Polyphenols from the extract and fraction of T. indica seeds protected HepG2 cells against oxidative stress

Flavan-3-ols, flavonoids, anthocyanidins and triterpenoids induces TIE2 phosphorylation -a candidate target for the vascular protective effects

Vascular system is essential for the body to maintain health. Dysregulated vascular system leads to cardiovascular diseases and are observed in ischaemic stroke, Alzheimer's disease, amyotrophic lateral sclerosis, and diabetes. TIE2 is a tyrosine kinase receptor expressed on vascular endothelial cells and contributes to the maintenance of a vascular system. In this paper, we screened for natural products with an activity to induce phosphorylation of TIE2, which will be beneficial for protection of a vascular system. Employing HeLa cells expressing TIE2, flavan-3-ols, flavonoids, anthocyanidins and triterpenoids were identified as active compounds that induce TIE2 phosphorylation. Several of the identified compounds are previously reported to protect endothelial cells from inflammation. Thus, the result provided TIE2 as the candidate receptor protein of those compounds for the protective effect of endothelial cells and the identified compounds will be a good candidate for maintenance of a vascular system.

Tamarind genus chemical composition and biological activities

Tamarindus indica L., the sole species in the genus Tamarind, which is a member of the subfamily Caesalpiniaceae in the family Leguminosae (Fabaceae), is extensively dispersed in many tropical and subtropical regions. This plant's Arabic name, Tamr Al-Hindi, is the basis for its English name, Tamarind. In traditional medicine, this genus has played a major role since the time of the ancient Egyptians. Folkloric medicine has traditionally used Tamarind to treat a variety of conditions, including diabetes mellitus, fever, malaria, ulcers, diarrhoea, dysentery and wounds. The primary bioactive components of this species, which have a variety of biological functions, have been identified as flavonoids, phenolic contents, sterols, triterpenes, fatty acids, sugars and other substances. Genus Tamarind has been shown to have anti-inflammatory, analgesic, anti-pyretic, antibacterial, hypolipidemic, anti-diabetic, hepatoprotective, anti-ulcerogenic and antioxidant properties. This article provides an overview of the identified chemicals from T. indica together with their stated biological activities.

Isolation and characterization of microcrystalline cellulose from an agro-waste tamarind (Tamarindus indica) seeds and its suitability investigation for biofilm formulation

The exploration of potential bio-fillers for bio-film application is a promising approach to ensure biodegradable, eco-friendly, good-quality materials with high-performance applications. This is a comprehensive study executed to establish the utility of an agro-waste Tamarindus indica seeds for microcrystalline cellulose production and to assess its feasibility for biofilm fabrication. The extraction was carried out through consecutive chemical-mediated alkalization, acid hydrolysis and bleaching. The isolated microcrystalline cellulose from Tamarindus indica seeds (TSMCC) was characterized through chemical, thermal and morphological characterization to validate the cellulose contribution, thermal resistance, and compatibility of the material. The physical parameters as density and yield percentage were assessed to evaluate its light-weight utility and economic productivity. These examinations revealed that TSMCC has good specific properties such as high cellulose content (90.57 %), average density (1.561 g/cm3), feasible average roughness (12.161 nm), desired particle size (60.40 ± 21.10 μm), good crystallinity (CI-77.6 %) and thermal stability (up to 230 °C); which are worthwhile to consider TSMCC for bio-film formulation. Subsequently, bio-films were formulated by reinforcing TSMCC in polylactic acid (PLA) matrix and the mechanical properties of the bio-films were then studied to establish the efficacy of TSMCC. It is revealed that the properties of pure PLA film increased after being incorporated with TSMCC, where 5 %TSMCC addition showed greater impact on crystalline index (26.16 % to 39.62 %), thermal stability (333oc to 389 °C), tensile strength (36.11 ± 2.90 MPa to 40.22 ± 3.22 MPa) and modulus (2.62 ± 0.55GPa to 4.15 ± 0.53GPa). In light of all promising features, 5 % TSMCC is recommended as a potential filler reinforcement for the groundwork of good quality bio-films for active packaging applications in future.

Composition of Polygonatum zanlanscianense Pamp. Steam and Leaf Phenolic Extract and Its Protective Mechanism on t-BHP-Induced Oxidative Damage of HepG2 Cells

Plant phenolic compounds have attracted considerable attention because of their health benefits. This study aimed to investigate the composition and antioxidant activity of phenol extracts from Polygonatum zanlanscianense Pamp. steam and leaf (PPP). The FTIR, UPLC-Q-Obtrip-MS, and HPLC-DAD methods were used to analyze the composition of PPP, and 20 phenolic compounds were preliminarily identified. Among them, the contents of hyperin, astragalin, and diosmetin levels were the highest. Treatment with PPP can significantly reduce t-BHP-induced cell damage in HepG2 cells, reactive oxygen species (ROS) accumulation, and malondialdehyde (MDA) content. Meanwhile, the superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GSH-Px) activities can be increased. Moreover, PPP enhanced Nrf2 expression, which was consistent with that of heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and NAD(P)H quinone oxidoreductase-1 (NQO1), whereas the expression of Keap1, the Nrf2 inhibitor, was decreased. All findings indicate that PPP can serve as a natural bioactive substance for preventing oxidative stress.

Procyanidin B2: A promising multi-functional food-derived pigment for human diseases

Natural edible pigments play a paramount part in the food industry. Procyanidin B2 (PB2), one of the most representative naturally occurring edible pigments, is usually isolated from the seeds, fruits, and leaves of lots of common plants, such as grapes, Hawthorn, black soybean, as well as blueberry, and functions as a food additive in daily life. Notably, PB2 has numerous bioactivities and possesses the potential to treat/prevent a wide range of human diseases, such as diabetes mellitus, diabetic complications, atherosclerosis, and non-alcoholic fatty liver disease, and the underlying mechanisms were partially elucidated, including mediating signaling pathways like NF-κB, MAPK, PI3K/Akt, apoptotic axis, and Nrf-2/HO-1. This paper presents a review of the natural sources, bioactivities, and the therapeutic/preventive potential of PB2 and the possible mechanisms, with the aim of promoting the development of PB2 as a functional food and providing references for its clinical application in the treatment of diseases.

In Vitro Cytotoxic Effect of Aqueous Extracts from Leaves and Rhizomes of the Seagrass Posidonia oceanica (L.) Delile on HepG2 Liver Cancer Cells: Focus on Autophagy and Apoptosis

Aqueous extracts from Posidonia oceanica's green and brown (beached) leaves and rhizomes were prepared, submitted to phenolic compound and proteomic analysis, and examined for their potential cytotoxic effect on HepG2 liver cancer cells in culture. The chosen endpoints related to survival and death were cell viability and locomotory behavior, cell-cycle analysis, apoptosis and autophagy, mitochondrial membrane polarization, and cell redox state. Here, we show that 24 h exposure to both green-leaf- and rhizome-derived extracts decreased tumor cell number in a dose-response manner, with a mean half maximal inhibitory concentration (IC₅₀) estimated at 83 and 11.5 μg of dry extract/mL, respectively. Exposure to the IC₅₀ of the extracts appeared to inhibit cell motility and long-term cell replicating capacity, with a more pronounced effect exerted by the rhizome-derived preparation. The underlying death-promoting mechanisms identified involved the down-regulation of autophagy, the onset of apoptosis, the decrease in the generation of reactive oxygen species, and the dissipation of mitochondrial transmembrane potential, although, at the molecular level, the two extracts appeared to elicit partially differentiating effects, conceivably due to their diverse composition. In conclusion, P. oceanica extracts merit further investigation to develop novel promising prevention and/or treatment agents, as well as beneficial supplements for the formulation of functional foods and food-packaging material with antioxidant and anticancer properties.

Potential of Tamarind Shell Extract against Oxidative Stress In Vivo and In Vitro

Tamarind shell is rich in flavonoids and exhibits good biological activities. In this study, we aimed to analyze the chemical composition of tamarind shell extract (TSE), and to investigate antioxidant capacity of TSE in vitro and in vivo. The tamarind shells were extracted with 95% ethanol refluxing extraction, and chemical constituents were determined by ultra-performance chromatography-electrospray tandem mass spectrometry (UPLC-MS/MS). The free radical scavenging activity of TSE in vitro was evaluated using the oxygen radical absorbance capacity (ORAC) method. The antioxidative effects of TSE were further assessed in 2,2-azobis (2-amidinopropane) dihydrochloride (AAPH)-stimulated ADTC5 cells and tert-butyl hydroperoxide (t-BHP)-exposed zebrafish. A total of eight flavonoids were detected in TSE, including (+)-catechin, taxifolin, myricetin, eriodictyol, luteolin, morin, apigenin, and naringenin, with the contents of 5.287, 8.419, 4.042, 6.583, 3.421, 4.651, 0.2027, and 0.6234 mg/g, respectively. The ORAC assay revealed TSE and these flavonoids had strong free radical scavenging activity in vitro. In addition, TSE significantly decreased the ROS and MDA levels but restored the SOD activity in AAPH-treated ATDC5 cells and t-BHP-exposed zebrafish. The flavonoids also showed excellent antioxidative activities against oxidative damage in ATDC5 cells and zebrafish. Overall, the study suggests the free radical scavenging capacity and antioxidant potential of TSE and its primary flavonoids in vitro and in vivo and will provide a theoretical basis for the development and utilization of tamarind shell.

Bioactive characterization and optimization of Tamarindus indica seed protein hydrolysate: technology and application of natural enzymes

Tamarind seeds are one of the major sources of different nutrients and minerals and are used as antioxidant components in various food products. Bioactive peptides are released by enzymatic hydrolysis of major food proteins followed by different separation techniques to isolate them from the mixture of other components. Further incorporation of bioactive peptides in various food products may lead to more diversification, fulfilling different nutritional requirements, and promoting health benefits. The objective of this study was to optimize the parameters for the formation of tamarind protein hydrolysates with the use of pepsin and trypsin. It was observed that pepsin and trypsin derived hydrolysate showed the maximum degree of hydrolysis and other bioactive characteristics (DPPH activity, reducing power, ABTS activity, and antidiabetic activity) under optimized conditions. High-performance liquid chromatography was performed for amino acid profiling on trypsin derived protein hydrolysate. From this study, pepsin and trypsin derived hydrolysate can be considered as a rich source of natural antioxidants for developing food formulation.

Surfactant-Mediated Ultrasonic-Assisted Extraction and Purification of Antioxidants from Chaenomeles speciosa (Sweet) Nakai for Chemical- and Cell-Based Antioxidant Capacity Evaluation

In this study, a surfactant-mediated ultrasonic-assisted process was used for the first time to produce an antioxidant-enriched extract from Chaenomeles speciosa (Sweet) Nakai (C. speciosa, a popular fruit grown widely in the temperate regions of China). Ultrasonic treatment at 51 °C and 200 W for 30 min with sodium dodecyl sulfate as the surfactant led to a phenolic yield of 32.42 mg/g from dried C. speciosa powder, based on single-factor experiments, the Plackett-Burman design and the Box-Behnken design. The phenolic content increased from 6.5% (the crude extract) to 57% (the purified extract) after the purification, using LSA-900C macroporous resin. Both the crude and purified extracts exhibited a significant total reducing power and DPPH/ABTS scavenging abilities, with the purified extract being more potent. The purified extract exerted significant antioxidant actions in the tert-butyl hydroperoxide-stimulated HepG2 cells, e.g., increasing the activities of superoxide dismutase and catalase, while decreasing the reactive oxygen species and malondialdehyde levels, through the regulation of the genes and proteins of the Nrf2/Keap1 signaling pathway. Therefore, the extract from C. speciosa is a desirable antioxidant agent for the oxidative damage of the body to meet the rising demand for natural therapeutics.

Anti-ischemic effect of Tamarindus indica L. seed extract against myocardial hypoxic injury

Background: Ischemic heart disease is a leading cause of death in patients with cardiovascular disease. Natural products containing high antioxidant activity have been used as an alternative therapy to improve the living conditions of patients. In this study, we examine the protective effect of tamarind seed (TS) on myocardial hypoxic injury. Methods: The hypoxia model was mimicked by mineral oil overlayed on H9c2 cardiomyoblasts for 4 h. TS extract was pretreated and administered during the hypoxic condition. Radical scavenging activity of TS extract was measured and exhibited very potent antioxidant activities on 2,2-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. Results: TS extract at a concentration of 10 µg/ml significantly reversed the effect of hypoxia-induced cell death and intracellular reactive oxygen species (ROS) production. We also observed hypoxia-induced over-expression of both inflammatory cytokine mRNA and activation of cellular apoptosis. Pretreatment of TS extract significantly reduced hypoxia-induced HIF-1a and pro-inflammatory cytokine production, IL-1b and IL-6. The Western blot analysis for apoptotic regulatory molecules, caspase 3, caspase 8 and Bax proteins, also showed hypoxia injury reversal by TS extract treatment. Conclusions: The results suggest that the anti-ischemic effect of TS extract protects against hypoxia-induced injury and has potential to be an effective alternative therapy for ischemic heart disease and oxidative-damage related disease.

Tamarind Seed Coat: A Catechin-Rich Source with Anti-Oxidation, Anti-Melanogenesis, Anti-Adipogenesis and Anti-Microbial Activities

Tamarindus indica L. or tamarind seed is an industrial by-product of interest to be investigated for its potential and value-added application. An ethanolic tamarind seed coat (TS) extract was prepared using the maceration technique and used to determine the phytochemical composition and bioactivities. The total phenolic and flavonoid contents were determined using colorimetric methods; moreover, chemical constituents were identified and quantified compared to the standard compounds using the HPLC-UV DAD technique. Bioactivities were investigated using various models: antioxidative activity in a DPPH assay model, anti-melanogenesis in B16 melanoma cells, anti-adipogenesis in 3T3-L1 adipocytes, and anti-microbial activity against S. aureus, P. aeruginosa, E. coli, and C. albican using agar disc diffusion and microdilution methods. The results manifested a high content of catechin as a chemical constituent and multiple beneficiary bioactivities of TS extract, including superior antioxidation to ascorbic acid and catechin, comparable anti-melanogenesis to deoxyarbutin, and significant anti-adipogenesis through inhibition of pre-adipocyte differentiation and reduction of lipid and triglyceride accumulation, and a broad spectral anti-microbial activity with a selectively high susceptibility to S. aureus when compared to 1% Parabens. Conclusively, TS extract has been revealed as a potential bioactive agent as well as an alternative preservative for application in food, cosmetic, and pharmaceutical product development.

Antioxidant mechanism of a newly found phenolic compound from adlay (NDPS) in HepG2 cells via Nrf2 signalling

An in-depth understanding of the bioactive mechanism of phytochemicals has a good guiding value for the design of related functional foods. Herein, the effect of N¹, N⁵- di-[(E)-p-coumaroyl]-spermidine (NDPS) originated from adlay on protecting HepG2 cells from oxidative stress was evaluated by MTT assay, western blot and qRT-PCR. After pre-treatment of NDPS, the activities of antioxidant enzymes (including superoxide dismutase, glutathione peroxidase, γ-glutamyl cysteine synthetase and heme oxygenase-1) were increased, as well as the level of proteins and gene expressions were elevated. Moreover, the γ-GCS, HO-1, SOD and GPx protein level were enhanced for the cells with NDPS treatment compared to both positive control and negative control groups. These findings suggested that NDPS could protect HepG2 cells from oxidative stress by increasing the antioxidant enzymes regulated by Nrf2/ARE pathway.

Separation and Identification of Antioxidants and Aldose Reductase Inhibitors in Lepechinia meyenii (Walp.) Epling

We previously reported that Lepechinia meyenii (Walp.) Epling has antioxidant and aldose reductase (AR) inhibitory activities. In this study, L. meyenii was extracted in a 50% MeOH and CH₂Cl₂/MeOH system. The active extracts of MeOH and 50% MeOH were subjected to fractionation, followed by separation using high-speed counter-current chromatography (HSCCC) and preparative HPLC. Separation and identification revealed the presence of caffeic acid, hesperidin, rosmarinic acid, diosmin, methyl rosmarinate, diosmetin, and butyl rosmarinate. Of these, rosmarinic acid, methyl rosmarinate, and butyl rosmarinate possessed remarkable antioxidant and AR inhibitory activities. The other compounds were less active. In particular, rosmarinic acid is the key contributor to the antioxidant and AR inhibitory activities of L. meyenii; it is rich in the MeOH extract (333.84 mg/g) and 50% MeOH extract (135.41 mg/g) of L. meyenii and is especially abundant in the EtOAc and n-BuOH fractions (373.71-804.07 mg/g) of the MeOH and 50% MeOH extracts. The results clarified the basis of antioxidant and AR inhibitory activity of L. meyenii, adding scientific evidence supporting its traditional use as an anti-diabetic herbal medicine. The HSCCC separation method established in this study can be used for the preparative separation of rosmarinic acid from natural products.

Protective effects of quercetin against hyperglycemia-induced oxidative stress in hepatic HepG2 cell line

OBJECTIVE

Hyperglycemia is a severe consequence of diabetes mellitus (DM). Throughinduction of oxidative stress, it plays a major role in the pathogenesis of several complications in DM. Therefore, new strategies and antioxidants should be implemented inthe treatment of DM. Quercetin is a flavonoid with strong antioxidant capacity found dominantly in vegetables, fruits, leaves, and grains. The current study aimed to investigate quercetin protective effects under D-glucose-induced oxidative stress by assessing antioxidant defense enzymes inHepG2 cells as an in vitro model.

MATERIALS AND METHODS

HepG2 cells were cultured with different concentrations of D-glucose (5.5, 30 and 50 mM) and/or 25 μM quercetin for 48 and 72 hr, respectively. The effect of treatments on cellular integrity, antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) activity, andcellular levels of glutathione (GSH) and malondialdehyde (MDA) wasdetermined.

RESULTS

D-glucose had various effects on intracellular antioxidant defense atdifferent doses and time-points and quercetin could attenuate oxidative stress and modulate antioxidant defenses.

CONCLUSION

The results of this study indicated that flavonoid quercetin could be proposed as an agent protecting hepatic HepG2 cells against oxidative stress associated with hyperglycemia.

Evaluation of Viburnum opulus L. Fruit Phenolics Cytoprotective Potential on Insulinoma MIN6 Cells Relevant for Diabetes Mellitus and Obesity

In this study, the influence of guelder rose (Viburnum opulus) fruit fresh juice (FJ) and a phenolic-rich fraction (PRF) isolated from juice on mice insulinoma MIN6 cells activities was investigated. Extracts were able to decrease intracellular oxidative stress at the highest non-cytotoxic concentrations. They induced glucagon-like peptide-1 (GLP-1) secretion in the presence of an elevated glucose concentration, and they inhibited in vitro activity of the dipeptidyl peptidase-4 (DPP4) enzyme. Nonetheless, inhibition of glucose-stimulated insulin secretion was detected, which was accompanied by a decrease of cellular membrane fluidity and hyperpolarization effect. In addition, the increase of free fatty acid uptake and accumulation of lipid droplets in MIN6 cells were observed. Elevated extract concentrations induced cell apoptosis through the intrinsic mitochondrial pathway with activation of initiatory caspase-9 and downstream caspases-3/7. The fluorescence-quenching studies indicated that PRF extract has binding affinity to human serum albumin, which is one of the factors determining drug bioavailability. Taken together, despite the cytoprotective activity against generated intracellular oxidative stress, V. opulus revealed potential toxic effects as well as decreased insulin secretion from MIN6 cells. These findings are relevant in understanding V. opulus limitations in developing diet supplements designed for the prevention and treatment of postprandial glucose elevation.

Tamarind: A diet-based strategy against lifestyle maladies

The modern-day review article is an exquisite attempt to demonstrate the extreme therapeutic potential of tamarind fruit (Tamarindus indica), particularly its pulp, seed, and leaf extract, against lifestyle-related chronic disorders. The rapid transition in the diet patterns and also the varying lifestyle of the people has made its way forth, a momentous upsurge in a number of chronic as well as degenerative diseases. An excess of foods having functional and nutraceutical significance has come into view recently. These foods have emerged as effective therapeutical remedies against these disorders owing to their natural phytochemical constituents present in them, in abundance. Tamarindus indica serves as a proverbial herbal medicine in each and every part of the world that is known to mankind. Also, the tamarind kernel powder (TKP) is of immense commercial significance in some of the major, leading industries of the World. The derivation of an important gel-forming substance (polysaccharide), named as "jellose," from the decorticated seed kernels of tamarind fruit has led to the manufacture of pectin. It is used in industrial scale in the preparation of various products like jams, jellies, and most important in the preparation of cheese. It plays an evident role as a stabilizer of commercial significance, and it has also been greatly recommend by the scientists to be used as a potent ingredient in a range of pharmaceutical products. The leaves of tamarind plant are also used as part of the daily diet in several countries where they are readily consumed in fresh form and especially during drought season.

The possible structural changes in the adrenal gland cortex after induction of hepatic ischemia-reperfusion injury in male albino rats: Light and electron microscopic study

The adrenal gland is an important endocrine gland in the body that secrets the adrenal hormones. One of the important clinical issues is the hepatic ischemia-reperfusion (IR) injury. Liver IR injury results in many distant organs dysfunctions such as lung, kidney, intestine, pancreas, and myocardium. The aim of the present study was to investigate the possible remote effects of hepatic IR on the structure of the adrenal cortex. Twenty healthy males, Sprague-Dawley albino rats aged 6-8 weeks were randomly divided into two groups (10 rats each): the sham control group (SC-group) and the ischemia-reperfusion group (IR-group). Sera were estimated for the following: aspartate transaminase (AST), alanine transaminase (ALT), lactic dehydrogenase (LDH), and corticosterone levels. Also oxidative markers such as malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α), and the antioxidative enzyme, catalase were measured. Adrenal glands were processed for light and transmission electron microscopic study. The results showed a significant increase in serum liver enzymes (AST, ALT, and LDH), corticosterone, MDA, and TNF-α levels and a significant decrease in serum levels of catalase in IR-group compared with SC-group. Adrenal cortical tissue of IR-group showed the loss of normal appearance. Some cells of zona glomerulosa and most of the zona fasciculata cells appeared swollen and degenerated with highly vacuolated cytoplasm. Other cells were shrunken with deeply acidophilic cytoplasm and pyknotic nuclei. Degenerated mitochondria with disrupted cristae, lipid droplets were confluent and dilated smooth endoplasmic reticulum were seen. Few zona reticularis cells had the dark nucleus and cytoplasmic vacuolations. In the different zones, blood capillaries were markedly congested and some inflammatory cells infiltrations were observed. Liver IR affected the structure of the adrenal cortex.

Anti-inflammatory and analgesic potential of Tamarindus indica Linn. (Fabaceae): a narrative review

Chronic inflammation is one of the causes of a number of non-infectious diseases in the world. Over the years, Tamarindus indica has played fundamental roles in traditional medicine as an anti-inflammatory and analgesic drug. It is a commercialized biocompatible medicinal plant species with a wide range of therapeutic window and with suggested LD50 greater than 5000 mg kg⁻¹ body weight when administered to the Wistar rats. This review examined the anti-inflammatory and analgesic potential and mechanism of various extracts from T. indica pulp, leaves, seeds, stem bark, and roots. The preclinical studies provided strong pharmacological evidence for the anti-inflammatory and analgesic activities of the different parts of T. indica and this may be attributed to the various bioactive compounds in it including alkaloids, flavonoids, tannins, phenols, saponins, and steroids. The anti-inflammatory and analgesic effects of the extracts from the different parts of T. indica may be due to its ability to inhibit a number of biological processes including cyclooxygenase-2 (COX-2) expression, inducible nitric oxide synthase (iNOS), 5-lipoxygenase biosynthesis, and tumor necrosis factor-α. The analgesic activity of T. indica may also be through the activation of the opioidergic mechanism at both the peripheral and central levels. Although further pre-clinical studies still need to be conducted, these results demonstrated that T. indica has potent anti-inflammatory and analgesic activities and hence provides justification for its use in traditional medicine to treat body pain and other inflammatory related diseases including arthritis and offers a basis for future clinical studies and possible drug development.

Preparation and Identification of Antioxidative Peptides from Pacific Herring (Clupea pallasii) Protein

The aim of this study was to isolate and purify antioxidative peptides from Pacific herring (Clupea pallasii) protein. Five enzymes (pepsin, trypsin, papain, flavourzyme, and neutrase) were used for protein hydrolysis, and Pacific herring protein hydrolysates (PHPH) were separated by ultrafiltration. The fraction with the molecular weight below 3500 Da exhibited the highest in vitro antioxidant activities and cellular antioxidant activity. The PHPH was isolated and purified by consecutive chromatographic methods including gel filtration chromatography and reverse high-performance liquid chromatography (RP-HPLC). The purified antioxidant peptides were identified as Leu-His-Asp-Glu-Leu-Thr (MW = 726.35 Da) and Lys-Glu-Glu-Lys-Phe-Glu (MW = 808.40 Da), and the IC₅₀ values of cellular antioxidant activity were 1.19 ± 0.05 mg/mL and 1.04 ± 0.06 mg/mL. The results demonstrate that is possible to produce natural antioxidative peptides from Pacific herring protein via enzymatic hydrolysis and purification.

UHPLC-UV Analysis of Morin and Structurally Related Flavonoids with Potential Anticancer Activity

Background:

Flavonoids as secondary metabolites of plants fulfill various functions in cell protection. They are of a considerable scientific interest because of their potentially medical use due to their anticancer, chemoprotective, antimicrobial, antiallergic, anti-inflammatory and antiviral activities. </P><P> Objective: The study aimed to develop a new UHPLC-UV method for morin and 2 other structurally related flavonoids - naringenin and kaempferol as the structural similarity of huge numbers of flavonoids does not limit their various biological functions and activities.

Methods:

Separation of morin and 2 other structurally related flavonoids - naringenin and kaempferol - was achieved by using BEH C18 (1.7 µm, 2.1 x 50 mm) analytical column (Waters® Acquity UPLC) and a mobile phase composed of 0.05%v/v Formic acid in water and acetonitrile in proportion of 77:23 v/v and pumped at a flow rate of 0.4 ml/min. Column temperature was set at 25 ºC and samples were analyzed (3 µl injection volume) at a wavelength of 340 nm. Waters® Xevo G2-S QToF coupled with Waters® Acquity UPLC system with binary Solvent Manager (I-Class) via electrospray ionization (ESI) interface was used to confirm the identity of the peaks in biological samples.

Results:

A rapid and simple UHPLC-UV separation of morin, kaempferol and naringenin is documented including methods validation. The developed method was applied to measuring morin, kaempferol and naringenin in human plasma after a solid phase extraction. Additionally, stability of morin in tissue culture medium was verified. The extraction method and UHPLC-UV elution conditions described provide a practical means to analyze morin, kaempferol and naringenin in biological matrices.

Conclusion:

The developed method is fast and highly sensitive. Moreover, the flavonoids used were stable in human plasma for more than 10 days.

Virgin coconut oil reverses hepatic steatosis by restoring redox homeostasis and lipid metabolism in male Wistar rats

BACKGROUND

Hepatosteatosis, a form of nonalcoholic fatty liver disease (NAFLD), is being increasingly recognized as a major health burden worldwide. Insulin resistance, dyslipidemia and imbalances in adipokine/cytokine interplay are reported to be involved in the onset and progression of this disease. Use of dietary nutraceuticals in prevention and treatment of NAFLD is emerging. Virgin coconut oil (VCO), a fermented product of fresh coconut kernel, has been shown to impede the development of hepatosteatosis in rats. This study analyzes the potential of VCO to reverse the already developed hepatosteatosis condition.

RESULTS

Hyperglycemia, reduced glucose tolerance, dyslipidemia, and hepatic macrovesicles in high-fructose-diet-fed rats (4 weeks) confirmed the development of hepatosteatosis. Natural reversion in these parameters was observed upon shifting to normal diet in untreated control animals. Administration of VCO, however, increased this natural reversion by improving high-density lipoprotein cholesterol level (53.5%) and reducing hepatic and serum triacylglycerols (78.0 and 51.7%). Increased hepatic glutathione level (P < 0.01), antioxidant enzyme activities (P < 0.05) and reduced lipid peroxidation were also noticed in these animals. These observations were in concordance with reduced liver enzyme activities (P < 0.01) and restoration of altered hepatic architecture.

CONCLUSION

The study indicates that VCO can be used as a nutraceutical against hepatosteatosis. © 2017 Society of Chemical Industry.

Screening and evaluation of active compounds in polyphenol mixtures by HPLC coupled with chemical methodology and its application

An off-line high performance liquid chromatography (HPLC) coupled with chemical methods has been developed to evaluate antioxidant activity of 11 standard polyphenol compounds (SPCs) and vitamin C (Vc) in terms of radical scavenging abilities. The structure-activity relationships of each SPC were also discussed. SPCs showed different abilities in scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethyl-benzthiazoline-6-sulphonate (ABTS+) and hydroxyl (OH) free radicals. Among SPCs, quercetin and kaempferol, as typical flavonoids, displayed the greatest radical-scavenging activities and even exhibited higher activity in OH radical removal ability than that of Vc. Furthermore, the proposed method was also applied to screening polyphenolic antioxidant components from Cichorium endivia L. (C. endivia) seed extract. The results indicated that cynarin in the extract was a more active compound to scavenge DPPH and ABTS+ radicals than chlorogenic acid, while chlorogenic acid had stronger capacity in scavenging OH free radicals.

Chemopreventive effects of a Tamarindus indica fruit extract against colon carcinogenesis depends on the dietary cholesterol levels in hamsters

Tamarind has significant antioxidant potential. We showed that tamarind protects hypercholesterolemic hamsters from atherosclerosis. Hypercholesterolemia might increase the risk of colon cancer. We investigated whether tamarind extract modulates the risk of colon cancer in hypercholesterolemic hamsters. Hamsters (n = 64) were given tamarind and a hypercholesterolemic diet for 8 weeks. The groups were the control, tamarind treatment, hypercholesterolemic, and hypercholesterolemic treated with tamarind groups. Half of each group was exposed to the carcinogen dimethylhydrazine (DMH) at the 8th week. All hamsters were euthanatized at the 10th week. In carcinogen-exposed hypercholesterolemic hamsters, tamarind did not alter the cholesterol or triglyceride serum levels, but it reduced biomarkers of liver damage (alanine transaminase [ALT], and aspartate aminotransferase [AST]). Tamarind decreased DNA damage in hepatocytes, as demonstrated by analysis with an anti-γH2A.X antibody. In liver and serum samples, we found that this fruit extract reduced lipid peroxidation (thiobarbituric acid reactive substances [TBARS]) and increased endogenous antioxidant mechanisms (glutathione peroxidase [GPx] and superoxide dismutase [SOD]). However, tamarind did not alter either lipid peroxidation or antioxidant defenses in the colon, which contrasts with DMH exposure. Moreover, tamarind significantly increased the stool content of cholesterol. Although tamarind reduced the risk of colon cancer in hypercholesterolemic hamsters that were carcinogenically exposed to DMH by 63.8% (Metallothionein), it was still ∼51% higher than for animals fed a regular diet. Staining colon samples with an anti-γH2A.X antibody confirmed these findings. We suggest that tamarind has chemoprotective activity against the development of colon carcinogenesis, although a hypercholesterolemic diet might impair this protection.

Histological effect of nicotine on adrenal zona fasciculata and the effect of grape seed extract with or without withdrawal of nicotine

Cigarette smoking is harmful to the health of both smokers and nonsmokers. It is a major cause of death. This study aimed to investigate the structural changes in the zona fasciculata of albino rats caused by nicotine and the protective effect of grape seeds with or without the stoppage of nicotine administration. Thirty-five adult male rats were used and equally divided into five groups: negative and positive control groups (Groups I and II), nicotine-treated group (Group III), nicotine- and grape seed extract-treated group (Group IV), and nicotine withdrawal and grape seed extract-treated group (Group V). Adrenal glands were dissected and prepared for histological studies. The majority of zona fasciculata cells of Group III showed striking changes in terms of swelling of the cells with marked cytoplasmic vacuolation, many pyknotic nuclei, and increased immunoexpression to caspase 3 antibodies. By electron microscopy, a marked increase in lipid deposition with its appearance in the capillary between zona fasciculata cells was noticed. Heterochromatic nuclei and dilated smooth endoplasmic reticulum were noted. Degenerated mitochondria and some mitochondria that had cavitation with a progressive loss of their cristae were seen. The zona fasciculata cells of Group IV were partially improved, while in Group V, those cells showed complete improvement. We can conclude that nicotine causes severe histological changes in zona fasciculata cells. Grape seed extract can partially ameliorate these changes, and complete recovery is achieved with grape seed extract after the stoppage of nicotine administration.