Morphological, cariological, and phytochemical studies of diploid and autotetraploid Hippeastrum papilio plants.

MAIN CONCLUSION: The polyploidization of Hippeastrum papilio influences its primary and secondary metabolism including the biosynthesis of bioactive alkaloids. Hippeastrum papilio is an ornamental plant that has advantages in comparison to the currently used plants for the extraction of galanthamine, a natural compound used for the cognitive treatment of Alzheimer's disease. In the present study, an autotetraploid line of H. papilio was induced for the first time, after treatment with 0.05% colchicine for 48 h. The chromosome number in diploids was found to be 2n = 2x = 22 and for autotetraploids 2n = 4x = 44. The flow cytometric analyses detected a DNA C-value of 14.88 ± 0.03 pg (1C) in diploids and 26.57 ± 0.12 pg in autotetraploids. The morphological, cytological, and phytochemical studies showed significant differences between diploids and autotetraploids. The length and width of stomata in autotetraploids were 22.47% and 17.94%, respectively, larger than those observed in the diploid leaves. The biomass of one-year-old autotetraploid H. papilio plants was reduced by 53.99% for plants' fresh weight, 56.53% for leaves' fresh weight, and 21.70% for bulb diameter. The GC-MS analysis of methanol extracts from one-year-old diploid and autotetraploid H. papilio plants revealed over 60 primary and secondary metabolites including alkaloids, phenolic acids, sterols, saccharides, and alcohols, among others. Principal component analysis of the metabolite profiles indicates a divergence of the metabolism between diploid and autotetraploid plants. The content of galanthamine and haemanthamine was found to be 49.73% and 80.10%, respectively, higher in the leaves of autotetraploids, compared to the diploid ones. The biosynthesis of the saccharides shows a tendency to be upregulated in tetraploid plants, while that of phenolic acids was downregulated. Polyploidization of H. papilio creates possibilities for further crop improvement aimed at high-galanthamine-producing genotypes.

COVID-19 and entrepreneurship entry and exit: Opportunity amidst adversity.

We theoretically and empirically examine how acquiring new skills and increased financial worries influenced entrepreneurship entry and exit intentions during the pandemic. To that end, we analyze primary individual-level survey data we collected in the aftermath of the COVID-19's first wave in Russia, which has had one of the highest COVID-19 infection rates globally. Our results show that acquiring new skills during the pandemic helped owners keep their existing businesses and encouraged start-ups in sectors other than information technology (IT). For IT start-ups, having previous experience matters more than new skills. While the pandemic-driven financial worries are associated with business closure intentions, they also inspire new business start-ups, highlighting the pandemic's creative destruction power. Furthermore, preferences for formal employment and remote work also matter for entrepreneurial intentions. Our findings enhance the understanding of entrepreneurship formation and closure in a time of adversity and suggest that implementing entrepreneurship training and upskilling policies during recurring waves of the COVID-19 pandemic can be an important policy tool for innovative small business development.

GC-MS analysis of Amaryllidaceae and Sceletium-type alkaloids in bioactive fractions from Narcissus cv. Hawera.

RATIONALE: Narcissus cv. Hawera has been found to biosynthesize some Sceletium-type alkaloids with antidepressant and anxiolytic activities. This ornamental plant has been poorly studied as a source of bioactive alkaloids including some contraversive reports on in vitro and intact plants. In this study, a detailed GC-MS characterization of its alkaloid fractions is presented. METHODS: GC-MS was used for the identification of compounds in the alkaloid fractions. Both underivatized and silylated samples were analyzed simultaneously. Elevated plus maze and tail suspension tests were used to assay the anxiolytic and antidepressant activities. Ellman's and MTT-dye reduction assays were used to evaluate the acetylcholinesterase (AChE) inhibitory and cytotoxicity activities, respectively. RESULTS: Of the 29 alkaloids, 13 of Sceletium-type were detected. Two new alkaloids were identified as 2-oxo-mesembrine and 2-oxo-epi-mesembrenol. Lycorine was found as a major compound (43.5%) in the crude silylated methanol extract. After the elimination of lycorine by pre-crystallization, the major alkaloids were 40.8% 6-epi-mesembranol, 16.2% 6-epi-mesembrenol, and 13.8% sanguinine. This fraction showed anxiolytic and antidepressant-like activities as well as potent AChE inhibitory and antineoplastic activities. CONCLUSIONS: Silylation of the alkaloid fractions from Narcissus cv. Hawera provides better separation, structural information, and improved sensitivity for compounds with two and more hydroxyl groups. The lycorine-free alkaloid fraction shows a great potential for further pharmacological studies.

Carotenoid-Related Volatile Compounds of Tobacco (Nicotiana tabacum L.) Essential Oils.

Tobacco (Nicotiana tabacum L.) aroma is an important attribute of tobacco quality and is influenced by a variety of minor chemical components, including carotenoid degradation products. The objectives of this work were to determine the content of the most important fragrance-shaping carotenoid degradation products in the essential oils (EOs) of the three types of Bulgarian tobacco-Oriental (OR), flue-cured Virginia (FCV), and Burley (BU)-and to compare them with other aromatic products from tobacco. The content of total carotenoids and ß-carotene was highest in BU tobacco (22.23 and 20.34 mg/100 g DW, respectively), followed by OR (13.60 and 12.09 mg/100 g DW in variety "Plovdiv 7" (Pd7); 6.27 and 5.45 mg/100 g DW in "Krumovgrad" (Kr), and FCV (5.93 and 3.73 mg/100 g DW). EOs were obtained by hydrodistillation in an acidified medium, and the main aroma-impact compounds from carotenoid degradation (identified by GC-MS) were as follows: FCV-α-ionone (0.61 mg/100 g DW), dihydro-ß-ionone (0.96 mg/100 g DW), ß-damascenone (1.26 mg/100 g DW); BU-α-ionone (0.73 mg/100 g DW), dihydro-ß-ionone (1.19 mg/100 g DW), ß-damascenone (1.35 mg/100 g DW); OR(Kr)-α-ionone (0.20 mg/100 g DW), ß-ionone (1.08 mg/100 g DW), dihydro-ß-ionone (1.34 mg/100 g DW), ß-damascenone (0.36 mg/100 g DW); OR(Pd7)-α-ionone (1.43 mg/100 g DW), dihydro-ß-ionone (1.73 mg/100 g DW), ß-damascenone (1.23 mg/100 g DW). Ionone and its derivatives were not identified in the aroma extraction products concrete, resinoid, or absolute. The results suggest that temperature, pH of the medium, process duration, and possibly other unknown factors affect carotenoid transformation. The study provides insight into the composition of tobacco EOs and may be of interest to the fragrance industry.

Dynamics of alkaloid accumulation in Narcissus cv. Hawera: a source of Sceletium-type alkaloids.

The Sceletium-type alkaloids, known for their anxiolytic and antidepressant activities, have been recently found to be biosynthesized in Narcissus cv. Hawera, which is largely used as an ornamental plant. An alkaloid fraction enriched with Sceletium-type alkaloids from the plant has shown promising antidepressant and anxiolytic activities. In the present study, qualitative and quantitative analyses of the alkaloids in the plant organs were performed during one vegetation season by GC-MS. The alkaloid pattern and total alkaloid content was found to depend strongly on the stage of development and plant organ. The alkaloid content of bulbs was found to be highest during the dormancy period and lowest in sprouting bulbs. The leaves showed the highest alkaloid content during the intensive vegetative growth and lowest during flowering. In total, 13 alkaloids were detected in the methanol extracts of Narcissus cv. Hawera, six Sceletium-type and seven typical Amaryllidaceae alkaloids. Major alkaloids in the alkaloid pattern were lycorine, 6-epi-mesembrenol, mesembrenone, sanguinine, and galanthamine. The leaves of flowering plants were found to have the highest amount of 6-epi-mesembrenol. Mesembrenone was found to be dominant alkaloid in the leaves of sprouting bulbs and in the flowers. Considering the biomass of the plant, the dormant bulbs are the best source of alkaloid fractions enriched with 6-epi-mesembrenol. The flowers and the young leaves can be used for preparation of alkaloid fractions enriched with mesembrenone. The results indicates that Narcissus cv. Hawera is an emerging source of valuable bioactive compounds and its utilization can be extended as a medicinal plant.

Metabolite profiling and histochemical localization of alkaloids in Hippeastrum papilio (Ravena) van Scheepen.

Hippeastrum papilio (Amaryllidaceae) is a promising new source of galanthamine - an alkaloid used for the cognitive treatment of Alzheimer's disease. The biosynthesis and accumulation of alkaloids are tissue - and organ-specific. In the present study, histochemical localization of alkaloids in H. papilio's plant organs with Dragendorff's reagent, revealed their presence in all studied samples. Alkaloids were observed in vascular bundles, vacuoles, and intracellular spaces, while in other plant tissues and structures depended on the plant organ. The leaf parenchyma and the vascular bundles were indicated as alkaloid-rich structures which together with the high proportion of alkaloids in the phloem sap (49.3% of the Total Ion Current - TIC, measured by GC-MS) indicates the green tissues as a possible site of galanthamine biosynthesis. The bulbs and roots showed higher alkaloid content compared to the leaf parts. The highest alkaloid content was found in the inner bulb part. GC-MS metabolite profiling of H. papilio's root, bulb, and leaves revealed about 82 metabolites (>0.01% of TIC) in the apolar, polar, and phenolic acid fractions, including organic acids, fatty acids, sterols, sugars, amino acids, free phenolic acids, and conjugated phenolic acids. The most of organic and fatty acids were in the peak part of the root, while the outermost leaf was enriched with sterols. The outer and middle parts of the bulb had the highest amount of saccharides, while the peak part of the middle leaf had most of the amino acids, free and conjugated phenolic acids.

Artemisia santonicum L. and Artemisia lerchiana Web. Essential Oils and Exudates as Sources of Compounds with Pesticidal Action.

The application of natural products for pest control is important in modern farming. In the present study, Artemisia santonicum L. and Artemisia lerchiana Weber essential oil and exudate profiles were determined, and their potential as inhibitors of seed germination, acetylcholinesterase, and phytopathogenic mycelium growth were evaluated. Essential oils (EO) were obtained via hydrodistillation and exudates (AE) by washing aerial parts of the species with acetone. EO and AE's composition was identified using GC/MS. Eucalyptol (1,8-cineole) and camphor were found to be the main components of A. lerchiana EO, while ß-pinene, trans-pinocarveol, α-pinene, α-terpineol, and spathulenol were established as major compounds of A. santonicum EO. Strong inhibition on Lolium perenne seed germination was found at 2 µL/mL and 5 mg/mL using aqueous solutions of EO and AE, respectively. An inhibitory effect on acetylcholinesterase was established, with an IC50 value of 64.42 and 14.60 µg/mL for EO and 0.961, >1 mg/mL for the AE of A. lerchiana and A. santonicum, respectively. The low inhibition on the mycelium growth of studied phytopathogenic fungi was established by applying 2 µL of EO and 15 µL of 100 mg/mL of AE, with the exception of A. lerchiana AE against Botrytis cinerea. These results show that the studied EO and AE exhibited strong phytotoxic and AChE inhibitory activities, providing new data for these species.

Elimination of autoreactive B cells in humanized SCID mouse model of SLE.

Although the exact etiology of systemic lupus erythematosus (SLE) remains elusive, B-cell hyperactivity and production of autoantibodies directed to components of the cell nucleus are a well-established pathogenetic mechanism of the disease. Therefore, the targeted inhibition of DNA-specific B cells is a logical therapeutic approach. The complement receptor type 1 (CR1, CD35) has been shown to suppress human B-cell activation and proliferation after co-cross-linking with the BCR, and may serve as a mediator for negative signal delivery. In order to evaluate this therapeutic approach in a human-like system, we used immune-restricted SCID mice transferred with PBMCs from SLE patients. The tolerance of these humanized SCID mice to native DNA was re-established after administration of a chimeric molecule consisting of a CR1-specific mAb coupled to the decapeptide DWEYSVWLSN that mimics dsDNA. The generated protein-engineered chimera was able to co-cross-link selectively native DNA-specific BCR with the B-cell inhibitory receptor CR1, thus delivering a strong inhibitory signal.

Metabolic Profiles, Genetic Diversity, and Genome Size of Bulgarian Population of Alkanna tinctoria.

Alkanna tinctoria (L.) Tausch Boraginaceae is a medicinal plant whose root is used for its antimicrobial and anti-inflammatory properties. A. tinctoria roots have been subject to numerous studies. However, the aerial parts have been explored less. The objective of the present study was to compare the chemical profile of aerial parts and roots as well as the total alkannin content in roots of 11 populations of the species from different floristic regions of Bulgaria. Methanolic extracts from 22 samples were analyzed by GC/MS. Phenolic, fatty, and organic acids, sterols, polyols, fatty alcohols, and sugars were identified. Ononitol (4-O-methyl-myo-inositol) was found as the main compound in the aerial parts. The total alkannin content in the roots was evaluated by the spectrophotometric method and compared with that of the commercial product. Populations with high alkannin content and rich in other bioactive compounds were identified. A relatively low genetic diversity in the studied populations was observed. The present study is the first comprehensive study on metabolite profiles and genetic diversity of the Bulgarian populations of A. tinctoria. The occurrence of ononitol in the aerial parts of the species is reported for the first time, as well as the phenolic acid profiles of the species in both aerial parts and roots. The results showed that aerial parts of the plant are also promising for use as a source of valuable biologically active substances.

Emigration, remittances, and the subjective well-being of those staying behind.

We offer the first global perspective on the well-being consequences of emigration for those staying behind using several subjective well-being measures (evaluations of best possible life, positive affect, stress, and depression). Using the Gallup World Poll data for 114 countries during 2009-2011, we find that having family members abroad is associated with greater evaluative well-being and positive affect, and receiving remittances is linked with further increases in evaluative well-being, especially in poorer contexts-both across and within countries. We also document that having household members abroad is linked with increased stress and depression, which are not offset by remittances. The out-migration of family members appears less traumatic in countries where migration is more common, indicating that people in such contexts might be able to cope better with separation. Overall, subjective well-being measures, which reflect both material and non-material aspects of life, furnish additional insights and a well-rounded picture of the consequences of emigration on migrant family members staying behind relative to standard outcomes employed in the literature, such as the left-behind's consumption, income, or labor market outcomes.

An antibody-based construct carrying DNA-mimotope and targeting CR1(CD35) selectively suppresses human autoreactive B-lymphocytes.

There is an urgent and unmet need for therapeutic agents targeting selectively disease-associated B-lymphocytes in autoantibody-mediated diseases. We have constructed a chimeric molecule able to cross-link cell surface immunoglobulin with the inhibitory complement receptor type 1 (CD35) on DNA-specific B cells from SLE (systemic lupus erythematosus) patients with the aim of selectively silencing them. This engineered molecule is made of copies of the DNA-mimotope peptide DWEYSVWLSN coupled to a monoclonal anti-CD35 antibody. We found that the DNA-like peptide chimera induced a dose-dependent decrease in the number of IgG anti-dsDNA antibody producing cells when PBMCs of lupus patients were cultured in its presence. Our data present evidence that clustering BCR and the inhibitory CR1 on disease-associated autoreactive B-lymphocytes selectively suppresses autoantibody production.

Rapid TLC/GC-MS identification of acetylcholinesterase inhibitors in alkaloid extracts.

Alkaloid extracts from 12 plant species of the families Amaryllidaceae, Fumariacae and Papaveraceae were studied with respect to their acetylcholinesterase inhibitory activity and alkaloid patterns. Fifty-three alkaloids were identified by GC-MS, including known acetylcholinesterase (AChE) inhibitors such as galanthamine, epigalanthamine, sanguinine and epinorgalanthamine in extracts of Amaryllidaceae plants and protopine in extracts of Fumariaceae and Papaveraceae plants. The galanthamine-containing extracts of the amaryllidaceous plants were found to be the most active while the extract of Corydalis bulbosa was the most active among the extracts of the tested plants from the Fumariaceae and Papaveraceae plants. TLC bioautographic assay, preparative TLC and GC-MS analysis were combined to identify the active compounds in the studied extracts. Galanthamine was isolated from the known AChE inhibitors in the extracts of Amaryllidaceae plants. Corydaline, bulbocapnine and stylopine were found to be active in the extracts of plant species of the families Fumariaceae and Papaveraceae. Available standards of deshydrocorydaline--a precursor of corydaline, corydaline and stylopine--were tested for AChE inhibitory activity. Deshydrocorydaline and corydaline showed potent inhibitory activity comparable with that of the positive control galanthamine.

Physiotherapy in Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: Physiotherapy is an essential for the treatment of patients with chronic respiratory non-inflammatory diseases especially for chronic obstructive pulmonary disease (COPD). AIM: To assess the effect of six months physiotherapy (PT) program on functional status in patients with COPD. MATERIAL AND METHODS: The patients were divided into two groups according to the severity of the disease. Group A included 33 patients (mean age 68.6 ± 7.3; GOLD II - III stages). Group B included 32 patients (mean age 71.7 ± 6.9; GOLD I -II). They were referred to supervised PT program performed three times weekly for a half a year. All the patients were on standard medical care. At entry and after PT, six minutes walking test (6 MWT), Borg scale and modified Medical Research Council (mMRC) scale were assessed. RESULTS: Significant changes in 6 MWT (p < 0.001) and mMRC scale (p < 0.001) were found after applied physical therapy program in patients of group A. Exertional dyspnoea decreased significantly in patients with group A (p < 0.001). Positive changes were found in physical tolerance in the patients of group B (p < 0.001). CONCLUSIONS: The present study revealed the positive effect of six months physiotherapy in physical tolerance and dyspnoea in patients with COPD at different stages of the disease.

Influence of Early Intensive Rehabilitation on Functional Mobility after Low Back Surgery.

AIM: The research aims to determine the influence of early goal-oriented physical therapy program in combination with educational booklet and standard physical therapy without written instructions on functional mobility outcomes in patients after low back surgery. MATERIAL AND METHODS: Thirty patients with similar functional impairments were randomly divided into two groups, a control group (CG n = 10) and an experimental group (EG n = 20). The outcome measures include time to move from lying to sitting position, the TUG test and the 6-meter walk test. Rehabilitation program includes daily physical therapy with mild to moderate intensity, achieving sitting position and education sessions how to perform activities of daily living (ADL) from the first day after surgery. RESULTS: There was a significant improvement from baseline in two groups for all performed tests (p < 0.001). Statistical significant differences between two groups for transfers in bed on discharge (p < 0.05), in one month (p < 0.01) and for TUG in one month (p < 0.05) were found. CONCLUSION: The study revealed that early rehabilitation program consists of therapeutic exercises and written educational booklet after low back surgery improves transfer abilities and basic activities in one month.

External flavonoid aglycones from Veronica chamaedrys L. (Scrophulariaceae).

External flavone aglycones in the overground parts of Veronica chamaedrys L. (Scrophulariaceae) have been analysed by isocratic reversed-phase high performance liquid chromatography. Luteolin, apigenin, luteolin-3'-methyl ether and scuterallein-6,4'-dimethyl ether have been identified. The latter compound is a new flavonoid identified in Veronica genus.

Clinical significance of antinuclear antibodies, anti-neutrophil cytoplasmic antibodies and anticardiolipin antibodies in heroin abusers.

BACKGROUND: Different autoantibodies and immunologic abnormalities have been described in heroin abusers positive for human immunodeficiency virus, hepatitis B surface antigen, or hepatitis C virus, as well as in addicts with negative viral markers. OBJECTIVES: To investigate the prevalence of different autoantibodies in heroin addicts. METHODS: We studied 10 heroin addicts (8 males and 2 females aged 18-30 years) with a mean duration of heroin abuse of 46.5 months (range 6-96) for the presence of the following autoantibodies: antinuclear antibodies and anti-neutrophil cytoplasmic antibodies--using indirect immunofluorescent technique; ds-DNA, ss-DNA, Sm, RNP, Ro and La antibodies--using counter immunoelectrophoresis; and immunoglobulins G and M anticardiolipin and beta 2-glycoprotein-I antibodies--using enzyme-linked immunosorbent assay. All patients were tested for VDRL, HIV, HBsAG and anti-HCV antibodies. RESULTS: Four patients were positive for ANA, of whom two were positive for anti-HCV and two for ANCA. Three patients were positive for IgM aCL, one of whom was positive for IgG beta 2 GPI with clinical data of acute renal failure in the course of heroin coma and antiphospholipid syndrome (deep vein thrombosis) and positive Sm and ds-DNA antibodies, and another had subacute endocarditis and biopsy-proven chronic tubulo-interstitial nephritis (in both these patients aCL gradually fell to normal levels after the cessation of heroin abuse). One patient was HBsAG positive with negative autoantibodies. All patients were HIV and VDRL negative. CONCLUSION: Our data support the importance of ANA and aCL determination as a predictor of some systemic complications in heroin addicts.

Essential oil composition of the Balkan endemic Thymus longedentatus (Degen & Urum. ) Ronniger / Composición del aceite esencial de Thymus longedentatus (Degen & Urum. ) Ronniger endemic de los Balcanes

The chemical composition of essential oil obtained from the aerial parts of the Balkan endemic species Thymus longedentatus was studied by GC-MS. Twenty eight compounds, consisting 98.2% of the total components were detected in amounts exceeding 0.1%. The oil was characterized by relatively high concencentration of oxygentated monoterpenes (78.7%), among which citral isomers neral (27.5%) and geranial (30.3%) were the principal ones. In addition, 1,8-cineole (7.8%), trans-ß-ocimene (7.5%), and ß-myrcene (3.7%) were detected in significant ammounts. Germacrene D (4.4%) was found to be the main sesquiterpene in the essential oil.

Se estudió mediante GC-MS la composición química del aceite esencial obtenido de las partes aéreas de Thymus longedentatus, especie endémica de los Balcanes. Se detectaron veintiocho compuestos, que representaban un 98,2% del total de compuestos y que se encontraban en cantidades superiores al 0,1%. El aceite se caracterizó por una concentración relativamente alta de monoterpenos oxigenados (78.7%), entre los cuales los isómeros de citral, neral (27.5%) y geranial (30.3%) eran los principales. Además, se detectó 1,8-cineol (7,8%), trans-ß-ocimeno (7,5%) y ß-mirceno (3,7%) en cantidades significativas. Se encontró que Germacreno D (4.4%) es el principal sesquiterpeno en el aceite esencial.

Influence of nutrient medium composition on in vitro growth, polyphenolic content and antioxidant activity of Alchemilla mollis.

Alchemilla mollis (Buser) Rothm. (Rosaceae) is a high-mountain medicinal plant growing in the Balkan Peninsula, with only one population in Bulgaria. Alchemilla plants (Lady's mantle) are commonly used in traditional medicine for treatment of many gynecological diseases. The commercial drugs "Herba Alchemillae" induce a rapid regeneration of skin epithelium and have styptic and anti-inflammatory actions. Because of the high content of phenolic compounds (tannins and flavonoids) and the ecological plasticity of the species, field cultivation or in vitro biomass production of A. mollis are possible alternatives to its collection from nature. Four MS based nutrient media differing in the concentration of the minerals and supplemented with alpha-naphthaleneacetic acid (NAA) and benzylaminopurine (BAP) were tested in order to examine their influence on the shoot multiplication effectiveness and the antioxidant activity of A. mollis, and also the possible relation between these parameters under the conditions of in vitro culture. The cultures grown for two months on these media differed significantly in their multiplication rates (p < 0.001), as well as in their morphological features--height, leaf color and root development. Methanol extracts of in vitro cultivated and ex vitro adapted and acclimated on Vitosha Mt. (1500 m a. s. l.) plants were analyzed for tannin and flavonoid content and for free radical scavenging activity. The contents of flavonoids and tannins in the in vitro cultures of A. mollis cultivated on the four tested media differed significantly (p < 0.05). The highest flavonoid content was found in the shoots cultivated on the control MS medium, as well as in the ex vitro adapted plants. The antioxidant activity of the in vitro cultures correlated positively with the concentrations of the PGRs in the respective media, and the ex vitro adapted plants had the highest antioxidant activity (IC50 13.1 +/- 1.9 microg/mL) commensurable with that of the commercial antioxidant butylated hydroxytoluene (BHT) used as a positive control, with an IC50 of 12.65 microg/mL.

The coexistence of systemic lupus erythematosus and thyrotoxicosis: the diagnostic value of antihistone antibodies.

We report four female patients with Graves' disease with positive ANA antibodies and possibility for development of systemic lupus erythematosus. All four patients have been treated with antithyroid drugs. SLE symptoms have appeared from 4 to 12 months after the beginning of therapy with methysol in two of them. The third patient had no symptoms for SLE, but her ANA, anti-DNA, and antihistone antibodies had been positive at the time of the onset of thyrotoxicosis. The fourth patient had alopecia areata with positive ANA and antihistone antibodies.

Screening of radical scavenging activity and polyphenol content of Bulgarian plant species.

BACKGROUND: Discovery of new plant species with antioxidant properties is a priority of many research teams. Most of the species included in this study are unstudied for antioxidant properties, but they are taxonomically related to reference plants with well-documented antioxidant activity. MATERIALS AND METHODS: Free radical scavenging activity of plant extracts was evaluated using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. An aluminum chloride colorimetric method was used for flavonoid determination. The amount of phenolic compounds in the extracts was estimated by using the Folin-Ciocalteu reagent. RESULTS: As a result of screening, it was found that the significant antioxidant properties possess several unstudied until now plant species (Veronica bellidioides L., V. kellereri Deg. et Urm, V. vindobonensis (M. Fisher) M. Fisher, V. beccabunga L., V. rhodopaea L., V. austriaca (Velen.) Degen., Clinopodium vulgare L., Stachysrecta L., Clematis vitalba L., and Xeranthemum annum L.). The antioxidant potential of the new species is comparable to that of reference medicinal plants. CONCLUSIONS: The existing data presented here provide new information for antioxidant potential of plant species that have not been traditionally used as medicinal plants.