Antioxidative phenolic compounds from the roots of Rhodiola sachalinensis A. Bor

Antidiabetic activity of Ipomoea cairica (L.) Sweet leaves: in-vitro and in-silico antidiabetic potential of isolated flavonoid glycosides and sulphated flavonoids

Antidiabetic activity of methanolic extract, petroleum ether, ethyl acetate and n-butanol fractions of Ipomoea cairica (L.) Sweet leaves was performed in-vitro using α-glucosidase and α-amylase inhibition methods. Phytochemical study of the ethyl acetate fraction which possessed the highest antidiabetic activity led to isolation of five flavonoids for the first time from this plant, including two rare flavonoid sulphates, ombuin-3-sulphate [1] and rhamnetin-3-sulphate [2] and three flavonoid glycosides, kaempferol 7-O-α-L-rhamnopyranoside [3], kaempferol 3,7-di-O-α-L-rhamnopyranoside [4] and quercetin 3-O-α-L-arabinopyranoside [5]. The 1H and 13C NMR of 1 and 13C NMR of 2, were reported here for the first time. Compounds [1-4] showed a concentration-dependent in-vitro inhibitory activity against α-glucosidase and α-amylase. Furthermore, in-silico study predicted that compounds (1-5) showed good interactions with α-glucosidase, α-amylase, and protein tyrosine phosphatase 1b.

Electrochemistry of Flavonoids: A Comprehensive Review

Flavonoids represent a large group of aromatic amino acids that are extensively disseminated in plants. More than six thousand different flavonoids have been isolated and identified. They are important components of the human diet, presenting a broad spectrum of health benefits, including antibacterial, antiviral, antimicrobial, antineoplastic, anti-mutagenic, anti-inflammatory, anti-allergic, immunomodulatory, vasodilatory and cardioprotective properties. They are now considered indispensable compounds in the healthcare, food, pharmaceutical, cosmetic and biotechnology industries. All flavonoids are electroactive, and a relationship between their electron-transfer properties and radical-scavenging activity has been highlighted. This review seeks to provide a comprehensive overview concerning the electron-transfer reactions in flavonoids, from the point of view of their in-vitro antioxidant mode of action. Flavonoid redox behavior is related to the oxidation of the phenolic hydroxy groups present in their structures. The fundamental principles concerning the redox behavior of flavonoids will be described, and the phenol moiety oxidation pathways and the effect of substituents and experimental conditions on flavonoid electrochemical behavior will be discussed. The final sections will focus on the electroanalysis of flavonoids in natural products and their identification in highly complex matrixes, such as fruits, vegetables, beverages, food supplements, pharmaceutical compounds and human body fluids, relevant for food quality control, nutrition, and healthcare research.

The protection effect of rhodionin against methicillin-resistant Staphylococcus aureus-induced pneumonia through sortase A inhibition

Methicillin-resistant Staphylococcus aureus (MRSA) is a zoonotic antibiotic-resistant pathogen that negatively impacts society from medical, veterinary, and societal standpoints. The search for alternative therapeutic strategies and innovative anti-infective agents is urgently needed. Among the pathogenic mechanisms of Staphylococcus aureus (S. aureus), sortase A is a virulence factor of great concern because it is highly linked with the ability of MRSA to invade the host. In this study, we identified that rhodionin, a natural compound of flavonoid glucosides, effectively inhibited the activity of SrtA without affecting the survival and growth of bacteria, and its half maximal inhibitory concentration (IC₅₀) value was 22.85 μg/mL. In vitro, rhodionin prominently attenuated the virulence-related phenotype of SrtA by reducing the adhesion of S. aureus to fibrinogen, reducing the capacity of protein A (SpA) on the bacterial surface and biofilm formation. Subsequently, fluorescence quenching and molecular docking were performed to verify that rhodionin directly bonded to SrtA molecule with K_A value of 6.22 × 10⁵ L/mol. More importantly, rhodionin showed a significant protective effect on mice pneumonia model and improved the survival rate of mice. According to the above findings, rhodionin achieved efficacy in the treatment of MRSA-induced infections, which holds promising potential to be developed into a candidate used for MRSA-related infections.

Rosiridin Attenuates Scopolamine-Induced Cognitive Impairments in Rats via Inhibition of Oxidative and Nitrative Stress Leaded Caspase-3/9 and TNF-α Signaling Pathways

AIM

A monoterpene and bioactive component of the plant Rhodiola rosea (R. rosea), rosiridin has beneficial effects on the human central nervous system and enhances brain function. The goal of this scientific study was to determine if rosiridin might shield rats from neurocognitive problems induced by scopolamine.

METHODS

To track the potential toxicities in rats, the acute toxicity in rats was clarified. Rosiridin at a dose of 10 mg/kg was tested in rats for 14 days. At the conclusion of the investigation, behavioral parameters that were used to identify the rats' cognitive and motor abilities were evaluated. Several biochemical parameters were estimated using the prepared homogenate, including acetylcholine esterase (AChE), choline acetyltransferase (ChAT), radical scavengers produced by the body (Catalase-CAT, superoxide dismutase-SOD, and reduced glutathione-GSH), indicators of oxidative and nitrative burnout, pro-inflammatory (Interleukins- IL-1β, IL-6, interferon gamma IFN-ꝩ, and tumor necrosis factor-TNF-α), and cell apoptosis caspases 3 and 9.

RESULTS AND CONCLUSION

A significant behavioral parameter restoration was seen in the rosiridin-treated group, including reduction in latency time during acquisition and retention trial in the Morris water maze test, and percentage of spontaneous alterations in the y-maze test, when compared to the disease control group that received scopolamine; rosiridin also altered the oxidative stress and neuroinflammatory markers, as well as restoring Ach and ChAT activities and normalizing GSH, SOD, MDA, TNF-α, nitrate, IL-1β, IL-6, IFN-ꝩ, caspases 3 and 9 levels. The results imply that rosiridin limits the effect of scopolamine on rat cognitive function.

Anti-Huntington’s Effect of Rosiridin via Oxidative Stress/AchE Inhibition and Modulation of Succinate Dehydrogenase, Nitrite, and BDNF Levels against 3-Nitropropionic Acid in Rodents

Background: Rosiridin is a compound extracted from Rhodiola sachalinensis; water extracts of Rhodiola root elicit positive effects on the human central nervous system and improve brain function. They are also thought to be beneficial to one’s health, in addition to being antioxidants. The present study aims to evaluate the anti-Huntington’s effect of rosiridin against 3-nitropropionic acid (3-NPA)-induced Huntington’s disease (HD)-like effects in rats. Materials and Methods: The acute toxicity in rats was elucidated to track the conceivable toxicities in the rats. The effectiveness of rosiridin at a dosage of 10 mg/kg was evaluated against several dose administrations of 3-NPA-induced HD-like symptoms in the rats for 22 days. At the end of the study, behavioral parameters were assessed as a hallmark for the cognitive and motor functions in the rats. Similarly, after the behavioral assessment, the animals were sacrificed to obtain a brain tissue homogenate. The prepared homogenate was utilized for the estimation of several biochemical parameters, including oxidative stress (glutathione, catalase, and malondialdehyde), brain-derived neurotrophic factor and succinate dehydrogenase activity, and the glutamate and acetylcholinesterase levels in the brain. Furthermore, inflammatory mediators linked to the occurrence of neuroinflammation in rats were evaluated in the perfused brain tissues. Results: The rosiridin-treated group exhibited a significant restoration of behavioral parameters, including in the beam-walk test, latency in falling during the hanging wire test, and percentage of memory retention during the elevated plus-maze test. Further, rosiridin modulated several biochemical parameters, including oxidative stress, pro-inflammatory activity, brain-derived neurotrophic factor, nitrite, and acetylcholinesterase as compared to disease control group that was treated with 3-NPA. Conclusions: The current study exhibits the anti-Huntington’s effects of rosiridin in experimental animal models.

Simultaneous Determination of 78 Compounds of Rhodiola rosea Extract by Supercritical CO2-Extraction and HPLC-ESI-MS/MS Spectrometry

The plant Rhodiola rosea L. of family Crassulaceae was extracted using the supercritical CO₂-extraction method. Several experimental conditions were investigated in the pressure range of 200–500 bar, with the used volume of cosolvent ethanol in the amount of 1% in the liquid phase at a temperature in the range of 31–70°C. The most effective extraction conditions are pressure 350 bar and temperature 60°C. The extracts were analyzed by HPLC with MS/MS identification. 78 target analytes were isolated from Rhodiola rosea (Russia) using a series of column chromatography and mass spectrometry experiments. The results of the analysis showed a spectrum of the main active ingredients Rh. rosea: salidroside, rhodiolosides (B and C), rhodiosin, luteolin, catechin, quercetin, quercitrin, herbacetin, sacranoside A, vimalin, and others. In addition to the reported metabolites, 29 metabolites were newly annotated in Rh. rosea. There were flavonols: dihydroquercetin, acacetin, mearnsetin, and taxifolin-O-pentoside; flavones: apigenin-O-hexoside derivative, tricetin trimethyl ether 7-O-hexosyl-hexoside, tricin 7-O-glucoronyl-O-hexoside, tricin O-pentoside, and tricin-O-dihexoside; flavanones: eriodictyol-7-O-glucoside; flavan-3-ols: gallocatechin, hydroxycinnamic acid caffeoylmalic acid, and di-O-caffeoylquinic acid; coumarins: esculetin; esculin: fraxin; and lignans: hinokinin, pinoresinol, L-ascorbic acid, glucaric acid, palmitic acid, and linolenic acid. The results of supercritical CO₂-extraction from roots and rhizomes of Rh. rosea, in particular, indicate that the extract contained all biologically active components of the plant, as well as inert mixtures of extracted compositions.

Natural phenolic antioxidants electrochemistry: Towards a new food science methodology

Natural phenolic compounds are abundant in the vegetable kingdom, occurring mainly as secondary metabolites in a wide variety of chemical structures. Around 10,000 different plant phenolic derivatives have been isolated and identified. This review provides an exhaustive overview concerning the electron transfer reactions in natural polyphenols, from the point of view of their in vitro antioxidant and/or pro-oxidant mode of action, as well as their identification in highly complex matrixes, for example, fruits, vegetables, wine, food supplements, relevant for food quality control, nutrition, and health research. The accurate assessment of polyphenols' redox behavior is essential, and the application of the electrochemical methods in routine quality control of natural products and foods, where the polyphenols antioxidant activity needs to be quantified in vitro, is of the utmost importance. The phenol moiety oxidation pathways and the effect of substituents and experimental conditions on their electrochemical behavior will be reviewed. The fundamental principles concerning the redox behavior of natural polyphenols, specifically flavonoids and other benzopyran derivatives, phenolic acids and ester derivatives, quinones, lignins, tannins, lignans, essential oils, stilbenes, curcuminoids, and chalcones, will be described. The final sections will focus on the electroanalysis of phenolic antioxidants in natural products and the electroanalytical evaluation of in vitro total antioxidant capacity.

Sulfated polysaccharides from Rhodiola sachalinensis reduce d-gal-induced oxidative stress in NIH 3T3 cells

In this study, three sulfated polysaccharides (S-RSP_1-2, S-RSP_1-4 and S-RSP_1-8) from Rhodiola sachalinensis were produced by chlorosulfonic acid-pyridine method. d-gal was used to develop an oxidative stress model in the mouse embryonic fibroblast cell line NIH 3T3. Effects of the three sulfated polysaccharides on d-gal-induced oxidative stress were investigated. The results showed that S-RSP_1-4 improved the viability of the d-gal-induced oxidative stress in NIH 3T3 cells. The sulfated polysaccharides were found to have a better protective effect against d-gal-induced oxidative stress as compared to the native polysaccharide. Scanning electronmicroscopy also showed a significant change in the surface morphology of sulfated polysaccharides. In addition, the sulfated polysaccharides had noticeable DPPH radical-scavenging activity. In summary, our results demonstrated that d-gal was able to induce oxidative stress in NIH 3T3 cells, and sulfated group might play an important role in resistance to d-gal-induced oxidative damage.

Natural Antioxidants as Potential Therapy, and a Promising Role for Melatonin Against Pulmonary Hypertension

Plasma and serum samples, and lung/heart tissue of pulmonary hypertension (PH) patients and animal models of PH display elevated oxidative stress. Moreover, the severity of PH and levels of oxidative stress increase concurrently, which suggests that oxidative stress could be utilized as a biomarker for PH progression. Accumulating evidence has well established that oxidative stress is also key role player in the development of PH. Preclinical studies have demonstrated that natural antioxidants improved PH condition, and, therefore, antioxidant therapy has been proposed as a potential therapeutic strategy against PH. These natural antioxidants include medicinal plant extracts and compounds such as resveratrol and melatonin. Recent studies suggest that melatonin provides health benefit against PH, by enhancing antioxidant capacity, increasing vasodilation, counteracting lung and cardiac fibrosis, and stunting right ventricular (RV) hypertrophy/failure. This chapter comprehensively reviews and discusses a variety of natural antioxidants and their efficacy in modulating experimental PH. This chapter also demonstrates that antioxidant therapy remains a therapeutic strategy for PH, and particularly identifies melatonin as a safe, cost-effective, and promising antioxidant therapy.

A new ferulic acid ester from Rhodiola wallichiana var. cholaensis (Crassulaceae)

A new ferulic acid ester, 6-feruloyloxyhexanoic acid (1), was isolated along with 10 known ones (2-11), from the concentrated water extract of Rhodiola wallichiana var. cholaensis. Their chemical structures were elucidated on the basis of extensive spectroscopic methods including Two-dimensional nuclear magnetic resonance (2D NMR) experiments. Compound 3 was isolated from this plant for the first time. The protective effects against H₂O₂-induced myocardial cell injury in cultured H9c2 cells were also evaluated. Compounds 1, 5 and 7-11 provided significant protective effects on H₂O₂-induced H9c2 cells injury at the concentration of 25 μg/mL. And the protective effects of compound 1 was also investigated by the oxygen-glucose deprivation/reperfusion (OGD/R) tests.

Preventive Effects of Rhodiola rosea L. on Bleomycin-Induced Pulmonary Fibrosis in Rats

Rhodiola rosea L. (RRL) possesses a wide range of pharmacological properties, including lung-protective activity, and has been utilized in folk medicine for several 100 years. However, the lung-protective mechanism remains unclear. This study investigated the possible lung-protective activity mechanism of RRL in a pulmonary fibrosis (PF) rat model. Lung fibrotic injury was induced in Sprague-Dawley rats by single intratracheal instillation of saline containing bleomycin (BLM; 5 mg/kg). The rats were administered 125, 250, or 500 mg/kg of a 95% ethanol extract of RRL for 28 days. The animals were killed to detect changes in body weight, serum levels of glutathione (GSH) and total superoxide dismutase (T-SOD), as well as lung tissue hydroxyproline (HYP) content. Tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and interleukin 6 (IL-6) levels were measured in bronchoalveolar lavage fluid (BALF) by enzyme-linked immunosorbent assay. Hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining were performed to observe the histopathological changes in lung tissues. Additionally, target-related proteins were measured by Western blotting. RRL alleviated the loss of body weight induced by instilling BLM in PF rats, particularly at the 500 mg/kg per day dose. RRL reduced HYP (p < 0.01) and increased GSH and T-SOD contents. BALF levels of TNF-α, TGF-β1, and IL-6 decreased significantly in the RRL-treated groups. Expression levels of matrix metalloproteinase-9 (MMP-9) and α-smooth muscle actin decreased significantly in a dose-dependent manner in response to RRL. Moreover, the levels of TGF-β1 and tissue inhibitor of metalloproteinase-1 in lung tissues also decreased in the RRL-treated groups. RRL alleviated BLM-induced PF in rats. Our results reveal that the protective effects of RRL against fibrotic lung injury in rats are correlated with its anti-inflammatory, antioxidative, and anti-fibrotic properties. MMP-9 may play important roles in BLM-induced PF.

Phenolic Compounds from the Roots of Rhodiola crenulata and Their Antioxidant and Inducing IFN-γ Production Activities

In the present study, two new phenolic compounds 1 and 11, a pair of lignan isomers 12 and 13 with their absolute configurations established for the first time, were isolated from the ethanol extract of the roots of Rhodiola crenulata, together with 13 known phenolic compounds, and their structures were elucidated via NMR, HRESIMS, UV, IR and CD analyses. All the isolated compounds were evaluated for their in vitro antioxidant activities using the 2,2-diphenyl-1-picryhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. Ten of them exhibited significant antioxidant activities compared to ascorbic acid. Furthermore, the inducibilities of the isolated compounds to IFN-γ production were also assessed. Compounds 1, 8, 9, 12, 13, 14 and 15 could moderately stimulate IFN-γ expression.

Biotechnological approaches to enhance salidroside, rosin and its derivatives production in selected Rhodiola spp. in vitro cultures

Rhodiola (Crassulaceae) an arctic-alpine plant, is extensively used in traditional folk medicine in Asian and European countries. A number of investigations have demonstrated that Rhodiola preparations exhibit adaptogenic, neuroprotective, anti-tumour, cardioprotective, and anti-depressant effects. The main compounds responsible for these activities are believed to be salidroside, rosin and its derivatives which became the target of biotechnological investigations. This review summarizes the results of the diverse biotechnological approaches undertaken to enhance the production of salidroside, rosin and its derivatives in callus, cell suspension and organ in vitro cultures of selected Rhodiola species.

Rhodiola: an ordinary plant or a promising future therapy for pulmonary hypertension? a brief review

Abstract Pulmonary hypertension (PH) is a chronic, complex, and progressive disease that eventuates in fatality. Research efforts over the past decades have resulted in therapeutic options that improve quality of life and prolong survival of patients, but they do not offer a cure. We propose a philosophical model that a disturbed balance of yin and yang results in pulmonary vascular remodeling, the hallmark of PH pathology. The model may be useful in exploring the wisdom of traditional Chinese medicine and incorporating it into mainstream PH research. In this context, the medicinal plant Rhodiola can be of profound interest owing to its variety of health-friendly attributes. Rhodiola has been shown to be beneficial in high-altitude-related symptoms and acute exacerbation of PH; moreover, improvement of PH has been demonstrated experimentally in chronically hypoxic rats. The beneficial effects of Rhodiola in PH may be attributable to its potential targeting of the signaling pathways, such as endothelin-1, nitric oxide, vascular endothelial growth factor, angiotensin-converting enzyme, nuclear factor κ-B, tumor necrosis factor α, and interleukin-6. Alterations in these mediators are implicated in PH pathogenesis, the characteristics of which include chronic pulmonary vasoconstriction, vasoproliferation, and vascular inflammation. Salidroside, one of the compounds extracted from Rhodiola, has been found to provide therapeutic benefits in experimental PH. As the data are limited and the field is in its infancy, further studies including in-depth analysis of the therapeutic effects on various animal models of PH are desirable. We believe that future PH research should place an adequate and special emphasis on exploring and promoting the potential of traditional Chinese medicine, and to this end, the medicinal plant Rhodiola offers a promising field on which to embark.

The chemotaxonomic classification of Rhodiola plants and its correlation with morphological characteristics and genetic taxonomy

Background

Rhodiola plants are used as a natural remedy in the western world and as a traditional herbal medicine in China, and are valued for their ability to enhance human resistance to stress or fatigue and to promote longevity. Due to the morphological similarities among different species, the identification of the genus remains somewhat controversial, which may affect their safety and effectiveness in clinical use.

Results

In this paper, 47 Rhodiola samples of seven species were collected from thirteen local provinces of China. They were identified by their morphological characteristics and genetic and phytochemical taxonomies. Eight bioactive chemotaxonomic markers from four chemical classes (phenylpropanoids, phenylethanol derivatives, flavonoids and phenolic acids) were determined to evaluate and distinguish the chemotaxonomy of Rhodiola samples using an HPLC-DAD/UV method. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were applied to compare the two classification methods between genetic and phytochemical taxonomy.

Conclusions

The established chemotaxonomic classification could be effectively used for Rhodiola species identification.

The chemotaxonomic classification of Rhodiola plants and its correlation with morphological characteristics and genetic taxonomy

BACKGROUND

Rhodiola plants are used as a natural remedy in the western world and as a traditional herbal medicine in China, and are valued for their ability to enhance human resistance to stress or fatigue and to promote longevity. Due to the morphological similarities among different species, the identification of the genus remains somewhat controversial, which may affect their safety and effectiveness in clinical use.

RESULTS

In this paper, 47 Rhodiola samples of seven species were collected from thirteen local provinces of China. They were identified by their morphological characteristics and genetic and phytochemical taxonomies. Eight bioactive chemotaxonomic markers from four chemical classes (phenylpropanoids, phenylethanol derivatives, flavonoids and phenolic acids) were determined to evaluate and distinguish the chemotaxonomy of Rhodiola samples using an HPLC-DAD/UV method. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were applied to compare the two classification methods between genetic and phytochemical taxonomy.

CONCLUSIONS

The established chemotaxonomic classification could be effectively used for Rhodiola species identification.

Neuroprotective effect of Rhodiola rosea Linn against MPTP induced cognitive impairment and oxidative stress

BACKGROUND

Ageing and age-related neurodegenerative changes including Parkinson's disease are characterized by an important role of reactive oxygen species. It is characterized by signs of major oxidative stress and mitochondrial damage in the pars compacta of substantia nigra.

PURPOSE

Present study was designed to investigate whether Rhodiola rosea extract would prevent MPTP induced neurotoxicity in Male wistar rats.

METHODS

Male Wistar rats were divided into following five groups: Group I received vehicle (saline (10 ml/kg for 21 days) orally); Group II received Rhodiola rosea extract (250 mg/kg for 21 days) orally; Group III was treated with 20 mg/kg MPTP i.p. for 21 days; Group IV received 20 mg/kg MPTP, i.p. along with 100 mg/kg Rhodiola rosea orally for 21 days. Group V received 20 mg/kg MPTP i.p. along with 250 mg/kg Rhodiola rosea orally for 21 days.

RESULTS

MPTP induced rats showed behavioral alterations in elevated plus maze testing. Group III rats elicited significant increase in lipid hydroperoxide along with reduction in level of glutathione peroxidase, catalase, superoxide dismutase and total antioxidants. Histological evidence revealed that MPTP treated rats shown pathological changes like cellular inflammation and vascular degeneration in brain tissue.

CONCLUSION

The oxidative stress and related biochemical alteration by MPTP were attenuated by Rhodiola rosea treatment. However, further studies may be necessary to elucidate the precise mechanism to support the clinical use of a plant source as antiparkinsonism drug.

The antioxidant and anti-inflammatory effects of phenolic compounds isolated from the root of Rhodiola sachalinensis A. BOR

Isolation of compounds from the root of Rhodiola sachalinensis (RRS) yielded tyrosol (1), salidroside (2), multiflorin B (3), kaempferol-3,4'-di-O-β-D-glucopyranoside (4), afzelin (5), kaempferol (6), rhodionin (7), and rhodiosin (8). Quantification of these compounds was performed by high-performance liquid chromatography (HPLC). To investigate the antioxidant and anti-inflammatory effects of the compounds, DPPH radical scavenging, NBT superoxide scavenging and nitric oxide production inhibitory activities were examined in LPS-stimulated Raw 264.7 cells. We suggest that the major active components of RRS are herbacetin glycosides, exhibiting antioxidant activity, and kaempferol, exhibiting anti-inflammatory activity.

Redox status is critical for stemness in skin equivalents

The skin is constantly exposed to environmental oxidative stress. Skin equivalent (SE) models are three-dimensional systems in which cell-cell or cell-matrix interactions can be investigated. In this study, the effects of vitamin C or plant extracts with high antioxidant activities were tested. There was no significant difference in the epidermal thickness, but the basal cells became cuboidal when vitamin C or plant extracts were supplemented. Furthermore, immunohistochemical staining showed linear and intense staining of α6 and β1 integrin along the basement membrane in vitamin C or plant extract treated models. The p63 and PCNA were also stained. Results showed that the number of p63 and PCNA positive cells was higher in the vitamin C or plant extract treated models than in the control SEs. Although the relationship between oxidative stress and stem cells is not known, our results suggest that redox status affects the stemness and the proliferative potential of epidermal basal cells by modulating microenvironment to epidermal basal stem cells.

Two new compounds from the roots of Rhodiola crenulata

Two new compounds, named (3R,5R,8R)-3-O-[α-l-arabinopyranosyl (1 → 6)-β-d-glucopyranosyl]-5-hydroxymegastigma-6,7-dien-9-one (1) and (1R)-1-O-(β-d-glucopyranosyl)-phenylethylene glycol (2), were isolated from the extract of Rhodiola crenulata. Their structures were determined on the basis of various spectroscopic methods, including IR, HR-ESI-MS, 1D and 2D NMR, and chemical evidences. The cytotoxicity of these two compounds was evaluated by using MTT method.

Isolation, identification and antioxidative capacity of water-soluble phenylpropanoid compounds from Rhodiola crenulata

Six water-soluble phenylpropanoid compounds obtained from Rhodiola crenulata (R. crenulata) were fractionated by high-speed counter-current chromatography (HSCCC), and purified by semi-preparative high-performance liquid chromatography (Semi-prep HPLC). The purities of the six compounds were all above 98.0% and their structures were identified by spectroscopic methods. Among them, a new compound, 2-(4-hydroxyphenyl)-ethyl-O-β-D-glucopyranosyl-6-O-β-D-glucopyranoside (1), together with two known phenylpropanoids, p-hydroxyphenacyl-β-D-glucopyranoside (3) and picein (4) were isolated from R. crenulata for the first time. Meanwhile, the contents of six isolated ingredients from the crude extract of R. crenulata had been simultaneously detected, with satisfactory results. Furthermore, the antioxidant activities of the six compounds were accessed by measuring the radical scavenging activity against 2,2-diphenyl-1-picrylhydrazy (DPPH), and four compounds exhibited potent antioxidative activity.

Chronic Rhodiola rosea Extract Supplementation Enforces Exhaustive Swimming Tolerance

We explored the effects and mechanisms of Rhodiola rosea extract supplementation on swimming-induced fatigue in rats. The concentrations of active components in Rhodiola rosea have been determined by high performance liquid chromatography-mass spectrometer. The Rhodiola rosea extract supplementation in water for 2–4 weeks was evaluated in male Wistar rats with 90-min unloaded swimming exercise and 5% body weight loaded swimming up to fatigue. We measured the fatigue biomarkers, including blood urea nitrogen (BUN), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT), lactate dehydrogenase (LDH), hepatic glycogen content, the activity of fat metabolism enzymes, sterol regulatory element-binding protein-1 (SREBP-1) and fatty acid synthase (FAS), the tissue oxygen content and ratio of red and white skeletal muscle fibers in rats. Rhodiola rosea significantly increased liver glycogen, SREBP-1, FAS, heat shock protein 70 expression, Bcl-2/Bax ratio and oxygen content before swimming. Rhodiola rosea supplementation significantly increased the swimming time in a dose-dependent manner and reduced swimming-enhanced serum BUN, GOT and GPT levels. The ratio of red and white muscle fibers was not altered after chronic Rhodiola rosea extract supplementation. Chronic Rhodiola rosea supplementation significantly improved exhaustive swimming-induced fatigue by the increased glycogen content, energy supply of lipogenic enzyme expressions and protective defense mechanisms.

Lignans from the root of Rhodiola crenulata

Rhodiola crenulata L. is an important species in genus Rhodiola widely used as a health food to reinforce immunity, improve memory and learning, scavenge active-oxygen species, and relieve altitude sickness. Eleven new lignans and a new benzonitrile compound, crenulatanoside A, were isolated from the roots of R. crenulata L. along with 25 known compounds, including 12 lignans. The structures of these compounds were elucidated by spectroscopic data and chemical evidence. Among them, compounds 1-4 and 5-7 were determined to be optical isomers of two 8-O-4' neolignan glycosides. Compounds 8-11 were aryl tetralin type lignans, and compounds 12 and 13 were dihydrobenzofuran neolignans. All of the isolated compounds were evaluated for their inhibitory activity against α-glucosidase. From the data obtained, compound 37 showed strong inhibitory activity against α-glucosidase with an IC(50) value of 96.8 μM.

Rapid Resolution Liquid Chromatography (RRLC) Analysis for Quality Control of Rhodiola Rosea Roots and Commercial Standardized Products

A simple, sensitive and reliable reversed phase Rapid Resolution Liquid Chromatography (RRLC) method was developed and validated for six biologically active compounds (salidroside, tyrosol, rosarin, rosavin, rosin and rosiridin) in Rhodiola rosea L. roots and powder extracts. The method uses a Phenomenex C18 (2)-HST column at 40°C with a neutral gradient system mobile phase (H2O and acetonitrile), a flow rate of 1.0 mL/min, and UV detection wavelengths set at 205 and 254 nm, simultaneously. Baseline separation of the six active compounds was achieved within 8 minutes. The average percentages of rosavins (rosarin, rosavin, and rosin) in authentic R. rosea roots and root powder extracts were quantitatively determined and a characteristic R. rosea roots RRLC profile was established. The RRLC method is accurate and sensitive; in addition, it effectively increases the sample analysis throughput compared with conventional HPLC.

Neuraminidase inhibitory activities of flavonols isolated from Rhodiola rosea roots and their in vitro anti-influenza viral activities

Five flavonols (3, 5, and 9-11) were isolated from Rhodiola rosea, and compared with commercially available flavonoids (1, 2, 4, 6-8, and 12-14) to facilitate analysis of their structure-activity relationship (SAR). All compounds (1-14) showed neuraminidase inhibitory activities with IC(50) values ranging from 0.8 to 56.9 microM. The in vitro anti-influenza virus activities of flavonoids 1-6, 8-12, and 14 were evaluated using two influenza viral strains, H1N1 (A/PR/8/34) and H9N2 (A/Chicken/Korea/MS96/96), testing their ability to reduce virus-induced cytopathic effect (CPE) in MDCK cells. We found that the activity of these compounds ranged from 30.2 to 99.1 microM against H1N1- and 18.5 to 133.6 microM against H9N2-induced CPE. Of compounds 1-14, gossypetin (6) exhibited the most potent inhibitory activity, with IC(50) values of 0.8 and 2.6 microM on neuraminidases from Clostridium perfringens and recombinant influenza virus A (rvH1N1), respectively. In contrast, kaempferol (3) exhibited the highest activity against two influenza viruses, H1N1 and H9N2 with EC(50) values of 30.2 and 18.5 microM, respectively. Activity depended on the position and number of hydroxy groups on the flavonoids backbone. In kinetic studies, all isolated compounds behaved as noncompetitive inhibitors.

Genotoxicity testing of the methanol extract of the plant Cotinus coggygria and gallic acid on Drosophila melanogaster

The genotoxic activity of methanol extract obtained from the stem of Cotinus coggygria Scop. and synthetic gallic acid were investigated using the Drosophila sex-linked recessive lethal test (or SLRL test). In the tested methanol extract of C. coggygria (1 g), 62.50 mg of pyrocatechol equivalent of phenols was detected. Also, 46.76 mg of flavonoids and 15.75 mg of nonflavonoids were observed in 1 g of dry weight of extract. Methanol extract of C. coggygria in a concentration of 5% and 5% synthetic gallic acid were shown to be clearly genotoxic, inducing sex-linked recessive lethal mutations on the X-chromosome of Drosophila melanogaster males in all three broods.

HPLC analysis, semi-preparative HPLC preparation and identification of three impurities in salidroside bulk drug

Salidroside is a bioactive compound mainly distributed in Rhodiola L. (Crassulaceae). It has been widely used in Chinese traditional medicine. In this paper, three impurities were found during the analysis of salidroside bulk drug. The enrichment of impurities was carried out by ODS column chromatography, using methanol-water (13:87, v/v) as eluent and the purification of impurities was achieved by semi-preparative HPLC, using methanol-water (11:89, v/v) as mobile phase, respectively. Three impurities were characterized as 4-(2-hydroxylethyl)-phenol-1-O-beta-D-glucopyranoside, 4-hydroxyphenacyl-D-glucopyranoside and p-acetylphenyl-O-beta-D-glucopyranoside by a variety of spectral data (IR, UV, MS, 1H NMR, 13C NMR, DEPT and 2D NMR). The simultaneous quantitative determination of salidroside and its impurities (Imp. 1, 2 and 3) was performed by reverse-phase HPLC method with UV detection. Specificity, linearity, sensitivity, precision and accuracy were evaluated.