Toxicological Evaluation of Kaempferol and Linearolactone as Treatments for Amoebic Liver Abscess Development in Mesocricetus auratus.

Several studies with kaempferol (KP) and linearolactone (LL) have demonstrated their antiparasitic activity. However, the toxicity of these treatments is unknown. Therefore, this study aimed to evaluate the possible toxicological effects of intraperitoneal (i.p.) administration of KP or LL on the amoebic liver abscess model (ALA) in Mesocricetus auratus. An ALA was induced in male hamsters with 1.5 × 105Entamoeba histolytica (E. histolytica) trophozoites inoculated in the left hepatic lobe. The lesion evolved for 4 days, and then KP (5 mg/kg body weight/day) or LL (10 mg/kg body weight/day) was administered for 4 consecutive days. Then, magnetic resonance imaging (MRI), paraclinical analyses, and necropsy for histopathological evaluation were performed. There was similar ALA inhibition by KP (19.42%), LL (28.16%), and metronidazole, the antiamoebic control (20.87%) (p ≤ 0.05, analysis of variance [ANOVA]). There were hepatic and renal biochemical alterations in all treatment groups, mainly for KP (aspartate aminotransferase: 347.5 ± 37.5 U/L; blood urea nitrogen: 19.4 ± 1.9 g/dL; p ≤ 0.05, ANOVA). Lesions found in the organs were directly linked to the pathology. In conclusion, KP and LL decreased ALA development and exerted fewer toxicological effects compared with metronidazole. Therefore, both compounds exhibit therapeutic potential as an alternative treatment of amoebiasis caused by E. histolytica. However, additional clinical studies in different contexts are required to reaffirm this assertion.

Oral Administration of Kaempferol Isolated from Baccharis Mattogrosensis Enables In Vivo Activity Against Schistosoma Mansoni.

Baccharis mattogrosensis is a species from Asteraceae which has been used in Brazilian folk medicine to treatment of several illnesses, including those caused by parasites. In the present work, the MeOH extract of aerial parts of B. mattogrosensis was subjected to chromatographic fractionation to afford three flavonoids: apigenin (1), quercetin (2), and kaempferol (3) as well as a mixture three chlorogenic acids: 3,4-O-dicaffeoylquinic (4), 3,5-O-dicaffeoylquinic (5), and 4,5-O-dicaffeoylquinic (6) acids. When tested in vitro, kaempferol (3) exhibited activity against Schistosoma mansoni with EC50=81.86 µM, whereas compounds 1, 2, 4-6 showed to be inactives. Considering this result, the effects of kaempferol (3) against S. mansoni infection using an experimental approach (in vivo assay) was tested at first time. Using a single oral dose (400 mg/kg) of kaempferol (3) to S. mansoni-infected mice reduced the worm burden by 25.5 %. Similarly, the number of eggs, which are responsible for a variety of pathologies and transmission of schistosomiasis, was decreased by 28.8 % in treated mice. Collectively, although kaempferol (3) is partially active when administered orally in a mouse model of schistosomiasis, our results suggest that this compound could be, in future studies, administered in different forms, such as nanoformulation.

The Beneficial Effect of Brazilian Propolis for Liver Damage through Endoplasmic Reticulum Stress.

There is evidence that propolis exhibits anti-inflammatory, anticancer, and antioxidant properties. We assessed the potential beneficial effects of Brazilian propolis on liver injury in nonalcoholic fatty liver disease (NAFLD). Our findings demonstrate that Brazilian propolis suppresses inflammation and fibrosis in the liver of mice with NAFLD by inhibiting the expression of genes involved in endoplasmic reticulum (ER) stress. Additionally, Brazilian propolis also suppressed the expression of ER stress-related genes in HepG2 cells treated with an excess of free fatty acids, leading to cell apoptosis. A deeper analysis revealed that kaempferol, one of the components present in Brazilian propolis, induces cell proliferation through the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway and protects against oxidative stress. In conclusion, Brazilian propolis exhibits hepatoprotective properties against oxidative stress by inhibiting ER stress in NAFLD-induced model mice.

Secondary Metabolites and Antioxidant Activity against Moko Disease as a Defense Mechanism of Musa spp. from the Ecuadorian Coast Area.

The Musa spp. represents the most commonly produced, transitioned, and consumed fruit around the globe, with several important applications in the biotechnology, pharmaceutical, and food industries. Moko disease is produced by Ralstonia solanacearum-a factor with a high impact on all crops in Ecuador, representing one of the biggest phytosanitary problems. Four of the most common varieties of Musa spp. were tested to identify the metabolic reaction of plants facing Moko disease. The phenolic and flavonoid content has been evaluated as a defense system, and the α-diphenyl-α-picrylhydrazyl free-radical-scavenging method (DPPH), free-radical-scavenging activity (ABTS), ferric-reducing antioxidant power (FRAP) assays, and liquid chromatography and mass spectrometry (LC-MS) have been adapted to analyze the active compounds with the antioxidant capacity necessary to counteract the pathogenic attack. Our results indicate that all the studied varieties of Musa spp. react in the same way, such that the diseased samples showed a higher accumulation of secondary metabolites with antioxidant capacity compared with the healthy ones, with high active compound synthesis identified during the appearance of Moko disease symptoms. More than 40 compounds and their derivatives (from kaempferol and quercetin glycosides) with protective roles demonstrate the implication of the Musa spp. defense system against R. solanacearum infection.

Comparative Analysis of Fluorescence Emission in Myricetin, Kaempferol, and Quercetin Powders and Solutions.

Myricetin is a flavonol with high antioxidant properties. In this research, the fluorescence emission of myricetin powder and its solutions in different solvents were measured and analyzed by comparing with the results of calculations. Comparison of the calculated and measured characteristic wavelengths allowed the identification of all the spectral features in the fluorescence spectra of myricetin powder and solutions with different concentrations. The computation was based on modeling the process of the excited state intermolecular proton transfer, which predicts the formation of tautomeric forms of the flavonol molecule. Characteristic emission wavelengths were obtained using TDDFT/M06-2X/6-31++G(d,p). To understand the influence of the hydroxyl groups in the B-ring of the flavonol molecule on the emission spectrum, we also compared the fluorescence spectra of myricetin with those of kaempferol and quercetin. Moreover, based on the analysis of the changes in the shape of the FL spectra with the concentration of the solution, a criterion for the complete dissolution of the flavonol powders was established, which is important for bioavailability of flavonoids.

The Anticancer Potential of Kaempferol: A Systematic Review Based on In Vitro Studies.

Given the heterogeneity of different malignant processes, planning cancer treatment is challenging. According to recent studies, natural products are likely to be effective in cancer prevention and treatment. Among bioactive flavonoids found in fruits and vegetables, kaempferol (KMP) is known for its anti-inflammatory, antioxidant, and anticancer properties. This systematic review aims to highlight the potential therapeutic effects of KMP on different types of solid malignant tumors. This review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Searches were performed in EMBASE, Medline/PubMed, Cochrane Collaboration Library, Science Direct, Scopus, and Google Scholar. After the application of study criteria, 64 studies were included. In vitro experiments demonstrated that KMP exerts antitumor effects by controlling tumor cell cycle progression, proliferation, apoptosis, migration, and invasion, as well as by inhibiting angiogenesis. KMP was also able to inhibit important markers that regulate epithelial-mesenchymal transition and enhanced the sensitivity of cancer cells to traditional drugs used in chemotherapy, including cisplatin and 5-fluorouracil. This flavonoid is a promising therapeutic compound and its combination with current anticancer agents, including targeted drugs, may potentially produce more effective and predictable results.

Excited-state proton transfer based fluorescence in Kaempferol powder and solutions with different concentrations.

Kaempferol (KMP) is one of the most common flavonoids, currently being extensively studied for its numerous beneficial health effects. Here we study the fluorescence (FL) emission of KMP powder and of its solutions prepared using different types of solvents (polar and non-polar). In the spectra of KMP powder and KMP solutions with high concentration, the same FL peak with maximum at 1.9 eV is observed. Another FL peak, at higher energy of 2.45 eV, emerges in solutions, its relative intensity increases with decreasing solution concentration. The FL emission of solutions with lowest concentration displays only that peak. To calculate characteristic energies of absorption and emission of KMP molecule in vacuum and in solutions we use time-dependent density functional theory. Comparing the results of computations with measured FL spectra, we associate the FL band at 1.9 eV with the emission due to excited state intramolecular transfer of the proton of -OH5 hydroxyl group. The FL emission at 2.45 eV is related to the -OH3 proton transfer. We measure the FL spectra of KMP powder using two different excitation energies, 3.06 eV and 2.33 eV, and find that its FL spectrum depends on the excitation energy. To understand that dependence, we compare the FL spectra of KMP and Q monohydrate powders. We consider the excited state intermolecular transfer of the proton from -OH3' hydroxyl group to a neighboring molecule in Q crystal and calculate the energy corresponding to the emission of the resulted anion of Q molecule. The spectral feature at 1.69 eV observed only in the FL spectrum of Q hydrate is attributed to the Q anion FL emission.

Kaempferol and Biomodified Kaempferol from Sophora japonica Extract as Potential Sources of Anti-Cancer Polyphenolics against High Grade Glioma Cell Lines.

The enzymatic hydrolysis of the extract of Sophora japonica by two glycosyl hydrolases (hesperidinase and galactosidase) was performed in order to obtain kaempferol (KPF)-enriched extract with an enhanced anticancer activity. The current study examined the effectiveness of both Sophora japonica extracts (before (KPF-BBR) and after (KPF-ABR) bioconversion reactions) in reducing cell viability and inducing apoptosis in human high-degree gliomas in vitro. Cytotoxicity was determined using an MTT assay. The effects of both compounds on the proliferation of glioma cell lines were measured using trypan blue exclusion, flow cytometry for cell cycle, wound healing (WH), and neurosphere formation assays. Cellular apoptosis was detected by DNA fragmentation and phosphatidylserine exposure. qPCR and luciferase assays evaluated NF-kB pathway inhibition. The survival rate of NG-97 and U-251 cells significantly decreased in a time- and dose-dependent manner after the addition of KPF-BBR or KPF-ABR. Thus, a 50% reduction was observed in NG-97 cells at 800 µM (KPF-BBR) and 600 µM (KPF-ABR) after 72 h. Both compounds presented an IC50 of 1800 µM for U251 after 72 h. The above IC50 values were used in all of the following analyses. Neither of the KPF presented significant inhibitory effects on the non-tumoral cells (HDFa). However, after 24 h, both extracts (KPF-BBR and KPF-ABR) significantly inhibited the migration and proliferation of NG-97 and U-251 cells. In addition, MMP-9 was downregulated in glioma cells stimulated by 12-O-tetradecanoylphorbol-13-acetate (TPA) plus KPF-BBR and TPA+KPF-ABR compared with the TPA-treated cells. Both KPF-BBR and KPF-ABR significantly inhibited the proliferation of glioma stem cells (neurospheres) after 24 h. DNA fragmentation assays demonstrated that the apoptotic ratio of KPF-ABR-treated cell lines was significantly higher than in the control groups, especially NG-97, which is not TMZ resistant. In fact, the flow cytometric analysis indicated that KPF-BBR and KPF-ABR induced significant apoptosis in both glioma cells. In addition, both KPF induced S and G2/M cell cycle arrest in the U251 cells. The qPCR and luciferase assays showed that both KPFs downregulated TRAF6, IRAK2, IL-1ß, and TNF-α, indicating an inhibitory effect on the NF-kB pathway. Our findings suggest that both KPF-BBR and KPF-ABR can confer anti-tumoral effects on human cell glioma cells by inhibiting proliferation and inducing apoptosis, which is related to the NF-κB-mediated pathway. The KPF-enriched extract (KPF-ABR) showed an increased inhibitory effect on the cell migration and invasion, characterizing it as the best antitumor candidate.

In Vitro Evaluation of the Antiamoebic Activity of Kaempferol against Trophozoites of Entamoeba histolytica and in the Interactions of Amoebae with Hamster Neutrophils.

Entamoeba histolytica (E. histolytica) is a parasite in humans that provokes amoebiasis. The most employed drug is metronidazole (MTZ); however, some studies have reported that this drug induces genotoxic effects. Therefore, it is necessary to explore new compounds without toxicity that can eliminate E. histolytica. Flavonoids are polyphenolic compounds that have demonstrated inhibition of growth and dysregulation of amoebic proteins. Despite the knowledge acquired to date, action mechanisms are not completely understood. The present work evaluates the effect of kaempferol against E. histolytica trophozoites and in the interactions with neutrophils from hamster, which is a susceptibility model. Our study demonstrated a significant reduction in the amoebic viability of trophozoites incubated with kaempferol at 150 µM for 90 min. The gene expression analysis showed a significant downregulation of Pr (peroxiredoxin), Rr (rubrerythrin), and TrxR (thioredoxin reductase). In interactions with amoebae and neutrophils for short times, we observed a reduction in ROS (reactive oxygen species), NO (nitric oxide), and MPO (myeloperoxidase) neutrophil activities. In conclusion, we confirmed that kaempferol is an effective drug against E. histolytica through the decrease in E. histolytica antioxidant enzyme expression and a regulator of several neutrophil mechanisms, such as MPO activity and the regulation of ROS and NO.

Preparative Fractionation of Phenolic Compounds and Isolation of an Enriched Flavonol Fraction from Winemaking Industry By-Products by High-Performance Counter-Current Chromatography.

High-performance counter-current chromatography (HPCCC) was used as a tool for the isolation and fractionation of phenolic compounds (PCs) in extracts from wine lees (WL) and grape pomace (GP). The biphasic solvent systems applied for HPCCC separation were n-butanol:methyl tert-butyl ether:acetonitrile:water (3:1:1:5) with 0.1% trifluoroacetic acid (TFA) and n-hexane:ethyl acetate:methanol:water (1:5:1:5). After refining the ethanol:water extracts of GP and WL by-products by ethyl acetate extraction, the latter system yielded an enriched fraction of the minor family of flavonols. Recoveries of 112.9 and 105.9 mg of purified flavonols (myricetin, quercetin, isorhamnetin, and kaempferol) in GP and WL, respectively, from 500 mg of ethyl acetate extract (equivalent to 10 g of by-product) were obtained. The HPCCC fractionation and concentration capabilities were also exploited for the characterization and tentative identification of constitutive PCs by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). In addition to the isolation of the enriched flavonol fraction, a total of 57 PCs in both matrixes were identified, 12 of which were reported for the first time in WL and/or GP. The application of HPCCC to GP and WL extracts may be a powerful approach to isolate large amounts of minor PCs. The composition of the isolated fraction demonstrated quantitative differences in the individual compound composition of GP and WL, supporting the potential exploitation of these matrixes as sources of specific flavonols for technological applications.

Oxidation of Quercetin and Kaempferol Markedly Amplifies Their Antioxidant, Cytoprotective, and Anti-Inflammatory Properties.

The contention that flavonoids' oxidation would necessarily lead to a loss of their antioxidant properties was recently challenged by the demonstration that quercetin oxidation leads to the formation of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (Que-BZF), a metabolite whose antioxidant potency was notably higher than that of its precursor. Here, we compared and expanded the former observation to that of the quercetin analogue kaempferol. Oxidation of kaempferol led to the formation of a mixture of metabolites that included the 2-(4-hydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (Kae-BZF). Following the chromatographic isolation of Kae-BZF from such a mixture, its antioxidant, mitochondria- and cell-protecting, and NF-kB-inhibiting effects were assessed, and compared with those of Que-BZF, in Caco-2 cells exposed to indomethacin as a source of ROS. The concentrations of Que-BZF (100 nm) and Kae-BZF (1 nm) needed to attain their maximal protection effects were 50- and 5000-fold lower than those of their respective precursors. The former differences in concentrations were also seen when the abilities of Que-BZF and Kae-BZF to inhibit the indomethacin-induced activation of NF-kB were compared. These data not only reveal that the oxidative conversion of quercetin and kaempferol into their respective 2-benzoyl-2-hydroxy-3(2H)-benzofuranones (BZF) results in a considerable amplification of their original antioxidant properties, but also that the in the case of kaempferol, such amplification is 100-fold greater than that of quercetin.

A Mixture of Kaempferol-3-O-sambubioside and Kaempferol-3-O-sophoroside from Malvaviscus arboreus Prevents Ethanol-Induced Gastric Inflammation, Oxidative Stress, and Histologic Changes.

Malvaviscus arboreus is used in traditional Mexican medicine to treat gastrointestinal diseases. Therefore, a mixture of Kaempferol-O-sambubioside and Kaempferol-O-sophoroside (MaSS) isolated from flowers of this species was tested as a preventive treatment on gastric lesions induced with ethanol in rats. MaSS was obtained by chromatographic methods and administered by oral pathway to male Sprague Dawley rats with ethanol-induced gastric lesions. Pretreatment with MaSS at doses of 30, 90, 120, and 180 mg/kg significantly prevents gastric lesions, inhibits the increment in relative stomach weight (%) in gastric IL-6, and also provokes an increment of IL-10 concentration and catalase activity. Finally, MaSS prevented edema in the mucosa and submucosa and diminished microscopic gastric lesions provoked by ethanol.

Estudo do potencial antiviral sobre Sars Cov-2 dos compostos identificados nas folhas do extrato bruto de Eugenia pyriformis / Study of the antiviral potential on Sars Cov-2 of compounds identified in the leaves of the gross extract of Eugenia pyriformis / Estudio del potencial antiviral sobre Sars Cov-2 de los compuestos identificados en las hojas del extracto crudo de Eugenia pyriformis

Eugenia pyriformis Cambess (Myrtaceae), conhecida popularmente como uvaia. Em seus frutos são encontrados compostos fenólicos com ação antioxidante e nas folhas foram detectados altos teores de flavonoides e taninos hidrolisados que se mostraram inibidor da protease de 2019 - nCoV e SARS-CoV. Neste sentido, o objetivo deste estudo foi a obtenção do extrato bruto das folhas, a análise da composição química e a possibilidade da ação antiviral frente ao SARS COV-2. O extrato bruto (EB) foi obtido a partir das folhas secas de E. pyriformis, pela técnica de maceração dinâmica com esgotamento do solvente (etanol 90º GL) e concentrado em evaporador rotativo. Seis gramas do EB foram fracionados em cromatografia em coluna, e eluído com hexano, diclorometano, acetato de etila e metanol, as frações foram concentradas em um evaporador rotativo (Tecnal TE-210). O EB e as frações foram identificadas por cromatografia líquida de alta eficiência à espectrometria de massas de alta resolução (CLAE-ESI/qTOF). A identificação química do extrato bruto e frações das folhas de E. pyriformis evidenciou a presença de compostos fenólicos destacando os ácidos fenólicos, flavonoides e taninos. De forma complementar, foi realizado um levantamento bibliográfico sobre a provável ação antiviral dos compostos fenólicos e taninos presentes nas folhas de uvaia. Os resultados evidenciaram que os flavonoides quercetina e kaempferol possuem ação antiviral quando se ligam a glicoproteína do envelope ou capsídeo viral interferindo na ligação e penetração do vírus na célula. Este resultado coloca as folhas de E. pyriformis na lista de plantas com ação antiviral.

Eugenia pyriformis Cambess (Myrtaceae), popularly known as uvaia. In its fruits, phenolic compounds with antioxidant action are found and in the leaves, high levels of flavonoids and hydrolyzed tannins were detected, which proved to be an inhibitor of the 2019 protease - nCoV and SARS-CoV. In this sense, the objective of this study was to obtain the crude extract of the leaves, the analysis of the chemical composition and the possibility of antiviral action against SARS COV-2. The crude extract (EB) was obtained from the dried leaves of E. pyriformis, by the dynamic maceration technique with solvent exhaustion (ethanol 90º GL) and concentrated in a rotary evaporator. Six grams of EB were fractionated in column chromatography, and eluted with hexane, dichloromethane, ethyl acetate and methanol, the fractions were concentrated on a rotary evaporator (Tecnal TE-210). EB and fractions were identified by high performance liquid chromatography using high resolution mass spectrometry (HPLC-ESI/qTOF). The chemical identification of the crude extract and fractions of E. pyriformis leaves evidenced the presence of phenolic compounds, highlighting phenolic acids, flavonoids and tannins. In addition, a bibliographic survey was carried out on the probable antiviral action of phenolic compounds and tannins present in uvaia leaves. The results showed that the flavonoids quercetin and kaempferol have antiviral action when they bind to the envelope glycoprotein or viral capsid, interfering with the binding and penetration of the virus into the cell. This result places E. pyriformis leaves in the list of plants with antiviral action.

Eugenia pyriformis Cambess (Myrtaceae), conocida popularmente como uvaia. En sus frutos se encuentran compuestos fenólicos con acción antioxidante y en las hojas se detectaron altos contenidos de flavonoides y taninos hidrolizados que demostraron inhibir la proteasa de 2019 - nCoV y SARS-CoV. En este sentido, el objetivo de este estudio fue obtener el extracto crudo de las hojas, el análisis de la composición química y la posibilidad de acción antiviral contra el SARS COV-2. El extracto crudo (EB) se obtuvo a partir de las hojas secas de E. pyriformis, mediante la técnica de maceración dinámica con agotamiento del disolvente (etanol 90º GL) y se concentró en evaporador rotatorio. Seis gramos de EB se fraccionaron en cromatografía en columna, y se eluyeron con hexano, diclorometano, acetato de etilo y metanol, las fracciones se concentraron en un evaporador rotatorio (Tecnal TE-210). El EB y las fracciones se identificaron mediante cromatografía líquida de alta resolución a espectrometría de masas de alta resolución (HPLC-ESI/qTOF). La identificación química del extracto crudo y de las fracciones de las hojas de E. pyriformis mostró la presencia de compuestos fenólicos destacando los ácidos fenólicos, los flavonoides y los taninos. De forma complementaria, se realizó un estudio bibliográfico sobre la probable acción antiviral de los compuestos fenólicos y los taninos presentes en las hojas de la uva. Los resultados mostraron que los flavonoides quercetina y kaempferol tienen acción antiviral cuando se unen a la glicoproteína de la envoltura o cápside viral, interfiriendo en la unión y penetración del virus en la célula. Este resultado sitúa a las hojas de E. pyriformis en la lista de plantas con acción antiviral.

Metabolite characterization of fifteen by-products of the coffee production chain: From farm to factory.

Approximately 11.4 million tonnes of solid by-products and an increased amount of waste water will be generated during the 2020/21 coffee harvest. There are currently no truly value-adding uses for these potentially environmentally threatening species. This work presents the most wide-ranging chemical investigation of coffee by-products collected from farms to factories, including eight never previously investigated. Twenty compounds were found for the first time in coffee by-products including the bioactive neomangiferin, kaempferol-3-O-rutinoside, lup-20(29)-en-3-one and 3,4-dimethoxy cinnamic acid. Five by-products generated inside a factory showed caffeine (53.0-17.0 mg.g-1) and/or chlorogenic acid (72.9-10.1 mg.g-1) content comparable to coffee beans, while mature leaf from plant pruning presented not only high contents of both compounds (16.4 and 38.9 mg.g-1, respectively), but also of mangiferin (19.4 mg.g-1) besides a variety of flavonoids. Such by-products are a source of a range of bioactive compounds and could be explored with potential economic and certainly environmental benefits.

Comparative characterization of cinnamon, cinnamaldehyde and kaempferol for phytochemical, antioxidant and pharmacological properties using acetaminophen-induced oxidative stress mouse model / Caracterización comparativa de canela, cinamaldehído y kaempferol para propiedades fitoquímicas, antioxidantes y farmacológicas utilizando el modelo de ratón con estrés oxidativo inducido por acetaminofeno

This study was aimed to explore the comparative efficacy of cinnamon bark extract, cinnamaldehyde and kaempferol against acetaminophen (APAP)-induced oxidative stress. Cinnamon bark extract, cinnamaldehyde and kaempferol were utilized or in-vivo analysis. From the results of in-vitro screening tests, cinnamon ethanolic extract was selected for in-vivo study in mouse model. For this, Balb/c albino mice were treated with cinnamon ethanolic extract (200 mg/kg), cinnamaldehyde (10 mg/kg) and kaempferol (10 mg/kg) orally for 14 days followed by single intraperitoneal administration of APAP during 8 hours. Blood and organ samples were collected for biochemical and histopathological analysis. The results showed that cinnamon bark ethanolic extract, cinnamaldehyde and kaempferol ameliorated APAP-induced oxidative stress and organ toxicity in mice. In conclusion, cinnamaldehyde and kaempferol possess comparable antioxidant potential even at 20-times less dose as compared to cinnamon bark ethanolic extract suggesting therapeutic potential in oxidative stress-related disorders.

Este estudio tuvo como objetivo explorar la eficacia comparativa del extracto de corteza de canela, cinamaldehído y kaempferol contra el estrés oxidativo inducido por acetaminofén (APAP). Se utilizaron extracto de corteza de canela, cinamaldehído y kaempferol para el análisis in vivo. De los resultados de las pruebas de detección in vitro, se seleccionó el extracto etanólico de canela para estudio in vivo en modelo de ratón. Para ello, los ratones albinos Balb/c fueron tratados con extracto etanólico de canela (200 mg/kg), cinamaldehído (10 mg/kg) y kaempferol (10 mg/kg) por vía oral durante 14 días, seguido de la administración intraperitoneal única de APAP durante 8 horas. Se recogieron muestras de sangre y órganos para análisis bioquímicos e histopatológicos. Los resultados mostraron que el extracto etanólico de la corteza de canela, el cinamaldehído y el kaempferol mejoraron el estrés oxidativo inducido por APAP y la toxicidad orgánica en ratones. En conclusión, el cinamaldehído y el kaempferol poseen un potencial antioxidante comparable, incluso a una dosis 20 veces menor en comparación con el extracto etanólico de la corteza de canela, lo que sugiere un potencial terapéutico en los trastornos relacionados con el estrés oxidativo.

Multi-response optimal hot pressurized liquid recovery of extractable polyphenols from leaves of maqui (Aristotelia chilensis [Mol.] Stuntz).

Multi-response optimization of hot pressurized liquid extraction (HPLE) was applied for the first time to obtain maqui (Aristotelia chilensis [Mol.] Stuntz) leaf extracts. The total polyphenol content (TPC), the antioxidant capacity (AC) as well as the total polyphenol purity of the maqui leaf extracts were accurately predicted (RSD < 8%) at the evaluated extraction scales. The optimum HPLE conditions that prioritized TPC and AC equally (OPT1) recovered ~3 times more TPC (205.14 mg GAE/g leaves) than maqui leaf extracts obtained by maceration, while the extract that prioritized purity over TPC and AC presented the highest purity (36.29%) and an EC50 ~3 times lower than currently reported values. It was found by multi-response optimization that maqui leaves and HPLE are among the best natural sources and extraction techniques, respectively, to recover protocatechuic acid, quercetin, and catechin.

Domestication of Plants of Ugni molinae Turcz (Myrtaceae) Interferes in the Biology of Chilesia rudis (Lepidoptera: Erebidae) Larvae.

In terms of the domestication process in murtilla, studies have found changes in the concentration of phenolic compounds, with reduction of chemical defense of plants, depending on the change in the feeding behavior of insects. Thus, we hypothesized that the domestication of Ugni molinae decreases the content of phenolic compounds and modifies the feeding preference of Chilesia rudis larvae. Leaves of three parental ecotypes and four cultivated ecotypes were used in preference experiments to evaluate the mass gain and leaves consumption of larvae. Phenolic extracts from leaves of U. molinae were analyzed by HPLC. Identified compounds were incorporated in an artificial diet to assess their effect on mass gain, consumption, and survival of the larvae. The presence of phenolic compounds in bodies and feces was also evaluated. In terms of choice assays, larvae preferred parental ecotypes. Regarding compounds, vanillin was the most varied between the ecotypes in leaves. However, plant domestication did not show a reduction in phenolic compound concentration of the ecotypes studied. Furthermore, there was no clear relation between phenolic compounds and the performance of C. rudis larvae. Whether this was because of sequestration of some compounds by larvae is unknown. Finally, results of this study could also suggest that studied phenolic compounds have no role in the C. rudis larvae resistance in this stage of murtilla domestication process.

Antioxidant and Antiproliferative Activity of The Ethanolic Extract of Equisetum Myriochaetum and Molecular Docking of Its Main Metabolites (Apigenin, Kaempferol, and Quercetin) on ß-Tubulin.

Equisetum myriochaetum is a semi-aquatic plant found on riverbanks that is commonly used in traditional medicine as a diuretic agent. Additionally, the genus Equisetum stands out for its content of the flavonoid kaempferol, a well-known antiproliferative agent. Therefore, in this study, E. myriochaetum ethanolic extract was tested in vitro against a cervical cancer cell line (SiHa). Additionally, the antioxidative activity was evaluated through a 2,2-diphenyl-1-picrilhidrazil (DPPH) assay. Finally, a molecular docking analysis of apigenin, kaempferol, and quercetin on the active site of ß-tubulin was performed to investigate their potential mechanism of action. All fractions of E. myriochaetum ethanolic extract showed antioxidative activity. Fraction 14 displayed an antiproliferative capacity with a half maximal inhibitory concentration (IC50) value of 6.78 µg/mL against SiHa cells.

Kaempferol Induces Cell Death and Sensitizes Human Head and Neck Squamous Cell Carcinoma Cell Lines to Cisplatin.

Cisplatin is a first-line chemotherapeutic drug commonly used to treat patients with head and neck cancer; nevertheless, cisplatin resistance poses a main challenge for its clinical efficacy. Recent studies have shown that kaempferol, a natural flavonoid found in various plants and foods, has an anticancer effect. The following study evaluated the cytotoxic effects of kaempferol on head and neck tumor cells and their mechanism of action, evaluating the effects on proliferation, the oxygen consumption rate, transmembrane potential, tumor cell migration and induction of apoptosis. Moreover, we determined the effects of a combination of kaempferol and cisplatin on head and neck tumor cells. We found that kaempferol inhibited the oxygen consumption rate and decreased the intracellular ATP content in tumor cells. This novel mechanism may inhibit the migratory capacity and promote antiproliferative effects and apoptosis of tumor cells. Additionally, our in vitro data indicated that kaempferol may sensitize head and neck tumor cells to the effects of cisplatin. These effects provide new evidence for the use of a combination of kaempferol and cisplatin in vivo and their future applications in head and neck cancer therapy.

Six months under uncontrolled relative humidity and room temperature changes technological characteristics and maintains the physicochemical and functional properties of carioca beans (Phaseolus vulgaris L.).

Carioca beans contribute to health maintenance around the world, and the evaluation of commercial postharvest storage (CPS) ensures their quality. This study aimed to evaluate the effect of CPS on technological, physicochemical and functional properties of carioca beans. Two genotypes (Pontal-PO and Madreperola-MP beans) were stored under CPS or controlled conditions and were evaluated after harvest and after three- and six-months storage. PO and MP hardened with time, but the cooking time did not differ. PO is darker than MP and both darkened over time. Storage time affected pH and acidity of the beans and MP presented better physicochemical properties than PO, with lower activity of peroxidase (p = 0.004) and polyphenoloxidase (p = 0.001) enzymes. Glycosylated kaempferol was suggested as a possible chemical marker to differentiate the aging of PO and MP beans. In conclusion, besides the technological differences, the storage was able to prevent physicochemical and functional alterations of beans.