Microbiota-Derived Natural Products Targeting Cancer Stem Cells: Inside the Gut Pharma Factory

Cancer stem cells (CSCs) have drawn much attention as important tumour-initiating cells that may also be crucial for recurrence after chemotherapy. Although the activity of CSCs in various forms of cancer is complex and yet to be fully elucidated, opportunities for therapies targeting CSCs exist. CSCs are molecularly distinct from bulk tumour cells, so they can be targeted by exploiting their signature molecular pathways. Inhibiting stemness has the potential to reduce the risk posed by CSCs by limiting or eliminating their capacity for tumorigenesis, proliferation, metastasis, and recurrence. Here, we briefly described the role of CSCs in tumour biology, the mechanisms involved in CSC therapy resistance, and the role of the gut microbiota in cancer development and treatment, to then review and discuss the current advances in the discovery of microbiota-derived natural compounds targeting CSCs. Collectively, our overview suggests that dietary intervention, toward the production of those identified microbial metabolites capable of suppressing CSC properties, is a promising approach to support standard chemotherapy

Genomic study, phytochemical characterization, and antiproliferative activity of two different genotypes of Jatropha curcas L. obtained by a breeding program

Jatropha curcas (Euphorbiaceaefamily) is a multipurpose plant with considerable potential in biodiesel production, and in cosmetic and medicinal uses. The part of J. curcas usually used is the oil obtained from its seeds, whereas the leaves generally represent the waste material. The aim of this study was to characterize the composition and to preliminary investigate the biological activity of J. curcas leaves obtained from plants by a breeding program. To describe genomic structure, molecular markers were applied. For biological study, two genotypes (JA and JB) that are genetically divergent were selected by cluster analysis. A phytochemical analysis was carried out to characterize the chemical composition of the extracts, which resulted rich in biologically active compounds, whereas toxic phorbol esters were absent. Biological assays showed an antiproliferative effect on the Buffalo normal rat liver cell line (BRL-3A), with genotype B being more potent than that of the counterpart (JA). The purified compounds isolated did not show antiproliferative activity, suggesting that the effect observed was due to the phytocomplex and should involve several secondary metabolites. This study highlights that a plant of the same genus and same species that has been cultivated in the same soil and climatic conditions can be characterized by a high variability. This is what makes research in pharmacognosya complex process

Attività esterasica, lipolitica e proteolitica in Armoracia rusticana

Introduzione Armoracia rusticana (comunemente nota come rafano) è una specie, appartenente alla famiglia delle Brassicaceae, caratterizzata dall'ampio uso sia per scopi etnomedicali che culinari. Il caratteristico gusto pungente che contraddistingue la sua radice deriva dall'abbondanza in glucosinolati. Ad oggi l'interesse verso questa specie, oltre che per la sua ricchezza in enzimi come la perossidasi, una glicoproteina comunemente utilizzata in ambito analitico, è rivolto soprattutto verso altre sostanze bioattive quali vitamine, minerali, isotiocianati e antiossidanti. In questo lavoro è stata valutata l'attività antiossidante negli estratti di A. rusticana ed il contenuto totale in polifenoli ed in flavonoidi. Inoltre, è stata determinata la presenza di attività enzimatiche poco investigate in questa specie come esterasi, lipasi e proteasi. Materiali e metodi In questo studio sono stati analizzati quattro differenti genotipi di A. rusticana, raccolti in un areale di Accettura (provincia di Matera, Basilicata). Le analisi sono state condotte sugli estratti acquosi e metanolici, ottenuti a partire dalle radici ridotte in polvere con azoto liquido e conservate a -80°C fino al momento delle analisi. Il contenuto totale in polifenoli ed in flavonoidi è stato determinato rispettivamente con il reagente di Folin-Ciocalteau e con il saggio dell'AlCl3. L'attività antiossidante è stata valutata mediante i test del FRAP e dell'ABTS. Le attività esterasica e lipolitica sono state determinate per via spettrofotometrica valutando la quantità di p-nitrofenolo liberato da diversi substrati sintetici (Sigma). L'attività proteolitica è stata determinata sia in soluzione che mediante zimografia utilizzando la gelatina come substrato. Risultati Nei quattro genotipi analizzati, l'attività antiossidante determinata con i metodi FRAP e ABTS è compresa rispettivamente tra 170-330 e 640-1000 mg a. ascorbico equivalente/g, mentre il contenuto in polifenoli totali varia tra 0.9-1.2 mg a. gallico equivalente/g, di cui circa il 9% è costituito da flavonoidi. Riguardo la presenza di attività esterasica e lipolitica, tutti i campioni hanno mostrato una maggior specificità nei confronti di acidi grassi a catena corta. Infine, per quanto riguarda la presenza di attività proteolitica, negli estratti è stata rilevata una moderata attività gelatinolitica sia in soluzione che su gel. Conclusioni I dati ottenuti dalle analisi condotte sugli estratti di A. rusticana mostrano una buona capacità di radical scavenging ed un contenuto in polifenoli simile a quello delle altre Brassicaceae. Un aspetto interessante di questo lavoro, considerando la scarsità di dati disponibili in letteratura, è rappresentato dallo studio preliminare circa la presenza di attività esterasica, lipolitica e proteolitica nelle radici di A. rusticana

Ethanol stress in Oenococcus oeni: transcriptional response and complex physiological mechanisms

Oenococcus oeni is the dominant species able to cope with a hostile environment of wines, comprising cumulative effects of low pH, high ethanol and SO2 content, nonoptimal growth temperatures and growth inhibitory compounds. Ethanol tolerance is a crucial feature for the activity of O. oeni cells in wine because ethanol acts as a disordering agent of its cell membrane and negatively affects metabolic activity; it damages the membrane integrity, decreases cell viability and, as other stress conditions, delays the start of malolactic fermentation with a consequent alteration of wine quality. The cell wall, cytoplasmic membrane and metabolic pathways are the main sites involved in physiological changes aimed to ensure an adequate adaptive response to ethanol stress and to face the oxidative damage caused by increasing production of reactive oxygen species. Improving our understanding of the cellular impact of ethanol toxicity and how the cell responds to ethanol stress can facilitate the development of strategies to enhance microbial ethanol tolerance; this allows to perform a multidisciplinary endeavour requiring not only an ecological study of the spontaneous process but also the characterization of useful technological and physiological features of the predominant strains in order to select those with the highest potential for industrial applications

Characterization of different genotypes of Jatropha curcas L.

Jatropha curcas L. (Euphorbiaceae family) is a perennial plant, which is widely distributed in tropical areas. Different parts of this plant have been traditionally used for various purposes. In particular, the oil from seeds has been used for soap production, for treatment of skin diseases, etc. The leaves have been used against coughs, as antiseptics and diuretics. Recently, J. curcas achieved significant importance for biodiesel production (green energy) from its seed oil (Thomas et al., 2008). Various active substances have been isolated from all parts of the plant, including: apigenin and vitexin (from leaves); alkaloids (from latex); other substances such as phorbol esters, responsible for the toxicity of J. curcas seeds. However, different genotypes from the same species could have different composition and, as a consequence, different biological activities. Aim of this study was to characterize genotypes of J.curcas at genomic, transcriptomic, phytochemical and biological levels. The genotypes were obtained by specific breeding program; to perform the study two divergent genotypes (A and B) were used. Genomic analysis were applied to estimate genetic distance into the segregant population. From each genotype leaves and petiole, at equal physiological phase, were collected and extracted using solvents with increasing polarity. Transcriptomic analysis (Milella et al., 2006) were carried out to isolate differentially expressed genome fraction. The sequence analysis of the differential fragments was obtained using FASTA and BLAST algorithm, and comparing with EMBL databases. Phytochemical studies were performed by chromatography (CC, TLC), spectroscopy (NMR). The biological activity (cell proliferation and cytotoxicity) of J. curcas was assessed in a wide range of concentrations (6-0.05 mg/ml of methanolic extract) on BRL-3A hepatic cell line, by MTT test, Trypan blue exclusion test and Neutral Red assay (Vitalone et al., 2003; Ganbold et al., 2010). The genomic analysis have shown sufficient differences between genotype A and B structures. This aspect was confirmed by transcriptomic analysis. Moreover, sequences analysis highlighted differences in enzyme activities and transcription factors among the genotypes. In vitro study indicated that petiole of two different genotypes of J. curcas did not affect BRL-3A cell proliferation. On the other hand, leaves inhibited cell proliferation in a concentration dependent manner. Genotype B was more potent than Genotype A (IC50= 0.12 mg/ml and 0.47 mg/ml, respectively in MTT test), and more cytotoxic at the higher concentrations tested (at 6 mg/ml, percentage of dead cells were 65% and 45% for Genotype B and A, respectively in Trypan blue test). Lysosomes appears less sensitive than mitochondria to genotype B effect (neutral red test), indicating that mitochondrial dysfunction occurs without the lysosomal permeabilization. A further characterization of the more potent Genotype B indicated that nonpolar fraction contained mainly polyunsaturated fatty acids, whereas several flavonoids were detected in the medium polarity fraction in their glycosides forms. Even if mitochondrial impairment without lysosomes destabilization, on hepatocytes, is generally due to fatty acids (Li et al., 2008) also flavonoids could contribute to this effect. In summary, this study provided evidence that two divergent genotypes of J. curcas have large differences at genomic and transcriptomic levels; this leads to a difference in the biological activity, with genotype B as more potent in the inhibition of cell proliferation. Further studies will additional characterize phytochemistry and other biological effects of J. curcas

Antibacterial Activity Of New Β-Lactam Compound

A new β-lactam molecule A1 was synthesized and formulated to introduce an innovative solution in order to circumvent the bacterial resistance and their defenses against antibiotics. This innovative molecule was tested towards representative Gram positive and Gram negative strains of antibiotic-resistant pathogenic bacteria to evaluate its antibacterial activity and to analyze the action spectrum and the antibacterial effectiveness. Results showed that the new compound A1 was synthesized with a yield of 55% and demonstrated the antimicrobial activity against all tested bacteria, except Pseudomonas aeruginosa, and all Gram-positive bacteria were more sensitive with a good antimicrobial activity. Moreover, as the determined MIC90, both strains of the Streptococcus genus were inhibited at a concentration of 16 μg/ml of the compound A1, while Staphylococcus aureus resulted sensitive to an inhibitory concentration of 64 μg/ml. The Gram-negative bacteria, instead, required an inhibitory concentration of 64 μg/ml for Escherichia coli and 128 μg/ml for Klebsiella pneumoniae. In conclusion, compound A1 is a promising molecule to develop a new class of safe and active antibiotics, with a predicted good inhibitory capacity not only against Gram positive, but also Gram negative microorganisms. Keywords: β-lactam compoun