RESUMEN

In mango pickle industry, a significant quantity of mango seed kernels is discarded as solid wastes. These seed kernels can be an ideal source for obtaining extracts rich in bioactive polyphenolic compounds with good antioxidant properties. The potential of mango kernel phenolic extract (MKPE) was investigated as a natural and effective antimicrobial agent for controlling major postharvest fungal pathogen infections, a significant threat to global food supply chains. Fungal pathogens contribute to the deterioration of fruits, vegetables, and grains during storage and transportation, leading to economic losses and compromised food safety. MKPE was obtained from pickling variety 'Ramkela' raw mango kernels, and its phenolic composition was characterized using LC-MS. The in vitro antifungal activity of MKPE against Botrytis cinerea, Colletotrichum gloeosporoides, and Rhizopus stolonifer was evaluated in vitro. A concentration-dependent inhibition of fungal radial growth against all three pathogens was observed, exhibiting the potential of MKPE as a valuable natural resource for addressing postharvest losses caused by fungal pathogens. The extraction process yielded a total phenolic content of 2128 mg GAE/100 g. Major polyphenolic bioactive compounds present were mangiferin, quercetin, and rhamnetin. The in-vitro antimicrobial assay showed reduction in the radial growth and inhibition percent of the pathogens. EC50 values of MKPE for B. cineria, C. gloeosporoides, and R. stolonifer was found to 364.17, 963.8 and 926 ppm, respectively. Our results demonstrate an economical, sustainable, and eco-friendly approach to manage post-harvest diseases rendered by fungi using mango MKPE from pickling industry waste.

RESUMEN

Bradykinin (BK) has been recognized as a stimulant for matrix metalloproteinase (MMP)-9 expression, contributing to neuroinflammation. Modulating the BK/MMP-9 pathway offers potential in the treatment of neuroinflammatory disorders. Rhamnetin (RNT), a flavonoid compound known for its antioxidant and anti-inflammatory effects, has shown promise. However, the specific mechanisms through which RNT inhibits BK-induced MMP-9 expression remain unclear. Therefore, this study aims to delve into the intricate mechanisms underlying this process. Here, we initially demonstrated that RNT effectively attenuated BK-induced MMP-9 expression and its associated cell migration in rat brain astrocyte-1 (RBA-1) cells. Further investigation revealed that BK-driven MMP-9 protein, mRNA, and promoter activity linked to cell migration relied on c-Src, Pyk2, EGFR, PDGFR, PI3K/Akt, JNK1/2, and c-Jun. This was validated by the inhibition of these effects through specific inhibitors, a finding substantiated by the introduction of siRNAs targeting these signaling molecules. Notably, the phosphorylated levels of these signaling components induced by BK were significantly reduced by their respective inhibitors and RNT, underscoring the inhibitory role of RNT in this process. These findings indicate that, in RBA-1 cells, RNT diminishes the heightened induction of MMP-9 triggered by BK through the inhibition of c-Src/Pyk2/PDGFR and EGFR/PI3K/Akt/JNK1/2-dependent AP-1 activation. This suggests that RNT holds promise as a potential therapeutic approach for addressing neuroinflammation in the brain.

RESUMEN

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a well-known harmful bacterium that causes severe health disorders and dysregulates the host immune response associated with inflammation. Upon examining the suppressive activity of natural flavonoid rhamnetin on various pro-inflammatory cytokines in a CRAB-induced septic shock mouse model, we found that rhamnetin inhibited the production of IL-1ß and IL-18, two pro-inflammatory cytokines associated with pyroptotic cell death, a process dependent on caspase-1. In this study, we investigated the antioxidant and anti-apoptotic activities of rhamnetin and the underlying mechanism of action in a CRAB infection. In the CRAB-induced septic shock mouse model, rhamnetin reduced the level of lipopolysaccharide (LPS) in lung lysates, resulting in the inhibition of TLR4-mediated inflammatory signaling. Notably, rhamnetin reduced intracellular reactive oxygen species (ROS) generation in macrophages and inhibited apoptotic and pyroptotic cell injury induced by CRAB infection. Therefore, rhamnetin inhibited LPS-induced pro-inflammatory mediators, hindering apoptotic and pyroptotic processes and contributing to a recovery effect in CRAB-induced sepsis mice by suppressing oxidative stress. Taken together, our study presents the potential role of rhamnetin in protecting against oxidative damage induced by CRAB infection through a TLR4 and ROS-mediated pyroptotic pathway, showing an alternative mechanism for sepsis prevention. Therefore, rhamnetin is a promising therapeutic candidate for treating CRAB-induced sepsis.

Asunto(s)

Acinetobacter baumannii , Sepsis , Choque Séptico , Ratones , Animales , Especies Reactivas de Oxígeno/farmacología , Lipopolisacáridos/toxicidad , Receptor Toll-Like 4 , Sepsis/inducido químicamente , Sepsis/tratamiento farmacológico , Citocinas/farmacología , Carbapenémicos/farmacología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pruebas de Sensibilidad Microbiana

RESUMEN

Overexpression of HDAC 2 promotes cell proliferation in ovarian cancer. HDAC 2 is involved in chromatin remodeling, transcriptional repression, and the formation of condensed chromatin structures. Targeting HDAC 2 presents a promising therapeutic approach for correcting cancer-associated epigenetic abnormalities. Consequently, HDAC 2 inhibitors have evolved as an attractive class of anti-cancer agents. This work intended to investigate the anti-cancer abilities and underlying molecular mechanisms of Rhamnetin in human epithelial ovarian carcinoma cells (SKOV3), which remain largely unexplored. We employed various in vitro methods, including MTT, apoptosis study, cell cycle analysis, fluorescence microscopy imaging, and in vitro enzymatic HDAC 2 protein inhibition, to examine the chemotherapeutic sensitivity of Rhamnetin in SKOV3 cells. Additionally, we conducted in silico studies using molecular docking, MD simulation, MM-GBSA, DFT, and pharmacokinetic analysis to investigate the binding interaction mechanism within Rhamnetin and HDAC 2, alongside the compound's prospective as a lead candidate. The in vitro assay confirmed the cytotoxic effects of Rhamnetin on SKOV3 cells, through its inhibition of HDAC 2 activity. Rhamnetin, a nutraceutical flavonoid, halted at the G1 phase of the cell cycle and triggered apoptosis in SKOV3 cells. Furthermore, computational studies provided additional evidence of its stable binding to the HDAC 2 protein's binding site cavity. Based on our findings, we conclude that Rhamnetin effectively promotes apoptosis and mitigates the proliferation of SKOV3 cells through HDAC 2 inhibition. These results highlight Rhamnetin as a potential lead compound, opening a new therapeutic strategy for human epithelial ovarian cancer.Communicated by Ramaswamy H. Sarma.

RESUMEN

The current research was performed to evaluate the ameliorative effects of Rhamnetin (RHM) on polystyrene microplastics (PS-MPs)-instigated testicular dysfunction in male albino rats. 48 albino rats were distributed in four groups, i.e., control, PS-MPs treated, PS-MPs + RHM co-treated and RHM only supplemented group. PS-MPs exposure considerably reduced anti-oxidant enzymes i.e., catalase (CAT), glutathione peroxidase (GSR), superoxide dismutase (SOD) and glutathione reductase (GPx) activities. Whereas, reactive oxygen species (ROS) level along with malondialdehyde (MDA) was considerably escalated in PS-MPs treated rats as well as a potential decline was observed in sperm progressive motility. Additionally, a substantial upsurge was noticed in the count of dead sperms, deformity in the tail, mid-piece and head of sperms in PS-MPs treated rats. PS-MPs exposure also decreased steroidogenic enzymes, 17ß-hydroxysteroid dehydrogenase (17ß-HSD), steroidogenic acute regulatory protein (StAR) and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) expressions. Moreover, the levels of inflammatory indices i.e., Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1ß (IL-1ß), tumour necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) activity were also increased in PS-MPs administrated group. Besides it increased the expression of apoptotic markers (Bax and caspase-3) expression. Whereas, anti-apoptotic marker i.e., Bcl-2 expression was reduced. Moreover, luteinizing hormone (LH), follicle-stimulating hormone (FSH) as well as plasma testosterone levels were also decreased. PS-MPs exposure also led to a substantial histopathological damage in testicular tissues. However, RHM supplementation potentially reduced the damaging effects of PS-MPs in the reproductive tissues of male albino rats. Thus, the current study revealed, RHM possesses potential to prevent PS-MPs-induced testicular damage due to its anti-oxidant anti-apoptotic, anti-inflammatory as well as androgenic properties.

Asunto(s)

Antioxidantes , Microplásticos , Masculino , Ratas , Animales , Antioxidantes/farmacología , Microplásticos/análisis , Microplásticos/metabolismo , Microplásticos/farmacología , Plásticos/análisis , Plásticos/metabolismo , Plásticos/farmacología , Poliestirenos/análisis , Poliestirenos/metabolismo , Poliestirenos/farmacología , Semen/metabolismo , Testículo , Estrés Oxidativo , Testosterona

RESUMEN

Rhamnetin is a flavonoid which contained in especially clove, such as apple, tea, and onion plant. Rhamnetin has been used in cancer research due to its antitumor and antioxidant properties. In this study, effects of rhamnetin administration at different doses on ascites and solid tumors were investigated in Balb/C mice bearing EAT model that originating from rat breast adenocarcinoma. Experimental procedure: Overall, 92 Balb-c mice were used in this study. EAT cells (1 × 106 cells) that harvested from stock animals were injected to all rats via intraperitoneal and subcutaneous route. Rhamnetin (100 µg/kg-200 µg/kg) were given intraperitoneally and subcutaneously during 10 and 15 days to the animals bearing ascites tumor and solid tumor, respectively. Throughout experiments, weight changes were recorded in all groups. The maximum weight increase was observed in the control group among all groups (ascites and solid tumor groups). In the treatment groups, the least weight increase were determined in 200-µg/kg rhamnetin applied. The lowest increase in tumor volume was observed in the group that received 200-µg/kg rhamnetin (2.84) when compared to tumor control group (3.67). Result and conclusion: We determined that the number of live and dead cells in the treatment groups administered with the mean rhamnetin dose (2.5 µg/ml) was found in the count made in the EAT cell line after the incubation periods. We observed that rhamnetin plays an important role against cancer formation. We have obtained important results in our study, but detailed studies on the relationship between rhamnetin and cancer are needed.

Asunto(s)

Carcinoma de Ehrlich , Ratones , Ratas , Animales , Carcinoma de Ehrlich/tratamiento farmacológico , Carcinoma de Ehrlich/patología , Ascitis , Quercetina/farmacología , Quercetina/uso terapéutico , Antioxidantes/uso terapéutico

RESUMEN

Non-alcoholic fatty liver (NAFLD) is a widespread disease with various complications including Non-alcoholic steatohepatitis (NASH) that could lead to cirrhosis and ultimately hepatocellular carcinoma (HCC). Up till now there is no FDA approved drug for treatment of NAFLD. Flavonoids such as Rhamnetin (Rhm) have been ascribed effective anti-inflammatory and anti-oxidative properties. Thus, Rhm as a potent flavonoid could target multiple pathological cascades causing NAFLD to prevent its progression into HCC. NAFLD is a multifactorial disease and its pathophysiology is complex and is currently challenged by the 'Multiple-hit hypothesis' that includes wider range of comorbidities rather than previously established theory of 'Two-hit hypothesis'. Herein, we aimed at establishing reliable in vitro NASH models using different mixtures of variable ratios and concentrations of oleic acid (OA) and palmitic acid (PA) combinations using HepG2 cell lines. Moreover, we compared those models in the context of oil red staining, triglyceride levels and their altered downstream molecular signatures for genes involved in de novo lipogenesis, inflammation, oxidative stress and apoptotic machineries as well. Lastly, the effect of Rhm on NASH and HCC models was deeply investigated. Over the 10 NASH models tested, PA 500 µM concentration was the best model to mimic the molecular events of steatosis induced NAFLD. Rhm successfully ameliorated the dysregulated molecular events caused by the PA-induced NASH. Additionally, Rhm regulated inflammatory and oxidative machinery in the HepG2 cancerous cell lines. In conclusion, PA 500 µM concentration is considered an effective in vitro model to mimic NASH. Rhm could be used as a promising therapeutic modality against both NASH and HCC pathogenesis.

Asunto(s)

Carcinoma Hepatocelular , Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Humanos , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/patología , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/patología , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/patología , Quercetina , Ácido Palmítico , Flavonoides

RESUMEN

In sepsis, the persistence of uncontrolled inflammatory response of infected host cells eventually leads to severe lung and organ failure and, ultimately, death. Carbapenem-resistant Acinetobacter baumannii (CRAB), causative bacteria of sepsis and lung failure in acute cases, belongs to a group of critical pathogens that cannot be eradicated using the currently available antibiotics. This underlines the necessity of developing new modes of therapeutics that can control sepsis at the initial stages. In this study, we investigated the anti-inflammatory activities in vitro and in vivo and the antiseptic effects of rhamnetin, a naturally occurring flavonoid. We found that among its isoforms, the potency of rhamnetin was less explored but rhamnetin possessed superior anti-inflammatory activity with least cytotoxicity. Rhamnetin showed significant anti-inflammatory effects in lipopolysaccharide-, CRAB-, and Escherichia coli (E. coli)-stimulated mouse macrophages by inhibiting the release of interleukin-6 and nitric oxide. In a mouse model of sepsis infected with clinically isolated CRAB or E. coli, rhamnetin significantly reduced the bacterial burden in the organs. In addition, normalized pro-inflammatory cytokine levels in lung lysates and histological analysis of lung tissue indicated alleviation of lung damage. This study implies that a potent natural product such as rhamnetin could be a future therapeutic for treating carbapenem-resistant gram-negative sepsis.

Asunto(s)

Infecciones por Acinetobacter , Acinetobacter baumannii , Sepsis , Ratones , Animales , Infecciones por Acinetobacter/tratamiento farmacológico , Infecciones por Acinetobacter/microbiología , Flavonoides/farmacología , Escherichia coli , Carbapenémicos/farmacología , Carbapenémicos/uso terapéutico , Sepsis/tratamiento farmacológico , Sepsis/microbiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Modelos Animales de Enfermedad , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Pruebas de Sensibilidad Microbiana

RESUMEN

BACKGROUND: DNA ligases are crucial for DNA repair and cell replication since they catalyze the final steps in which DNA breaks are joined. DNA Ligase III (LIG3) exerts a pivotal role in Alternative-Non-Homologous End Joining Repair (Alt-NHEJ), an error-prone DNA repair pathway often up-regulated in genomically unstable cancer, such as Multiple Myeloma (MM). Based on the three-dimensional (3D) LIG3 structure, we performed a computational screening to identify LIG3-targeting natural compounds as potential candidates to counteract Alt-NHEJ activity in MM. METHODS: Virtual screening was conducted by interrogating the Phenol Explorer database. Validation of binding to LIG3 recombinant protein was performed by Saturation Transfer Difference (STD)-nuclear magnetic resonance (NMR) experiments. Cell viability was analyzed by Cell Titer-Glo assay; apoptosis was evaluated by flow cytometric analysis following Annexin V-7AAD staining. Alt-NHEJ repair modulation was evaluated using plasmid re-joining assay and Cytoscan HD. DNA Damage Response protein levels were analyzed by Western blot of whole and fractionated protein extracts and immunofluorescence analysis. The mitochondrial DNA (mtDNA) copy number was determined by qPCR. In vivo activity was evaluated in NOD-SCID mice subcutaneously engrafted with MM cells. RESULTS: Here, we provide evidence that a natural flavonoid Rhamnetin (RHM), selected by a computational approach, counteracts LIG3 activity and killed Alt-NHEJ-dependent MM cells. Indeed, Nuclear Magnetic Resonance (NMR) showed binding of RHM to LIG3 protein and functional experiments revealed that RHM interferes with LIG3-driven nuclear and mitochondrial DNA repair, leading to significant anti-MM activity in vitro and in vivo. CONCLUSION: Taken together, our findings provide proof of concept that RHM targets LIG3 addiction in MM and may represent therefore a novel promising anti-tumor natural agent to be investigated in an early clinical setting.

Asunto(s)

ADN Ligasa (ATP) , Reparación del ADN , Flavonoides , Mieloma Múltiple , Animales , Ratones , Anexina A5/genética , Anexina A5/metabolismo , ADN Ligasa (ATP)/genética , ADN Ligasa (ATP)/metabolismo , ADN Ligasas/química , ADN Ligasas/genética , ADN Ligasas/metabolismo , Reparación del ADN/efectos de los fármacos , Reparación del ADN/genética , ADN Mitocondrial/efectos de los fármacos , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo , Flavonoides/farmacología , Flavonoides/uso terapéutico , Ratones Endogámicos NOD , Ratones SCID , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Mieloma Múltiple/metabolismo , Fenoles , Proteínas Recombinantes/metabolismo

RESUMEN

Bradykinin (BK) has been shown to induce matrix metalloproteinase (MMP)-9 expression and participate in neuroinflammation. The BK/MMP-9 axis can be a target for managing neuroinflammation. Our previous reports have indicated that reactive oxygen species (ROS)-mediated nuclear factor-kappaB (NF-κB) activity is involved in BK-induced MMP-9 expression in rat brain astrocytes (RBA-1). Rhamnetin (RNT), a flavonoid compound, possesses antioxidant and anti-inflammatory effects. Thus, we proposed RNT could attenuate BK-induced response in RBA-1. This study aims to approach mechanisms underlying RNT regulating BK-stimulated MMP-9 expression, especially ROS and NF-κB. We used pharmacological inhibitors and siRNAs to dissect molecular mechanisms. Western blotting and gelatin zymography were used to evaluate protein and MMP-9 expression. Real-time PCR was used for gene expression. Wound healing assay was applied for cell migration. 2',7'-dichlorodihydrofluorescein diacetate (H2DCF-DA) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) were used for ROS generation and NOX activity, respectively. Promoter luciferase assay and chromatin immunoprecipitation (ChIP) assay were applied to detect gene transcription. Our results showed that RNT inhibits BK-induced MMP-9 protein and mRNA expression, promoter activity, and cell migration in RBA-1 cells. Besides, the levels of phospho-PKCδ, NOX activity, ROS, phospho-ERK1/2, phospho-p65, and NF-κB p65 binding to MMP-9 promoter were attenuated by RNT. In summary, RNT attenuates BK-enhanced MMP-9 upregulation through inhibiting PKCδ/NOX/ROS/ERK1/2-dependent NF-κB activity in RBA-1.

Asunto(s)

Antiinflamatorios/farmacología , Astrocitos/enzimología , Astrocitos/patología , Bradiquinina/farmacología , Encéfalo/patología , Movimiento Celular , Metaloproteinasa 9 de la Matriz/metabolismo , Quercetina/análogos & derivados , Animales , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Línea Celular , Movimiento Celular/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Modelos Biológicos , NADPH Oxidasas/metabolismo , FN-kappa B/metabolismo , Regiones Promotoras Genéticas/genética , Proteína Quinasa C-delta/metabolismo , Quercetina/farmacología , Ratas , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos

RESUMEN

We developed adventitious roots from the leaf explants of Baccharoides anthelmintica (L.) Moench (syn. Vernonia anthelmintica) cultured on Murashige and Skoog (MS) medium. We tested MS and White's media fortified with different Indole Butyric Acid concentrations for their effect on root biomass production. MS medium supplemented with 1 mg L-1 IBA produced the highest biomass of adventitious roots compared to White's medium. HPLC and LC-Q-TOF analyses confirmed the ability of the adventitious roots of B. anthelmintica to produce rhamnetin. When the 15-day old root cultures were treated with 0.6 mM methyl jasmonate, on the 6th-day, rhamnetin content was enhanced to 0.443 mg g-1DW, which was 1.5 folds compared to untreated roots. Similarly, Salicylic acid also improved rhamnetin production to 0.36 mg g-1 DW, which was 1.2 folds increment compared to untreated roots. Rhamnetin content in the roots of field-grown plants was 0.112 mg g-1DW.

Asunto(s)

Asteraceae , Ácido Salicílico , Acetatos , Ciclopentanos , Oxilipinas/farmacología , Raíces de Plantas , Quercetina/análogos & derivados , Ácido Salicílico/farmacología

RESUMEN

OBJECTIVES: Numerous natural products, including rhamnetin, have been studied in recent years owing to the need for new herbal remedies to treat different illnesses. This study aimed to review the salient properties of rhamnetin and its pharmacological potential and possible toxicological effects. KEY FINDINGS: A search carried out in the ScienceDirect database using the term 'rhamnetin' yielded 573 articles published between 1977 and 2021. However, only those studies that mentioned pharmacological activity of rhamnetin were included in this study. As a result of this selection process, this study included reports that describe rhamnetin as a secondary metabolite with several pharmacological properties. SUMMARY: Rhamnetin (2-(3,4-dihydroxyphenyl)-3,5-dihydroxy-7-methoxychromen-4-one) is a secondary metabolite, belonging to the flavonoid class, present in various plants and fruits; it has different pharmacological properties, including antioxidant, anticancer, anti-inflammatory, antiviral and antibacterial activity. However, conclusive results on the toxicology of rhamnetin have not been reported yet. Therefore, further research is needed to gather detailed information about the effects of rhamnetin.

Asunto(s)

Flavonoides , Quercetina , Antiinflamatorios/farmacología , Antioxidantes/farmacología , Flavonoides/farmacología , Fitoquímicos , Extractos Vegetales , Quercetina/análogos & derivados

RESUMEN

Vernonia anthelmintica (L.) Willd. belongs to the family Asteraceae and has anthelmintic, anti-diabetic, diuretic and anti-asthmatic properties. Present study describes the production of rhamnetin: an O-methylated flavonol with anti-oxidant and anti-inflammatory activities; in cell suspension cultures of V. anthelmintica. Suspension cultures were established from cream coloured friable calli initiated from leaf explants and cultured in liquid MS medium supplemented with combinations of IAA (1.5 mg L-1) and BAP (1.5 mg L-1). After 20 days of cell suspension culture, the initial inoculum size of 0.5 g was increased to 1.05 g 100 mL-1 dry weight at exponential phase. When the culture was treated with 0.8 mM methyl jasmonate for 6 days; 2.2 fold accumulation of rhamnetin production was obtained on a dry weight basis compared to unelicited control. Likewise, the elicitation with salicylic acid 1 mM for 6 days brought about 2.7 fold rhamnetin production compared to unelicited control. The rhamnetin content in dried leaf tissue of field grown plants was found to be 0.143 mg g-1. Elicitation with methyl jasmonate and salicylic acid brought about 7.7 and 9.4 fold increments in rhamnetin production, compared to leaf tissue of field grown plants on a dry weight basis.

RESUMEN

This study developed comprehensive quantification methods for major nutritive and antinutritive phytochemical aglycones in edible African nightshade leaves, an underutilized food resource in the sub-Saharan area. A simultaneous hydrolysis and extraction method was developed using methanol with 2 M sulfuric acid with incubation at 65 °C for 60 min. UHPLC-QqQ-MS/MS methods were developed and validated for hydrolysis optimization and for quantification of eight major aglycones of polyphenols, alkaloids and sapogenins in 20 differently sourced nightshade leaves, comprising two African species Solanum scabrum and S. nigrum, and from two distinct cultivation sites, one in New Jersey, US and the other in Kenya Eldoret. Variation in species, accessions and cultivation environment played an important role in affecting the phytochemical profile. Total antinutritive alkaloids and sapogenins in all nightshade leaves were evaluated and found to be safe for consumption. This work provides evidence that the consumption of African nightshade leaves as a nutrient rich leafy green vegetable is safe and can contribute to food security and nutritional improvement in the sub-Saharan area.

Asunto(s)

Alcaloides/análisis , Polifenoles/análisis , Saponinas/análisis , Solanum/química , Cromatografía Líquida de Alta Presión/métodos , Glicosilación , Hidrólisis , Kenia , Análisis Multivariante , Hojas de la Planta/química , Espectrometría de Masas en Tándem

RESUMEN

Plants are a rich source of natural bioactive compounds with a wide range of applications in the food and pharmaceutical industries. Citrus × clementina leaves extracts and essential oils may be a potential candidate for formulation of products characterized by hypoglycaemic, antioxidant and anti-browning properties. C. × clementina leaves collected in three different areas in Calabria (South Italy) were extracted by Soxhlet apparatus, maceration, Ultrasound assisted maceration, and hydrodistillation. Hesperidin, tangeritin, and sinensetin were identified by HPLC-DAD analysis as dominant constituents of the extracts. The absence of coumarins and furanocoumarins was demonstrated. GC-MS analyses of essential oils evidenced the presence of sabinene, linalool, and (E)-ß-ocimene as main compounds. Based on RACI and GAS values calculated by the integration of data obtained by DPPH, ABTS, FRAP and ß-carotene bleaching methods, hydroalcoholic extract obtained by Ultrasound assisted maceration of the leaves collected in Corigliano Calabro showed the highest antioxidant activity. Ultrasound assisted hydroalcoholic extract of Cetraro leaves revealed the highest α-amylase inhibitory activity (IC50 of 64.37 µg/ml). Promising results of C. × clementina extracts as tyrosinase inhibitors were also obtained. To evaluate the relationship between identified compounds and bioactivity PCA was performed. Taking into account results obtained by this study, C. × clementina leaves that were considered Citrus-by-products could be utilized for formulation of food additives, nutraceuticals and functional foods.

Asunto(s)

Fraccionamiento Químico/métodos , Citrus/química , Fitoquímicos/química , Hojas de la Planta/química , Antioxidantes/química , Extractos Vegetales/química

RESUMEN

Quercetin (QCT) and isorhamnetin (ISO), natural flavonoids, were both shown to possess antifibrotic activity in in vivo and in vitro models of hepatic fibrosis. Although ISO is a direct metabolite of QCT differing by a methyl group, it has been reported to be absorbed more adequately and eliminated slower than QCT after oral administration. Our aim of the study was to investigate biological effect of mono-methylated QCT derivatives against fibrosis using rat hepatic stellate cells (HSC-T6). All test derivatives were synthesized from QCT. HSC-T6 cells were induced by TGFß and treated with derivatives followed by cell proliferation assay, immunofluorescence staining of αSMA, and gene expression analysis of fibrosis markers. All compounds showed a dose- and time-dependent antiproliferation effect. ISO, 3-O-methylquercetin (3MQ), and rhamnetin (RHA) reduced αSMA mRNA; 3MQ prevented the augmentation of collagen I mRNA; and compounds, except azaleatin and 3MQ, reduced Timp1 mRNA expression in TGFß-induced HSCs. In conclusion, each compound had singular effect against different features of fibrosis depending on the position of methyl group although the further mechanism of action of compounds during fibrosis development remains to be investigated. These findings suggest that antifibrotic effect of quercetin can be enhanced by adding methyl group on functionally important position.

RESUMEN

The present study aimed to investigate whether rhamnetin induced apoptosis in human breast cancer cells and the underlying molecular mechanism of this anti cancer effect. The treatment of MCF-7 cells with rhamnetin was able to significantly inhibit cell proliferation and induce caspase-3/9 activity in a dose- and time-dependent manner, compared with untreated cells. In addition, treatment with rhamnetin was able to significantly promote the expression of p53 protein and microRNA (miR-)34a compared with untreated cells. The treatment with rhamnetin also suppressed the expression of Notch1 protein in MCF-7 cells compared with untreated cells. Subsequently, miR-24a expression was promoted in rhamnetin-treated MCF-7 cells using a miR-34a plasmid. The overexpression of miR-34a was able to significantly inhibit cell viability and induce caspase-3/9 activity in MCF-7 cells following treatment with rhamnetin. Furthermore, the overexpression of miR-34a was able to significantly promote the expression of p53 protein and miR-34a, and suppress the expression of Notch1 protein in rhamnetin-treated MCF-7 cells. Therefore, the results of the present study demonstrated that rhamnetin induced apoptosis in human breast cancer cells via the miR-34a/Notch-1 signaling pathway.

RESUMEN

Rhamnetin (Rhm), 3-O-methylquercetin (3MQ), and Rhamnazin (Rhz) are methylated derivatives of quercetin commonly found in fruits and vegetables that possess antioxidant and anti-inflammatory properties. Phospholipase A2 (PLA2) displays several important roles during acute inflammation; therefore, this study aimed at investigating new compounds able to inhibit this enzyme, besides evaluating creatine kinase (CK) levels and citotoxicity. Methylated quercetins were compared with quercetin (Q) and were incubated with secretory PLA2 (sPLA2) from Bothrops jararacussu to determine their inhibitory activity. Cytotoxic studies were performed by using the J774 cell lineage incubated with quercertins. In vivo tests were performed with Swiss female mice to evaluate decreasing paw edema potential and compounds' CK levels. Structural modifications on sPLA2 were made with circular dichroism (CD). Despite Q and Rhz showing greater enzymatic inhibitory potential, high CK was observed. Rhm exhibited sPLA2 inhibitory potential, no toxicity and, remarkably, it decreased CK levels. The presence of 3OH on the C-ring of Rhm may contribute to both its anti-inflammatory and enzymatic inhibition of sPLA2, and the methylation of ring A may provide the increase in cell viability and low CK level induced by sPLA2. These results showed that Rhm can be a candidate as a natural compound for the development of new anti-inflammatory drugs.

Asunto(s)

Antiinflamatorios/química , Fosfolipasas A2 Secretoras/química , Quercetina/análogos & derivados , Proteínas de Reptiles/química , Animales , Antiinflamatorios/farmacología , Bothrops , Línea Celular , Venenos de Crotálidos/enzimología , Evaluación Preclínica de Medicamentos , Femenino , Ratones , Fosfolipasas A2 Secretoras/antagonistas & inhibidores , Fosfolipasas A2 Secretoras/aislamiento & purificación , Quercetina/química , Quercetina/farmacología , Proteínas de Reptiles/antagonistas & inhibidores , Proteínas de Reptiles/aislamiento & purificación

RESUMEN

Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α-glucosidase/radical scavenging inhibition profiling. The high-resolution biochromatograms obtained by this technique were used to target subsequent structural elucidation by HPLC-HRMS-SPE-NMR analysis towards the bioactive constituents. This led to identification of 4-hydroxybenzoic acid (1) and 3-indolecarboxylic acid (6) associated with radical scavenging activity, and the amide alkaloids N-trans-p-coumaroyloctopamine (3), N-trans-p-feruloyloctopamine (4), N-trans-p-coumaroyltyramine (8) and N-trans-p-feruloyltyramine (9) correlated with α-glucosidase inhibitory activity as well as radical scavenging activity. Further analysis revealed a new lactone, methyl 5-ethyl-4-hydroxy-5-methyl-2-oxotetrahydro-2H-pyran-4-carboxylate (7) and a new steroid with a rare F ring (11). Corchorifatty acid B (12) was reported for the first time in the Solanaceae family. Their structures were elucidated by extensive use of 1D and 2D NMR spectroscopy as well as HRMS analysis.

Asunto(s)

Depuradores de Radicales Libres/química , Inhibidores de Glicósido Hidrolasas/química , Solanum/química , Cromatografía Líquida de Alta Presión , Depuradores de Radicales Libres/aislamiento & purificación , Inhibidores de Glicósido Hidrolasas/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Estructura Molecular , Componentes Aéreos de las Plantas/química , Extractos Vegetales/química , Plantas Medicinales/química , alfa-Glucosidasas/metabolismo

RESUMEN

BACKGROUND: The rapid development of multi-drug resistance (MDR) process has hindered the effectiveness of advanced hepatocellular carcinoma (HCC) treatments. Notch-1 pathway, which mediates the stress-response, promotes cell survival, EMT (epithelial-mesenchymal transition) process and induces anti-apoptosis in cancer cells, would be a potential target for overcoming MDR process. This study investigated the potential application of rhamnetin, a specific inhibitor of Notch-1 pathway, in anti-tumor drug sensitization of HCC treatment. METHODS: The expression of miR-34a, proteins belonging to Notch-1 signaling pathway or MDR-related proteins was detected by quantitative polymerase chain reaction (qPCR) and western blot assay. To identify whether rhamnetin induces the chemotherapeutic sensitization in HCC cells, the MTT-assays, flow cytometry, soft agar, trans-well and nude mice assays were performed. RESULTS: The endogenous expression of miR-34a was significantly increased and the expression of Notch-1 and Survivin was downregulated after rhamnetin treatment. Treatment of rhamnetin also reduced the expression of MDR related proteins P-GP (P-glycoprotein) and BCRP (breast cancer resistance protein). Rhamnetin increased the susceptibility of HCC cells and especially HepG2/ADR, a MDR HCC cell line, to a small molecular kinase inhibitor sorafenib or chemotherapeutic drugs etoposide and paclitaxel. The IC(50) value of those drugs correspondingly decreased. CONCLUSIONS: Together, our findings suggest that rhamnetin treatment may attenuate the MDR process in HCC cells. These findings may contribute to more effective strategies for HCC therapy. GENERAL SIGNIFICANCE: Rhamnetin acts as a promising sensitizer to chemotherapy and may be a novel approach to overcome the MDR process of HCC.

Asunto(s)

Antineoplásicos Fitogénicos/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Resistencia a Antineoplásicos/efectos de los fármacos , Etopósido/farmacología , Neoplasias Hepáticas/tratamiento farmacológico , Niacinamida/análogos & derivados , Paclitaxel/farmacología , Compuestos de Fenilurea/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Quercetina/análogos & derivados , Animales , Carcinoma Hepatocelular/enzimología , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica , Células Hep G2 , Humanos , Concentración 50 Inhibidora , Neoplasias Hepáticas/enzimología , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Masculino , Ratones SCID , MicroARNs/genética , MicroARNs/metabolismo , Niacinamida/farmacología , Quercetina/farmacología , Receptor Notch1/antagonistas & inhibidores , Receptor Notch1/metabolismo , Transducción de Señal/efectos de los fármacos , Sorafenib , Transfección , Ensayos Antitumor por Modelo de Xenoinjerto