Petar Hrischev

Prof. Dr. Petar Hrischev

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 June 2023 in Molecules
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BLBorislava Lechkova
Borislava Lechkova
Diana Karcheva-BahchevanskaDiana Karcheva-Bahchevanska
Diana Karcheva-Bahchevanska
KIKalin Valentinov Ivanov
Kalin Valentinov Ivanov
Velislava TodorovaVelislava Todorova
Velislava Todorova
NBNiko Benbassat
Niko Benbassat
Stanislava IvanovaStanislava Ivanova
Stanislava Ivanova
Background: Tanacetum parthenium (L.) Sch.Bip. (T. parthenium) is an aromatic perennial plant belonging to the Asteraceae family, also known as feverfew. It is widely distributed in various regions of Europe and other parts of the world. The plant has a rich background in the traditional medicine of many nations and has been used as a remedy for fever, pain, inflammation, asthma, rheumatism, menstrual disorders, etc. Methods: GC–MS analysis was conducted to determine the chemical composition of the isolated essential oil (EO). Using the method proposed by Litchfield and Wilcoxon, the average lethal dose (LD50) of the EO on Wistar rats was determined for two routes of administration: oral (p.o.) and intraperitoneal (i.p.). The subacute toxicity of the EO was also tested by oral administration of a daily dose of 1.0 g/kg body weight (BW) for 28 days. The toxicity of the EO was evaluated by observing and evaluating changes in behavior, body weight, basic hematological and serum biochemical parameters, and histopathological changes of the internal organs. Results: Thirty-seven volatile organic compounds representing 94.58% of the total oil composition were tentatively detected in the obtained T. parthenium EO. The dominant compounds were camphor (45.47%), trans-chrisantenyl acetate (21.65%), camphene (9.48%), and cis-isogeraniol (5.42%). The results showed that the EO was not toxic when administered in acute oral doses. The acute mean lethal dose for intraperitoneal administration was LD50 i.p. = 2.13 g/kg BW. In the subacute study involving administration of an oral dose of EO for 28 days, there were a number of changes in the hematological and serum biochemical parameters of the blood compared with the control group of animals. However, no symptoms of toxicity, changes in the body weight of the rats, death, or pathological changes in the histological indicators of the examined organs—brain, heart, stomach, liver, spleen and kidney—were found. Extrapolating the results obtained from the rat experiments, we can state that the EO is safe for use in doses below 1 g/kgBW for a period not exceeding one month.

25 March 2022 in Physiology & Behavior
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Jana Dimitrova TchekalarovaJana Dimitrova Tchekalarova
Jana Dimitrova Tchekalarova
PHPetar Hrischev
Petar Hrischev
PIPetya Ivanova
Petya Ivanova
NBNikolai Boyadjiev
Nikolai Boyadjiev
KGKaterina Georgieva
Katerina Georgieva

30 December 2014 in Folia Biologica
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PAPepa Atanasova
Pepa Atanasova
PHPetar Hrischev
Petar Hrischev
MOMaria Mitkova Orbetzova
Maria Mitkova Orbetzova
PNPeter Nikolov
Peter Nikolov
JNJulia Nikolova
Julia Nikolova
EGElenka Georgieva
Elenka Georgieva
Adipose tissue secretes a variety of adipokines involved in the regulation of energy metabolism and insulin resistance. Metabolic syndrome corresponds to a clinical condition in which white adipose tissue is characterized by an increased production and secretion of inflammatory molecules which may have local effects on adipose tissue physiology but also systemic effects on other organs. The aim of this study was to assess the expression of leptin, NGF and adiponectin in women with metabolic syndrome compared to healthy controls. Plasma leptin, NGF and adiponectin levels were measured by the ELISA method. Leptin and NGF immunohistochemical expression was analyzed in subcutaneous adipose tissue. The results indicated that in women with metabolic syndrome waist circumference, body mass index, HOMA index, glucose, total cholesterol and triglyceride levels were significantly increased in parallel with over-expressed plasma levels of leptin and NGF and decreased adiponectin. The immunohistochemical expression of leptin and NGF was very strong. In conclusion, this is the first study demonstrating a complex of immunochemical and immunohistochemical expression of the key adipokines including leptin, NGF and adiponectin in women with metabolic syndrome. Locally-produced pro-inflammatory adipokines probably contribute to the ethiopathogenic mechanisms of metabolic syndrome.

30 June 2023 in Folia Medica
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NVNatalia Vilmosh
Natalia Vilmosh
MGMaria Georgieva-Kotetarova
Maria Georgieva-Kotetarova
SDStela Dimitrova
Stela Dimitrova
MZMaria Zgureva
Maria Zgureva
PAPepa K. Atanassova
Pepa K. Atanassova
IKIvanka Kostadinova
Ivanka Kostadinova
Introduction: Satureja montana is a wild growing medicinal plant, part of the Lamiaceae family. This herb is well known as a source of phenolic compounds, which can vary in a broad range depending on different factors and exert many pharmacological activities. Aim: The aim of the study was to investigate the composition and chronic toxicity of dry extract of Satureja montana. Material and methods: The composition was investigated by high-performance liquid chromatographic system with diode-array detector. To establish the chronic toxicity of dry extract of Satureja montana we used 40 eight-week-old male Wistar rats, treated orally with saline, olive oil (control groups), Satureja montana at a dose of 500 mg/kg bw, carvacrol – 500 mg/kg bw, and rosmarinic acid – 15 mg/kg bw. The animals were sacrificed at the end of the experiment and blood samples and organs for histological examination were obtained. Statistical analysis was performed with one-way analysis of variance (ANOVA) using IBM SPSS 19.0. Results: Rosmarinic acid and small quantities of carvacrol were found in the dry extract of Satureja montana. Full blood count and the biochemical parameters ASAT, ALAT, uric acid, cholesterol, triglycerides, glucose and ionized Ca were in the reference values for 17+ weeks old male Wistar rats. The histological samples showed no signs of organ toxicity. Conclusions: The main ingredient in the dry extract of Satureja montana is rosmarinic acid. The extract is not toxic after 90-days oral administration.

1 December 2015 in West Indian Medical Journal
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Journal Article
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PNP Nikolov
P Nikolov
JNJ Nikolova
J Nikolova
MOM Orbecova
M Orbecova
TDT Deneva
T Deneva
LVL Vladimirova
L Vladimirova
FNF Nikolov
F Nikolov

4 December 2024 in Molecules
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BLBorislava Lechkova
Borislava Lechkova
MSMichaela Shishmanova-Doseva
Michaela Shishmanova-Doseva
NBNiko Benbassat
Niko Benbassat
RGReneta Gevrenova
Reneta Gevrenova
PAPepa Atanasova
Pepa Atanasova
Stanislava IvanovaStanislava Ivanova
Stanislava Ivanova
Tanacetum vulgare L. has been traditionally applied as a remedy for headaches, rheumatism, digestion, respiratory and neurological problems, and other medical conditions. However, the literature data on its effects on cognitive function are scarce. The aim of the present work was to evaluate the effects of two doses of T. vulgare alcohol extract on cognitive functions, hippocampal brain-derived neurotrophic factor (BDNF) expression, and organ toxicity in rats. Rats were treated with T. vulgare 200 mg/kg (TV 200) and 1000 mg/kg (TV 1000) for 28 days. After one week of pre-treatment, the animals were subjected to a series of tests. We found that in the active avoidance test, only TV 200 improved learning and memory, while in the passive avoidance test, both doses facilitated these processes. In addition, the two doses enhanced spatial memory. In the elevated plus maze test, only the higher dose of TV 1000 resulted in anxiolytic-like behavior. Both doses of the extract significantly increased the hippocampal expression of BDNF. We suggest that increased neurotrophic factor expression could be one of the important mechanisms underlying the cognition-enhancing effects of T. vulgare extract.