Investigation of the cytotoxic, genotoxic, and apoptosis-inducing effects of estragole isolated from fennel (Foeniculum vulgare)

A novel black poplar propolis extract with promising health-promoting properties: focus on its chemical composition, antioxidant, anti-inflammatory, and anti-genotoxic activities

Propolis is a resinous mixture produced by honeybees which has been used since ancient times for its useful properties. However, its chemical composition and bioactivity may vary, depending on the geographical area of origin and the type of tree bees use for collecting pollen. In this context, this research aimed to investigate the total phenolic content (using the Folin-Ciocalteu assay) and the total antioxidant capacity (using the FRAP, DPPH, and ABTS assays) of three black poplar (Populus nigra L.) propolis (BPP) solutions (S1, S2, and S3), as well as the chemical composition (HPLC-ESI-MSn) and biological activities (effect on cell viability, genotoxic/antigenotoxic properties, and anti-inflammatory activity, and effect on ROS production) of the one which showed the highest antioxidant activity (S1). The hydroalcoholic BPP solution S1 was a prototype of an innovative, research-type product by an Italian nutraceutical manufacturer. In contrast, hydroalcoholic BPP solutions S2 and S3 were conventional products purchased from local pharmacy stores. For the three extracts, 50 phenolic compounds, encompassing phenolic acids and flavonoids, were identified. In summary, the results showed an interesting chemical profile and the remarkable antioxidant, antigenotoxic, anti-inflammatory and ROS-modulating activities of the innovative BPP extract S1, paving the way for future research. In vivo investigations will be a possible line to take, which may help corroborate the hypothesis of the potential health benefits of this product, and even stimulate further ameliorations of the new prototype.

Mechanical Transfer of Black Phosphorus on a Silk Fibroin Substrate: A Viable Method for Photoresponsive and Printable Biomaterials

Despite the technological importance of semiconductor black phosphorus (BP) in materials science, maintaining the stability of BP crystals in organic media and protecting them from environmental oxidation remains challenging. In this study, we present the synthesis of bulk BP and the exploitation of the viscoelastic properties of a regenerated silk fibroin (SF) film as a biocompatible substrate to transfer BP flakes, thereby preventing oxidation. A model based on the flow of polymers revealed that the applied flow-induced stresses exceed the yield stress of the BP aggregate. Raman spectroscopy was used to investigate the exfoliation efficiency as well as the environmental stability of BP transferred on the SF substrate. Notably, BP flakes transferred to the SF substrate demonstrated improved stability when SF was dissolved in a phosphate-buffered saline medium, and in vitro cancer cell viability experiments demonstrate the tumor ablation efficiency under visible to near-infrared (Vis-nIR) radiation. Moreover, the SF and BP-enriched SF (SF/BP) solution was shown to be processable via extrusion-based three-dimensional (3D) printing. Therefore, this work paves the way for a general method for the transferring of BP on natural biodegradable polymers and processing them via 3D printing toward novel functionalities and complex shapes for biomedical purposes.

Evaluation of mutagenic, cytotoxic, mitochondrial dysfunction, apoptotic activity, and acute toxicity of ethanolic extract of Cissus quadrangularis

Recent studies have focused on exploring the efficacy of Cissus quadrangularis extract (EECQ) against various metabolic disorders involving the liver as the prime target organ, suggesting a considerable threat of hepatotoxicity in the person encountering it. Consequently, the current study was aimed to unravel the mutagenic, cytotoxic, mitochondrial dysfunction, apoptotic activity in HepG2 cells, and acute toxicity of EECQ. MTT, SRB, trypan blue dye exclusion, and lactate dehydrogenase (LDH) assay were performed in HepG2 cell lines to determine the cytotoxicity of the extract. The mutagenic potential was determined by the Ames test using various strains of Salmonella typhimurium. Acute toxicity was done at a dose of 2000 mg/kg in Sprague Dawley rats. MTT and SRB cytotoxicity assays demonstrated dose-dependent cytotoxicity of extract. The three highest noncytotoxic doses from the above assay, investigated by trypan blue dye exclusion and LDH assay, did not reveal cytotoxicity. Besides, mitochondrial dysfunction was determined by measuring cellular and mitochondrial ROS, ATP, NAD, mitochondrial membrane potential, Bax/Bcl2 ratio, mitochondrial and cytoplasmic cytochrome c, and apoptosis-inducing factor, were found to be equivalent in both extract exposed and unexposed cells. Moreover, the apoptotic cell morphology and the expression of pro-apoptotic mRNAs and proteins were equivalent in both the group. In acute toxicity, EECQ in rats did not cause any significant change in body weight, liver index, and liver function test. All-encompassing, the present study unraveled that EECQ is not mutagenic, cytotoxic, nor apoptotic in human hepatic cells, as well as neither acute toxicity.

Cytotoxicity and Genotoxicity of Senecio vulgaris L. Extracts: An In Vitro Assessment in HepG2 Liver Cells

Senecio vulgaris L. is a herbaceous species found worldwide. The demonstrated occurrence of pyrrolizidine alkaloids in this species and its ability to invade a great variety of habitats result in a serious risk of contamination of plant material batches addressed to the herbal teas market; this presents a potential health risk for consumers. In light of the above, this work aimed to assess the cytotoxic and genotoxic activity of S. vulgaris extracts in HepG2 cells. Dried plants were ground and extracted using two different methods, namely an organic solvent-based procedure (using methanol and chloroform), and an environmentally friendly extraction procedure (i.e., aqueous extraction), which mimicked the domestic preparation of herbal teas (5, 15, and 30 min of infusion). Extracts were then tested in HepG2 cells for their cytotoxic and genotoxic potentialities. Results were almost superimposable in both extracts, showing a slight loss in cell viability at the highest concentration tested, and a marked dose-dependent genotoxicity exerted by non-cytotoxic concentrations. It was found that the genotoxic effect is even more pronounced in aqueous extracts, which induced primary DNA damage after five minutes of infusion even at the lowest concentration tested. Given the broad intake of herbal infusions worldwide, this experimental approach might be proposed as a screening tool in the analysis of plant material lots addressed to the herbal infusion market.

In vitro toxicological assessment of PhSeZnCl in human liver cells

Phenylselenenylzinc chloride (PhSeZnCl) is an air-stable selenolate, easily synthesizable through oxidative insertion of elemental zinc into the Se-halogen bond of the commercially available phenylselenyl chloride. PhSeZnCl was shown to possess a marked GPx-like activity both in NMR and in vitro tests, and to effectively react with cellular thiols, and was supposed for a potential use in the chemotherapy of drug-resistant cancers. However, activity of PhSeZnCl in hepatic cells has never been tested before now. In this in vitro approach, we evaluated the cytotoxic, genotoxic, and apoptotic activities, as well as the effects on cell cycle of PhSeZnCl in two preclinical hepatic models, namely HepG2 and HepaRG cells. Results showed that cell viability of HepG2 and HepaRG cells decreased in a dose-dependent manner, with a more marked effect in HepG2 tumour cells. Moreover, treatment with 50 µg/mL PhSeZnCl caused an increase of primary DNA damage (4 h) and a statistically significant increase of HepG2 cells arrested in G₂/M phase. In addition, it altered mitochondrial membrane potential and induced chromosomal DNA fragmentation (24 h). In HepaRG cells, PhSeZnCl was able to determine a cell cycle-independent induction of apoptosis. Particularly, 50 µg/mL induced mitochondrial membrane depolarization after 24 h and apoptosis after 4 h treatment. Futhermore, all PhSeZnCl concentrations tested determined a significant increase of apoptotic cells after 24 h. Apoptosis was also highlighted by the detection of active Caspase-3 by Western Blot analysis after 24 h exposure. In conclusion, this first toxicological assessment provides new insights into the biological activity of PhSeZnCl in preclinical hepatic models that will be useful in future safety assessment investigation of this compound as a potential pharmaceutical.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-022-00148-y.

Evaluation of antibacterial activity and reversal of the NorA and MepA efflux pump of estragole against Staphylococcus aureus bacteria

The antibacterial activity of the monoterpene estragole was evaluated against two strains of bacteria with an efflux pump mechanism, which are Staphylococcus aureus 1199B and S. aureus K2068, which have a NorA and MepA pump, respectively. For that, the methodology proposed by CLSI with modifications was followed, and to evaluate the reversal of the efflux pump, subinhibitory concentrations (MIC/8) of estragole and standard pump inhibitors, CCCP and Chlorpromazine were used and it was verified whether they managed to modulate the action of Norfloxacin, Ciprofloxacin and Ethidium Bromide, an indicator of an efflux pump. It was observed that estragole positively modulated norfloxacin and ethidium bromide against the strain of S. aureus 1199B and that it also managed to reduce the MIC of ethidium bromide against the strain of S. aureus K2068. In the non-clinical acute toxicity tests with estragole, the animals treated with the dose of 625 mg/kg/v.o. showed no clinical signs of toxicity, according to the parameters evaluated. These results are promising, since it places estragole as a possible inhibitor of the efflux pump, thus managing to inhibit this mechanism of action in the strains tested.

Pro-Apoptotic Activity of Artichoke Leaf Extracts in Human HT-29 and RKO Colon Cancer Cells

(1) Background: Cynara cardunculus L. subsp. scolymus (L.) Hegi, popularly known as artichoke, is an herbaceous plant belonging to the Asteraceae family. Artichoke leaf extracts (ALEs) have been widely used in traditional medicine because of their hepatoprotective, cholagogic, hypoglycaemic, hypolipemic and antibacterial properties. ALEs are also recognized for their antioxidative and anti-inflammatory activities. In this study, we evaluated the cytotoxic, genotoxic, and apoptotic activities, as well as effect on cell growth of ALEs on human colon cancer HT-29 and RKO cells. HT-29 and RKO cells exhibit a different p53 status: RKO cells express the wild-type protein, whereas HT-29 cells express a p53-R273H contact mutant. (2) Methods: Four different ALEs were obtained by sequential extraction of dried artichoke leaves; ALEs were characterized for their content in chlorogenic acid, cynaropicrin, and caffeoylquinic acids. HT-29 and RKO cells were used for in vitro testing (i.e., cytotoxicity and genotoxicity assessment, cell cycle analysis, apoptosis induction). (3) Results: Two out of the four tested ALEs showed marked effects on cell vitality toward HT-29 and RKO tumour cells. The effect was accompanied by a genotoxic activity exerted at a non-cytotoxic concentrations, by a significant perturbation of cell cycle (i.e., with increase of cells in the sub-G₁ phase), and by the induction of apoptosis. (4) Conclusions: ALEs rich in cynaropicrin, caffeoylquinic acids, and chlorogenic acid showed to be capable of affecting HT-29 and RKO colon cancer cells by inducing favourable biological effects: cell cycle perturbation, activation of mitochondrial dependent pathway of apoptosis, and the induction of genotoxic effects probably mediated by the induction of apoptosis. Taken together, these results weigh in favour of a potential cancer chemotherapeutic activity of ALEs.

Foeniculum vulgare seed extract induces apoptosis in lung cancer cells partly through the down-regulation of Bcl-2

The factors behind the pathogenesis of lung cancer are not clear, and treatment failure is generally caused by drug resistance, recurrence, and metastasis. Development of new therapeutic agents to overcome drug-resistance remains a challenge clinically. Various extracts of Foeniculum vulgare have shown promising anticancer activity; however, effects on lung cancer and the underlying molecular mechanisms of action are not clear. In the present study, we found that the ethanol extract of Foeniculum vulgare seeds (EEFS) significantly reduced lung cancer cell growth in vitro and in vivo. EEFS decreased the viability of and triggered apoptosis in the lung cancer cell lines NCI-H446 and NCI-H661. EEFS induced apoptosis mainly through inhibition of Bcl-2 protein expression, reduction of mitochondrial membrane potential, and release of Cytochrome C. Moreover, EEFS significantly inhibited colony formation and cell migration in lung cancer cells. EEFS also effectively inhibited the growth of xenograft tumors derived from NCI-446 cells by reducing Bcl-2 protein expression and inducing apoptosis. Taken together, these findings suggest that EEFS exerts anti-lung cancer activity by targeting the Bcl-2 protein and may have potential as a therapeutic drug for lung cancer.

Exploring the Potential of Aromatherapy as an Adjuvant Therapy in Cancer and its Complications: A Comprehensive Update

BACKGROUND

Aromatherapy is a traditional practice of employing essential oils for the therapeutic purposes, currently headed under the category of complementary and adjuvant medicine.

OBJECTIVE

The aim of this review article is to summarize the potential health benefits of aromatic essential oil from traditional times till the present. It also proposed some mechanisms which can be utilized as basis for using aromatherapy in cancer and cancer linked complications.

METHODS

To find out the relevant and authentic data, several search engines like Science direct, Pubmed, research gate, etc. were thoroughly checked by inserting key words like aromatherapy, complementary, adjuvant therapy etc. to collect the relevant material in context of article. Also, the chemical components of essential oil were classified based on the presence of functional groups, which are further explored for their cytotoxic potential.

RESULTS

The result depicted the anti-cancer potential of chemical constituents of essential oil against different types of cancer. Moreover, the essential oils show promising anti-inflammatory, anti-microbial, anti-oxidant and anti-mutagenic potential in several studies, which collectively can form the basis for initiation of its anti-cancer utility.

CONCLUSION

Aromatherapy can serve as adjuvant economic therapy in cancer after the standardization of protocol.

Effect of estragole over the RN4220 Staphylococcus aureus strain and its toxicity in Drosophila melanogaster

Among the bacterial resistance mechanisms, efflux pumps are responsible for expelling xenobiotics, including bacterial cell antibiotics. Given this problem, studies are investigating new alternatives for inhibiting bacterial growth or enhancing the antibiotic activity of drugs already on the market. With this in mind, this study aimed to evaluate the antibacterial activity of Estragole against the RN4220 Staphylococcus aureus strain, which carries the MsrA efflux pump, as well as Estragole's toxicity in the Drosophila melanogaster arthropod model. The broth microdilution method was used to perform the Minimum Inhibitory Concentration (MIC) tests. Estragole was used at a Sub-Inhibitory Concentration (MIC/8) in association with erythromycin and ethidium bromide to assess its combined effect. As for Estragole's toxicity evaluation over D. melanogaster, the fumigation bioassay and negative geotaxis methods were used. The results were expressed as an average of sextuplicate replicates. A Two-way ANOVA followed by Bonferroni's post hoc test was used. The present study demonstrated that Estragole did not show a direct antibacterial activity over the RN4220 S. aureus strain, since it obtained a MIC ≥1024 μg/mL. The association of estragole with erythromycin demonstrated a potentiation of the antibiotic effect, reducing the MIC from 512 to 256 μg/mL. On the other hand, when estragole was associated with ethidium bromide (EtBr), an antagonism was observed, increasing the MIC of EtBr from 32 to 50.7968 μg/mL, demonstrating that estragole did not inhibited directly the MsrA efflux pump mechanism. We conclude that estragole has no relevant direct effect over bacterial growth, however, when associated with erythromycin, this reduced its MIC, potentiating the effect of the antibiotic.

Imbalance in the antioxidant defence system and pro-genotoxic status induced by high glucose concentrations: In vitro testing in human liver cells

It has been hypothesized that high glucose concentrations might contribute to the overall intracellular oxidative stress either by the direct generation of reactive oxygen species (ROS) or by altering the redox balance. Moreover, it has also been suggested that high glucose concentration can increase the susceptibility of DNA to genotoxic effects of xenobiotics. The aim of this approach was to test high glucose concentrations for pro-genotoxicity in human liver cells by setting up an in vitro model for hyperglycaemia. The experimental design included performing of tests on both human HepG2 tumour cells and HepaRG immortalized cells. Increased cell susceptibility to genotoxic xenobiotics was tested by challenging cell cultures with 4-nitroquinoline-N-oxide (4NQO) and evaluating the extent of primary DNA damage by comet assay. Moreover, we evaluated the relationship between glucose concentration and intracellular ROS, as well as the effects of glucose concentration on the induction of Nrf2-dependent genes such as Glutathione S-transferases, Heme‑oxygenase-1, and Glutathione peroxidase-4. To investigate the involvement of ROS in the induced pro-genotoxic activity, parallel experimental sets were set up by considering co-treatment of cells with the model mutagen 4NQO and the antioxidant, glutathione precursor N-acetyl-L-cysteine. High glucose concentrations caused a significant increase in the levels of primary DNA damage, with a pro-genotoxic condition closely related to the concentration of glucose in the culture medium when cells were exposed to 4NQO. High glucose concentrations also stimulated the production of ROS and down-regulated genes involved in contrasting of the effects of oxidative stress. In conclusion, in the presence of high concentrations of glucose, the cells are in unfavourable conditions for the maintenance of genome integrity.

Genotoxicity of source, treated and distributed water from four drinking water treatment plants supplied by surface water in Sardinia, Italy

High levels of disinfection by-products (DBPs) are constantly found in drinking water distributed in Sardinia, an Italian island with a tourist vocation and critical issues related to the drinking water supply. To reduce the concentration of trihalomethanes the disinfectant in use was changed - chlorine dioxide was adopted instead of hypochlorite. However, this caused the appearance of other DBPs (e.g., chlorites) in water distributed to the population. Thus, the use of monochloramine as a secondary disinfectant (associated with chlorine dioxide as the primary disinfectant) was evaluated in four drinking water treatment plants supplied by artificial basins located in the central-northern part of Sardinia. Raw, disinfected and distributed waters were studied for genotoxicity using a battery of in vitro tests on different cells (bacteria, plant and mammalian cells) to detect different genetic endpoints (i.e., point and chromosome mutations and DNA damage). Moreover, a chemical and microbiological characterisation of water samples was performed. All samples of water distributed to the people showed mutagenic or genotoxic effects in different cells/organisms. In particular, chromosome aberrations in plant cells and DNA damage in human cells were observed. In this study, the use of chloramines associated with other disinfectants did not eliminate the mutagenicity present in the raw water and when the raw water was not mutagenic it introduced mutagenic/genotoxic substances. A careful management of drinking water is needed to reduce health hazards associated with the mutagenicity of drinking water.

Protective effects of fennel essential oil against oxidative stress and genotoxicity induced by the insecticide triflumuron in human colon carcinoma cells

The increased use of pesticides is the origin of multiple damages to the environment and to humans; thus, the search for new strategies to reduce or even protect the toxic effects caused by these synthetic products became a necessity. In this context, our study attempted to evaluate the protective effects of fennel essential oil (FEO), the main essential oil extracted from Faeniculum vulgare Mill., a plant with aromatic, flavorful, and medicinal uses, against toxicity induced by an insecticide-triflumuron (TFM)-in human carcinoma cells (HCT116). Our methodological approach consists of the cytotoxicity assay starting with the cell viability test, the ROS generation, the malondialdehyde (MDA) production, the DNA fragmentation, and the measurement of some antioxidant enzymes activities such as catalase (CAT) and superoxide dismutase (SOD). Also, we measured the mitochondrial transmembrane potential. The outcome of the current study showed clearly that after 2 h of HCT 116 cell pretreatment with FEO, there were increase in cell viability, reduction in ROS generation, and modulation in CAT and SOD activities induced by TFM. In the same manner, significant decreases in MDA levels were found. Mainly, the results indicated a perceptible decrease in DNA damages and a significant reduction in the mitochondrial membrane potential loss. Our work demonstrates that FEO can be an important protector against toxic effects induced by TFM in HCT 116 cells.

Foeniculum Vulgare and Pelargonium Graveolens Essential Oil Mixture Triggers the Cell Cycle Arrest and Apoptosis in MCF-7 Cells

Background:

Fennel (Foeniculum vulgare) and rose geranium (Pelargonium graveolens) oils are known for their various biological effects including anticancer properties.

Objective:

This study aimed to evaluate the anticancer mechanism of fennel and geranium oils combined treatment on MCF-7 cells.

Methods:

The GC-MS method for essential oil characterization as well as the in vitro cytotoxicity, morphological changes, real-time PCR and immunocytochemical investigation for apoptosis-related markers, in addition, to flow cytometric cell cycle distribution analysis were done.

Results:

The major constituents of both essential oils were anethole (55.33 %) and estragole (11.57 %) for fennel essential oil. However, cintronellol (34.40 %) and geraniol (8.67 %) were identified in geranium oil. The results revealed an IC50 of 220±5.7 and 60±2.1µg/ml for fennel and geranium oils, respectively. The mechanistic anticancer properties were investigated throughout the 70, 50, and 25µg/ml of oils mixture. The marked apoptotic morphology and the flow cytometric cell cycle distribution analysis in addition to the levels of apoptosisrelated makers such as p53, caspase-3, mir-21, mir-92a, Bcl-2, and ki-67 confirmed that fennel and geranium oils combination induced cell cycle arrest and apoptosis in MCF-7 cells. Moreover, the oils mixture did not exert any significant (P<0.01) toxicity on normal human peripheral blood lymphocytes in vitro.

Conclusion:

The findings showed that the mixture of oils exerted selective cytotoxicity towards MCF-7 cells through induction of cell cycle arrest and apoptosis which may be triggered by the synergistic effect between the active ingredients of fennel and geranium oils.

Antioxidant Activity of Natural Allylpolyalkoxybenzene Plant Essential Oil Constituents

Free-radical-scavenging capacity antioxidant and membrane-protective properties of natural and related synthetic allylpolyalkoxybenzenes with different numbers of alkoxy/methoxy groups in the aromatic ring were evaluated using several in vitro models. These included the DPPH assay, inhibition of lipid peroxidation products accumulation, inhibition of H₂O₂-induced hemolysis, and oxidation of oxyhemoglobin. A synthetic protocol for the synthesis of natural nothoapiol (9) from a parsley seed metabolite, apiol (7), was developed. A structure-activity relationship study revealed that both the methylenedioxy fragment and methoxy groups in the aromatic ring are favorable for antioxidant activity. Hydroxyapiol (14), containing a hydroxy group in the aromatic core, was identified as the most potent compound. The pentaalkoxy-substituted nothoapiol (9) showed antioxidant activity in mouse brain homogenates, whereas in mouse erythrocytes it exhibited a marked pro-oxidant effect. Despite their low free-radical-scavenging capacity, allylpolyalkoxybenzenes can contribute to the total antioxidant potencies of plant essential oils.

Induction of apoptosis and cell cycle arrest by ethyl acetate fraction of Phoenix dactylifera L. (Ajwa dates) in prostate cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Phoenix dactylifera L. (Ajwa date) has high nutritive value and are consumed in Arabian Peninsula as an essential diet. Phoenix dactylifera L. have been mentioned in folk remedies of traditional Egyptian medicine and alternative medicine, for numerous health benefits including cancer treatment. The aim of the study is to evaluate the anticancer effects of the extract of Ajwa Date on human Prostate cancer cell line (PC3).

MATERIALS AND METHODS

Antiproliferative effect was measured using MTT assay. The long-term effect of EAFAD was determined using colony assay. Different stains like Giemsa and fluorescent stains (DAPI and acridine orange / Ethidium bromide) measured morphological changes. Loss of mitochondrial membrane potential and increased oxidative stress were measured using JC-1 and DCFH-DA dyes. DNA degradation was analyzed by comet assay. Cell cycle distribution was measured by flow cytometer. The apoptotic cell was quantified by annexin V-FITC and Propidium iodide dual staining using flow cytometer.

RESULTS

PC3 cell line was treated with ethyl acetate fractions of Ajwa dates (EAFAD) to study their morphological and cellular changes and induction of apoptosis. MTT assay showed the strong inhibitory effect of EAFAD on PC3 cells. Loss of mitochondrial membrane potential and increased oxidative stress were observed in EAFAD treated cells, which suggested mitochondrial involvement in apoptosis. Comet assay proved DNA fragmentation induced by EAFAD. Flow Cytometer results demonstrated that Annexin V-FITC and propidium iodide staining showed that EAFAD induced apoptosis and arrest the cell cycle in S phase.

CONCLUSION

Our results suggested EAFAD has potential therapeutics properties for prostate cancer.

Synchronous application of antibiotics and essential oils: dual mechanisms of action as a potential solution to antibiotic resistance

Antibiotic resistance has increased dramatically in recent years, yet the antibiotic pipeline has stalled. New therapies are therefore needed to continue treating antibiotic resistant infections. One potential strategy currently being explored is the use of non-antibiotic compounds to potentiate the activity of currently employed antibiotics. Many natural products including Essential Oils (EOs) possess broad spectrum antibacterial activity and so have been investigated for this purpose. This article aims to review recent literature concerning the antibacterial activity of EOs and their interactions with antibiotics, with consideration of dual mechanisms of action of EOs and antibiotics as a potential solution to antibiotic resistance. Synergistic interactions between EOs and their components with antibiotics have been reported, including several instances of antibiotic resensitization in resistant isolates, in support of this strategy to control antibiotic resistance. However, a lack of consistency in methods and interpretation criteria makes drawing conclusions of efficacy of studied combinations difficult. Synergistic effects are often not explored beyond preliminary identification of antibacterial interactions and mechanism of action is rarely defined, despite many hypotheses and recommendations for future study. Much work is needed to fully understand EO-antibiotic associations before they can be further developed into novel antibacterial formulations.

Cytotoxicity of the Essential Oil of Fennel (Foeniculum vulgare) from Tajikistan

The essential oil of fennel (Foeniculum vulgare) is rich in lipophilic secondary metabolites, which can easily cross cell membranes by free diffusion. Several constituents of the oil carry reactive carbonyl groups in their ring structures. Carbonyl groups can react with amino groups of amino acid residues in proteins or in nucleotides of DNA to form Schiff's bases. Fennel essential oil is rich in anise aldehyde, which should interfere with molecular targets in cells. The aim of the present study was to investigate the chemical composition of the essential oil of fennel growing in Tajikistan. Gas chromatographic-mass spectrometric analysis revealed that the main components of F. vulgare oil were trans-anethole (36.8%); α-ethyl-p-methoxy-benzyl alcohol (9.1%); p-anisaldehyde (7.7%); carvone (4.9%); 1-phenyl-penta-2,4-diyne (4.8%) and fenchyl butanoate (4.2%). The oil exhibited moderate antioxidant activities. The potential cytotoxic activity was studied against HeLa (human cervical cancer), Caco-2 (human colorectal adenocarcinoma), MCF-7 (human breast adenocarcinoma), CCRF-CEM (human T lymphoblast leukaemia) and CEM/ADR5000 (adriamycin resistant leukaemia) cancer cell lines; IC50 values were between 30-210 mg L-1 and thus exhibited low cytotoxicity as compared to cytotoxic reference compounds.

Epilobium angustifolium L.: A medicinal plant with therapeutic properties

Epilobium angustifolium L. is a medicinal plant belonging to the Onagraceae family, which includes more than 200 different species from all over the world. Traditional medicinal applications include treatment of prostate, gastrointestinal, menstrual disorders and recently it has been used for its analgesic and anti-inflammatory activity. In this investigation E. angustifolium was collected in Ternopil region of Ukraine. The obtained data demonstrated that E. angustifolium herb extract, rich in polyphenolic compounds such as flavonoids and tannins, display high antioxidant properties. In addition the potential anticancer activity has been investigated in vitro on human hepatocellular carcinoma cells (HepG2). Furthermore the cytotoxic and genotoxic effects of E. angustifolium have been investigated respectively by MTT and Comet assay. Results showed that at low concentration, up to 25 μg/mL, the cytotoxic effect was not observed. Increasing concentration from 50 to 75 μg/mL reduced significantly cell viability and induced an important DNA damage in hepatocellular carcinoma. These promising data were also confirmed with mitochondrial potential test. It is possible to conclude that E. angustifolium has beneficial properties in low concentration, in term of antioxidant activity, and it could be a potential antitumoral natural product if it will be used at high concentration

Cytotoxic and genotoxic effects of two hair dyes used in the formulation of black color

According to the International Agency for Research on Cancer (IARC), some hair dyes are considered mutagenic and carcinogenic in in vitro assays and exposed human populations. Epidemiological studies indicate that hairdressers occupationally exposed to hair dyes have a higher risk of developing bladder cancer. In Brazil, 26% of the adults use hair dye. In this study, we investigated the toxic effects of two hair dyes, Basic Red 51 (BR51) and Basic Brown 17 (BB17), which are temporary dyes of the azo group (R-N=N-R'), used in the composition of the black hair dye. To this end, MTT and trypan blue assays (cytotoxicity), comet and micronucleus assay (genotoxicity) were applied, with HepG2 cells. For cytotoxic assessment, dyes were tested in serial dilutions, being the highest concentrations those used in the commercial formula for hair dyes. For genotoxic assessment concentrations were selected according to cell viability. Results showed that both dyes induced significant cytotoxic and genotoxic effects in the cells, in concentrations much lower than those used in the commercial formula. Genotoxic effects could be related to the azo structure present in the composition of the dyes, which is known as mutagenic and carcinogenic. These results point to the hazard of the hair dye exposure to human health.

In Vitro Safety/Protection Assessment of Resveratrol and Pterostilbene in a Human Hepatoma Cell Line (HepG2)

The aim of this work was to evaluate in vitro the genotoxic and/or antigenotoxic effects of resveratrol (RESV) and pterostilbene (PTER) on HepG2 cells. Moreover, additional tests were performed to evaluate early and late apoptosis events induced by the tested stilbenes. RESV and PTER did not show any genotoxic activity. As regards antigenotoxicity testing, RESV and PTER showed a typical, U-shaped hormetic dose-response relationship characterized by a biphasic trend with small quantities having opposite effects to large ones. HepG2 cells treated with PTER exhibited a marked increase in early apoptosis (40.1 %) at 250 μM; whereas, the highest concentration tested for both RESV and PTER significantly increased the proportion of HepG2 cells undergoing late apoptosis (32.5 and 51.2 %, respectively). The observed pro-apoptotic activity could, at least in part, explain the hormetic response observed when the compounds were tested for antigenotoxicity ( i.e., in the presence of induced DNA damage).