Central administration of afzelin extracted from Ribes fasciculatum improves cognitive and memory function in a mouse model of dementia.

Neurodegenerative disorders are characterized by the decline of cognitive function and the progressive loss of memory. The dysfunctions of the cognitive and memory system are closely related to the decreases in brain-derived neurotrophic factor (BDNF) and cAMP response element-binding protein (CREB) signalings. Ribes fasciculatum, a medicinal plant grown in diverse countries, has been reported to pharmacological effects for autoimmune diseases and aging recently. Here we found that afzelin is a major compound in Ribes fasciculatum. To further examine its neuroprotective effect, the afzelin (100 ng/µl, three times a week) was administered into the third ventricle of the hypothalamus of C57BL/6 mice for one month and scopolamine was injected (i.p.) to these mice to impair cognition and memory before each behavior experiment. The electrophysiology to measure long-term potentiation and behavior tests for cognitive and memory functions were performed followed by investigating related molecular signaling pathways. Chronic administration of afzelin into the brain ameliorated synaptic plasticity and cognitive/memory behaviors in mice given scopolamine. Studies of mice's hippocampi revealed that the response of afzelin was accountable for the restoration of the cholinergic systems and molecular signal transduction via CREB-BDNF pathways. In conclusion, the central administration of afzelin leads to improved neurocognitive and neuroprotective effects on synaptic plasticity and behaviors partly through the increase in CREB-BDNF signaling.

Determination of Afzelin and Astragalin from Lespedeza cuneata on Aldose Reductase Inhibition.

The bioactive chemicals in L. cuneata were investigated by repeated column chromatography and their effect on aldose reductase (AR), obtained from rat lenses, was examined. Results showed that the ethyl acetate and n-butanol fractions of L. cuneata exhibited potential inhibitory effect against AR with IC50 values of 0.57 and 0.49 µg/mL, respectively. Phytochemical analysis of these two fractions resulted in the isolation of five flavonoids namely, acacetin (1), afzelin (2), astragalin (3), kaempferol (4) and scutellarein 7-O-glucoside (5). The AR inhibitory effect of compounds 1-5 was explored; compounds 2, 3 and 5 showed potential AR-inhibitory effects with IC50 values of 2.20, 1.91 and 12.87 µM, respectively. Quantitative analysis of afzelin (2) and astragalin (3) in L. cuneata by high performance liquid chromatography with ultraviolet detection revealed its content to be 0.722-11.828 and 2.054-7.006 mg/g, respectively. Overall, this study showed that L. cuneata is rich in flavonoids with promising AR-inhibitory activities, which can be utilized for the development of natural therapies for treating and managing diabetic complications.

Discovery of Lipid Peroxidation Inhibitors from Bacopa Species Prioritized through Multivariate Data Analysis and Multi-Informative Molecular Networking.

A major goal in the discovery of bioactive natural products is to rapidly identify active compound(s) and dereplicate known molecules from complex biological extracts. The conventional bioassay-guided fractionation process can be time consuming and often requires multi-step procedures. Herein, we apply a metabolomic strategy merging multivariate data analysis and multi-informative molecular maps to rapidly prioritize bioactive molecules directly from crude plant extracts. The strategy was applied to 59 extracts of three Bacopa species (B. monnieri, B. caroliniana and B. floribunda), which were profiled by UHPLC-HRMS2 and screened for anti-lipid peroxidation activity. Using this approach, six lipid peroxidation inhibitors 1‒6 of three Bacopa spp. were discovered, three of them being new compounds: monnieraside IV (4), monnieraside V (5) and monnieraside VI (6). The results demonstrate that this combined approach could efficiently guide the discovery of new bioactive natural products. Furthermore, the approach allowed to evidence that main semi-quantitative changes in composition linked to the anti-lipid peroxidation activity were also correlated to seasonal effects notably for B. monnieri.

Geographic Variation in the Chemical Composition and Antioxidant Properties of Phenolic Compounds from Cyclocarya paliurus (Batal) Iljinskaja Leaves.

Cyclocarya paliurus has been widely used as an ingredient in functional foods in China. However, the antioxidant properties of phenolic compounds and the effect of the plant origin remain unclear. The present study evaluated the geographical variation of this plant in term of its phenolic composition and antioxidant activities based on leaf materials collected from five regions. high-performance liquid chromatography (HPLC) analysis showed that there are three major components, quercetin-3-O-glucuronide, kaempferol-3-O-glucuronide, and kaempferol-3-O-rhamnoside, and their contents varied significantly among sampling locations. The investigated phenolic compounds showed substantial antioxidant activities, both in vitro and in vivo, with the highest capacity observed from Wufeng and Jinzhongshan. Correlation analysis revealed that quercetin and kaempferol glycosides might be responsible for the antioxidant activities. Our results indicate the importance of geographic origin, with sunny hours and temperature as the main drivers affecting the accumulation of C. paliurus phenolics and their antioxidant properties.

Simultaneous Enrichment and Separation of Four Flavonoids from Zanthoxylum bungeanum Leaves by Ultrasound-Assisted Extraction and Macroporous Resins with Evaluation of Antioxidant Activities.

Quercitrin, hyperoside, rutin, and afzelin are the dominant flavonoids compounds from Zanthoxylum bungeanum leaves, and they play major roles in the antioxidant activity. Macroporous adsorption resin (MAR) treatment, a simple, low-cost and efficient method, was combined with ultrasound-assisted extraction (UAE) to enrich and purify these four flavonoids from Z. bungeanum leaves efficiently. The optimal conditions for UAE based on Response Surface Methodology (RSM) were determined to be an ethanol concentration of 60%, leaves size of 40 mesh, temperature of 50 °C and ultrasonic power of 400 W with four flavonoids contents of 120.84 mg/g. After the extraction process, five kinds of MARs (D4020, D-101, NKA-9, AB-8, and X-5) were tested through static adsorption/desorption to enrich and purify the ultrasonic-assisted extracts, and D-101 was selected as the most suitable resin. The optimal adsorption conditions were 5 bed volumes (BV) of sample solution with an initial concentration of 7.5 mg/mL and pH 5.0. Meanwhile, the optimal desorption parameters were 5 BV each of deionized water and 30% ethanol, then 10 BV 70% ethanol, and a flow rate of 2 BV/hr. Under the optimized conditions, the contents of quercitrin, hyperoside, rutin, and afzelin increased by 276.39%, 187.46%, 221.81%, and 288.45%, respectively, and the recovery yields were 85.47%, 73.53%, 81.35%, and 65.06%. In addition, laboratory preparative-scale separation indicated that the preparative separation of four flavonoids was feasible and easy. Moreover, the antioxidant activities of the purified products were significantly increased after enrichment. In conclusion, all of the results indicated that these methods are highly efficient, low cost, environmentally friendly and easy to scale up. PRACTICAL APPLICATION: This study provided an environmentally friendly, rapid, and highly productive method for the extraction and purification of four active compounds from Zanthoxylum bungeanum leaves. The results can be used for the utilization of Z. bungeanum leaves as a kind of food supplement in an industrial setting.

Wound Healing Potential of Chlorogenic Acid and Myricetin-3-O-ß-Rhamnoside Isolated from Parrotia persica.

Wound healing is a complex physiological process that is controlled by a well-orchestrated cascade of interdependent biochemical and cellular events, which has spurred the development of therapeutics that simultaneously target these active cellular constituents. We assessed the potential of Parrotia persica (Hamamelidaceae) in wound repair by analyzing the regenerative effects of its two main phenolic compounds, myricetin-3-O-ß-rhamnoside and chlorogenic acid. To accomplish this, we performed phytochemical profiling and characterized the chemical structure of pure compounds isolated from P. persica, followed by an analysis of the biological effects of myricetin-3-O-ß-rhamnoside and chlorogenic acid on three cell types, including keratinocytes, fibroblasts, and endothelial cells. Myricetin-3-O-ß-rhamnoside and chlorogenic acid exhibited complementary pro-healing properties. The percentage of keratinocyte wound closure as measured by a scratch assay was four fold faster in the presence of 10 µg/mL chlorogenic acid, as compared to the negative control. On the other hand, myricetin-3-O-ß-rhamnoside at 10 µg/mL was more effective in promoting fibroblast migration, demonstrating a two-fold higher rate of closure compared to the negative control group. Both compounds enhanced the capillary-like tube formation of endothelial cells in an in vitro angiogenesis assay. Our results altogether delineate the potential to synergistically accelerate the fibroblastic and remodelling phases of wound repair by administering appropriate amounts of myricetin-3-O-ß-rhamnoside and chlorogenic acid.

New naphthalene derivative from the leaves of Cassia grandis L.

Cassia grandis is used for the treatment of skin disorders, back pain, aches, etc. in Vietnamese traditional medicine. In this paper, phytochemicals of the leaves were investigated. A new naphthalene derivative (1, cassgranon D) and, seven known compounds rutin (2), afzelin (3), quercitrin (4), epicatechin (5), (-)-epiafzelechin (6), isoquercitrin (7) and aloe emodin (8) were isolated from the ethyl acetate and methanol extracts. Their structures were elucidated by spectral evidences (UV, IR, MS, 1H, 13C, DEPT, HSQC and HMBC NMR), as well as by comparing with published data.

Chemical constituents from Cordia alliodora and C. colloccoca (Boraginaceae) and their biological activities.

Two new natural products, 5-O-[ß-D-apiofuranosyl-(1→6)-ß-d-glucopyranosyl]-1-isoindolinone (1) as well as N-(2E)-3-[(2S,3R)-2-(4-hydroxy-3-methoxyphenyl)-3-(hydroxymethyl)-7-methoxy-2,3-dihydro-1-benzofuran-5-yl]acryloylglycine (2), along with four known compounds (3-6), were isolated from the methanolic extract of Cordia alliodora root bark. Furthermore, the methanolic extract of Cordia colloccoca leaves, afforded the known flavonoids afzelin (7) and quercitrin (8). The isolated secondary metabolites were assayed for their antimicrobial activities against a panel of 6g positive and negative bacteria and three human pathogenic fungi. Moreover, their antiproliferative effect was also evaluated in vitro against the human non-small-cell bronchopulmonary carcinoma line NSCLC-N6, the epidermoid lung cancer cell line A549 as well as the normal human skin fibroblast cell line (AG01523).

Extraction and Purification of Quercitrin, Hyperoside, Rutin, and Afzelin from Zanthoxylum Bungeanum Maxim Leaves Using an Aqueous Two-Phase System.

In this study, an aqueous two-phase system (ATPS) based on ethanol/NaH2 PO4 was developed for the extraction and purification of quercitrin, hyperoside, rutin, and afzelin from Zanthoxylum bungeanum Maxim leaves. These 4 flavonoids were 1st extracted from dried Z. bungeanum leaves using a 60% ethanol solution and subsequently added to the ATPS for further purification. The partition behavior of the 4 flavonoids in ATPS was investigated. The optimal ATPS conditions were: 29% (w/w) NaH2 PO4 , 25% (w/w) ethanol concentration, 1% (w/w) added amount of leaf extracts, no pH adjustment, and repeated 1 h extractions at 25 °C. Under the optimal conditions for the 10 g ATPS, the absolute recovery of quercitrin, hyperoside, rutin, and afzelin reached 90.3%, 83.5%, 92.3%, and 89.1%, respectively. Compared to the 60% ethanol extracts, the content of quercitrin (44.8 mg/g), hyperoside (65.6 mg/g), rutin (56.4 mg/g), and afzelin (6.84 mg/g) in the extracts increased by 49.9%, 38.8%, 45.6%, and 36.8% respectively. The extracts after ATPS also exhibited stronger antioxidant activities, the 2,2-diphenyl-1-picrylhydrazyl IC50 value (10.5 µg/mL) decreased by 41.8%, and the 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt value (966 µmol Trolox/g) and ferric reducing power value (619 µmol Trolox/g) increased by 29.8% and 53.7%, respectively. Furthermore, scale-up experiments indicated that a larger scale experiment was feasible for the purification of the 4 flavonoids.

Pharmacological reports about gastroprotective effects of methanolic extract from leaves of Solidago chilensis (Brazilian arnica) and its components quercitrin and afzelin in rodents.

Solidago chilensis Meyenmost (Asteraceae), popularly known as "Brazilian arnica" or "arnica-do-campo," is widely used in the folk medicine to treat gastric disorders. Based on this, the gastroprotective activity of S. chilensis methanolic extract was investigated. Besides, a phytochemical study allowed isolation of two flavonoids (quercitrin and afzelin). The gastroprotective effects were investigated in acute gastric ulcer models, and the antisecretory activity was assessed in vivo and in vitro. The adhered mucus levels, reduced glutathione (GSH) content and myeloperoxidase (MPO) activity were quantified in ulcerated tissues. The contribution of isolated compounds in extract effects was evaluated, and its doses were calculated according to its yield. To evaluate the in vivo healing properties of S. chilensis methanolic extract, a chronic gastric ulcer was induced in mice by 10 % acetic acid. Evaluation of tumor necrosis factor (TNF) levels was also performed at the site of the acetic acid-induced gastric ulcer. In parallel, effects on cell viability and cell proliferation of fibroblasts (L929 cells) were determined by in vitro trials. Firstly, the S. chilensis methanolic extract (100 or 300 mg/kg) reduced the ulcer area induced by ethanol/HCl in mice when compared to the vehicle group. Moreover, the S. chilensis extract (300 mg/kg) prevented the mucus depletion, the increase in MPO activity and the decrease in the GSH levels in the ulcerated gastric tissue. The S. chilensis extract also was able to decrease the indomethacin-induced gastric ulcer in rats at a dose of 100 mg/kg. The antisecretory effect of the extract (100 mg/kg, intraduodenal (i.d.)) was confirmed by the reduction in the volume and acidity in parallel to an increase in the pH of gastric content. In addition, quercitrin (1.38 mg/kg, but not 0.46 mg/kg) and afzelin (0.026 and 0.078 mg/kg) decreased the ethanol/HCl-induced gastric ulcer. In this model, quercitrin (1.38 mg/kg) prevented the depletion of gastric GSH content and both quercitrin (1.38 mg/kg) and afzelin (0.078 mg/kg) reduced the MPO activity. These compounds also inhibited the H(+),K(+)-ATPase activity at a concentration of 1-100 µg/ml. In addition, the participation of quercitrin and afzelin in these effects also was confirmed. Furthermore, after 4 days of the treatment, an oral administration of S. chilensis methanolic extract (100 mg/kg) reduced the area of the gastric ulcer induced by acetic acid and the regeneration of the gastric mucosa was accompanied by a reduction in gastric TNF levels. The healing properties of the extract also were confirmed by enhancement of proliferation and coverage of scratched wounds in a fibroblast monolayer. Together, our results confirmed the gastroprotective effect of S. chilensis methanolic extract as well as its gastric healing potential and provided some support to the traditional use of S. chilensis for prevention and treatment of gastric lesions in complementation to its known anti-inflammatory properties.

Antiedematogenic Evaluation of Copaifera langsdorffii Leaves Hydroethanolic Extract and Its Major Compounds.

Inflammatory disorders affect many people worldwide, and medicinal plants are used to ameliorate these health problems. This paper reports the antiedematogenic and analgesic evaluation of Copaifera langsdorffii Desf. leaves hydroethanolic extract (Cop) and two of its isolated compounds: quercetin-3-O-α-l-rhamnopyranosyl (quercitrin) and kaempferol-3-O-α-l-rhamnopyranosyl (afzelin). For that, the following experimental protocols were undertaken locomotor performance, writhing induced by acetic acid, antinociceptivity induced by formalin, hot plate latency, paw oedema induced by carrageenan and dextran, and cell migration induced by lipopolysaccharide (LPS), as well as the measurement of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 10 (IL-10) in macrophages. Neither the extract nor the isolated compounds displayed analgesic activity. The obtained results showed that C. langsdorffii extract possesses antiedematogenic properties acting on peripheral sites, whereas quercitrin and afzelin are not involved. Moreover, these properties are not associated with cell migration inhibition, TNF-α, IL-6, or IL-10 regulation.

Flavonoids from the aerial parts of Houttuynia cordata attenuate lung inflammation in mice.

The aerial parts of Houttuynia cordata used for treating inflammation-related disorders contain flavonoids as major constituents. Since certain flavonoids possess anti-inflammatory activity, especially in the lung, the pharmacological activities of H. cordata and the flavonoid constituents were evaluated using in vitro and in vivo models of lung inflammation. The 70 % ethanol extract of the aerial parts of H. cordata inhibited the production of inflammatory biomarkers IL-6 and NO in lung epithelial cells (A549) and alveolar macrophages (MH-S), respectively. And the same plant material, administered orally (100 and 400 mg/kg), significantly inhibited lung inflammatory response in a mouse model of lipopolysaccharide (LPS)-induced acute lung injury. From the extract, major flavonoids including afzelin, hyperoside and quercitrin were successfully isolated and they also attenuated LPS-induced lung inflammation in mice by oral administration. In particular, quercitrin showed most potent activity at 100 mg/kg. These results demonstrate for the first time that H. cordata and three flavonoid constituents have a therapeutic potential for treating lung inflammatory disorders.

Antibacterial effects of afzelin isolated from Cornus macrophylla on Pseudomonas aeruginosa, a leading cause of illness in immunocompromised individuals.

The crude ethyl acetate extract of the leaves of Cornus macrophylla showed antibacterial activity against Pseudomonas aeruginosa, a leading cause of illness in immunocompromised individuals. Bioactivity-guided separation led to the isolation of kaempferol 3-O-α-L-rhamnopyranoside (afzelin). The structure was determined based on evaluation of its spectroscopic (UV, MS, and NMR) data. The minimum inhibitory concentration (MIC) of afzelin against Pseudomonas aeruginosa was found to be 31 µg/mL. In addition, the results indicated that a hydroxyl group at C3 of the C-ring of the flavone skeleton and the rhamnose group may act as a negative factor and an enhancing factor, respectively, in the antibacterial activities of afzelin.

Separation of the antioxidant compound quercitrin from Lindera obtusiloba Blume and its antimelanogenic effect on B16F10 melanoma cells.

Considering the growing evidence of the presence of antioxidant compounds in plant extracts, the objectives of this study were to identify antioxidant compounds in Lindera obtusiloba Blume (Lauraceae) and to evaluate their antimelanogenic activities on B16F10 melanoma cells. Organic solvent fractions were separated from L. obtusiloba extracts (LOE). The ethyl acetate fraction (LOE-E) was significantly active against oxidative damage induced by tert-butyl hydroperoxide in primary rat hepatocytes. Two single purified compounds, quercitrin (quercetin-3-O-α-L-rhamnopyranoside) and afzelin (kaempferol-3-O-α-L-rhamnoside), were identified by HPLC and NMR. These compounds were evaluated for antioxidant activities by 1,1-diphenyl 2-picrylhydrazyl (DPPH) radical scavenging assay and ferric reducing antioxidant power (FRAP) assay, and for their antimelanogenic activities by tyrosinase inhibitory assay melanin formation inhibition assay and Western bolt analysis for the signaling pathway. The significant effects of quercitrin on antioxidant and antimelanogenic activities, and signal modulation of ERK and MITF in B16F10 melanoma cells were observed. This is the first report to identify quercitrin in L. obtusiloba and its whitening effect.

Antioxidant activities of the leaves of Chrysophyllum albidum G.

Chrysophyllum albidum G. is a tropical plant and commonly found in Nigeria. It belongs to the sapotaceae family and used in folklore in the treatment of yellow fever, malaria, diarrhea, vaginal and dermatological infections. The study was aimed at investigating the antioxidant properties of this plant by employing the in vitro and in vivo experimental models. The effect of DPPH free radical scavenging activity on the fractions of petroleum ether, ethanol, butanol, ethylacetate, and water of C. albidum was determined. The ethyl acetate fraction was purified in column chromatography to obtain myricetin rhamnoside. Structure elucidation was done by NMR and mass spectroscopic techniques. Furthermore, ethanol extract was administered to five groups of eight rats per group. The animals in the normal group were administered with vehicle alone for 7 days. The positive control animals were given vehicle on the first four days, and with the vehicle and hepatotoxin (CCl(4)) on the fifth, sixth and seventh day. The animals in the treatment category were respectively administered with 500, 1000 and 1500 mg/kg b.w. of extract & distilled water for the first four days, and with distilled water, extract and CCl(4) on the last three days. Animals were subsequently anaesthetized and blood samples were collected for catalase (CAT), malondialdehyde (MDA), reduced gluthathione (GSH) and superoxide dismutase (SOD) assays. The petroleum ether fraction showed the least antiradical activity (4057.5 ± 809.6 g/kg) while ethyl ether exhibited the highest activity (414.4 ± 92.0 g/kg). Myricetin rhamnoside also exhibited an excellent radical scavenging activity (314.1 ± 60.2) which was comparable to the positive control. Result from animal study showed that C. albidum exhibited significant (p < 0.05) differences on the activity of CAT, MDA and GSH. The plant could therefore be employed as sources of natural antioxidant boosters and for the treatment of some oxidative stress disorders in which free radicals are implicated.

Lecythomycin, a new macrolactone glycoside from the endophytic fungus Lecythophora sp.

A new macrolactone glycoside, lecythomycin (1), 23-methyl-3-(1-O-mannosyl)-oxacyclotetracosan-1-one, was isolated from the endophytic fungus Lecythophora sp. (code 30.1), an endopyte of the Indonesian plant Alyxia reinwardtii. The structure of 1 was elucidated on the basis of NMR spectroscopic and mass spectrometric data. The isolated compound displayed antifungal activity against strains of Aspergillus fumigatus and Candida kruzei at minimal inhibitory concentrations (MIC) of 62.5-125 microg/mL.

Urease inhibitors from Indigofera gerardiana Wall.

Three new phloroglucinol type compounds Indigoferin-A (1), Indigoferin-B (2) and Indigoferin-C (3), along with a known compound ß-sitosterol were isolated from the Indegofera gerardiana Wall. The structures of Indigoferin-A (1), Indigoferin-B (2), and Indigoferin-C (3) were deduced on the basis of spectroscopic techniques (EI-MS, HREI-MS, (1)H NMR, (13)C NMR, HMQC, and HMBC). The urease inhibition studies on all the four compounds have also been carried out.

Changes in flavonoid content and tyrosinase inhibitory activity in kenaf leaf extract after far-infrared treatment.

The tyrosinase inhibitory activity of ethanolic extract of kenaf (Hibiscus cannabinus L.) leaf was evaluated before and after subjecting it to far-infrared (FIR) irradiation. The main component of the extract was analyzed as kaempferitrin (kaempferol-3,7-O-α-dirhamnoside). Prior to FIR irradiation, no inhibitory activity of the extract was detected in a tyrosinase assay. However, after FIR irradiation for 1h at 60°C, significant tyrosinase inhibitory activity (IC(50)=3500 ppm) was observed in it. In HPLC analysis, derhamnosylation products (kaempferol, afzelin, and α-rhamnoisorobin) were detected. The inhibitory activity may be due to the existence of derhamnosylation products. This study demonstrated that FIR irradiation can be used as a convenient tool for deglycosylation of flavonoid glycoside.

In vivo anti-inflammatory effect of a new steroidal saponin, mannioside A, and its derivatives isolated from Dracaena mannii.

A new steroidal saponin, mannioside A (1), was isolated from the stem bark of Dracaena mannii, together with the known pennogenin (2), pennogenin-3-O-beta-D-glucopyranoside (3) and pennogenin-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->3)]-beta-D-glucopyranoside (4). Their structures were determined using 1D-and 2D-NMR spectroscopy and mass spectrometry. Compounds 1 and 3 significantly inhibited carrageenan-induced paw edema in the rat; compound 4 was moderately active whereas 2 showed very weak activity.

[Two new flavonoids from the flower of Castanea mollissima Blume].

AIM: To study the bioactive constituents from the flower of Castanea mollissima Blume. METHODS: Compounds were isolated and purified by column chromatography on silica gel and polyamide. Structures were determined by various spectroscopic data,including UV, IR, 1H and 13CNMR, EIMS and FABMS, 1H-13C-COSY and HMBC. RESULTS: Two compounds were isolated from the ethyl acetate fraction of 95% ethanol extract and the structures were elucidated as kaempferol-3-O-[6"-(E)-p-coumaroyl]-alpha-D-mannopyranoside (1) and kaempferol-3-O-[6", 4"-di-(E)-p-coumaroyl]-alpha-D-mannopyranoside (2). CONCLUSION: Compounds 1 and 2 are new compounds, named castanoside A and B respectirely.