Polyphenol-rich Fraction Research Articles

Prooxidative Potential of Photo-Irradiated Aqueous Extracts of Grape Pomace, a Recyclable Resource from Winemaking Process

Our previous study revealed that aqueous extract of grape pomace obtained from a winemaking process could exert bactericidal action upon photo-irradiation via reactive oxygen species (ROS) formation. In the present study, we focused on chemical composition and prooxidative profile of the extract. Liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) analysis showed that polyphenolic compounds including catechin monomers, dimers, trimers, and polyphenolic glucosides were contained. The polyphenol rich fraction used for the LC-ESI-MS analysis generated hydrogen peroxide (H2O2) upon photo-irradiation possibly initiated by photo-oxidation of phenolic hydroxyl group. That is, reduction of dissolved oxygen by proton-coupled electron transferred from the photo-oxidized phenolic hydroxyl group would form H2O2. The resultant H2O2 was then photolyzed to generate hydroxyl radical (•OH). The prooxidative profile of the extract in terms of •OH generation pattern upon photo-irradiation was similar to that of grape seed extract (GSE) as an authentic polyphenol product and (+)-catechin as a pure polyphenolic compound, and in all the three samples •OH generation could be retained during photo-irradiation for at least a couple of hours. The prooxidant activity of the photo-irradiated extract indicated by •OH yield was more potent than that of the photo-irradiated GSE and (+)-catechin, and this was well reflected in their bactericidal activity in which the photo-irradiated extract could kill the bacteria more efficiently than did the photo-irradiated GSE and (+)-catechin.

Immune-system-dependent anti-tumor activity of a plant-derived polyphenol rich fraction in a melanoma mouse model.

Recent findings suggest that part of the anti-tumor effects of several chemotherapeutic agents require an intact immune system. This is in part due to the induction of immunogenic cell death. We have identified a gallotannin-rich fraction, obtained from Caesalpinia spinosa (P2Et) as an anti-tumor agent in both breast carcinoma and melanoma. Here, we report that P2Et treatment results in activation of caspase 3 and 9, mobilization of cytochrome c and externalization of annexin V in tumor cells, thus suggesting the induction of apoptosis. This was preceded by the onset of autophagy and the expression of immunogenic cell death markers. We further demonstrate that P2Et-treated tumor cells are highly immunogenic in vaccinated mice and induce immune system activation, clearly shown by the generation of interferon gamma (IFN-γ) producing tyrosine-related protein 2 antigen-specific CD8+ T cells. Moreover, the tumor protective effects of P2Et treatment were abolished in immunodeficient mice, and partially lost after CD4 and CD8 depletion, indicating that P2Et's anti-tumor activity is highly dependent on immune system and at least in part of T cells. Altogether, these results support the hypothesis that the gallotannin-rich fraction P2Et's anti-tumor effects are mediated to a great extent by the endogenous immune response following to the exposure to immunogenic dying tumor cells.

Wound healing activity of the ethanol root extract and polyphenolic rich fraction from Potentilla fulgens

Context: Potentilla fulgens Wall. ex Hook (Rosaceae) is a potent medicinal plant of the Western Himalayas, where its roots are traditionally used by the local people of Uttaranchal (India) to treat wounds and tiger bites.Objective: The present study scientifically evaluates the wound healing activity of P. fulgens ethanol root extract (EPF) and its ethyl acetate fraction (PFEA) on experimental rats.Materials and methods: Wounds were inflicted on animals by using both excision and incision models. The wounded animals were treated for 16 days with EPF (oral: 200–400 mg/kg and topical: 5–10% w/w) and PFEA (oral: 75 mg/kg; topical: 1.75% w/w). Various physical (wound contraction, epithelialization rate, tensile strength) and biochemical parameters (hydroxyproline, hexosamine, proteins, DNA) were examined during the study. Oxidant product (lipidperoxidase), antioxidant enzymes (catalase, superoxide-dismutase) and reduced glutathione were determined. Morphological and histopathological studies of the skin tissues were monitored.Results: A significant (p < 0.05) wound healing property was observed when the animals were treated topically with EPF (10% w/w) and PFEA (1.75% w/w). A significantly (p < 0.05) increased in the levels of hydroxyproline, hexosamine, protein and DNA up to 59.22, 70.42, 61.01 and 60.00% was observed, respectively. This effect was further demonstrated by the morphological and histopathological representation, thus showing significant (p < 0.05) re-epethelialization on the healing area. EPF and PFEA also showed significant (p < 0.05) antioxidant activity.Conclusions: The present study provided the scientific evidence, where P. fulgens rich in polyphenolic components possess remarkable wound healing activities, thereby supporting the traditional claims.

Polyphenol-Rich Fraction from Larrea divaricata and its Main Flavonoid Quercetin-3-Methyl Ether Induce Apoptosis in Lymphoma Cells Through Nitrosative Stress.

Larrea divaricata is a plant with antiproliferative principles. We have previously identified the flavonoid quercetin-3-methyl ether (Q-3-ME) in an ethyl acetate fraction (EA). Both the extract and Q-3-ME were found to be effective against the EL-4 T lymphoma cell line. However, the mechanism underlying the inhibition of tumor cell proliferation remains to be elucidated. In this work, we analyzed the role of nitric oxide (NO) in the induction of apoptosis mediated by Q-3-ME and EA. Both treatments were able to induce apoptosis in a concentration-dependent and time-dependent manner. The western blot analysis revealed a sequential activation of caspases-9 and 3, followed by poly-(ADP-ribose)-polymerase cleavage. EA and Q-3-ME lowered the mitochondrial membrane potential, showing the activation of the intrinsic pathway of apoptosis. Q-3-ME and EA increased NO production and inducible NO synthase expression in tumor cells. The involvement of NO in cell death was confirmed by the nitric oxide synthases inhibitor L-NAME. In addition, EA and Q-3-ME induced a cell cycle arrest in G0/G1 phase. These drugs did not affect normal cell viability. This data suggested that EA and Q-3-ME induce an increase in NO production that would lead to the cell cycle arrest and the activation of the intrinsic pathway of apoptosis. Copyright © 2016 John Wiley & Sons, Ltd.

A polyphenol-rich fraction obtained from table grapes decreases adiposity, insulin resistance and markers of inflammation and impacts gut microbiota in high-fat-fed mice

The objective of this study was to determine if consuming an extractable or nonextractable fraction of table grapes reduced the metabolic consequences of consuming a high-fat, American-type diet. Male C57BL/6J mice were fed a low fat (LF) diet, a high fat (HF) diet, or an HF diet containing whole table grape powder (5% w/w), an extractable, polyphenol-rich (HF-EP) fraction, a nonextractable, polyphenol-poor (HF-NEP) fraction or equal combinations of both fractions (HF-EP+NEP) from grape powder for 16weeks. Mice fed the HF-EP and HF-EP+NEP diets had lower percentages of body fat and amounts of white adipose tissue (WAT) and improved glucose tolerance compared to the HF-fed controls. Mice fed the HF-EP+NEP diet had lower liver weights and triglyceride (TG) levels compared to the HF-fed controls. Mice fed the HF-EP+NEP diets had higher hepatic mRNA levels of hormone sensitive lipase and adipose TG lipase, and decreased expression of c-reactive protein compared to the HF-fed controls. In epididymal (visceral) WAT, the expression levels of several inflammatory genes were lower in mice fed the HF-EP and HF-EP+NEP diets compared to the HF-fed controls. Mice fed the HF diets had increased myeloperoxidase activity and impaired localization of the tight junction protein zonula occludens-1 in ileal mucosa compared to the HF-EP and HF-NEP diets. Several of these treatment effects were associated with alterations in gut bacterial community structure. Collectively, these data demonstrate that the polyphenol-rich, EP fraction from table grapes attenuated many of the adverse health consequences associated with consuming an HF diet.

Polyphenolic extract from coconut kernel modulates apoptotic genes, reactive oxygen species production, and prevents proliferation of human colon cancer cell line

Background and Aim: The modern diet along with sedentary lifestyle has led to an increasing mortality rate for colon cancer. Several dietary phytochemicals have been investigated for colon cancer therapy, so as to replace the synthetic drugs having adverse health side effects. The aim of the study was to evaluate the antiproliferative effect of polyphenol-rich fraction from coconut kernel (CK f ) on human colon cancer cell lines (HT-29). Methods: The total flavonoids and polyphenols present in CK f were determined colorimetrically. The cytotoxic and apoptotic effect of CK f was determined using 3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyl tetrazolium bromide assay, acridine orange/ethidium bromide staining, and 4',6-diamidino-2-phenylindole-2 staining. Levels of caspase-3 activity were measured colorimetrically. The expression levels of apoptotic genes BAK, BAX, BID and p53 were measured using real-time polymerase chain reaction. The effect of CK f in inducing reactive oxygen species (ROS) was studied using 2′,7′-dichlorofluorescein diacetate staining. Mitochondrial potential of HT-29 cells treated with CK f was determined by Rhodamine 123 staining. Results: Experimental results showed that CK f contains significant amount of polyphenols. CK f showed cytotoxicity against HT-29 cells (Lethal Dose 50% of 8 μg/ml) by increasing the free radical concentration, caspase 3 enzyme levels, and decreasing the mitochondrial membrane potential in dose-dependent manner. The levels of p53 and BAX showed a major increase in a dose-dependent manner, while BAK gene levels showed a slight but significant increase. Conclusion: These results clearly indicate that coconut kernel which contains cytotoxic phenols affect the growth of colon cancer cells by modulating the apoptotic machinery mediated through mitochondrial ROS production.

Polyphenols from Cymbopogon citratus leaves as topical anti-inflammatory agents

Ethnopharmacological relevanceA variety of plant polyphenols have been reported to have anti-inflammatory, frequently associated with erythema, edema, hyperplasia, skin photoaging and photocarcinogenesis. Cymbopogon citratus (DC). Stapf (Poaceae) is a worldwide known medicinal plant, used in traditional medicine in inflammation-related conditions. Aim of the studyIn this work, the anti-inflammatory potential of C. citratus infusion (CcI) and its polyphenols as topical agents was evaluated in vivo. Materials and methodsThe plant extract was prepared and its fractioning led two polyphenol-rich fractions: flavonoids fraction (CcF) and tannins fraction (CcT). An oil/water emulsion was developed with each active (CcI, CcF+CcT and diclofenac), pH and texture having been evaluated. Release tests were further performed using static Franz diffusion cells and all collected samples were monitored by HPLC-PDA. In vivo topical anti-inflammatory activity evaluation was performed by the carrageenan-induced rat paw edema model. ResultsThe texture analysis revealed statistically significant differences for all tested parameters to CcF+CcT, supporting its topical application. Release experiments lead to the detection of the phenolic compounds from each sample in the receptor medium and the six major flavonoids were quantified, by HPLC-PDA: carlinoside, isoorientin, cynaroside, luteolin 7-O-neohesperidoside, kurilesin A and cassiaoccidentalin B. The CcF+CcT formulation prompted to the higher release rate for all these flavonoids. CcI4%, CcI1% and CcF+CcT exhibited an edema reduction of 43.18, 29.55 and 59.09%, respectively. ConclusionsOur findings highlight that CcI, containing luteolin 7-O-neohesperidoside, cassiaoccidentalin B, carlinoside, cynaroside and tannins have a potential anti-inflammatory topical activity, suggesting their promising application in the treatment of skin inflammatory pathologies.

Polyphenol-Rich Fraction of Ecklonia cava Improves Nonalcoholic Fatty Liver Disease in High Fat Diet-Fed Mice.

Ecklonia cava (E. cava; CA) is an edible brown alga with beneficial effects in diabetes via regulation of various metabolic processes such as lipogenesis, lipolysis, inflammation, and the antioxidant defense system in liver and adipose tissue. We investigated the effect of the polyphenol-rich fraction of E. cava produced from Gijang (G-CA) on nonalcoholic fatty liver disease (NAFLD) in high-fat diet (HFD)-fed mice. C57BL6 mice were fed a HFD for six weeks and then the HFD group was administered 300 mg/kg of G-CA extracts by oral intubation for 10 weeks. Body weight, fat mass, and serum biochemical parameters were reduced by G-CA extract treatment. MRI/MRS analysis showed that liver fat and liver volume in HFD-induced obese mice were reduced by G-CA extract treatment. Further, we analyzed hepatic gene expression related to inflammation and lipid metabolism. The mRNA expression levels of inflammatory cytokines and hepatic lipogenesis-related genes were decreased in G-CA-treated HFD mice. The mRNA expression levels of cholesterol 7 alpha-hydroxylase 1 (CYP7A1), the key enzyme in bile acid synthesis, were dramatically increased by G-CA treatment in HFD mice. We suggest that G-CA treatment ameliorated hepatic steatosis by inhibiting inflammation and improving lipid metabolism.

Immune system activation through immunogenic cell death and tumor recruitment of dendritic cells is required for anti-tumor activity of a plant-derived polyphenol rich fraction

Chemotherapy faces the problem of chemo-resistance in large part of tumors, leading to the appearance of metastasis difficult to eliminate. Over the past decade an improved understanding of the effect of immunogenic chemotherapy on tumor-host interactions has led to the concept of immunogenic cell death (ICD), a type of cell death capable to convert a tumor into an in situ vaccine through the generation of danger signals, dendritic cells activation an finally breaking tolerance, which leads to the destruction of residual tumor cells. Polyphenols are natural compounds from plants, traditionally used for cancer treatment, that exhibit multiple biological activities including anti-oxidation, anti-angiogenesis and pro-apoptosis, which together may exert potent anti-tumor activity. However, little is known about the mechanism of action of polyphenols. We previously obtained a normalized polyphenol rich fraction from Ceasalpina spinosa (P2Et) that exerted cytotoxic activity on several tumor cell lines. Moreover, P2Et showed anti-tumor activity in the 4T1 transplantable model through ICD induction. Vaccination with P2Et-pretreated 4T1 cells yielded long lasting ex vivo IL-2, TNF-α, IL-4, IL-5, and IFN-γ secreting multifunctional T cells after specific 4T1 cell stimulation. In this work we investigate the activation of the immune system after in vivo P2Et treatment of B16 tumor bearing mice. Analysis of spleen, lymph nodes and tumors shows increase numbers of CD44 high, CD4 and CD8 T cells, as well as NK cells in P2Et treated mice compared to non-treated ones. In addition, in vitro, phagocytosis of P2Et treated tumor cells induce activation of DC, and in vivo P2Et induces recruitment and activation of cross-presenting DCs (CD11c+, CD11b+, Ly6C+ or CD11c+ CD8α+) in spleen and tumors, which could lead to the effective activation of CD8 T cells favoring a better tumor control. In fact, vaccinated mice treated with P2Et cells are able to effectively control the growth of transplanted tumor. Accordingly, we observed that P2Et anti-tumor activity is highly dependent on an intact immune system, as P2Et anti-tumor activity is lost in RAG γc KO immunodeficient mice. In summary, P2Et exert its anti-tumor activity through the activation of the endogenous immune system, playing an important role not only in the destruction of the primary tumor but also in controlling metastasis.

Protection against oxidative damage in human erythrocytes and preliminary photosafety assessment of Punica granatum seed oil nanoemulsions entrapping polyphenol-rich ethyl acetate fraction

The main purpose of the present study is to evaluate the ability of nanoemulsion entrapping pomegranate peel polyphenol-rich ethyl acetate fraction (EAF) prepared from pomegranate seed oil and medium chain triglyceride to protect human erythrocyte membrane from oxidative damage and to assess preliminary in vitro photosafety. In order to evaluate the phototoxic effect of nanoemulsions, human red blood cells (RBCs) are used as a biological model and the rate of haemolysis and photohaemolysis (5Jcm−2 UVA) is assessed in vitro. The level of protection against oxidative damage caused by the peroxyl radical generator AAPH in human RBCs as well as its effects on bilayer membrane characteristics such as fluidity, protein profile and RBCs morphology are determined. EAF-loaded nanoemulsions do not promote haemolysis or photohaemolysis. Anisotropy measurements show that nanoemulsions significantly retrain the increase in membrane fluidity caused by AAPH. SDS-PAGE analysis reveals that AAPH induced degradation of membrane proteins, but that nanoemulsions reduce the extension of degradation. Scanning electron microscopy examinations corroborate the interaction between AAPH, nanoemulsions and the RBC membrane bilayer. Our work demonstrates that Punica granatum nanoemulsions are photosafe and protect RBCs against oxidative damage and possible disturbance of the lipid bilayer of biomembranes. Moreover it suggests that these nanoemulsions could be promising new topical products to reduce the effects of sunlight on skin.

Photoprotection by Punica granatum seed oil nanoemulsion entrapping polyphenol-rich ethyl acetate fraction against UVB-induced DNA damage in human keratinocyte (HaCaT) cell line

There has been an increase in the use of botanicals as skin photoprotective agents. Pomegranate (Punica granatum L.) is well known for its high concentration of polyphenolic compounds and for its antioxidant and anti-inflammatory properties. The aim of this study was to analyze the photoprotection provided by P. granatum seed oil nanoemulsion entrapping the polyphenol-rich ethyl acetate fraction against UVB-induced DNA damage in the keratinocyte HaCaT cell line. For this purpose, HaCaT cells were pretreated for 1h with nanoemulsions in a serum-free medium and then irradiated with UVB (90–200mJ/cm2) rays. Fluorescence microscopy analysis provided information about the cellular internalization of the nanodroplets. We also determined the in vitro SPF of the nanoemulsions and evaluated their phototoxicity using the 3T3 Neutral Red Uptake Phototoxicity Test. The nanoemulsions were able to protect the cells' DNA against UVB-induced damage in a concentration dependent manner. Nanodroplets were internalized by the cells but a higher proportion was detected along the cell membrane. The SPF obtained (~25) depended on the concentration of the ethyl acetate fraction and pomegranate seed oil in the nanoemulsion. The photoprotective formulations were classified as non-phototoxic. In conclusion, nanoemulsions entrapping the polyphenol-rich ethyl acetate fraction show potential for use as a sunscreen product.

Polyphenolic extract of Termitomyces heimii: antioxidant activity and phytochemical constituents

Polyphenol rich fraction of Termitomyces heimii, a wild edible mushroom, was prepared to investigate its antioxidant activity and presence of different bioactive constituents. A preliminary chemical investigation was performed and it revealed that the fraction possessed various types of components with maximum amount of phenol. The other found components were in the following consequence flavonoid > ascorbic acid > s-carotene > lycopene. HPLC data analyses showed presence of cinnamic acid and a good amount of pyrogallol (9603 µg/g of dry tissue of mushroom). The extract showed best hydroxyl radical scavenging activity (EC50 = 0.021 mg/ml). EC50 values for SOD radical scavenging assay was as low as 0.19 mg/ml. That of the rest of the antioxidant assays i.e., DPPH radical scavenging assay and reducing assay were only 0.49 and 1.31 mg/ml respectively. Thus T. heimii can be used as an easily accessible source of natural antioxidants or for the development of a new health medicine for fighting against various human stress related diseases.

Protective role of polyphenols from Bauhinia hookeri against carbon tetrachloride-induced hepato- and nephrotoxicity in mice

The hepatoprotective and nephroprotective activity of a polyphenol-rich fraction (BHPF) obtained from Bauhinia hookeri was investigated against CCl4-induced acute hepatorenal toxicity in mice. BHPF was administered (100, 200 and 400 mg/kg/day) for 5 days, then CCl4 was administered. BHPF pretreatment significantly (p < 0.001) inhibited the CCl4-induced increase in ALT, AST, ALP, LDH, total bilirubin, cholesterol, creatinine, uric acid, urea and malondialdehyde in a dose-dependent manner. In contrast, BHPF pretreatment markedly increased the contents of glutathione and superoxide dismutase in the liver and kidney tissues, indicating the strong in vivo antioxidant activity of BHPF. Pretreatment with BHPF preserved the hepatic architecture and conferred marked protection against necrosis and ballooning degeneration. Pretreatment with BHPF reduced the inflammatory cell aggregation and degenerative changes in the lining epithelium of the kidney tubules. It can be concluded that BHPF has a remarkable hepato- and nephroprotective activity by enhancing the antioxidant defense status, reducing lipid peroxidation and protecting against the histopathological changes induced by CCl4 in the liver and kidney tissues.

Antioxidant activity of Moringa oleifera isothiocyanates

Moringa oleifera Lam. (Brassicales) is an edible tropical tree with medicinal properties. Here, we describe a fractionation process of moringa leaves by fast centrifugal partition chromatography (FCPC) to generate polyphenol and isothiocyanate (ITC) rich fractions (Fig. 1). The polyphenol-rich fraction showed direct antioxidant activity assayed by oxygen radical absorbance capacity (ORAC), while the ITC-rich fraction demonstrated indirect antioxidant properties assayed by NQO1 activity in Hepa1c1c7 cells. Also, purified 4-[(α-l-rhamnosyloxy) benzyl] isothiocyanate (ITC-1), and 4-[(4'-O-acetyl-α-l-rhamnosyloxy)benzyl] isothio-cyanate (ITC-4) were evaluated for their ORAC and NQO1 inducer potency in comparison with sulforaphane (SF) at 5µM (Fig. 2). Both ITCs were as potent as SF in inducing NQO1 activity. These findings suggest that edible M. oleifera leaves contain a potent mixture of antioxidants that could explain its health promoting effects.

Polyphenols rich fraction from Geoffroea decorticans fruits flour affects key enzymes involved in metabolic syndrome, oxidative stress and inflammatory process

Geoffroea decorticans (chañar), is widely distributed throughout Northwestern Argentina. Its fruit is consumed as flour, arrope or hydroalcoholic beverage. The chañar fruits flour was obtained and 39 phenolic compounds were tentatively identified by HPLC-MS/MSn. The compounds comprised caffeic acid glycosides, simple phenolics (protocatechuic acid and vanillic acid), a glycoside of vanillic acid, p-coumaric acid and its phenethyl ester as well as free and glycosylated flavonoids. The polyphenols enriched extract with and without gastroduodenal digestion inhibited enzymes associated with metabolic syndrome, including α-amylase, α-glucosidase, lipase and hydroxyl methyl glutaryl CoA reductase. The polyphenolic extract exhibited antioxidant activity by different mechanisms and inhibited the pro-inflammatory enzymes (ciclooxygenase, lipoxygenase and phospholipase A2). The polyphenolic extract did not showed mutagenic effect by Ames test against Salmonella typhimurium TA98 and TA100 strains.These findings add evidence that chañar fruit flour may be considered a functional food with preventive properties against diseases associated with oxidative stress, inflammatory mediators and metabolic syndrome.

Protective effect of Terminalia muelleri against carbon tetrachloride-induced hepato and nephro-toxicity in mice and characterization of its bioactive constituents

Context: Terminalia is used in folk medicine for the treatment of various diseases.Objective: The objective of this study is to investigate the hepatonephro protective activity of a polyphenol-rich fraction (TMEF) obtained from Terminalia muelleri Benth. (Combretaceae) against CCl4-induced toxicity in mice.Materials and methods: TMEF was administered (100, 200, and 400 mg/kg/d) for 5 d. CCl4 was administered at the end of the experiment. Hepatic and renal biomarkers were measured in the serum. Glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) were estimated in the liver and kidney tissues. The active constituents of TMEF were identified by HPLC–PDA–ESI/MS/MS.Results: TMEF is rich in ellagitannins, galloyl esters, phenolic acids, and flavone-C-glucosides. TMEF pretreatment significantly (p < 0.001) inhibited the CCl4-induced increase in ALT (17, 43, and 53%), AST (20, 46, and 58%), ALP (20, 48, and 56%), LDH (21, 47, and 58%), hepatic MDA (23, 49, and 54%), renal MDA (22, 35, and 52%), creatinine (48, 66, and 91%), uric acid (16, 34, and 59%), urea (22, 39, and 59%), and cholesterol (20, 27, and 46%). Furthermore, TMEF administration significantly (p < 0.001) increased hepatic GSH (15, 51, and 79%), renal GSH (23, 45, and 73%), hepatic SOD (9, 52, and 95%), renal SOD (39, 66, and 85%) and protein levels (17, 24, and 29%) at the tested doses of TMEF, respectively. Pretreatment with TMEF preserved the hepatic architecture and protected from ballooning degeneration, liver necrosis, renal inflammation, and degeneration of the kidney tubules.Conclusion: TMEF has a marked hepato-nephro protective effect.

Combination of spices and herbal extract restores macrophage foam cell migration and abrogates the athero-inflammatory signalling cascade of atherogenesis

The trapping of lipid-laden macrophages in the arterial intima is a critical but reversible step in atherogenesis. However, information about possible treatments for this condition is lacking. Here, we hypothesized that combining the polyphenol-rich fractions (PHC) of commonly consumed spices (Allium sativum L (Liliaceae), Zingiber officinale R (Zingiberaceae), Curcuma longa L (Zingiberaceae)) and herbs (Terminalia arjuna (R) W & A (Combretaceae) and Cyperus rotundus L (Cyperaceae)) prevents foam cell formation and atherogenesis. Using an in vitro foam cell formation assay, we found that PHC significantly inhibited lipid-laden macrophage foam cell formation compared to the depleted polyphenol fraction of PHC (F-PHC). We further observed that PHC attenuated the LDL and LPS induced CD36, p-FAK and PPAR-γ protein expression in macrophages and increased their migration. NK-κB–DNA interaction, TNF-α, ROS generation, and MMP9 and MMP2 protein expression were suppressed in PHC-treated macrophages. The anti-atherosclerotic activity of PHC was investigated in a high fat- and cholesterol-fed rabbit model. The inhibition of foam cell deposition within the aortic intima and atheroma formation confirmed the atheroprotective activity of PHC. Therefore, we conclude that the armoury of polyphenols in PHC attenuates the CD36 signalling cascade-mediated foam cell formation, enhances the migration of these cells and prevents atherogenesis.

Polyphenols rich fraction of Dicranopteris linearis promotes fibroblast cell migration and proliferation in vitro

Ethnopharmacological relevanceDicranopteris linearis is a fern used traditionally for the treatment of skin afflictions such as external wounds, boils and ulcers. However, there are no scientific studies to date to demonstrate its ability to induce wound recovery. The objective of the present study was to explore the wound healing properties of an active fraction of D. linearis through several in vitro assays and to determine its chemical profile. Materials and methodsThe antioxidant activities were evaluated by DPPH and FRAP assays. The ability of the active fraction to induce fibroblast cell proliferation in serum deprived medium or under the challenge of exogenous hydrogen peroxide was evaluated by MTT assay. Cell migration was investigated using the scratch-wound assay. Chemical constituents of the active fraction were isolated and their structures were determined by NMR and MS spectroscopic techniques. Chemical profiling was carried out by the HPLC–UV method. ResultsThe fifth subfraction of the methanol extract of D. linearis (sF5) showed prominent antioxidant activities. It was non-cytotoxic at the concentration tested and was able to induce cell proliferation of selected fibroblast cells under serum deprived conditions. In addition, sF5 was found to enhance cell migration and promote cellular repair following oxidative damage caused by hydrogen peroxide through a mechanism which was independent of its hydroxyl radical scavenging capability. Six phenolic glycosides were identified in sF5 where three were known, two were new and one phenolic glycoside first time reported from the plant. ConclusionThe active fraction of D. linearis which was rich in polyphenolic substances exhibited substantial antioxidant activities, induced cellular repair and contributed positively to fibroblasts proliferation and migration in vitro. Hence, it may have potential application in inducing wound recovery and supports its ethnopharmacological use for treating skin problems.

Antioxidant activity of polyphenolic extract of Phyllanthus emblica against lead acetate induced oxidative stress

Phyllanthus emblica (Euphorbiaceae) possesses a vast ethnomedical history and represents a phytochemical reservoir of heuristic medicinal value. Polyphenolic extract of P. emblica fruits, was investigated for antioxidant potential against lead acetate induced toxicity in female Wistar rats. The liver of female Wistar rats treated with lead acetate at different concentrations showed significant increase in lipid peroxidation and decrease in activities of superoxide dismutase and catalase. Furthermore, lead acetate also caused decrease in reduced glutathione content in rat liver. However, the co-incubation of extract and lead acetate showed significant protection in concentration-dependent manner. Furthermore, the polyphenolic extract of P. emblica fruits also found to have potent free radical scavenging activity as assessed by reducing power assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (IC50 15.5 μg/mL), superoxide radical (IC50 26 μg/mL) and hydrogen peroxide scavenging assays (IC50 22 μg/mL) under in vitro conditions. Moreover the phytochemical characterization of the extract was also measured by determining total phenolic, flavonoids and tannin contents. This activity of the extract may be due to the total polyphenolic contents present in it. The present study concluded that a polyphenolic rich fraction of P. emblica fruits is a potential source of natural antioxidants and thus could prevent oxidative stress induced by heavy metal toxicants.

Direct and indirect antioxidant activity of polyphenol- and isothiocyanate-enriched fractions from Moringa oleifera.

Moringa oleifera Lam. is a fast-growing, tropical tree with various edible parts used as nutritious food and traditional medicine. This study describes an efficient preparatory strategy to extract and fractionate moringa leaves by fast centrifugal partition chromatography (FCPC) to produce polyphenol and isothiocyanate (ITC) rich fractions. Characterization and further purification of these fractions showed that moringa polyphenols were potent direct antioxidants assayed by oxygen radical absorbance capacity (ORAC), whereas moringa ITCs were effective indirect antioxidants assayed by induction of NAD(P)H quinone oxidoreductase 1 (NQO1) activity in Hepa1c1c7 cells. In addition, purified 4-[(α-l-rhamnosyloxy)benzyl]isothiocyanate and 4-[(4'-O-acetyl-α-l-rhamnosyloxy)benzyl]isothiocyanate were further evaluated for their ORAC and NQO1 inducer potency in comparison with sulforaphane (SF). Both ITCs were as potent as SF in inducing NQO1 activity. These findings suggest that moringa leaves contain a potent mixture of direct and indirect antioxidants that can explain its various health-promoting effects.