in two steps. Multilayer countercurrent chromatography was applied to separate different extracts of plant material. Preparative HPLC was then used to obtain pure substances. The purity and identity of isolated compounds was confirmed by different NMR experiments, HR-MS and HPLC-DAD analysis.

A Study on the Content of Pectic Substances in Vegetables

In recent years it has been reported that pectic substances have the action of lowering the level of cholesterol in blood plasma.The contents of pectic substances in twenty-four kinds of vegetables were examined. At first, the vegetables were treated with boiled 70% ethyl alcohol so as to remove sugars and dried. The thus obtained dried materials were successively divided by the fractional extraction into three fractions, i.e. soluble in water at 30°C, 0.4% sodium hexametaphosphate at 30°C, and 0.05N hydrochloric acid at 85°C. The pectin content (Ca-pectate) in each pectin-soluble fraction was quantitatively determined.The total content of pectin contained in fresh vegetables was as follows:2% or over: Soybeans, immature.1.00-1.99%: Pumpkin, Garlic, Great edible burdock.0.50-0.99%: Eschallot, Garden beet, Arrowhead, Potato white, Carrot, Yam, Peas with pod, immature, Sweet pepper, Kidney beans with pod, immature.0.10-0.49%: Dasheen taro, Eggplant, Garden rhubarb, “Udo”, Onion, Japanese radish root, Turnip, Cucumber, Green pepper, Indian lotus.

The process of charring Vegetable Tissue as applied to the examination of the Stomata in the Epidermis of Garden Rhubarb

The process of charring Vegetable Tissue as applied to the examination of the Stomata in the Epidermis of Garden Rhubarb

XL. The leaf-stalks of garden rhubarb as a source of malic acid

XL. <i>The leaf-stalks of garden rhubarb as a source of malic acid</i>

XXXII. The leaf-stalks of garden Rhubarb as a source of malic acid

XXXII. The leaf-stalks of garden Rhubarb as a source of malic acid