Catechin Extract Research Articles

Preliminary extraction of catechin in cashew testa

The water extraction procedure (WE) was critically selected to extract (+)-catechin and (-)-epicatechin in cashew testa. The effects of different extracting factors, including multiple extraction, extracting temperature, extracting duration, and solvent-material ratio, on catechin amounts were evaluated. Under optimal conditions, a gram of water extract (WE’) contained 151.2±4.7 mg of (+)-catechin and 85.2±2.3 mg of (-)-epicatechin. These values were nearly three-folded compared to raw material, 55.0±1.4 and 31.0±0.6 mg, respectively. By using fractional extraction with ethyl acetate, the amounts of (+)-catechin and (-)-epicatechin per gram of ethyl acetate extract (WE2) in the present extracts respectively increased to 219.4±16.5 and 123.6±8.9 mg.

Characterization of the Trans-Epithelial Transport of Green Tea (C. sinensis) Catechin Extracts with In Vitro Inhibitory Effect against the SARS-CoV-2 Papain-like Protease Activity.

This work describes an untargeted analytical approach for the screening, identification, and characterization of the trans-epithelial transport of green tea (Camellia sinensis) catechin extracts with in vitro inhibitory effect against the SARS-CoV-2 papain-like protease (PLpro) activity. After specific catechin extraction, a chromatographic separation obtained six fractions were carried out. The fractions were assessed in vitro against the PLpro target. Fraction 5 showed the highest inhibitory activity against the SARS-CoV-2 PLpro (IC50 of 0.125 μg mL−1). The untargeted characterization revealed that (−)-epicatechin-3-gallate (ECG) was the most abundant compound in the fraction and the primary molecule absorbed by differentiated Caco-2 cells. Results indicated that fraction 5 was approximately 10 times more active than ECG (IC50 value equal to 11.62 ± 0.47 μg mL−1) to inhibit the PLpro target. Overall, our findings highlight the synergistic effects of the various components of the crude extract compared to isolated ECG.

Beneficial effects of dietary supplementation with green tea catechins and cocoa flavanols on aging-related regressive changes in the mouse neuromuscular system.

Besides skeletal muscle wasting, sarcopenia entails morphological and molecular changes in distinct components of the neuromuscular system, including spinal cord motoneurons (MNs) and neuromuscular junctions (NMJs); moreover, noticeable microgliosis has also been observed around aged MNs. Here we examined the impact of two flavonoid-enriched diets containing either green tea extract (GTE) catechins or cocoa flavanols on age-associated regressive changes in the neuromuscular system of C57BL/6J mice. Compared to control mice, GTE- and cocoa-supplementation significantly improved the survival rate of mice, reduced the proportion of fibers with lipofuscin aggregates and central nuclei, and increased the density of satellite cells in skeletal muscles. Additionally, both supplements significantly augmented the number of innervated NMJs and their degree of maturity compared to controls. GTE, but not cocoa, prominently increased the density of VAChT and VGluT2 afferent synapses on MNs, which were lost in control aged spinal cords; conversely, cocoa, but not GTE, significantly augmented the proportion of VGluT1 afferent synapses on aged MNs. Moreover, GTE, but not cocoa, reduced aging-associated microgliosis and increased the proportion of neuroprotective microglial phenotypes. Our data indicate that certain plant flavonoids may be beneficial in the nutritional management of age-related deterioration of the neuromuscular system.

Acid Stable Yeast Cell-Associated Tannase with High Capability in Gallated Catechin Biotransformation.

Previously, nine tannin-tolerant and tannase-producing yeasts were isolated from Miang; all produced cell-associated tannase (CAT) during growth in tannin substrate. Among which, only CAT from Sporidiobolus ruineniae showed better stability than its purified form. Yet, it is of particular interest to directly characterize CATs from the latter yeasts. In this study, four CATs from yeasts, namely Cyberlindnera rhodanensis A22.3, Candida sp. A39.3, Debaryomyces hansenii A45.1, and Cy. rhodanensis A45.3 were characterized. The results indicate that all CATs were produced within the same production yield (11 mU/mL). Most CATs exhibited similar pH and temperature optima and stabilities, except for CAT from Cy. rhodanensis A22.3. This CAT was assigned as acid-stable tannase due to its unusual optimum pH of 2.0 with pH stability and half-life thermostability in the range of pH 2.0–4.0, and 70 °C, respectively. All CATs demonstrated high substrate specificity toward epigallocatechin gallate and epicatechin gallate, thus forming epigallocatechin and epicatechin, respectively. Moreover, they showed operational stability to repeated use for up to five cycles without loss of the initial activity. Therefore, CATs from these yeasts could be useful for the extraction and biotransformation of tea catechins and related applications.

The Extraction of Gambier by Using Ultrasonic Assisted at Various Temperature

Gambier is an extract from the leaves Uncaria gambier Roxb plant that contain polyphenolic compounds. One of polyphenol compounds in gambier is catechin, that can act as antioxidant and antimicrobial. This study aimed to determine the effect of heat on the catechin extraction from gambier by using ultrasonic assisted. The experimental design used a completely randomized design with four temperature treatments, i.e. 50°C, 60°C, 70°C, and 80°C with 3 replications. The variables measured were IC50, polyphenol content and catechin content. This study showed that the heating process during the extraction with ultrasonic waves has an impact on the content of antioxidants, polyphenols and catechins of the extract produced. The extraction process using ultrasonic assisted at 50°C showed the best result for antioxidant activity, polyphenol content, and catechin content. The value of IC50 was 1.3538 mg/L, polyphenol content was 6.6724 mg/L, and catechin content was 957.01 μg/mg.

Gambir catechins modulates amyloid-β concentration in cerebrospinal fluid of Alzheimer’s model rat

Neurodegeneration in Alzheimer’s disease has been reported as the consequences of amyloid-β accumulation in the brain resulted from oxidative stress. Gambir, which contains catechins as a potential antioxidant, is abundant in West Sumatra. This study aims to evaluate the effect of gambir catechins administration on amyloid-β concentration in cerebrospinal fluid [CSF] of the rats. An experimental study with a post-test only design was carried out on 12-week old female Sprague Dawley, an Alzheimer’s model rat. As many as 30 rats were divided into the control and treatment groups. Four of the six groups were treated with the catechins extract doses of 20 mg, 40 mg, 60 mg, and 100 mg per 200 g BW. Meanwhile, the other two groups were positive and negative control groups. After four weeks, the rats were sacrificed and the CSF was collected. Amyloid-β concentration measurement was using the ELISA method. The statistical analysis was using One-way ANOVA with posthoc test Tukey HSD. Treatment groups exhibited a linear decrease in amyloid-β concentration in all doses, particularly in CC3. The CC3-treated group showed the lowest amyloid-β concentration [13.325 ± 4.625 ng/ml], which is significantly lower [p < 0.05] when compared to the PC group [45.280 ± 7.590 ng/ml]. This result provides experimental evidence that gambir catechin reached its optimum neuroprotective effect on amyloid-β level in cerebrospinal fluid by 60 mg/200 g BW.

EFEK KATEKIN DAUN GAMBIR (UNCARIA GAMBIR ROXB) TERHADAP KADAR MALONDIALDEHID SERUM DAN EKSPRESI GEN SIRTUIN 1 PADA HIPOKAMPUS MENCIT BETINA MODEL PENUAAN

Aging is a physiological process characterized by progressive loss of physiological integrity that leads to impaired function and increased susceptibility to death. Oxidative stress is one of the factors that cause aging due to an imbalance between the amount of oxidants and antioxidants. In oxidative stress condition, malondialdehyde levels increase. D-galactose can induce aging in various organ systems. D-galactose induces oxidative stress in various organs through increased production of reactive oxygen species (ROS) and advanced glycation endproducts. In oxidative stress condition, sirtuin1 (Sirt1) produces ribose O-acetyl-ADP which, later, is reduced into ribose ADP. Both of them have a protective effect against oxidative stress. Consumption of antioxidants may prevent aging. Gambir contains health-promoting ingredients such as catechins. This study aims to determine the effect of gambier leaves catechin extract on serum malondialdehyde levels and the expression of sirtuin 1 gene in female mice aging model induced by d-galactose. This is an in vivo experiment with post test-only control group study. The samples were 28 female mice which were divided into 4 groups namely P0, P1, P2, and P3. Each group was injected 150 mg/kgBW d-galactose intraperitoneally. P1, P2, and P3 were treated orally with 100, 200, and 400 mg/kgBW gambir leaves catechin extract, respectively. Statistical test use descriftive analisys. There were significant differences in serum MDA levels in all groups (p=0.002) and there were significant differences between the P0 and P2 groups (p=0.010) and between the P0 and P3 groups (p=0.010). Sirtuin1 gene relative expressions decresead in P1 (0,49), P2 (0,74), and P3 (0,43) as compared to P0 (1.00). Conclusion. Gambir leaves catechin extract reduces serum malondialdehyde levels in aging mouse models induced by d-galactose with an optimal dose of 200mg/kgBW. and cannot reduce the relative expression of Sirt1

Valorization of waste Syzygium cumini seed kernels by three-phase partitioning extraction and evaluation of in vitro antioxidant and hypoglycemic potential

Diabetes is one of the leading causes of morbidity and mortality worldwide. Replacement of the chemically synthesized medicines with phytomedicines is of great importance. Syzygium cumini fruit has around 30% hard seed kernel part that is considered solid waste and can be a good source of bioactive phenolic compounds. Thus, this work was performed to valorize Syzygium cumini kernels powder (SCKP) using a three-phase partitioning technique (TPP) and evaluate in vitro antioxidant and hypoglycemic activities. The extraction yield of catechin, gallic acid, TFC, and TPC obtained through TPP was 0.52, 33.24 mg/g, 7.78 mg CE/g, and 82.66 mg GAE/g, respectively, in 45 min, 40% ammonium sulfate, 1:1 (V/V) extraction slurry to t-butanol, 30 ± 2 °C temperature, pH 4, 1:20 (g/mL) SCKP to water and SCKP size 106 µm. IC50 values 12.15, 9.33, and 7.55 in µg/mL for TPP extract were obtained from DPPH, α-amylase, and α-glucosidase in vitro assays, respectively. TPP for extraction of bioactive compounds was found superior over traditional extraction techniques (devoid of t-butanol and ammonium sulfate). The extract obtained shows enormous antioxidant and hypoglycemic potential for use in nutraceutical and pharmaceutical industries. Highlights First report on three-phase partitioning (TPP) extraction of catechin and gallic acid from SCKP. Effective extraction of total phenolic and flavonoid compounds. Proved the enormous antioxidant and hypoglycemic potential of SCKP’s TPP extract. TPP extraction, the selective, efficient, and economically viable option.

Tea Catechin Inhibits Biofilm Formation of Methicillin-Resistant S. aureus

Staphylococcus aureus (S. aureus) is the most common pathogen causing infections from skin to systemic infections. The success of S. aureus infections can partially be attributed to its antibiotic resistance and to its ability to form biofilm. An increasing prevalence of methicillin-resistant S. aureus (MRSA) becomes a global public health problem in recent decades. Here, the effects of tea catechin extracts on the growth and biofilm formation of three MRSA strains were investigated. The results revealed that tea catechin extracts potently suppressed MRSA growth, and the minimal inhibitory concentration of tea catechin extracts against these MRSA strains was 0.1 g/L. Then, tea catechin extracts inhibited biofilm formation of these strains in a dose-dependent manner measured with a colorimetric method, and the inhibitory effect was also demonstrated by scanning electron microscopy assay. Moreover, adhesin genes biofilm-associated protein (bap), bone sialoprotein-binding protein (bbp), collagen-binding protein (cna), clumping factors A (clfA), fibronectin binding protein A and B (fnbA and fnbB), and intercellular adhesion gene BC (icaBC) were scanned, and the results shown that fnbA and icaBC were present in these three strains. Furthermore, tea catechin extracts depressed fnbA and icaBC expression in the strains. Therefore, inhibition of biofilm formation by tea catechin extracts probably was associated with downregulation of fnbA and icaBC expression in these strains.

Effect of polyphenols extracted from Punica granatum and Acacia saligna plants on glutathione S-transferase of the cattle tick Rhipicephalus (Boophilus) annulatus (Acari: Ixodidae).

Ticks are hematophageal ectoparasites that transport major pathogens around the world. Glutathione S-transferases (GST) are involved in resistance to acaricide and redox balancing during the life cycle of the tick. The inhibition of tick GST enzymes by certain phenolic compounds, such as phenolic acids and tannins, can be a promising approach to tick control. The objective of this study was to evaluate the effects of Punica granatum red peel and Acacia saligna leaf extracts on Rhipicephalus (Boophilus) annulatus GST activity in order to reduce the resistance of cattle to acaricide. The results showed that P. granatum ethanol extract (70%) contained the highest total phenol content (350 ± 1.2μM GAE g-1), the highest condensed tannin content (270 ± 1.3μM CE g-1) and the highest hydrolysable tannin content (70 ± 5.0μM TAE g-1). Adult immersion test with a dosage of 100mg ml-1 of A. saligna ethanol extracts had a significant mortality of 50% and 75% after 24h and 96h, respectively (p < 0.01). A simple and reproducible procedure was established to purify the whole R. annulatus GST (wRaGST) while a full-length cDNA of GST was cloned from a cDNA library of the local Egyptian cattle tick R. (B.) annulatus (rRaGST). Aqueous extracts of P. granatum inhibited both wRaGST and rRaGST with values of IC50 = 0.114 and 0.07µgml-1, respectively, compared to A. saligna extracts (IC50 values = 2.08 and 1.35µgml, respectively). These inhibitory effects were attributed to the presence of a high tannin concentration (≥ 80%). HPLC analysis indicated the presence of gallic acid and catechin in both extracts, in addition to the rutin, which was only observed in A. saligna extracts. The addition of a tannin inhibitor, polyethylene glycol, suggested the existence of other phenolic compounds in combination with catechins responsible for inhibiting the activity of these extracts. Non-competitive behaviour of catechins may be helpful in preventing, or at least delaying, the development of chemical acaricide resistancein R. annulatus.

Effects of Standardized Green Tea Extract and Its Main Component, EGCG, on Mitochondrial Function and Contractile Performance of Healthy Rat Cardiomyocytes.

We recently showed that the long-term in vivo administration of green tea catechin extract (GTE) resulted in hyperdynamic cardiomyocyte contractility. The present study investigates the mechanisms underlying GTE action in comparison to its major component, epigallocatechin-3-gallate (EGCG), given at the equivalent amount that would be in the entirety of GTE. Twenty-six male Wistar rats were given 40 mL/day of a tap water solution with either standardized GTE or pure EGCG for 4 weeks. Cardiomyocytes were then isolated for the study. Cellular bioenergetics was found to be significantly improved in both GTE- and EGCG-fed rats compared to that in controls as shown by measuring the maximal mitochondrial respiration rate and the cellular ATP level. Notably, the improvement of mitochondrial function was associated with increased levels of oxidative phosphorylation complexes, whereas the cellular mitochondrial mass was unchanged. However, only the GTE supplement improved cardiomyocyte mechanics and intracellular calcium dynamics, by lowering the expression of total phospholamban (PLB), which led to an increase of both the phosphorylated-PLB/PLB and the sarco-endoplasmic reticulum calcium ATPase/PLB ratios. Our findings suggest that GTE might be a valuable adjuvant tool for counteracting the occurrence and/or the progression of cardiomyopathies in which mitochondrial dysfunction and alteration of intracellular calcium dynamics constitute early pathogenic factors.

Implementation of subcritical water extraction with natural deep eutectic solvents for sustainable extraction of phenolic compounds from winemaking by-products

In attempt to recover valuable phenolic compounds from grape pomace by-products, a new implemented methodology has been proposed. The subcritical water extraction technique has been implemented with the use of emerging eco-solvents such as natural deep eutectic solvents (NADESs). The extraction efficiency of different NADESs were screened. Among them, choline chloride containing urea as hydrogen bond donor was selected (ChClU). However, due to pressurised system and the viscosity of NADESs, ChClU could not be used as truly solvent but as a solvent modifier in an promising percentage of 30%. The optimum extraction temperature for the isolation of phenolic compounds was 100 °C since extractions above this temperature implied the loss of the original composition of grape pomace due to thermaldegradation reactions and neoformation of Maillard compounds. The employ of subcritical water combined with 30% of ChClU led to a significant rise of extracted phenolic compounds quantities in comparison with the solely use of subcritical water. Among them, the extraction of catechin and epicatechin suffered an increase of 45.05 and 47.98% respectively, so this implementation led to highly efficient and truly eco-friendly extraction method. The implementation of subcritical water with NADESs to extract valuable compounds from winery by-products has not been applied until now.

Application of Deep Eutectic Solvents and Ionic Liquids in the Extraction of Catechins from Tea.

This work aimed to comprehensively evaluate the potential and effectiveness of deep eutectic solvents (DESs) in the extraction of seven catechins from various tea samples. Different combinations of DES were used, consisting of Girard’s reagent T (GrT) in various mixing ratios with organic acids and choline chloride. The yields of the DES extractions were compared with those from ionic liquids and conventional solvent. DES contained malic acid, as the hydrogen bond donors showed a good solubility of catechins with different polarities. In the second part of the study, a solid-phase extraction (SPE) method was applied to the extraction of catechins from tea infusions. The method was applied to the determination of selected catechins in tea leaves and tea infusions. Furthermore, we demonstrated that the proposed procedure works well in the simultaneous monitoring of these polyphenols, which makes it a useful tool in the quality control of tea.

Physiological Importance of Pectin Modifying Genes During Rice Pollen Development.

Although cell wall dynamics, particularly modification of homogalacturonan (HGA, a major component of pectin) during pollen tube growth, have been extensively studied in dicot plants, little is known about how modification of the pollen tube cell wall regulates growth in monocot plants. In this study, we assessed the role of HGA modification during elongation of the rice pollen tube by adding a pectin methylesterase (PME) enzyme or a PME-inhibiting catechin extract (Polyphenon 60) to in vitro germination medium. Both treatments led to a severe decrease in the pollen germination rate and elongation. Furthermore, using monoclonal antibodies toward methyl-esterified and de-esterified HGA epitopes, it was found that exogenous treatment of PME and Polyphenon 60 resulted in the disruption of the distribution patterns of low- and high-methylesterified pectins upon pollen germination and during pollen tube elongation. Eleven PMEs and 13 PME inhibitors (PMEIs) were identified by publicly available transcriptome datasets and their specific expression was validated by qRT-PCR. Enzyme activity assays and subcellular localization using a heterologous expression system in tobacco leaves demonstrated that some of the pollen-specific PMEs and PMEIs possessed distinct enzymatic activities and targeted either the cell wall or other compartments. Taken together, our findings are the first line of evidence showing the essentiality of HGA methyl-esterification status during the germination and elongation of pollen tubes in rice, which is primarily governed by the fine-tuning of PME and PMEI activities.

Phytochemical screening, antioxidant and antilithiasis activities of Juncus acutus

The objective of this work was to perform a phytochemical screening of Juncus acutus and to evaluate its antioxidant activity and antilithiasis activity. Phytochemical screening has demonstrated the presence of catechin, tannins and alkaloids in the various extracts studied. The antioxidant activity of the methanolic and ethyl acetate extracts by ultrasound and maceration was evaluated by the method of DPPH, FRAP and phosphomolybdate. The ethyl acetate extract by ultrasound, the methanolic extract by maceration and ultrasound respectively showed IC 50 with DPPH of 1,449mg / ml, 1,535mg / ml and 4,771mg / ml and a reducing power was observed at concentrations of 419,561mgBHA /100g, 207,143mgBHA /100g and 142,20mgBHA /100g by FRAP and at concentrations of 839,470mgAAE/100g, 283,260mgAAE/100g and 141,018mgAAE/100g by the phosphomolybdate test. The determination of the total polyphenols of the ethyl acetate extract by ultrasound, the methanolic extract by maceration and by ultrasound presented respectively contents of 2,428 mg GAE / g, 1,960mg GAE / g and 1,172mg GAE / g, likewise, the flavonoid assay showed respectively concentrations of 14,469mg EQ/g, 6,466 mg EQ/g and 3,143 mg EQ/g. Antilithiasis activity was evaluated on carbapatite, cystine and uric acid stones. The mass loss of uric acid, carbapatite and cystine stones was respectively 42%, 7% and 16%.

Bergenia pacumbis from Nepal, an astonishing enzymes inhibitor

BackgroundThe Bergenia species are perennial herbs native to central Asia, and one of the most promising medicinal plants of the family Saxifragaceae which are popularly known as ‘Pashanbheda’. The aim of this study was to evaluate antioxidant and α-amylase, α-glucosidase, lipase, tyrosinase, elastase, and cholinesterases inhibition potential of Bergenia pacumbis of Nepali origin collected from the Karnali region of Nepal.MethodsThe sequential crude extracts were made in hexane, ethyl acetate, methanol, and water. Antioxidant activities were analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The α-amylase, α-glucosidase, lipase, tyrosinase, elastase, acetylcholinesterase, and butyrylcholinesterase inhibition were analyzed by the 3,5-Dinitrosalicylic acid (DNSA), p-Nitrophenyl-α-D-glucopyranoside (p-NPG), 4-nitrophenyl butyrate (p-NPB), l-3,4-dihydroxyphenylalanine (L-DOPA), N-Succinyl-Ala-Ala-p-nitroanilide (AAAPVN), acetylthiocholine, and butyrylcholine as a respective substrate. The major metabolites were identified by high performance liquid chromatography with electron spray ionization- quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS) profiling.ResultsOur results revealed the great antioxidant ability of crude extract of B. pacumbis in ethyl acetate extract against both DPPH (IC50 = 30.14 ± 0.14 μg/mL) and ABTS (IC50 = 17.38 ± 1.12 μg/mL). However, the crude methanol extract of B. pacumbis showed the comparable enzymes inhibitions with standard drugs; α-amylase (IC50 = 14.03 ± 0.04 μg/mL), α-glucosidase (IC50 = 0.29 ± 0.00 μg/mL), lipase (IC50 = 67.26 ± 0.17 μg/mL), tyrosinase (IC50 = 58.25 ± 1.63 μg/mL), elastase (IC50 = 74.00 ± 3.03 μg/mL), acetylcholinesterase (IC50 = 31.52 ± 0.58 μg/mL), and butyrylcholinesterase (IC50 = 11.69 ± 0.14 μg/mL). On the basis of HPLC-ESI-QTOF-MS profiling of metabolites, we identified major compounds such as Bergenin, Catechin, Arbutin, Gallic acid, Protocatechuic acid, Syringic acid, Hyperoside, Afzelechin, Methyl gallate, Paashaanolactone, Astilbin, Quercetin, Kaempferol-7-O-glucoside, Diosmetin, Phloretin, and Morin in methanol extract which has reported beneficial bioactivities.ConclusionOur study provides a plethora of scientific evidence that the crude extracts of B. pacumbis from Nepalese origin in different extracting solvents have shown significant potential on inhibiting free radicals as well as enzymes involved in digestion, skin related problems, and neurological disorders compared with the commercially available drugs.

Efficacy of Pluronic F-127 gel containing green tea catechin extract on chronic periodontitis – A clinical study

Purpose: To evaluate the efficacy of pluronic F-127 gel containing green tea catechin extract as a local drug delivery system in the treatment of chronic periodontitis.&#x0D; Methods: A total of 20 chronic periodontitis patients participated as per the set inclusion and exclusion criteria. Complete scaling and root planing (SRP) was done for all subjects and pluronic F-127 gel containing green tea catechin was applied on one site. The contralateral site received SRP alone. The plaque index (PI), gingival index (GI), and probing pocket depth (PPD) were recorded at baseline and on the 28th day.&#x0D; Results: At the 28th-day follow-up, green tea catechin tooth sites showed significantly lower mean scores (GI = 0.55, p = 0.30 and PPD = 3.35 mm) than the corresponding SRP tooth sites (GI = 1.25, PI = 1.15, and PPD = 4.40 mm) (p &lt; 0.05).&#x0D; Conclusion: When compared to scaling and root planing alone, the local drug delivery gel containing green tea catechin as an adjuvant was more effective in reducing the clinical parameters of periodontitis.&#x0D; Keywords: Adjuvant therapy, Camellia sinensis, Local drug delivery, Periodontal pocket

Anti-Cancer Activity of Catechin against A549 Lung Carcinoma Cells by Induction of Cyclin Kinase Inhibitor p21 and Suppression of Cyclin E1 and P–AKT

Catechin is one of the major polyphenols in teas, beans, and berry fruits. A number of studies have confirmed that catechins extract possesses health benefits in the prevention of various chronic diseases. In this study, the anti-cancer activity and mechanism of catechin against non-small cell lung cancer A549 cells were investigated. The inhibitory rate of catechin on the proliferation of A549 cells reached 19.76% at a concentration of 600 μmol·L−1 with 24 h incubation. The results demonstrated that catechin inhibits A549 cells by increasing the expressions of p21 and p27 in the cancer cells. Furthermore, the catechin treatment inhibited the expressions of cyclin E1 and phosphorylation of protein kinase (P–AKT) in a dose-dependent manner, which also contributed to the inhibition of cancer cell proliferation. Therefore, the results of this study indicated that catechin can effectively inhibit the proliferation of A549 cells through regulating its cell cycle arrest or indirectly via the p21 signaling pathway. It would provide important information for developing catechin and catechin-rich functional food or co-therapy for antitumor purposes.

Dispersion‐assisted extraction of guarana processing wastes on the obtaining of polyphenols and alkaloids

AbstractThis is the first work to evaluate the effects of high shear mixing (HSM) on the recovery of valuable polar compounds from guarana processing wastes (peels and depleted seeds), which results may server to support researches on the valorization of guarana. Under the optimum condition, the HSM was led to extract catechin (11.11–42.93 g/100 g raw material), epicatechin (7.83–24.78 g/100 g raw material) and caffeine (9.99–28.80 g/100 g raw material) from guarana products, which contents were comparable with those obtained with ultrasound assisted extraction and maceration, and significantly higher than those obtained with infusion and decoction. Besides the relatively low reducing sugar content (0.02–0.23 g glucose equivalent/100 g raw material), HSM extracts also presented high antioxidant capacity (25–533 mg ascorbic acid equivalent/g raw material) and phenolic compounds (0.5–45 g catechin equivalent/100 g raw material and 0.1–66.38 g gallic acid equivalent/100 g raw material). The use of pectinase enhanced the HSM to recover target compounds in depleted seeds.Practical applicationsThe use of guarana has emerged as a source of antioxidants, associated to enhancement of cognitive function, to prevent cancer‐related symptoms, and to control the weight. This paper is the first research to use high‐shear mixing (HSM) to maximize the recovery of bioactive compounds from the peels and depleted seeds of guarana, the wastes derived from the Brazilian carbonated beverage industry. The extraction efficiency of HSM for 1 min to recover polyphenols and alkaloids was like those of ultrasound assisted assisted and maceration, performed for 30 min. Our results confirm that HSM is an environmentally friendly, rapid and low‐cost method to extract bioactive compounds from guarana. Our results are expected to support further researches on the use of HSM as an extraction protocol for analysis and to evaluate the multipurpose potential of guarana processing wastes for food and non‐food formulations.

EKSTRAKSI KATEKIN DARI BIJI ALPUKAT DENGAN VARIASI PELARUT MENGGUNAKAN METODE MASERASI

Avocado is one of the fruits favored by many people because of the avocado's taste and content. Avocados contain antioxidants and nutrients such as fat which is 9.8 g / 100 g of fruit flesh. But until now, the use of avocados is still focused on the fruit while other parts such as seeds are underutilized. Catechins are flavonoid compounds contained in avocado seeds. Extraction of catechins in avocado seeds was carried out by maceration method, namely immersion using three variations of solvents namely ethyl acetate, 95% ethanol, and acetone for 24 hours. The results of maceration were filtered and then remaserated for 24 hours to obtain more filtrate, then concentrated with an evaporator rotary vaccum to obtain thick extracts of avocado seeds which were then tested using the TLC-Densitometry method. The results obtained were the highest levels of catechins obtained in maceration using ethyl acetate solvents, with levels of 25.55% b / b.&#x0D; Keywords: avocado seeds, catechins, maceration