Antimutagenicity and induction of antioxidant defense by flavonoid rich extract of Myrcia bella Cambess. in normal and tumor gastric cells

Exploring the Potential of Myrcia Genus Essential Oils: A Review of Biological Activities and Recent Advances

The present study provides a comprehensive analysis of the chemical composition of essential oils from species of the Myrcia genus and their applications. The compiled results highlight the chemical diversity and biological activities of these oils, emphasizing their potential importance for various therapeutic and industrial applications. The findings reveal that Myrcia essential oils present a variety of bioactive compounds, such as monoterpenes and sesquiterpenes, which demonstrate antimicrobial activities against a range of microorganisms, including Gram-positive and Gram-negative bacteria, as well as yeasts. Furthermore, this study highlights the phytotoxic activity of these oils, indicating their potential for weed control. The results also point to the insecticidal potential of Myrcia essential oils against a range of pests, showing their viability as an alternative to synthetic pesticides. Additionally, species of the genus Myrcia have demonstrated promising hypoglycemic effects, suggesting their potential in diabetes treatment. This comprehensive synthesis represents a significant advancement in understanding Myrcia essential oils, highlighting their chemical diversity and wide range of biological activities. However, the need for further research is emphasized to fully explore the therapeutic and industrial potential of these oils, including the identification of new compounds, understanding of their mechanisms of action, and evaluation of safety and efficacy in different contexts.

New Therapeutic Strategies for Obesity and Its Metabolic Sequelae: Brazilian Cerrado as a Unique Biome

Brazil has several important biomes holding impressive fauna and flora biodiversity. Cerrado being one of the richest ones and a significant area in the search for new plant-based products, such as foods, cosmetics, and medicines. The therapeutic potential of Cerrado plants has been described by several studies associating ethnopharmacological knowledge with phytochemical compounds and therapeutic effects. Based on this wide range of options, the Brazilian population has been using these medicinal plants (MP) for centuries for the treatment of various health conditions. Among these, we highlight metabolic diseases, namely obesity and its metabolic alterations from metabolic syndrome to later stages such as type 2 diabetes (T2D). Several studies have shown that adipose tissue (AT) dysfunction leads to proinflammatory cytokine secretion and impaired free fatty acid (FFA) oxidation and oxidative status, creating the basis for insulin resistance and glucose dysmetabolism. In this scenario, the great Brazilian biodiversity and a wide variety of phytochemical compounds make it an important candidate for the identification of pharmacological strategies for the treatment of these conditions. This review aimed to analyze and summarize the current literature on plants from the Brazilian Cerrado that have therapeutic activity against obesity and its metabolic conditions, reducing inflammation and oxidative stress.

Morphine decreases cytotoxicity and mutagenicity of doxorubicin in vitro: Implications for cancer chemotherapy

Morphine is the most common opioid analgesic administered to treat pain in patients undergoing cancer chemotherapy. This study aimed to evaluate the cytotoxic and mutagenic effects of morphine alone and in combination with doxorubicin (Dox), an antineoplastic agent largely used in patients with solid cancers. Cytotoxicity was evaluated in neuroblastoma (SH-SY5Y) and fibroblast (V79) cells using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay while mutagenicity was assessed using the Salmonella/microsome assay in the absence and in the presence of S9 mix. Morphine showed a cytotoxic effect mainly on SH-SY5Y cells and reduced the cytotoxic effects of Dox when evaluated in a co-treatment procedure. In the Salmonella/microsome assay, it was observed that morphine did not induce mutations and, in fact, decreased the mutagenic effects induced by Dox in TA98 and TA102 strains in the absence of metabolic activation. Furthermore, in the presence of metabolic activation, no induction of mutations was observed with morphine. In conclusion, morphine decreased Dox cytotoxicity in both neuronal and non-neuronal cells and showed antimutagenic effects in the TA102 strain which detects mutagens inducing DNA oxidative damages. However, morphine decreased frameshift mutations induced by Dox in non-cytotoxic concentrations, an effect suggesting interference of Dox intercalation activity that could decrease its chemotherapeutic efficacy. These compelling findings highlight the importance of conducting further studies to explore the potential implications of co-administering morphine and Dox during cancer chemotherapy.

Flavonoid brachydin B decreases viability, proliferation, and migration in human metastatic prostate (DU145) cells grown in 2D and 3D culture models

Brachydin B (BrB) is a unique dimeric flavonoid extracted from Fridericia platyphylla (Cham.) LG Lohmann with different biological activities. However, the antitumoral potential of this flavonoid is unclear. In our study, we evaluated the effects of the BrB flavonoid on cell viability (MTT, resazurin, and lactate dehydrogenase assays), proliferation (protein dosage and clonogenic assay), and migration/invasion (3D ECM gel, wound-healing, and transwell assays) of metastatic prostate (DU145) cells cultured both as traditional 2D monolayers and 3D tumor spheroids in vitro. The results showed that the BrB flavonoid promotes cytotoxic effects from ≥1.50 μM after 24 h of treatment in DU145 cells in monolayers. In 3D prostate tumor spheroids, BrB also induced cytotoxic effects at higher concentrations after longer treatment (48, 72, and 168 h). Furthermore, BrB treatment is associated with reduced DU145 clonogenicity in 2D cultures, as well as decreased area/volume of 3D tumor spheroids. Finally, BrB (6 μM) reduced cell migration/invasion in 2D monolayers and promoted antimigratory effects in DU145 tumor spheroids (≥30 μM). In conclusion, the antitumoral and antimigratory effects observed in DU145 cells cultured in 2D and 3D models are promising results for future studies with BrB using in vivo models and confirm this molecule as a candidate for metastatic prostate cancer therapy.

Chemical characterization of Brazilian savannah Byrsonima species (muricis) and their impact on genomic instability and chemopreventive effects

The identification of new drugs with few or no adverse effects is of great interest worldwide. In cancer therapy, natural products have been used as chemopreventive and chemotherapeutic agents. Plants from the Brazilian savannah belonging to the Byrsonima genus are popularly known as muricis and have attracted much attention due to their various pharmacological activities. However, there are currently no data on these plants concerning their use as chemopreventive or chemotherapeutic agents in human cell lines. The present study assessed the potential of B. correifolia, B. verbascifolia, B. crassifolia, and B. intermedia extracts as natural alternatives in the prevention and/or treatment of cancer. The chemical constituents present in each extract were analyzed by electrospray ionization-mass spectrometry (ESI-MSN). The mutagenic/antimutagenic (micronucleus assay), genotoxic/antigenotoxic (comet assay), apoptotic/necrotic (acridine orange/ethidium bromide uptake), and oxidative/antioxidative (CM-H₂DCFDA) effects of the extracts and their influence on gene expression (RTqPCR) were investigated in nonmetabolizing gastric (MNP01) and metabolizing hepatocarcinoma (HepG2) epithelial cells to evaluate the effects of metabolism on the biological activities of the extracts. The genotoxicity, mutagenicity, and apoptotic effects observed in HepG2 cells with B. correifolia and B. verbascifolia extracts are probably associated with the presence of proanthocyanidins and amentoflavone. In MNP01 cells, none of the four extracts showed mutagenic effects. B. crassifolia and B. intermedia extracts exhibited strong antimutagenicity and enhanced detoxification in HepG2 cells and antioxidant capacities in both types of cells, possibly due to the presence of gallic and quinic acids, which possess chemopreventive properties. This study identifies for the first time B. correifolia and B. verbascifolia extracts as potential agents against hepatocarcinoma and B. crassifolia and B. intermedia extracts as putative chemopreventive agents.

Kaempferol: Antimicrobial Properties, Sources, Clinical, and Traditional Applications

Flavonoids are a category of plant-derived compounds which exhibit a large number of health-related effects. One of the most well-known and studied flavonoids is kaempferol, which can be found in a wide variety of herbs and plant families. Apart from their anticarcinogenic and anti-inflammatory effects, kaempferol and its associated compounds also exhibit antibacterial, antifungal, and antiprotozoal activities. The development of drugs and treatment schemes based on these compounds is becoming increasingly important in the face of emerging resistance of numerous pathogens as well as complex molecular interactions between various drug therapies. In addition, many of the kaempferol-containing plants are used in traditional systems all over the world for centuries to treat numerous conditions. Due to its variety of sources and associated compounds, some molecular mechanisms of kaempferol antimicrobial activity are well known while others are still under analysis. This paper thoroughly documents the vegetal and food sources of kaempferol as well as the most recent and significant studies regarding its antimicrobial applications.

Anticancer activities of Brachydin C in human prostate tumor cells (DU145) grown in 2D and 3D models: stimulation of cell death and downregulation of metalloproteinases in spheroids

Brachydin C (BrC) has demonstrated in vitro cytotoxic and antiproliferative effects in prostate cancer cells. In the present study, we compare the anticancer effects of BrC in DU145 cells grown in common bidimensional cultures (2D) and multicellular tumor spheroids (MCTS), often denominated 3D in vitro models, that can better mimic the microenvironment of tissues. BrC IC₅₀ values obtained in the resazurin assay after 24 h of treatment were 47.31 μM (2D) and 229.8 μM (3D) and these cytotoxic effects were time dependent only in 3D. BrC (5 to 60 μM) interfered with the growth of MCTS and reduced cell viability after 11 days of treatment, a result that is not attributable to oxidative stress evaluated using the CM-H₂ DCFDA probe. BrC (6.0 μM) impaired horizontal (wound healing) and vertical cell migration and invasion (transwell assay) in 2D and BrC (5.0 to 60 μM) in 3D (ECM Gel®). BrC modulated the expression of genes BIRC5, TNF-α, CASP3, NKX3.1, MMP9, MMP11, CDH1, and ITGAM and downregulated proteins CASP7, BAX, and TNF-α in western blotting analysis. In conclusion, BrC stimulated cell death and decreased epithelial-mesenchymal transition. Furthermore, DU145 MCTS displayed higher resistance to BrC- induced cell death than 2D cultures, a difference that should be considered in future approaches in prostatic cancer studies.

Hydroalcoholic Extract of Myrcia bella Loaded into a Microemulsion System: A Study of Antifungal and Mutagenic Potential

Myrcia bella is a medicinal plant used for the treatment of diabetes, hemorrhages, and hypertension in Brazilian folk medicine. Considering that plant extracts are attractive sources of new drugs, the aim of the present study was to verify the influence of incorporating 70% hydroalcoholic of M. bella leaves in nanostructured lipid systems on the mutagenic and antifungal activities of the extract. In this work, we evaluated the antifungal potential of M. bella loaded on the microemulsion against Candida sp for minimum inhibitory concentration, using the microdilution technique. The system was composed of polyoxyethylene 20 cetyl ether and soybean phosphatidylcholine (10%), grape seed oil, cholesterol (10%: proportion 5/1), and purified water (80%). To investigate the mutagenic activity, the Ames test was used with the Salmonella Typhimurium tester strains. M. bella, either incorporated or free, showed an important antifungal effect against all tested strains. Moreover, the incorporation surprisingly inhibited the mutagenicity presented by the extract. The present study attests the antimicrobial properties of M. bella extract, contributing to the search for new natural products with biological activities and suggesting caution in its use for medicinal purposes. In addition, the results emphasize the importance of the use of nanotechnology associated with natural products as a strategy for the control of infections caused mainly by the genus Candida sp.

Evaluation of Myrcia bella in murine osteosarcoma cells: Effect of the extract and enriched fractions of tannins and flavonoids

Myrcia bella Cambess (Myrtaceae) is an important and common plant, native to the Brazilian Cerrado, with cytotoxicity, antimicrobial, and antidiabetic properties. Therefore, the effects of crude hydroalcoholic extract (CE) and fractions of ellagitannins (ELT) and flavonoids (FV) from Myrcia bella leaves were evaluated in a UMR-106 murine osteosarcoma cells and MC3T3 (normal cell). Cell viability and migration, production of reactive oxygen species (ROS) and matrix metalloproteinase (MMP) -2 and -9 activities were evaluated. In general, CE (80 µg/mL), ELT (160 µg/mL) and FV (64 µg/mL) reduced cell viability (p < 0.05). FV (64 µg/mL) was more effective in inhibition of cell migration, ROS production, and MMP-2 activity when compared to CE and ELT. Myrcia bella a rich source of phenolic compounds and its fraction of flavonoids have cytotoxic effects on osteosarcoma cells, preserving the viability of normal osteoblasts. Due to its antioxidant capacity, flavonoid may be a new therapeutic strategy for cancer.

Aglycone flavonoid brachydin A shows selective cytotoxicity and antitumoral activity in human metastatic prostate (DU145) cancer cells

In prostate cancer, flavonoids possess a wide variety of anticancer effects, focused on the antioxidant/pro-oxidant activity, inactivation of the androgen receptor, cell cycle arrest, apoptosis induction, metastasis inhibition, among others. This current research investigated the antitumoral in vitro activity of Brachydin A (BrA), a dimeric flavonoid isolated from Fridericia platyphylla, in human castration-resistant prostate cancer DU145. It was compared BrA selective effects in tumor prostate DU145 cells with non-tumor prostate epithelial PNT2 cells. Cell viability experiments (resazurin, neutral red, MTT, and LDH release assays) showed that BrA was sevenfold more cytotoxic to tumor cells than non-tumor prostate cells, with IC₅₀ values of 77.7 µM and 10.7 µM for PNT2 and DU145 cells, respectively. Furthermore, BrA induced necrosis and apoptosis (triple fluorescence staining assay) without interfering with oxidative stress (CM-H₂DCFDA) in DU145 cells. Also, BrA (15.36 µM) reduced cell proliferation on clonogenic assay (DU145 cells) but no change in cell number and protein content was observed when cell growth curve assay was used. Wound healing and transwell assays were used for checking the effects of BrA on cell migration and invasion, and BrA impaired these processes in PNT2 (wound healing) and DU145 cells (transwell). Our results inspire further studies to test BrA as a novel chemotherapeutic drug and to evaluate its effects on drug-resistant metastatic cancer cells.

Epiphytic Bacteria from Sweet Pepper Antagonistic In Vitro to Ralstonia solanacearum BD 261, a Causative Agent of Bacterial Wilt

Biological control of plant pathogens, particularly using microbial antagonists, is posited as the most effective, environmentally-safe, and sustainable strategy to manage plant diseases. However, the roles of antagonists in controlling bacterial wilt, a disease caused by the most devastating and widely distributed pathogen of sweet peppers (i.e., R. solanacearum), are poorly understood. Here, amplicon sequencing and several microbial function assays were used to depict the identities and the potential antagonistic functions of bacteria isolated from 80 red and green sweet pepper fruit samples, grown under hydroponic and open soil conditions, with some plants, fungicide-treated while others were untreated. Amplicon sequencing revealed the following bacterial strains: Bacillus cereus strain HRT7.7, Enterobacter hormaechei strain SRU4.4, Paenibacillus polymyxa strain SRT9.1, and Serratia marcescens strain SGT5.3, as potential antagonists of R. solanacearum. Optimization studies with different carbon and nitrogen sources revealed that maximum inhibition of the pathogen was produced at 3% (w/v) starch and 2,5% (w/v) tryptone at pH 7 and 30 °C. The mode of action exhibited by the antagonistic isolates includes the production of lytic enzymes (i.e., cellulase and protease enzymes) and siderophores, as well as solubilization of phosphate. Overall, the results demonstrated that the maximum antimicrobial activity of bacterial antagonists could only be achieved under specific environmental conditions (e.g., available carbon and nitrogen sources, pH, and temperature levels), and that bacterial antagonists can also indirectly promote crop growth and development through nutrient cycling and siderophore production.

Characterization of the invitro cytotoxic effects of brachydins isolated from Fridericia platyphylla in a prostate cancer cell line

Brachydins (Br) A, B, and C are flavonoids extracted from Fridericia platyphylla (Cham.) L.G. Lohmann roots (synonym Arrabidaea brachypoda), whose extract previously exhibited cytotoxic and antitumor activity. In vitro cell culture of human prostate tumor cell line (PC-3) was used to determine cell viability as evidenced by MTT, neutral red, and LDH release using nine concentrations (0.24 to 30.72 µM) of each brachydin. A triple-fluorescent staining assay assessed the mechanism resulting in cell death. Genomic instability and protein expression were evaluated using comet assay and western blot analysis, respectively. The pro-oxidant status was analyzed using the5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate (CM-H₂DCFDA) probe. The IC₅₀ values for brachydins BrA, BrB, and BrC were 23.41, 4.28, and 4.44 µM, respectively, and all compounds induced apoptosis and necrosis. BrB and BrC increased p21 levels indicating a possible G1 cell cycle arrest. BrA (6 µM) and BrB (3.84 µM) decreased phospho-AKT (AKT serine/threonine kinase) expression, which also influenced cell cycle and proliferation. BrA, BrB, and BrC elevated cleaved PARP (poly (ADP-ribose) polymerase), a protein related to DNA repair and induction of apoptotic processes. Therefore, this study determined the IC₅₀ values of brachydins in the PC-3 cell line as well as the influence on cell proliferation and cell death processes, such as apoptosis and necrosis, indicating the proteins involved in these processes.

ABBREVIATIONS

ANOVA: Analysis of Variance; BrA: Brachydin A; BrB: Brachydin B; BrC: Brachydin C; CGEN: Genetic Heritage Management Council; CID: Compound identification number; CM-H₂DCFDA, 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester; CO₂: Carbon dioxide; DMSO: Dimethyl sulfoxide; DNA: Deoxyribonucleic acid; DTT: Dithiothreitol; DXR: Doxorubicin; ECL: Chemiluminescence; EDTA: Ethylenediaminetetraacetic acid; FBS: Fetal bovine serum; H₂O₂: Hydrogen peroxide; HRMS: High-Resolution Mass Spectrometry; IC50: Half maximal inhibitory concentration; LDH: Lactate dehydrogenase; MTT, 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide; Na3VO4: Sodium Orthovanadate; NaOH: Sodium hydroxide; NCBI: National Center for Biotechnology Information; NMR: Nuclear Magnetic Resonance; PBS: Phosphate buffer saline; PCR: Polymerase chain reaction; PSMF: Phenylmethylsulfonyl fluoride; RPMI: Roswell Park Memorial Institute Medium; SDS-PAGE: Sodium Dodecyl Sulfate-Polyacrylamide gel electrophoresis; STR: Short tandem repeat; TBS-T: Tris-buffered saline and Polysorbate 20; UPHLC: Ultra-Performance Liquid Chromatography.

Metabolomics of Myrcia bella Populations in Brazilian Savanna Reveals Strong Influence of Environmental Factors on Its Specialized Metabolism

Environmental conditions influence specialized plant metabolism. However, many studies aiming to understand these modulations have been conducted with model plants and/or under controlled conditions, thus not reflecting the complex interaction between plants and environment. To fully grasp these interactions, we investigated the specialized metabolism and genetic diversity of a native plant in its natural environment. We chose Myrcia bella due to its medicinal interest and occurrence in Brazilian savanna regions with diverse climate and soil conditions. An LC-HRMS-based metabolomics approach was applied to analyze 271 samples harvested across seven regions during the dry and rainy season. Genetic diversity was assessed in a subset of 40 samples using amplified fragment length polymorphism. Meteorological factors including rainfall, temperature, radiation, humidity, and soil nutrient and mineral composition were recorded in each region and correlated with chemical variation through multivariate analysis (MVDA). Marker compounds were selected using a statistically informed molecular network and annotated by dereplication against an in silico database of natural products. The integrated results evidenced different chemotypes, with variation in flavonoid and tannin content mainly linked to soil conditions. Different levels of genetic diversity and distance of populations were found to be correlated with the identified chemotypes. These observations and the proposed analytical workflow contribute to the global understanding of the impact of abiotic factors and genotype on the accumulation of given metabolites and, therefore, could be valuable to guide further medicinal exploration of native species.

Carvacrol Promotes Cell Cycle Arrest and Apoptosis through PI3K/AKT Signaling Pathway in MCF-7 Breast Cancer Cells

OBJECTIVE

To examine the role of carvacrol in modulating PI3K/AKT signaling involved in human breast cancer pathogenesis using in vitro experimental model MCF-7 cells.

METHODS

MTT and lactate dehydrogenase assays were performed with cells treated with different doses of carvacrol (0-250 p mol/L) at different time points (24 and 48 h). The nuclear morphology was assessed in MCF-7 cells with propidium iodide (PI) and acridine orange/ethidium bromide (AO/EB) staining and analyzed by fluorescence microscopy. Events like cell cycle arrest, apoptosis was observed by flow cytometric analysis and expressions of p-Rb, cyclin D1, cyclin-dependent kinase 4 (CDK4), CDK6, Bax, Bcl-2, PI3K/p-AKT was analyzed by immunoblot.

RESULTS

Carvacrol significantly reduced cell viability with the half maximal inhibitory concentration value of 200 µmol/L at 24 and 48 h (P<0.05). importantly, there was a significant increase in the accumulation of the G₀/G₁ phase upon treatment with carvacrol in MCF-7 cells (P<0.05 or P<0.01). A remarkable decrease in protein expressions of p-Rb, cyclin D1, CDK4 and CDK6 denotes cell cycle arrest (P<0.05 or P<0.01). In addition, carvacrol treatment significantly inhibited PI3K/p-AKT protein expressions leading to induction of apoptosis mediated by decreased Bcl2 and increased Bax protein expressions. Further, Annexin V/PI staining by FACS analysis, dual staining by AO/EB and PI staining studies suggests induction of apoptosis by carvacrol through PI3K/Akt signaling pathway in MCF-7 cells.

CONCLUSION

Carvacrol significantly inhibited the breast cancer MCF-7 cell proliferation and induced apoptosis via suppressing PI3/AKT signaling pathway.

Fridericia platyphylla (Cham.) L.G. Lohmann root extract exerts cytotoxic and antiproliferative effects on gastric tumor cells and downregulates BCL-XL, BIRC5, and MET genes

Fridericia platyphylla (Cham.) L.G. Lohmann (FP) has cytotoxic, anti-inflammatory, and analgesic properties. We aimed to characterize the cytotoxic and antiproliferative effects of FP extract on normal (GAS) and tumor-derived (ACP02 and HepG2) cell lines. The effective concentrations (EC50s) by tetrazolium bromide assay (MTT) were 56.16, 43.68, and 42.57 µg mL−1 and 69.38, 41.73, and 52.39 µg mL−1 by neutral red assay for GAS, ACP02, and HepG2 cells, respectively. The extract decreased nuclear division indices, which was not reflected in cell proliferation curves. Flow cytometric analyses showed that even 30 µg mL−1 extract (shown to be noncytotoxic by MTT assay) increased the sub-G1 population, indicating cell death due to apoptosis and necrosis. A cytokinesis-block micronucleus cytome assay showed that 30 µg mL−1 of the extract increased the frequency of nuclear buds in tumor cells. Real-time quantitative polymerase chain reaction showed CCND1 upregulation in doxorubicin-treated GAS cells and BCL-XL, BIRC5, and MET downregulation in 5 or 30 µg mL−1 in FP extract-treated ACP02 cells. In conclusion, FP extract modulated apoptosis- and cell cycle-related genes and presented selective cytotoxicity toward tumor cells that deserves further investigation by testing other cell types. Our results demonstrated that even medicinal plants exert adverse effects depending on the extract concentrations used and tissues investigated.

Flavonoids from Brazilian Cerrado: Biosynthesis, Chemical and Biological Profile

Flavonoids are highly bioactive compounds with very low toxicity, which makes them attractive starting points in drug discovery. This study aims to provide information on plant species containing flavonoids, which are found in the Brazilian Cerrado. First, we present the characterization and plant diversity with emphasis on the families of flavonoid-producing plants, and then we describe the phenylpropanoid pathway which represents the flavonoids’ main route biosynthesis—generally conserved in all species. Chemical structures and biological activities of flavonoids isolated from the Cerrado’s plant species are also described based on examples from the relevant literature studies. Finally, research on the biodiversity of the Cerrado biome should be encouraged, due to the discovery of new sources of flavonoids which can provide several benefits to human health and the possibility of developing new drugs by the pharmaceutical industry.

Pouteria ramiflora (Mart.) Radlk. extract: Flavonoids quantification and chemopreventive effect on HepG2 cells

Pouteria ramiflora (Mart.) Radlk., popularly known as curriola, is commonly used in Brazil as medicinal plant to treat worm infections, dysentery, pain, inflammation, hyperlipidemia, and obesity. At present the safety of this extract when used therapeutically in human remains to be determined. Thus, the aim of this study was to examine cytotoxicity, antiproliferative, and antimutagenic actions of this extract. The hydroalcoholic extract from P. ramiflora leaves consisted of flavonoids identified and quantified as myricetin-3-O-β-D-galactopyranoside (13.55 mg/g) and myricetin-3-O-α-L-rhamnopyranoside (9.61 mg/g). The extract exhibited cytotoxicity at concentrations higher than 1.5 µg/ml in human hepatocarcinoma (HepG2)and 2.5 µg/ml in non-tumoral primary gastric (GAS) cells using the MTT assay, and at concentrations higher than 3 µg/ml in HepG2 and 3.5 µg/ml in GAS cells by the neutral red assay. The extract did not show antiproliferative effect as evidenced by the nuclear division index (NDI). However, in the presence of benzo[a]pyrene (BaP) (positive control), an enhanced cytostatic effect in the NDI and flow cytometry was noted. It is of interest that when the extract was co-incubated with BaP a significant decrease in DNA damage was observed indicating an antimutagenic action. This protective effect might be attributed to myricetin and gallic acid found in P. ramiflora extract. The low cytotoxicity action and protective effect observed in the present study encourage further studies regarding other biological effects of P. ramiflora, as well as its potential use as a chemopreventive agent.

Antioxidative, Antiproliferative and Antimicrobial Activities of Phenolic Compounds from Three Myrcia Species

Myrcia bella Cambess., Myrcia fallax (Rich.) DC. and Myrcia guianensis (Aubl.) DC. (Myrtaceae) are trees found in Brazilian Cerrado. They have been widely used in folk medicine for the treatment of gastrointestinal disorders, hemorrhagic and infectious diseases. Few reports have been found in the literature connecting their phenolic composition and biological activities. In this regard, we have profiled the main phenolic constituents of Myrcia spp. leaves extracts by ESI(−)Q-TOF-MS. The main constituents found were ellagic acid (M. bella), galloyl glucose isomers (M. guianensis) and hexahydroxydiphenic (HHDP) acid derivatives (M. fallax). In addition, quercetin and myricetin derivatives were also found in all Myrcia spp. extracts. The most promising antioxidant activity, measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, was found for M. fallax extracts (EC50 8.61 ± 0.22 µg·mL−1), being slightly less active than quercetin and gallic acid (EC50 2.96 ± 0.17 and 2.03 ± 0.02 µg·mL−1, respectively). For in vitro antiproliferative activity, M. guianensis showed good activity against leukemia (K562 TGI = 7.45 µg·mL−1). The best antimicrobial activity was observed for M. bella and M. fallax to Escherichia coli (300 and 250 µg·mL−1, respectively). In conclusion, the activities found are closely related to the phenolic composition of these plants.

Phytochemical study and evaluation of cytotoxicity, mutagenicity, cell cycle kinetics and gene expression of Bauhinia holophylla (Bong.) Steud. in HepG2 cells in vitro

Bauhinia holophylla (Bong.) Steud. (Fabaceae) is a plant used in Brazilian folk medicine to treat diabetes and inflammation. This study evaluated the phytochemical properties, cytotoxic, apoptotic, mutagenic/antimutagenic effects and alterations in gene expression (RNAm) in HepG2 cells treated with the B. holophylla extract. The phytochemical profile highlight the presence of flavonoids isorhamentin and quercetin derivates. The MTT assay was used to evaluate the cytotoxicity of different concentrations for different treatment times. Three concentrations (7.5, 15, 30 µg/mL) were chosen for assessment of apoptosis (AO/EB), mutagenicity (micronucleus), and cell cycle kinetics (flow cytometry). Thereafter, the concentration of 7.5 µg/mL was chosen to evaluate the protective effects against DNA damage induced by benzo[a]pyrene (B[a]P). At concentrations higher than 7.5 µg/mL (between 10 and 50 µg/mL), the extract was cytotoxic, induced apoptosis, and caused antiproliferative effects. However, it did not induce micronucleus and a reduction of apoptotic and micronucleated cells was observed in treatments that included the extract and B[a]P. The protective effect is attributable to the presence of flavonoids, described as antioxidants, inhibitors of DNA adduct and activators of detoxifying enzymes. The results of the present study such as absence of cytotoxic and mutagenic effects and protective effects against known carcinogens suggest that B. holophylla has potential for use soon as herbal medicine.

The Chemical Profile of Senna velutina Leaves and Their Antioxidant and Cytotoxic Effects

Natural products can be a source of biomolecules with antioxidant activity which are able to prevent oxidative stress-induced diseases and show antitumor activity, making them important sources of new anticancer drug prototypes. In this context, this study aimed to analyze the chemical composition of an ethanol extract of Senna velutina leaves and to assess its antioxidant and cytotoxic activities in leukemic cells. The antioxidant properties were evaluated using a DPPH free radical scavenging assay and by examining the extract's inhibition of AAPH-induced lipid peroxidation in human erythrocytes. Its cytotoxicity and possible mechanisms of action were assessed in Jurkat and K562 leukemic cell lines. The ethanol extract contained flavonoids, such as epigallocatechin, epicatechin, kaempferol heteroside, rutin, and dimeric and trimeric proanthocyanidin derivatives. The extract exhibited antioxidant activity by scavenging free radicals and antihemolytic action, and it decreased malondialdehyde content in human erythrocytes. Furthermore, the extract also induced leukemic cell death by activating intracellular calcium and caspase-3, decreasing mitochondrial membrane potential, and arresting the cell cycle in S and G2 phases. Hence, S. velutina leaf extract contains antioxidant and antileukemic biomolecules with potential applications in diseases associated with oxidative stress and in the inhibition of tumor cell proliferation.

Purification of Cucurbitacins D, E, and I from Ecballium Elaterium (L.) A. Rich Fruits and Study of Their Cytotoxic Effects on the AGS Cell Line

Background:

The plant Ecballium elaterium (L.) A. Rich, belongs to the Cucurbitaceae family which occupies an important position in traditional medicine prescriptions. It has been reported that a freeze-dried aqueous extract of E. elaterium fruits has cytotoxic effects on the AGS human stomach adenocarcinoma cell line. We here focused on anticancer effects of the main chemicals purified from E. elaterium fruits.

Materials and Methods:

We isolated cucurbitacins D, E, and I from chloroform, and ethyl acetate fractions of a methanolic extract of E. elaterium fruits and assessed their cytotoxic effects on the AGS cell line by MTT assay. The methanolic extract was fractionated to petroleum ether, chloroform, and ethyl acetate fractions. The compounds isolated by column chromatography were identified by NMR spectroscopy.

Results:

After 24 h of incubation with AGS cells, the IC50 values were 0.3, 0.1, and 0.5 μg/ml for cucurbitacins D, E, and I respectively.

Conclusions:

This finding suggests that because of its cucurbitacins, E. elaterium fruit may have some cytotoxic effects on gastric cancer cells. Also, compared with D and I, cucurbitacin E showed greater potency in this regard.

LDH, proliferation curves and cell cycle analysis are the most suitable assays to identify and characterize new phytotherapeutic compounds

Brazilian flora biodiversity has been widely investigated to identify effective and safe phytotherapeutic compounds. Among the investigated plant species, the Byrsonima genus exhibits promising biological activities. This study aimed at evaluating the cytotoxicity of B. correifolia, B. verbascifolia, B. fagifolia and B. intermedia extracts using different assays in two cell lines (primary gastric and HepG2 cells). The different extract concentrations effects on cell viability were assayed using the MTT, aquabluer, neutral red and LDH assays. Non-cytotoxic concentrations were selected to generate cell proliferation curves and to assess cell cycle kinetics by flow cytometry. Byrsonima extracts differentially affected cell viability depending on the metabolic cellular state and the biological parameter evaluated. B. fagifolia and B. intermedia extracts exhibited lower cytotoxic effects than B. correifolia and B. verbascifolia in all assays. The results obtained with LDH and flow cytometry assays were more reliable, suggesting that they can be useful in the screening for herbal medicine and to further characterize these extracts as phytotherapeutic compounds.