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Species of Rheum have high medicinal value, with the center of diversity in the Qinghai–Tibet Plateau (QTP) and adjacent regions. However, phylogenetic relationships of Rheum are still unclear due to fragment markers providing insufficient informative loci. Here, we sequenced and annotated plastomes of nine Rheum species, and compared the genome structure among the novel nine species along with three published species. Comparative analyses revealed that plastomes of Rheum share a relatively conserved structure. Five highly divergent regions (accD, ccsA, matK, ndhF, and ndhH) can be used as valuable molecular markers for further species delimitation and population genetic studies. Twenty‐two accessions representing 17 species were used for phylogenetic analysis, which generated a robust phylogenetic tree and revealed two major clades within Rheum. Phylogenetic results showed that glasshouse structures and cushions of Rheum are results of parallel evolution during adaptation to similar environments. Inconsistent tree topology between concatenated and coalescent methods was detected, implying that incomplete lineage sorting and hybridization may have occurred in the evolutionary history of Rheum. Divergence time estimation based on two fossil calibrations and three secondary calibrations revealed a Miocene to middle Oligocene origin of Rheum. Our study provides valuable genomic resources for the medicinally important genus Rheum, while gaining helpful insights into its systematics and evolution. [ABSTRACT FROM AUTHOR]

Three Linnaean names in the genus Rheum are lectotypified: R. compactum, R. palmatum and R. undulatum. [ABSTRACT FROM AUTHOR]

BACKGROUND 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. RESULTS: 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. CONCLUSION: 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 [ABSTRACT FROM AUTHOR]

The aim of this study was to synthesize nickel oxide nanoparticle (NiO‐NPs) by Rheum turkestanicum (RT) root extract, which is a local medicinal plant. The synthesized NiO‐NPs have been characterized by field emission scanning electron microscopy (FESEM), energy‐dispersive X‐ray spectroscopy (EDX), fourier‐transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD) methods. We have evaluated the cytotoxicity of NiO‐NPs on the WEHI 164 murine fibrosarcoma cells by MTT assay. The photocatalytic properties of NiO‐NPs was investigated by observing the removal of Rhodamine‐B (RB) in aqueous media. It has been displayed by the obtained results that NiO‐NPs have been synthesized in a Hexagonal (Rhombohedral) lattice system with the size of about 12–15 nm. According to the results, almost 95% of RB has apparently degraded in the presence of NiO‐NPs under UV‐light after 30 h. It has been illustrated by the cytotoxicity effects against the WEHI 164 murine fibrosarcoma cells that 250 μg/ml of NiO‐NPs is capable of eliminating about 70% of these tumors' cells. The IC50 of the NiO‐NPs has been calculated to be 25 μg/ml. The introduced green method can replace the available chemical procedures, which involve using hazardous substances that are a threat to the human health. The photocatalytic activities of green synthesized of NiO‐NPs (in RT extract media) in RB removal were examined and its cytotoxicity against the WEHI 164 cancer cells was investigated. It was displayed almost 95% of RB degradation under UV‐light after 30 h and evaluation of anticancer properties of NiO‐NPs was illustrated (IC50) of 25 μg/ml. The introduced green method can replace the available chemical procedures, which involve using hazardous substances that are a threat to the human health. [ABSTRACT FROM AUTHOR]

Studying the drivers of host specificity can contribute to our understanding of the origin and evolution of obligate pollination mutualisms. The preference-performance hypothesis predicts that host plant choice of female insects is related mainly to the performance of their offspring. Soil moisture is thought to be particularly important for the survival of larvae and pupae that inhabit soil. In the high Himalayas, Rheum nobile and R. alexandrae differ in their distribution in terms of soil moisture; that is, R. nobile typically occurs in scree with well-drained soils, R. alexandrae in wetlands. The two plant species are pollinated by their respective mutualistic seed-consuming flies, Bradysia sp1. and Bradysia sp2. We investigated whether soil moisture is important for regulating host specificity by comparing pupation and adult emergence of the two fly species using field and laboratory experiments. Laboratory experiments revealed soil moisture did have significant effects on larval and pupal performances in both fly species, but the two fly species had similar optimal soil moisture requirements for pupation and adult emergence. Moreover, a field reciprocal transfer experiment showed that there was no significant difference in adult emergence for both fly species between their native and non-native habitats. Nevertheless, Bradysia sp1., associated with R. nobile, was more tolerant to drought stress, while Bradysia sp2., associated with R. alexandrae, was more tolerant to flooding stress. These results indicate that soil moisture is unlikely to play a determining role in regulating host specificity of the two fly species. However, their pupation and adult emergence in response to extremely wet or dry soils are habitat-specific. [ABSTRACT FROM AUTHOR]

Rhubarb is one of the most popular traditional Chinese medicines and has been used for thousands of years in many Asian countries. Prepared rhubarb is obtained by steaming raw rhubarb with glutinous rice wine until it turned black in appearance both inside and outside. After processing, the therapeutic effects of prepared rhubarb change a lot. To find out the exact compound changes of the chemical profile in a decoction of rhubarb after processing and to clarify the material basis of the changed therapeutic effects, an ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry method coupled with automated data analysis software and statistical strategy was developed. As a result, 63 peaks in raw rhubarb and 54 peaks in prepared rhubarb were detected, and a total of 45 chemical compounds were identified. The analysis data were subjected to a principle component analysis and a t-test. Based on the results, 16 peaks were found to be the main contributors to the significant difference ( p < 0.05) between raw and prepared rhubarb. Compared with raw rhubarb, the content of 15 components in prepared rhubarb was lower, while only rhein (1,8-dihydroxy-3-carboxy anthraquinone) showed a higher intensity. [ABSTRACT FROM AUTHOR]

• Pollinating seed-consuming mutualisms are regarded as exemplary models for studying coevolution, but they are extremely rare. In these systems, olfactory cues have been thought to play an important role in facilitating encounters between partners. We present a new pollinating seed-consuming mutualism from the high Himalayas between the endemic herb, Rheum nobile, and a fly fungus gnat, Bradysia sp. • Seed production resulting from pollination by Bradysia flies and seed consumption by their larvae were measured to determine the outcome of this interaction. Floral scent analyses and behavioural tests were conducted to investigate the role of olfactory cues in pollinator attraction. • Rheum nobile is self-compatible, but it depends mainly on Bradysia sp. females for pollination. Seed production resulting from pollination by adult flies is substantially higher than subsequent seed consumption by their larvae. Behavioural tests showed that an unusual floral compound, 2-methyl butyric acid methyl ester, emitted by plants only during anthesis, was attractive to female flies. • Our results indicate that the R. nobile-Bradysia sp. interaction represents a new pollinating seed-consuming mutualism, and that a single unusual compound is the specific signal in the floral scent of R. nobile that plays a key role in attracting its pollinator. [ABSTRACT FROM AUTHOR]

Background Renal fibrosis is common in progressive kidney disease. Transforming growth factors β ( TGF-β) are important mediators of all types of fibrosis, including renal fibrosis. Chinese rhubarb has been shown to have antifibrotic properties in part because of inhibition of TGF-β and has slowed the progression of kidney disease in rodent models. Hypothesis That administration of a Chinese rhubarb supplement will slow the progression of chronic kidney disease ( CKD) in cats and the concurrent administration of Chinese rhubarb and benazepril will be more effective than either alone. Animals Twenty-nine client-owned cats with naturally occurring IRIS Stage 2 or early Stage 3 CKD and without comorbidity such as cancer, urinary tract obstruction, urinary tract infection, poorly controlled hyperthyroidism, or systemic hypertension were enrolled in the study. Methods A randomized, positive-controlled, prospective study was performed. Cats received Chinese rhubarb, benazepril, or both in addition to standard treatment for CKD. Repeated measures ANOVA was used to assess changes in serum creatinine concentration, body weight, hematocrit, urine protein: urine creatinine ratio ( UPC), and systemic arterial blood pressure over time between and within treatment groups over an average of 22 months. Results No significant differences were detected in serum creatinine concentration, body weight, hematocrit, UPC, and systemic arterial pressure over time between or within treatment groups. Conclusions and Clinical Importance This study failed to detect a significant difference in the progression of CKD in cats treated with Chinese rhubarb, benazepril, or both. Further study in specific subsets of cats with CKD is warranted. [ABSTRACT FROM AUTHOR]

This study was performed to compare the noncapsulated with nanoliposome-encapsulated phenolic-rich fraction (PRF) obtained from Rheum ribes as a dietary additive and to assess their health-promoting potentials in the mice infected by enteropathogenic Escherichia coli (O157:H7). Upon fractionation, the ethyl acetate fraction with 46.9 ± 2.17 mg GAE/g DW was found as a highest phenolic content. The PRF successfully loaded into nanoliposome structure with a nanometer in size (193.2 nm) and spherical shape and homogeneous dispersion. The gallic acid, salicylic acid, caffeic acid, cinnamic acid, catechin, ellagic acid, and ferulic acid are bioactive phenolics present in the nanoliposome-loaded PRF; however, the main bioactive compounds are cinnamic acid (911 μg/g DW) and ellagic acid (826 μg/g DW). The infection caused by E. coil impaired the weight gain and food intake, liver function, morpho structural characteristics of jejunum, upregulated the expression of inflammatory genes (Cox2, iNOS), downregulation of antioxidant-related genes (SOD, GPX), and increased the ileal population of E. coil. The addition of nonencapsulated PRF and nanoliposome-encapsulated PRF at the concentration of 10 mg TPC/kg BW/day improved these parameters although the nanoliposome-encapsulated PRF revealed more potential as compared with the nonencapsulated PRF in improving the health parameters in mice. The higher health-promoting activity of nanoliposome-encapsulated PRF could be associated with its enhanced intestinal absorption, bioavailability, bioaccessibility, and bioactivity. Consequently, the nanoliposome-encapsulated PRF could be considered as a promising phytobiotic against E. coil infection in mice., (© 2021 International Union of Biochemistry and Molecular Biology, Inc.)

The article presents a study about the synergistic interaction of physcion and chrysophanol, which are contained in the extract of the plant Rheum officinale Baill, on plant powdery mildew. Experiments were conducted to determine the interaction on cucumber powdery mildew and on wheat powdery mildew. Results indicate that physcion was more bioactive that chrysophanol against the powdery mildews. The study concludes on the need to determine the contents and proportion of the two compounds' main ingredients in order to ensure constant efficacy of the extract on the disease.

In this second of two articles regarding the renal toxicities or benefits of medicinal herbs, herbs are reported as being‘potentially beneficial’ to the kidneys if there is strongin vivoevidence of renal protection from toxic substances or drugs; potent, specific renal anti-oxidant effects;in vivocancer antiproliferative effects specific to the kidneys; orin vivoevidence of being beneficial in renal disease or failure. Among the herbs, polyherbal formulae and fungi with potential renal benefits areCordyceps sinensis, Sairei-to, Rheum spp.,Salvia miltiorrhizaand its component, magnesium lithospermate B and others. [ABSTRACT FROM AUTHOR]

Inhibitory effects of a rhubarb (Rhei rhizoma) solution and its fractions on the formation of calcium phosphate precipitates were studied, The rhubarb solution inhibited both the amorphous calcium phosphate (ACP) formation and the rate of hydroxyapatite (HAP) transformation, and extended the induction time. When the solution was fractionated using membrane filters, a filtrate with the molecular weight between 3 and 10 kDa (with 2/3 recovery of polyphenols) was found to be responsible for both the ACP formation and the extension of the induction time. Another filtrate with the molecular weight below 3 kDa (with 1/3 recovery of polyphenols) may be responsible for the inhibition of both the ACP formation and the rate of HAP transformation, and the extension of the induction time. When the extract of rhubarb was fractionated using a Sephadex LH-20 column chromatography, fraction IV greatly inhibited the formation of calcium phosphate precipitates, while fractions I, II, and 111 slightly inhibited that reaction. Our finding suggests that fraction IV may contain useful substance(s) for the prevention of oral calcium phosphate precipitation (calculus formation). However, strong calcium chelating properties would limit the concentration that could be safely employed. [ABSTRACT FROM AUTHOR]

The article focuses on the degeneration of Rhubarb caused by Nectria radicicola. Severe stunting was noted in a crop of rhubarb in Surrey, England in 1970. Affected plants showed weak growth, severe stunting and premature death of leaves and petioles. The young leaves were cordate with simple margins and a smooth surface. The leaves were a dull grey-green in colour and the vascular tissue in the crown and roots showed a dark chocolate brown discolouration