Helicobacter pylori (H. pylori) is considered the most common bacterial pathogen colonizing stomach mucosa of almost half the world’s population and is associated with various gastrointestinal diseases (from digestive problems and ulcers to gastric cancer). A lack of new drugs and a growing number of H. pylori antibiotic-resistant strains is a serious therapeutic problem.As a mixture of natural compounds, propolis has antimicrobial activity based on high concentrations of bioactive polyphenols (mainly flavonoids and phenolic acid derivates). The chemical composition of tested Georgian propolis is characterized by the presence of flavonoids aglycones, and phenolic acid monoesters, e.g., pinobanksin-5-methyl ether, pinobanksin, chrysin, pinocembrin, galangin, pinobanksin-3-O-acetate, pinostrobin and pinobanksin-3-O-butanoate, or isobutanoate and methoxycinnamic acid cinnamyl ester. The anti-H. pylori activity of 70% ethanol water extracts of 10 Georgian propolis samples was evaluated in vitro by MIC (minimal inhibitory concentration) against the reference strain (H. pylori ATCC 43504) and 10 clinical strains with different antibiotic-resistance patterns. The strongest anti-Helicobacter activity (MIC and MBC = 31.3 µg/mL) was observed for propolis from Orgora, Ota, and Vardzia and two from Khaheti. Lower levels of activity (MIC = 62.5 µg/mL) were found in propolis obtained from Qvakhreli and Pasanauri, while the lowest effect was observed for Norio and Mestia (MIC = 125.0 µg/mL). However, despite differences in MIC, all evaluated samples exhibited bactericidal activity. We selected the most active propolis samples for assessment of urease inhibition property. Enzyme activity was inhibited by propolis extracts, with IC50 ranging from 4.01 to 1484.8 µg/mL. Principal component analysis (PCA) and hierarchical fuzzy clustering (dendrograms) coupled with matrix correlation analysis exhibited that the strongest anti-Helicobacter activity was connected with black poplar origin and high flavonoid content of propolis. Samples with lower activity contained higher presence of aspen markers and/or dominance of non-flavonoid polyphenols over flavonoids. In summary, Georgian propolis can be regarded as a source bioactive compounds that can be used as adjuvant in therapy of H. pylori infection.
Propolis (bee glue) is a resinous substance produced by different species of bees i.a. from available plant resins, balsams, and exudates. It is characterized by significant biological activity (e.g., antimicrobial and antioxidant) and phytochemical diversity related to the available plant sources in specific geographical regions. The available scientific literature on propolis is quite extensive; however, there are only a few reports about propolis originating from Georgia. Therefore, our research was focused on the characterization of Georgian propolis in terms of phytochemical composition and antimicrobial/antioxidant activity. Performed research included UHPLC-DAD-MS/MS phytochemical profiling, determination of total phenolic and flavonoid content, antiradical and antioxidant activity (DPPH and FRAP assays) as well as antibacterial activity of propolis extracts obtained using 70% ethanol (70EE). Georgian propolis extracts exhibited strong activity against Gram-positive bacteria (22 mm—disc assay/64 µg/mL—MIC for S. aureus, sample from Imereti) and weaker against Gram-negative strains as well as strong antioxidant properties (up to 117.71 ± 1.04 mgGAE/g in DPPH assay, up to 16.83 ± 1.02 mmol Fe2+/g in FRAP assay for samples from Orgora and Qvakhreli, respectively). The phytochemical profile of Georgian propolis was characterized by the presence of flavonoids, free phenolic acids, and their esters. In most of the samples, flavonoids were the main chemical group (52 compounds), represented mainly by 3-O-pinobanksin acetate, pinocembrin, chrysin, galangin, and pinobanksin. The primary plant precursor of the Georgian bee glue is black poplar (Populus nigra L.) while the secondary is aspen poplar (P. tremula L.).
In recent years, an increasing interest in phytotherapy has been observed. Parallel to the research on the total extracts of plant material, numerous studies on the activity of single molecules derived from plants are being conducted to address their mechanisms of action and determine active doses and eventual interactions. Despite this phenomenon, the isolation of individual compounds is a bottleneck due to its difficulty and cost. This work presents the results of a careful optimization of magnoflorine and berberine (isoquinoline alkaloids) recovery from a commonly distributed shrub, Berberis vulgaris, growing in Poland and Georgia, using CPC. Both compounds are known for their numerous medicinal properties, which makes the isolation methodology an important area of research. Additionally, CPC has the ability to isolate high-quality compounds in large quantities, which makes it an effective and easy-to-commercialize method. For a successful separation, the biphasic solvent system composed of hexane, butanol, ethanol, and water in a ratio (3:12:4:16 v/v/v/v) was used in the ascending mode, together with the flow rate of 8 mL/min and rotation speed of 1600 rpm. The method was selective for both compounds, and it delivered good results for both root and stem extracts from the plant. The qualitative composition of alkaloids in the studied extracts determined by HPLC-ESI-QTOF-MS/MS confirmed the presence of berberine, magnoflorine, jatrorhizine, and palmatine alkaloids from the group of isoquinolines. The isolates, magnoflorine and berberine, were subjected to the Helicobacter pylori growth inhibition assay and urease inhibition test to assess whether, next to the previously proved anticancer properties, these compounds are characterized by H. pylori inhibition. MGN was found to exhibit inhibitory potential against urease (IC50 = 25 mg/L).
Salinization threatens a growing proportion of arable land worldwide, making halophytic plants valuable sources of stress-adapted bioactive metabolites. The aim of this study was to investigate the polyphenolic profile and antioxidant activity of halophytic species from Lake Kumisi in Eastern Georgia – Petrosimonia brachiata, P. triandra, P. glaucescens and Gamanthus pilosus – in order to evaluate their pharmacological potential. Aerial parts were collected from the saline shores of Lake Kumisi in three phenological stages (pre-flowering, flowering and fruiting). Seventy percent ethanol extracts were prepared and analysed by GC–MS and LC–MS-DAD. Total phenolic content was determined using the Folin–Ciocalteu method and expressed as gallic acid equivalents (mg GAE/g DW), while total flavonoids were evaluated spectrophotometrically with the aluminium chloride method and expressed as quercetin equivalents (mg QE/g DW). Antioxidant activity was assessed by the DPPH radical scavenging assay, calculating inhibition percentages and IC₅₀ values. The chromatographic profiles revealed a rich composition of terpenoids, phytosterols and polyphenols, including β-sitosterol, phenolic acids and quercetin-type flavonoids. Total phenolic content ranged from approximately 10 to 25 mg GAE/g, with the highest value in flowering P. triandra. Total flavonoid content varied between 6.6 and 18.8 mg QE/g and accounted for about 60–75% of total phenolics, particularly in P. brachiata and P. triandra. In the DPPH assay, radical scavenging activity reached 45–90%, whereas IC₅₀ values ranged from 30 to 130 µg/mL. The lowest IC₅₀ values, indicating the strongest antioxidant activity, were recorded for flowering samples of P. brachiata and P. triandra, while G. pilosus showed comparatively weaker effects. A clear positive correlation was observed between total polyphenolic content and DPPH scavenging capacity. These findings demonstrate that halophytic species inhabiting the saline ecosystems of Lake Kumisi are phytochemically rich sources of natural antioxidants and represent promising candidates for further phytochemical isolation, pharmacological evaluation and potential application in medicinal and nutraceutical preparations.
Melanoma is the most aggressive and life-threatening form of skin cancer. Propolis possesses diverse biological activities and is considered a promising source of compounds for anticancer therapy. This study evaluated the cytotoxic effects of propolis from endemic regions of Nepal, Greece, Kazakhstan, Ukraine, and Georgia on melanoma cell lines (A375, SK-MEL-3) and normal human skin fibroblasts (BJ). Chemical characterization was performed using UHPLC-UV-ESI-qTOF-MS/MS. Total flavonoid and polyphenol contents, as well as antioxidant activity, were also determined. Biological effects were assessed by measuring cell viability, apoptosis (fluorescent staining and confocal microscopy), and caspase-6 activity (fluorometric assay). Most analyzed extracts contained markers characteristic of black poplar-type propolis, including chrysin, pinocembrin, galangin, pinobanksin-3-acetate, and caffeic acid monoesters such as caffeic acid phenethyl ester (CAPE) and isomers of the 1,1-dimethylallyl ester. Three propolis samples from Georgia showed the strongest anticancer activity against melanoma cells while exhibiting low toxicity toward normal fibroblasts (SI > 1). These extracts also displayed high antioxidant activity and elevated polyphenol content. Apoptosis predominated in A375 cells, whereas necrosis was more evident in SK-MEL-3 cells, consistent with increased caspase-6 activity in A375 cells. These results suggest that Georgian propolis may be a promising candidate for further investigation in melanoma therapy.