Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
1.
MMW Fortschr Med ; 165(18): 74, 2023 10.
Artículo en Alemán | MEDLINE | ID: mdl-37828341
2.
Cell Biol Int ; 46(10): 1612-1624, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35819083

RESUMEN

Biogenic synthesis of selenium nanoparticles (SeNPs) using plant extracts has emerged as a promising alternative approach to traditional chemical synthesis. The current study aims to introduce a safe, low-cost, and green synthesis of SeNPs using fresh fruit extract of Vaccinium arctostaphylos L. The biogenic synthesis of SeNPs was confirmed by different analyses including ultraviolet-visible spectrophotometry, Fourier transform infrared, and energy-dispersive X-ray. Also, the crystalline nature, size, and morphology of the obtained SeNPs were characterized by X-ray diffraction, dynamic light scattering, field emission scanning electron microscopy, and transmission electron microscopy techniques. The SeNPs were successfully synthesized with fruit extract of V. arctostaphylos L. in a regular spherical form and narrow size distribution with suitable zeta-potential values and exhibited appropriate biocompatibility. It revealed that the synthesized SeNPs can significantly inhibit the growth of 4T1 breast cancer cells with an IC50 of ∼84.19 ± 25.96 µg/ml after 72 h treatment. Overall, it can be concluded that the green synthesized SeNPs can be attractive, nontoxic, and eco-friendly candidates for drug delivery or medicinal applications.


Asunto(s)
Arctostaphylos , Neoplasias de la Mama , Nanopartículas del Metal , Nanopartículas , Selenio , Vaccinium , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Frutas , Humanos , Nanopartículas del Metal/química , Nanopartículas/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Selenio/química , Selenio/farmacología
3.
BMJ Open ; 12(6): e057982, 2022 06 24.
Artículo en Inglés | MEDLINE | ID: mdl-35750460

RESUMEN

BACKGROUND: Bearberry (Arctostaphylos uva-ursi) leaf is available as a treatment of uncomplicated cystitis in several European countries. The antimicrobial activity of its extracts and some of its individual constituents has been observed in vitro; however, the efficacy of bearberry compared with standard antimicrobial therapy has not been assessed yet. OBJECTIVE: The objective of the study is to assess the safety and non-inferiority of bearberry as an alternative therapy in the treatment of acute uncomplicated cystitis in comparison with standard antibiotic therapy (fosfomycin). METHODS AND ANALYSIS: This is a randomised controlled double-blinded multicentre trial. Eligible patients will be premenopausal women with a sum score of ≥6 for the typical acute uncomplicated cystitis symptoms (frequency, urgency, painful urination, incomplete emptying, suprapubic pain and visible haematuria) reported on the Acute Cystitis Symptom Score (ACSS) typical domain and pyuria. Patients will be randomly assigned to receive 3 g single dose of fosfomycin powder and two placebo tablets three times a day for 7 days or B a single dose of placebo powder and two tablets containing a dry extract of Uvae ursi folium. At least 504 patients (allocated as 1:1) will need to be enrolled to access non-inferiority with a non-inferiority limit of 14% for the primary endpoint.Improvement of symptoms of uncomplicated cystitis (based on the ACSS score) at day 7 is defined as the primary endpoint, whereas several secondary endpoints such as the number and ratio of patients with bacteriuria at day 7, frequency and severity of side effects; recurrence of urinary tract infection, concurrent use of other over the counter (OTC) medications and food supplements will be determined to elucidate more detailed differences between the groups. The number of recurrences and medications taken for treatment will be monitored for a follow-up period of 90 days (80-100 days). ETHICS AND DISSEMINATION: This study has been approved by the Scientific and Research Ethics Committee of the Hungarian Medical Research Council (IV/4225-1/2021/EKU). The results will be disseminated by publication of peer-reviewed manuscripts. TRIAL REGISTRATION NUMBER: NCT05055544.


Asunto(s)
Arctostaphylos , Cistitis , Fosfomicina , Enfermedad Aguda , Antibacterianos , Cistitis/inducido químicamente , Cistitis/tratamiento farmacológico , Método Doble Ciego , Femenino , Fosfomicina/uso terapéutico , Humanos , Estudios Multicéntricos como Asunto , Polvos/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Comprimidos/uso terapéutico , Resultado del Tratamiento
4.
Phytopathology ; 112(11): 2341-2350, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35731020

RESUMEN

Dieback and mortality in wildland plant species due to climate change have been on the rise in recent decades, and latent fungal pathogens might play a significant role in these events. During a severe multiyear drought, canopy dieback associated with latent pathogens in the Botryosphaeriaceae (Bot) family was observed in stands of a dominant shrub species, big berry manzanita (Arctostaphylos glauca), across chaparral landscapes in California. These fungi are significant pathogens of woody agricultural species, especially in hosts experiencing stress, and have become a threat to economically important crops worldwide. However, little is known regarding their occurrence, distribution, and impact in wildland systems. We conducted a field survey of 300 A. glauca shrubs across an elevational gradient to identify Bot species infection as it relates to (i) A. glauca dieback severity and (ii) landscape variables associated with plant drought stress. Our results show that Bots are widely infecting A. glauca across the landscape, and there is a significant correlation between elevation and dieback severity. Dieback severity was significantly higher at lower elevations, suggesting that infected shrubs at lower elevations are at greater risk than those at higher elevations. Furthermore, two Bot species, Neofusicoccum australe and Botryosphaeria dothidea, were most frequently isolated, with N. australe being the most common and, based on haplotype analysis, likely the most recently introduced of the two. Our results confirm the wide distribution of latent Bot fungi in a wild shrubland system and provide valuable insight into areas of greatest risk for future shrub dieback and mortality. These findings could be particularly useful for informing future wildlands management strategies with regard to introduced latent pathogens.


Asunto(s)
Arctostaphylos , Frutas/microbiología , Enfermedades de las Plantas/microbiología , Sequías , Madera
5.
J Hered ; 113(2): 188-196, 2022 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-35575079

RESUMEN

Arctostaphylos (Ericaceae) species, commonly known as manzanitas, are an invaluable fire-adapted chaparral clade in the California Floristic Province (CFP), a world biodiversity hotspot on the west coast of North America. This diverse woody genus includes many rare and/or endangered taxa, and the genus plays essential ecological roles in native ecosystems. Despite their importance in conservation management, and the many ecological and evolutionary studies that have focused on manzanitas, virtually no research has been conducted on the genomics of any manzanita species. Here, we report the first genome assembly of a manzanita species, the widespread Arctostaphylos glauca. Consistent with the genomics strategy of the California Conservation Genomics project, we used Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology to produce a de novo assembled genome. The assembly comprises a total of 271 scaffolds spanning 547Mb, close to the genome size estimated by flow cytometry. This assembly, with a scaffold N50 of 31Mb and BUSCO complete score of 98.2%, will be used as a reference genome for understanding the genetic diversity and the basis of adaptations of both common and rare and endangered manzanita species.


Asunto(s)
Arctostaphylos , Animales , Ecosistema , Especies en Peligro de Extinción , Frutas , Tamaño del Genoma , Genómica
6.
Molecules ; 27(7)2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-35408643

RESUMEN

The bearberry Arctostaphylos uva-ursi (L.) Spreng. has a long history of ethnopharmacological use. This species has been used in folk medicine for centuries as a rich source of raw material abundant in secondary metabolites and is important for medicinal and pharmacological purposes. The plant is a source of herbal material-Uvae ursi folium, which is highly valued and sought by pharmaceutical and cosmetic industries. The studied bearberry leaves can be classified as a suitable herbal material for use in pharmacy; therefore, the investigated populations can be a potentially valuable source of plant material for cultivation and can be used in in vitro cultures and in biotechnological processes. The objective of this study was to characterize the variability of the phytochemical composition and antioxidant activity of water and ethanol bearberry extracts from raw material collected from different natural populations. In each of the twelve A. uva-ursi sites, three leaf samples were collected and analyzed. The water extracts from bearberry leaves were characterized by similar concentration of arbutin (77.64-105.56 mg g-1) and a significantly higher concentration of hydroquinone (6.96-13.08 mg g-1) and corilagin (0.83-2.12 mg g-1) in comparison with the ethanol extracts -77.21-103.38 mg g-1, 10.55-16.72 mg g-1, 0.20-1.54 mg g-1, respectively. The concentration of other metabolites in the water extracts was significantly lower in comparison with the ethanol extracts. In the case of the water extracts, a significant effect of not only total phenolic compounds, but also hydroquinone on the antioxidant parameters, was observed, which indicates the solvent-related activity of these metabolites. Therefore, it is suggested that special attention should be paid to the concentration of not only arbutin, but also hydroquinone in Uvae ursi folium. The latter metabolite serving a very important function as an active bearberry ingredient should be controlled not only in alcoholic extracts but also in water extracts, since bearberry leaves are applied as infusions and decoctions. The results presented in this paper can contribute to appropriate selection of plant material for pharmaceutical, cosmetic, and food industries, with special emphasis on the antioxidant activity of different types of extracts.


Asunto(s)
Arctostaphylos , Antioxidantes/farmacología , Arbutina , Arctostaphylos/química , Etanol , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta , Solventes , Agua
7.
J Ethnopharmacol ; 289: 115092, 2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35143933

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Arctostaphylos uva-ursi (L.) Spreng. (bearberry) is a well-known traditional herbal plant used as a urinary tract disinfectant. Its antiseptic and diuretic properties can be attributed to hydroquinone, obtained by hydrolysis of arbutin. AIM OF THE STUDY: This study aimed to determine the toxic profile of free hydroquinone on urinary bladder cells (T24) as a target of therapeutic action. MATERIALS AND METHODS: Quantitative and qualitative analysis of the extract and the digestive stability and bioavailability of arbutin and hydroquinone were performed by HPLC assay and simulated in vitro digestion, respectively. Cytotoxic effect, reactive oxygen species induction and proteome changes in T24 cells after hydroquinone treatment were determined using Neutral red assay, 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay and mass spectrometry, respectively. RESULTS: Through in vitro digestion, arbutin was stable, but hydroquinone increased after pepsin treatment (109.6%) and then decreased after the small intestine phase (65.38%). The recommended doses of Uva-ursi had a cytotoxic effect on T24 cells only when all hydroquinone conjugates were converted to free hydroquinone (320 and 900 µg/mL) and the toxic effect was enhanced by recovery. One cup of the therapeutic dose had a prooxidative effect after 4 h of incubation. Shorter time of cell exposure (2 h) to hydroquinone did not have any impact on reactive oxygen species induction. Proteomic analysis found 17 significantly up-regulated proteins compared to control. Hydroquinone activated proteins related to oxidative stress response, stress-adaptive signalling, heat shock response and initiation of translation. CONCLUSIONS: Despite the therapeutic properties of bearberry, up-regulated T24 cell proteins are evidence that plant compounds, although from a natural source, may exhibit negative properties.


Asunto(s)
Arctostaphylos/química , Hidroquinonas/toxicidad , Extractos Vegetales/toxicidad , Vejiga Urinaria/efectos de los fármacos , Arbutina/química , Arbutina/aislamiento & purificación , Células CACO-2 , Línea Celular Tumoral , Cromatografía Líquida de Alta Presión , Humanos , Hidroquinonas/aislamiento & purificación , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/química , Proteoma , Proteómica , Vejiga Urinaria/citología
8.
Nat Prod Res ; 36(24): 6312-6317, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35019793

RESUMEN

Comparative phytochemical and pharmacological analysis of leaves and shoots of Arctostaphylos uva-ursi (L.) Spreng. and endemic of Transcaucasia and North Caucasia Arctostaphylos caucasica Lipsch. was carried out. Phenolic compounds in methanol extracts were investigated by HPLC-PDA-ESI-MS. Pharmacological investigation was carried out at the models of generation of superoxide, DPPH, hydroxyl and nitrosyl radicals. The antityrosinase properties were evaluated in the reaction of tyrosinase inhibition using L -tyrosine as a substrate. Five new compounds were identified in the shoots and leaves of A. uva-ursi: 4,6-di-О-galloylglucose; 2,3-di-О-galloylglucose; 1,4,6-tri-О-galloylglucose; 1,2,4,6-tetra-О-galloylglucose; tetra-О-galloylhexose. Thirty-five phenolic compounds and two saponins were identified for the first time in A. caucasica. Water-alcohol extract (70% ethanol) from A. caucasica had the highest antiradical activity. Water extracts from both species had antityrosinase activity and possessed comparable efficiency (IC50 = 36.4 ± 1.2 µg/ml and IC50 = 35,5 ± 2 µg/ml, respectively).


Asunto(s)
Arctostaphylos , Arctostaphylos/química , Antioxidantes/farmacología , Antioxidantes/análisis , Extractos Vegetales/química , Hojas de la Planta/química , Fenoles/farmacología , Fenoles/análisis , Agua/análisis
9.
Acta Chim Slov ; 68(4): 896-903, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34918773

RESUMEN

This study was performed to examine the effects of medicinal plant extracts of corn silk (Stigma maydis), parsley leaf (Petroselini folium), and bearberry leaf (Uvae ursi folium) on antioxidant status of the brain of experimental animals (mice) under the physiological conditions. Biological properties of these plants are insufficiently investigated and the aim was to explore their possible antioxidant effects that can alleviate oxidative damage of the brain tissue. Corn silk extract showed positive effect on activities of antioxidant enzymes in mice brain tissue. Parsley extract induced the increase in glutathione content and decrease of lipid peroxidation. Bearberry leaf extract induced catalase activity and decrease of hydroxyl radical content, while malonyldialdehide accumulation was maintained at the control level. Results obtained in this study support the use of corn silk, parsley and bearberry leaves as natural antioxidant sources in the prevention and treatment of brain tissue damages and different diseases caused by oxidative stress.


Asunto(s)
Arctostaphylos/química , Encéfalo/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Petroselinum/química , Extractos Vegetales/farmacología , Plantas Medicinales/química , Zea mays/química , Animales , Antioxidantes/química , Arctostaphylos/metabolismo , Encéfalo/metabolismo , Cromatografía Líquida de Alta Presión , Glutatión/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Masculino , Malondialdehído/metabolismo , Ratones , Petroselinum/metabolismo , Extractos Vegetales/química , Plantas Medicinales/metabolismo , Polifenoles/análisis , Espectrofotometría , Zea mays/metabolismo
10.
Molecules ; 26(24)2021 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-34946773

RESUMEN

The bearberry (Arctostaphylos uva-ursi L. Spreng.) is a source of herbal material-bearberry leaf (Uvae ursi folium), which is highly valued and sought by pharmaceutical and cosmetic industries. For many years, leaves of this plant have been used in traditional medicine as a diuretic, antimicrobial, and anti-inflammatory agent for various diseases of the urogenital tract. The bearberry has also been proposed as a natural antioxidant additive due to the high contents of phenolic compounds in its leaves. The study was focused on characterization of the basic phytochemical composition and antioxidant activity of extracts derived from bearberry leaves collected from plants located at the southern border of the geographical range of the species in Europe. The investigated herbal material is characterized by a different chemical profile compared to the chemical profiles of bearberry found in other parts of the continent. Bearberry extracts from plants growing in two different habitat types-heathlands and pine forests showed a wide range of variation, especially in the concentration of hyperoside, corilagin, and methylartutin and the total flavonoid contents. In addition to arbutin, bearberry can be a valuable source of phenolic compounds, which are mainly responsible for the antioxidant properties of extracts. The high content of phenols and high values of antioxidant parameters indicate a high potential of bearberry leaves to be used as a powerful natural source of antioxidants in herbal preparations. Therefore, the A. uva-ursi populations can be a source of plant material for pharmaceutical, cosmetic, and food industries.


Asunto(s)
Antioxidantes/química , Arctostaphylos/química , Hojas de la Planta/química , Arctostaphylos/crecimiento & desarrollo , Europa (Continente) , Hojas de la Planta/crecimiento & desarrollo
11.
J Agric Food Chem ; 69(37): 10856-10868, 2021 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-34493038

RESUMEN

The characterization and quantification of phenolic compounds in bearberry leaves were performed using hyphenated ion mobility spectroscopy (IMS) and a quadrupole time-of-flight mass spectrometer. A higher identification confidence level was obtained by comparing the measured collision cross section (TWCCSN2) with predicted values using a machine learning algorithm. A total of 88 compounds were identified, including 14 arbutin derivatives, 33 hydrolyzable tannins, 6 flavanols, 26 flavonols, 9 saccharide derivatives, and glycosidic compounds. Those most reliably reproduced in all samples were quantified against respective standards. Arbutin (47-107 mg/g), 1,2,3,4,6-pentagalloylglucose (6.6-12.9 mg/g), and quercetin 3-galactoside/quercetin 3-glucoside (2.7-5.7 mg/g) were the most abundant phenolic components in the leaves. Quinic acid and ellagic acid were also detected at relatively high concentrations. The antioxidant activity of the most abundant compounds was evaluated. A critical view of the advantages and limitations of traveling wave IMS and CCS for the discovery of natural products is given.


Asunto(s)
Arctostaphylos , Arbutina , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Espectrometría de Masas , Hojas de la Planta
12.
Clin Microbiol Infect ; 27(10): 1441-1447, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34111592

RESUMEN

OBJECTIVE: We explored whether initial treatment with the herbal drug uva ursi (UU) reduces antibiotic use in women with uncomplicated urinary tract infection (UTI) without increasing symptom burden and complication frequency compared with antibiotic treatment. METHODS: A double-blind randomized controlled trial was conducted in 42 family practices in Germany. The participants were adult women with suspected uncomplicated UTIs receiving either UU 105 mg 3 × 2 tablets for 5 days (intervention) or fosfomycin a 3-g single dose (control), and their respective placebos. Participants and investigators were blinded. The primary outcome included (1) antibiotic courses day 0-28 as superiority, and (2) symptom burden (sum of daily symptom scores) day 0-7, as non-inferiority outcome (margin 125%). Clinicaltrials.gov: NCT03151603. RESULTS: Overall, 398 patients were randomly allocated to groups receiving UU (n = 207) and fosfomycin (n = 191). The number of antibiotic courses was 63.6% lower (95% CI 53.6%-71.4%; p < 0.0001) in the UU group than in the fosfomycin group. The ratio of total symptom burden in the UU group compared with control was 136.5% (95% CI 122.7-151.9; p 0.95), failing non-inferiority. Eight women developed pyelonephritis in the UU group compared with two in the fosfomycin group (mean difference 2.8; 95% CI 0.2-5.9; p 0.067). Adverse events were similar between the groups. DISCUSSION: In women with uncomplicated UTIs, initial treatment with UU reduced antibiotic use but led to a higher symptom burden and more safety concerns than fosfomycin.


Asunto(s)
Arctostaphylos , Fosfomicina , Extractos Vegetales/uso terapéutico , Infecciones Urinarias , Adulto , Antibacterianos/uso terapéutico , Arctostaphylos/química , Femenino , Fosfomicina/efectos adversos , Fosfomicina/uso terapéutico , Alemania , Humanos , Extractos Vegetales/efectos adversos , Atención Primaria de Salud , Resultado del Tratamiento , Infecciones Urinarias/tratamiento farmacológico
13.
Am J Bot ; 107(12): 1798-1814, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33274449

RESUMEN

PREMISE: Hybridization plays a key role in introgressive adaptation, speciation, and adaptive radiation as a source of evolutionary innovation. Hybridization is considered common in Arctostaphylos, yet species boundaries are retained in stands containing multiple species. Arctostaphylos contains diploids and tetraploids, and recent phylogenies indicate two clades; we hypothesize combinations of these traits limit or promote hybridization rates. METHODS: We statistically analyzed co-occurrence patterns of species by clade membership and ploidy level from 87 random 0.1 ha plots. We sampled multiple sites to analyze for percent hybridization based on morphology. Finally, phenophases were analyzed by scoring herbarium sheets for a large number of taxa from both clades as well as tetraploids, and second, surveying three field sites over two years for divergence in phenological stages between co-occurring taxa. RESULTS: Most taxa in Arctostaphylos are allopatric relative to other congenerics. When two taxa co-occur, the patterns are a diploid with a tetraploid, or two diploids from different clades. When three taxa co-occur, the pattern is two diploids from different clades and a tetraploid. Field and herbarium data both indicate flowering phenology is displaced between diploids from the two clades; one of the diploid clades and tetraploids overlap considerably. CONCLUSIONS: The two deep clades in Arctostaphylos are genetically distant, with hybrids rare or non-existent when taxa co-occur. Reproductive isolation between clades is enhanced by displaced flowering phenology for co-occurring species. Within clades, taxa appear to have few reproductive barriers other than an allopatric distribution or different ploidy levels.


Asunto(s)
Arctostaphylos , Aislamiento Reproductivo , Diploidia , Hibridación Genética , Simpatría
14.
Plant Dis ; 104(12): 3173-3182, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33044918

RESUMEN

The Sudden Oak Death (SOD) Blitzes consist of yearly surveys led by citizen scientists designed to map the distribution of Phytophthora ramorum, cause of the forest disease called SOD, across northern California. During the 2017 Santa Cruz County SOD Blitz, six rare or endangered Arctostaphylos (manzanita) species were found to be possibly symptomatic for the first time. Symptoms included branch cankers and associated canopy mortality, and affected multiple individuals per species. Isolates of P. ramorum were obtained from each of the six species and, through a 30-day-long inoculation experiment on live plants, Koch's postulates were completed for each one of them, conclusively determining that they all are hosts of this pathogen. Two additional manzanita species were later found to be apparently symptomatic in Marin County. Inoculations on detached branches using an isolate of P. ramorum obtained from one of the six rare species from Santa Cruz County were successful, suggesting that these two species may also be hosts of P. ramorum. Detached leaves of all eight species were also successfully inoculated at the University of California-Berkeley in fall 2018 and then again in spring 2019. In these cases, the same isolate was used for all inoculations, in order to obtain information on the comparative susceptibility of the eight species in question. Both branch and leaf inoculations identified significant interspecific differences in susceptibility. The production of sporangia was low on all species but it was not zero, suggesting that sporulation may cause within-plant and limited across-plant contagion, especially in rainy years.


Asunto(s)
Arctostaphylos , Phytophthora , Animales , California , Ciencia Ciudadana , Especies en Peligro de Extinción , Enfermedades de las Plantas
15.
Mol Med Rep ; 22(4): 3525-3532, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32945423

RESUMEN

α­glucosidase is a key enzyme that plays a role in glucose absorption in the gastrointestinal tract, and the inhibition of its activity induces the prevention of postprandial hyperglycemia. Several α­glucosidase inhibitors have been used as medicines for type 2 diabetes, but a similar effect is observed in natural resources, including traditional herbs and their phytochemicals. To identify the presence of the α­glucosidase inhibitory activity in herbs, in which various functional effects have been known to occur, the present study investigated the effects of hot­water extracts of 26 types of herbs on α­glucosidase activity in an in vitro assay. The results indicated significant increases in the inhibition of α­glucosidase activity in 1,000 µg/ml olive (P<0.01), white willow (P<0.01) and red rooibos hot­water extracts. Furthermore, ≥50% inhibition of α­glucosidase activity was determined to be significant in 1,000 µg/ml coltsfoot, green tea and bearberry hot­water extracts. In addition, the effects of bearberry, green tea and coltsfoot hot­water extracts on α­glucosidase activity in vivo were evaluated according to the blood glucose levels (BGLs) in maltose and glucose load model rats. It was indicated that the administration of these three herb extracts significantly reduced the increasing BGLs after maltose loading until 0.5 h compared with the control group. However, only coltsfoot extract significantly reduced the increasing BGLs after glucose loading until 0.5 h compared with the control group. Thus, the present results may facilitate the understanding of a novel functionality in traditional herbs, which could be useful for the prevention of disease onset and progression, such as in hyperglycemia and type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inhibidores de Glicósido Hidrolasas/administración & dosificación , Plantas Medicinales/química , Agua/administración & dosificación , alfa-Glucosidasas/metabolismo , Animales , Arctostaphylos/química , Aspalathus/química , Diabetes Mellitus Tipo 2/inducido químicamente , Diabetes Mellitus Tipo 2/enzimología , Modelos Animales de Enfermedad , Glucosa/efectos adversos , Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/farmacología , Calor , Masculino , Maltosa/efectos adversos , Olea/química , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Extractos Vegetales/farmacología , Ratas , Salix/química , Té/química , Tussilago/química , Agua/química , Agua/farmacología
16.
Am J Bot ; 107(8): 1136-1147, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32864741

RESUMEN

PREMISE: Mortality events involving drought and pathogens in natural plant systems are on the rise due to global climate change. In Santa Barbara, California, United States, big berry manzanita (Arctostaphylos glauca) has experienced canopy dieback related to a multi-year drought and infection from fungal pathogens in the Botryosphaeriaceae family. A greenhouse experiment was conducted using Neofusicoccum australe to test the specific influences of drought and fungal infection on A. glauca. METHODS: A full factorial design was used to compare four treatment groups (drought + inoculation; drought - inoculation; watering + inoculation; and control: watering - inoculation). Data were collected for 10 weeks on stress symptoms, changes in leaf fluorescence and photosynthesis, and mortality. RESULTS: Results indicated significant effects of watering and inoculation treatments on net photosynthesis, dark-adapted fluorescence, and disease symptom severity (P < 0.05), and a strong correlation was found between physiological decline and visible stress (P < 0.0001). Mortality differed between treatments, with all groups except for the control experiencing mortality (43% mortality in drought - inoculation, 83% in watering - inoculation, and 100% in drought + inoculation). A Kaplan-Meier survival analysis showed drought + inoculation to have the least estimated survivorship compared to all other treatment groups. CONCLUSIONS: In addition to a possible synergistic interaction between drought and fungal infection in disease onset and mortality rates in A. glauca, these results indicate that young, non-drought-stressed plants are susceptible to mortality from N. australe infection, with important implications for the future of wildland shrub communities.


Asunto(s)
Arctostaphylos , Ascomicetos , Sequías , Fotosíntesis , Hojas de la Planta
17.
Phytochem Anal ; 31(6): 884-891, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32495959

RESUMEN

INTRODUCTION: Arbutin is a phenol glucoside found in high concentrations in bearberry leaves and associated with the antimicrobial activity of the plant. Hydroquinone can also be found in leaves or be formed by degradation of arbutin. Lengthy exposure to free hydroquinone is associated with induction of toxicity in different organs. OBJECTIVE: To develop and validate a stability-indicating method by high-performance liquid chromatography diode array detector (HPLC-DAD) for simultaneous quantification of arbutin and hydroquinone in bearberry leaves and perform a comprehensive forced degradation study comparing synthetic arbutin and the arbutin in bearberry leaves. METHODS: Separation was performed using a C18 column, mobile phase with water-methanol (95:5), flow rate 1.0 mL/min and detection at 280 nm. Bearberry leaves were assayed and a forced degradation study of arbutin was performed in different conditions. RESULTS: The method complied with all required validation parameters. Contents varied from 1.19 to 4.15% (w/w) of arbutin and from 0.022 to 0.604% (w/w) of hydroquinone. Synthetic arbutin was susceptible to acid hydrolysis and oxidative degradation, forming hydroquinone as the main degradation product. The same study using bearberry leaves showed that constituents of the plant matrix may act as antioxidants, reducing the oxidative degradation of arbutin, however acid hydrolysis of arbutin occurred in higher intensity. CONCLUSION: Analysis of bearberry leaves evidenced high variation in arbutin and hydroquinone levels, demonstrating the need for standardisation and control. The stability profiles of synthetic arbutin and the arbutin in bearberry leaves were considerably different and the results may be useful for determining the most appropriate conditions for extraction and production of bearberry-based formulations.


Asunto(s)
Arctostaphylos , Arbutina , Cromatografía Líquida de Alta Presión , Extractos Vegetales , Hojas de la Planta
18.
Talanta ; 213: 120831, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32200925

RESUMEN

The total phenolic content (TPC) and antioxidant capacity have been considered as important quality parameters for plant extracts. In this study, bearberry leaves were regarded as studied subject and a reliable method was established to predict the TPC and antioxidant capacity of bearberry leaves. Ultraviolet-visible spectrometry (UV-Vis) and ultra high pressure liquid chromatography coupled to time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) were used to provide spectral fingerprinting and metabolomic profiling. The data obtained (separately and merged) were used to build partial least squares (PLS) regression model. The PLS model built by using ultraviolet-visible spectra provided a satisfactory prediction result. Mid-level data fusion using the scores significantly improved the performance of PLS regression model, the residual predictive deviations (RPDs) for TPC and α, α-diphenyl-ß-picrylhydrazyl (DPPH) were 6.258 and 6.699, respectively, showing an excellent predictive ability. This study proved the potential of combination of UV-Vis spectrometry and UHPLC/Q-TOF-MS in the prediction of TPC and antioxidant capacity of plant extracts.


Asunto(s)
Antioxidantes/análisis , Arctostaphylos/química , Fenoles/análisis , Extractos Vegetales/química , Hojas de la Planta/química , Antioxidantes/farmacología , Cromatografía Líquida de Alta Presión , Análisis de los Mínimos Cuadrados , Espectrometría de Masas , Metabolómica , Fenoles/farmacología , Extractos Vegetales/farmacología
19.
Complement Ther Med ; 44: 296-300, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31126570

RESUMEN

OBJECTIVES: To evaluate the antihypertensive efficacy and safety of a standardized Vaccinium arctostaphylos (V. arctostaphylos) berry hydro-alcoholic extract in the overweight/obese hypertensive patients. DESIGN: Randomized placebo-controlled trial. SETTING: Baqiyatallah hospital (Tehran, Iran). INTERVENTIONS: The antihypertensive efficacy and safety of 3-month intake of 400 mg extract capsule three times daily alongside standardized anti-hypertensive regimen in the treatment of 50 patients was compared with the placebo (n = 50). MAIN OUTCOME MEASURES: SBP (systolic blood pressure), DBP (diastolic blood pressure), body mass index, waist circumference, CBC (complete blood count), blood levels of AST (aspartate aminotransferase), ALT (alanine aminotransferase), ALP (alkaline phosphatase), BUN (blood urea nitrogen) and creatinine. RESULTS: SBP decreased from 152.1 ± 7.7 to 140.5 ± 10.7 in the V. arctostaphylos group and from 152.9 ± 8.1 to 150.8 ± 9.3 in the placebo group (P < 0.001). DBP decreased from 90.3±8 to 82.1±8.8 in the V. arctostaphylos group and from 89.6 ± 7.8 to 87.6 ± 7.9 in the placebo group (P < 0.001). The extract capsule had no significant effect on the other parameters (P > 0.05). Moreover, no drug side effect and adverse interaction with other antihypertensive drugs was observed in the patients. CONCLUSIONS: V. arctostaphylosberry extract improves blood pressure control and has safety and tolerability in the overweight/obese hypertensive patients taking standard antihypertensive drugs.


Asunto(s)
Antihipertensivos/efectos adversos , Antihipertensivos/uso terapéutico , Arctostaphylos/química , Hipertensión/tratamiento farmacológico , Obesidad/tratamiento farmacológico , Sobrepeso/tratamiento farmacológico , Extractos Vegetales/uso terapéutico , Vaccinium/química , Adulto , Anciano , Anciano de 80 o más Años , Arctostaphylos/efectos adversos , Presión Sanguínea/efectos de los fármacos , Índice de Masa Corporal , Método Doble Ciego , Femenino , Frutas/química , Humanos , Irán , Masculino , Persona de Mediana Edad , Extractos Vegetales/efectos adversos , Vaccinium/efectos adversos , Circunferencia de la Cintura/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...