Tamus communis L. is a plant distributed in a number of geographical areas whose rhizome has been used for centuries as an anti-inflammatory and analgesic remedy. This review aims to summarize the current knowledge of the chemical composition and biological activity of the extracts or individual compounds of the rhizome. The data for the principal secondary metabolites are systematized: sterols, steroidal saponins, phenanthrenes, dihydrophenanthrenes, etc. Results of biological tests for anti-inflammatory action, cytotoxicity, anticholinesterase effect, and xanthine oxidase inhibition are presented. Some open questions about the therapeutic properties of the plant are also addressed.

The increasing prevalence of diabetes mellitus, together with the limited access of many patients to conventional antidiabetic drugs and the side effects resulting from their use, are the reason for the ever-increasing need for new agents. One of the most important strategies used in the therapy of this disease is to reduce the postprandial blood glucose level by inhibiting the carbohydrate-degrading enzymes α-amylase and α-glucosidase. The purpose of the present study was to provide in vitro evidence for the potential hypoglycemic effect of leaf and inflorescence aqueous extracts of Bulgarian endemic species Betonica bulgarica Degen and Neič. Total phenolic and flavonoid contents and antioxidant activities were determined by spectrophotometric methods. Qualitative and quantitative determinations of principal phenolic acids and flavonoids were performed using HPLC with a dual absorbance detector. The plant extracts were able to retard the enzymatic breakdown of starch to glucose with 50% inhibiting concentrations of 1.86 mg/mL and 1.54 mg/mL respectively for leaf and flower extract. Some of the plant constituents are proven inhibitors of α-amylase and/or α-glucosidase, but their adsorption on starch seems to be one additional mechanism for the inhibition of glucose release. Combination index analysis carried out with binary mixtures of acarbose and plant extracts showed a tendency toward synergism with an increase in concentrations and level of inhibition.

Ginkgo biloba has been cultivated in Bulgaria since the end of the 19th century. Ividual specimens can be seen in almost every park. Females of the tree are considered contaminants of the landscape because their ripe seeds have a strong odor and are not utilized. We undertook this study to clarify whether ginkgo seeds of local origin can be converted from an unwanted and unused environmental pollutant into a source of beneficial compounds. Various analytical and chromatographic methods were used to quantify the major constituents and ten biologically active compounds in methanol seed extract. The results showed that the seeds are low in proteins (5%) and fats (1%); the seeds were also rich in unsaturated fatty acids and tocopherols. About 44% of nut starch was resistant to in vitro enzymatic hydrolysis. The amount of terpene trilactones in an aqueous-methanol seed extract was significantly higher than the number of flavonoids. Ginkgotoxin and ginkgolic acid were also found. The extract demonstrated weak antimicrobial activity against thirteen microorganisms. This study revealed that seeds of locally grown Ginkgo trees can be used as a source of biologically active substances. The chemical composition show similarity to those of seeds from other geographical areas.

Background: Ferns are underestimated as medicinal plants and their use in traditional medicine is limited despite their diversity. Most of the research on their healing properties and phytochemical composition related to their biological activity has been focused on the secondary metabolites synthesized by ferns. Objective: In this study, we aimed to make an in-depth chemical characterization of three ferns widely spread in Bulgaria - Asplenium ceterach L., Asplenium scolopendrium L. and Asplenium trichomanes L. Methods: Micro elemental analysis was carried out using ICP-MS. Standard laboratory methods were used to determine the content of proteins, fats and fatty acids. Chromatographic methods were applied to quantify some secondary metabolites. Two antioxidant methods and two antimicrobial tests were used to evaluate the biological properties of the ferns tested. Results: Micro elemental analysis showed that these ferns could be useful source of zinc and iron. Protein content slightly varied among the species (13.6% - 18.4% of the dried plant weight). Negligible was the variation in oil content (3.1% - 4.0%, dry weight base); oil composition was dominated by saturated fatty acids. Some principal classes secondary metabolites, individual phenolic acids and flavonoids were quantified. The extract obtained from Asplenium ceterach L. demonstrated the highest antioxidant capacity. Fern extracts showed moderate antimicrobial activity against six of the 14 microorganisms tested. Conclusion: The results obtained may reveal new areas of application for ferns and are a solid basis for comparison with the same species growing in other geographical and climatic conditions, which may affect their healing properties.

The influence of accelerated electrons on neuronal structures is scarcely explored compared to gamma and X-rays. This study aims to investigate the effects of accelerated electron radiation on some pivotal neurotransmitter circuits (cholinergic and serotonergic) of rats’ myenteric plexus. Male Wistar rats were irradiated with an electron beam (9 MeV, 5 Gy) generated by a multimodality linear accelerator. The contractile activity of isolated smooth muscle samples from the gastric corpus was measured. Furthermore, an electrical stimulation (200 μs, 20 Hz, 50 s, 60 V) was performed on the samples and an assessment of the cholinergic and serotonergic circuits was made. Five days after irradiation, the recorded mechanical responses were biphasic—contraction/relaxation in controls and contraction/contraction in irradiated samples. The nature of the contractile phase of control samples was cholinergic with serotonin involvement. The relaxation phase involved ACh-induced nitric oxide release from gastric neurons. There was a significant increase in serotonergic involvement during the first and second contractile phases of the irradiated samples, along with a diminished role of acetylcholine in the first phase. This study demonstrates an increased involvement of serotonergic neurotransmitter circuits in the gastric myenteric plexus caused by radiation with accelerated electrons.

In the present study, the phenolic profile, the antioxidant activity, and the antimicrobial activity of an aqueous-methanolic extract prepared from the aerial parts of Echinophora tenuifolia subsp. sibthorpiana growing in Bulgaria were investigated for the first time. The evaluation of the phenolic composition of the extract revealed high levels of total phenols (111.3 ± 9.1 mg GAE/g dry extract) and the presence of the phenolic acids chlorogenic acid, p-coumaric acid, ferulic acid, salicylic acid, rosmarinic acid, the flavonol glycoside rutin, and the flavanone glycoside hesperidin. The highest concentration was observed for rutin (29.625 mg/g). The extract demonstrated good radical scavenging activity in the DPPH assay (IC₅₀ 71.3 ± 0.01 μg/mL) and antioxidant capacity in the ferric-ferrozine assay (405.1 ± 39.9 μmol/g). In addition, the extract exhibited antibacterial activity against E. coli (MIC 1.85 mg/mL, MBC 3.5 mg/mL) and S. aureus (MIC 3.7 mg/mL). In contrast, no antifungal activity against C. albicans was observed.