The effect of in vitro digestion, food matrix, and hydrothermal treatment on the potential bioaccessibility of selected phenolic compounds

The effects of in vitro digestion, hydrothermal treatment, and food matrices (wheat flour, durum wheat flour, wholemeal wheat flour, corn flour, rice flour) on the bioaccessibility of phenolic compounds (gallic acid, p-coumaric acid, ferulic acid, chlorogenic acid, catechin) were investigated. The influence of experimental factors and their combinations was estimated based on the "Dose Correction Index" (DCI) concept. Generally, the applied conditions had a negative effect on the bioaccessibility of polyphenols; however, the effect depended on the type of compound and food matrix, which was reflected in different DCI values. A less unfavorable effect on the bioaccessibility was exerted by the rice flour (the lowest DCI values), but the most negative impact was found in the case of the wholemeal wheat flour. The DCI concept provides basic knowledge of the magnitude of factors affecting the bioaccessibility of polyphenols, which can be useful for designing fortified products with desirable bioactivity.

Chemical characteristics and colorimetric properties of non-centrifugal cane sugar ("panela") obtained via different processing technologies

Non-centrifugal cane sugar (NCS) samples obtained by traditional moulding and granulation, and also via a novel spray-drying powdering process without additives, were assessed to characterise their sugar and phenolic profiles, flavonoid content, as well as colour parameters. As expected, sucrose was the predominant sugar (91.9-95.5%), followed by glucose (2.9-4.6%), and fructose (1.6-3.7%). Total phenolic content was between 0.4 and 0.6% and total flavonoid content into the range of 0.2-0.4%. Six phenolic acids were found in all NCS samples: protocatechuic acid (0.36-0.94 µg/100 g), vanillic acid (0.70-1.45 µg/100 g), chlorogenic acid (2.08-3.82 µg/100 g), syringic acid (1.08-2.80 µg/100 g), p-coumaric acid (0.69-1.35 µg/100 g), and ferulic acid (0.50-0.95 µg/100 g). The thermal treatment under high temperatures required in the production of granulated products was related with darker colours and changes in phenol and flavonoid contents. In contrast, spray drying generates clearer products, but with slightly less phenol and flavonoid contents.

Antidiabetic effects of Olea europaea L. leaves in diabetic rats induced by high-fat diet and low-dose streptozotocin

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, insulin resistance, and dyslipidemia. It has broad occurrence worldwide, affecting millions of people, and can cause serious complications. The olive (Olea europaea L.) has important pharmacological functions, including anti-inflammatory, antioxidant, and hypoglycemic activities. Olive leaves are used in traditional medicine for diabetes and hypertension.

AIM OF THE STUDY

To evaluate the effect of the ethanolic extract of olive leaves (EEOL) on the metabolism of rats with diabetes induced by a high-fat diet and low dose of streptozotocin (STZ).

MATERIALS AND METHODS

Male Wistar rats were either given normal feed or a high-fat diet (70% standard laboratory feed, 15% sucrose, 10% lard and 5% yolk powder) for four weeks, followed by administration of STZ (35 mg/kg, via ip). Animals with fasting glucose levels above 200 mg/dL were considered diabetic. Animals were divided into 5 groups, which received ethanol (10 mL/kg), metformin (250 mg/kg), or EEOL at doses of 200 and 400 mg/kg during 10 weeks by oral gavage. Blood samples were used to measure hematological and biochemical parameters, and kidneys were removed for posterior analysis. Body weight was recorded weekly.

RESULTS

A significant decrease in body weight was observed among diabetic animals treated with ethanol and EEOL compared to the control group. Moreover, animals treated with EEOL showed an improvement in glucose levels and in levels of inflammatory and metabolic markers when compared to diabetic animals.

CONCLUSIONS

The results indicate a potential anti-diabetic activity of olive leaves, however more studies are needed to validate clinical effects.

Changes in organic acids, polyphenolic and elemental composition of rosé sparkling wines treated with mannoproteins during over-lees aging

The effect of mannoproteins on the evolution of rosé sparkling wines during over-lees aging was investigated on the basis of the chemical characterization of polyphenols, organic acids, macro- and microelements using a combined analytical approach. Variations on these constituents were assessed using Raman and near-infrared spectroscopy. During the biological aging, caffeic acid, catechin, gallic acid and malvidin-3-O-glucoside were the most abundant polyphenolics in the rosé wines. The phenolic compound tyrosol, a fermentation derivative, was found at concentrations up to 98.07 mg L^-1. The addition of mannoproteins significantly affected the concentrations of organic acids and individual polyphenolic compounds, particularly trans-resveratrol, quercetin, catechin, p-coumaric and hydroxybenzoic acids that showed increased concentrations over time. The positive effects of mannoproteins were mainly observed at the end of the biological aging. The mineral composition remained stable, while potassium was the most abundant mineral in all wines. The observed changes involving these constituents may offer new insights on their behavior during wine aging and on the bioactive and nutritional quality of rosé sparkling wines.

A water-soluble derivative of propolis augments the cytotoxic activity of natural killer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis, a resinous material collected from numerous plants by honeybees, has historically been used as a health-promoting food. Recently, due to its potential anti-tumor effects, use of propolis has been proposed as an adjuvant therapy to chemotherapy; however, the effects of propolis on immune responses remain unclear.

AIM OF THE STUDY

In this study, we examined the effects of the oral ingestion of propolis on natural killer (NK) cell activity, which is important in immune surveillance against cancer and viral infections. In addition, we assessed the effects of the major components of the water-soluble powder derivative of propolis (WPP).

MATERIALS AND METHODS

C57BL/6 (B6) wild-type (WT) and RAG 2-deficient (RAG^-/-) mice and BALB/c WT, interferon (IFN)-γ-deficient (IFN-γ^-/-), IFN-γ receptor-deficient (IFN-γR^-/-) and RAG^-/- mice were orally administered WPP or its major components. NK cell populations and cytotoxic activity were then examined by flow cytometry and ⁵¹Cr release assay, respectively.

RESULTS

While the cytotoxic activity of NK cells was increased following administration of 100 mg/kg/day of WPP for 7 days or 200 or 500 mg/kg/day of WPP for 4 days in WT mice, the proportions of NK cell populations were unaltered. Similar activation of NK cell cytotoxicity was observed when RAG^-/-, but not IFN-γ^-/- or IFN-γR^-/-, mice were orally administered 200 mg/kg/day of WPP for 4 days. Oral ingestion of artepillin C or p-coumaric acid, but not drupanin, augmented NK cell cytotoxicity in a manner similar to WPP and to the mixture of these three components.

CONCLUSION

These results suggest that oral ingestion of WPP enhances NK cell cytotoxic activity, but not proliferation, in a manner dependent on IFN-γ and without the contribution of acquired immune responses. Further, artepillin C or p-coumaric acid, but not drupanin, may be the components responsible for this augmentation of NK cell cytotoxicity. These findings suggest the possible utility of WPP as a therapeutic for prevention of cancer development and against viral infection through NK cell activation.

Influence of controlled deficit irrigation on tomato functional value

The effect of controlled deficit irrigation (CDI) on the accumulation of carotenoids, polyphenols and l-ascorbic acid was studied in conventional and high lycopene tomato cultivars. Plants were initially irrigated to cover 100%ET_c and after the fruit set phase, the dose was reduced to 75% or 50% of ET_c. CDI had no significant effect on the accumulation of carotenoids, while it increased the levels of the hydroxycinnamic acids chlorogenic and ferulic acids, the flavonoid rutin and l-ascorbic acid. Nevertheless, there were important interactions and this effect was highly dependent on the year and site of cultivation. Certain growing areas would be more favorable to supply high quality markets, and, fortunately, CDI would maximize polyphenol (100-75%ET_c) and l-ascorbic acid (100-50%ET_c) in these areas. A combination of the best genotype and growing area with CDI would offer high quality products, preserving a scarce resource: water.

Polyphenol and l-ascorbic acid content in tomato as influenced by high lycopene genotypes and organic farming at different environments

The accumulation of polyphenols and l-ascorbic acid was evaluated under conventional (integrated pest management, IPM) and organic farming, as means to increase the accumulation of chemoprotective compounds. The effect of genotype was considerably higher than the growing system, in fact it is determining. 'Kalvert', a high-lycopene cultivar, outstood for the accumulation of most polyphenols, though low-carotenoid cultivars with high accumulation were also detected. Organic farming significantly increased the levels of caffeic acid by 20%, but reduced those of ferulic acid and naringenin by 13% and 15% respectively. A strong interaction with the environment was detected: in Navarra the differences were limited, while in Extremadura lower contents of ferulic acid and higher contents of chlorogenic acid and rutin were found in organic farming for certain cultivars. The effect of organic farming on l-ascorbic acid was dependent on cultivar and environment and it only led to an increase in Extremadura by 58%.

Caffeoyl and coumaroyl derivatives from Acacia cochliacantha exhibit ovicidal activity against Haemonchus contortus

ETHNOPHARMACOLOGY RELEVANCE

Acacia cochliacantha is a small tree whose foliage is traditionally used in Mexico for treatment of kidney pain, gastrointestinal illnesses and to kill intestinal parasites. In recent decades, the study of vegetal extracts has offered other possible alternatives for the control of Haemonchus contortus. Considering that this nematode affects dramatically the health and productivity of small ruminants, the aim of this study was to identify the anthelmintic compounds from A. cochliacantha hydro-alcoholic extract (HA-E) through an ovicidal test.

MATERIAL AND METHODS

In vitro egg hatch assay was conducted to determinate the anthelmintic effects of a HA-E (60g). Liquid-liquid ethyl acetate/water extraction gave two fractions (EtOAc-F, 1.92g; Aq-F; 58.1g). The less polar compounds from ethyl acetate fraction were extracted by addition of dichloromethane offering a precipitate phase (Mt-F, 1.25g) and a soluble mixture (DCMt-F 1.15g). All fractions were evaluated for ovicidal activity obtaining the egg hatching inhibition (EHI, 0.07-25mg/mL). Ivermectin (0.5mg/mL) was used as a reference drug (positive control), and distilled water, 2.5% DMSO and 2% methanol were used as negative controls. The isolated compounds from the most active fractions were subjected to spectroscopic (¹H NMR) Spectrometric (MS) and UV HPLC analysis in order to identify the bioactive compounds.

RESULTS

The less polar treatments (AcOEt-F, DCMt-F, DCMt-P) showed the highest ovicidal activities (98-100% EHI; at 0.62-1.56mg/mL) and the major compounds found in these fractions were identified as caffeoyl and coumaroyl derivatives, including caffeic acid (1), p-coumaric acid (2), ferulic acid (3), methyl caffeate (4), methyl-p-coumarate (5), methyl ferulate (6) and quercetin. In case of the less active fractions (Aq-F, Mt-F) were constituted principally by glycosylated flavonoids.

CONCLUSION

These results show that caffeoyl and coumaroyl derivatives from Acacia cochliacantha leaves had promising anthelmintic activity against Haemonchus contortus. This leguminous may offer an alternative source for the control of gastrointestinal nematodes of small ruminants.

Evaluation of acute and subacute toxicity of hydroethanolic extract of Dolichandra unguis-cati L. leaves in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Dolichandra unguis-cati L. is a native climbing plant of Brazil, popularly known as "unha de gato". It has been traditionally used mainly as an antipyretic, anti-inflammatory and anti-tumor agent, yet little toxicological information is found in the literature.

AIM OF THE STUDY

To identify the chemical composition of the hydroethanolic extract obtained from the leaves of Dolichandra uniguis-cati and to evaluate the acute and subacute toxicity in male and female rats, in order to assess the safety profile of this plant.

MATERIALS AND METHODS

In the acute study, a single dose (2000mg/kg) of the extract was orally administered to male and female rats. In the subacute study, the extract was orally administered to male and female rats at doses 100, 200 and 400mg/kg for 28 days. Behavioral changes, catalase and tbars evaluations, biochemical, hematological and histopathological analysis were determined. The extract' chemical composition was accessed through UHPLC/MS.

RESULTS

Chlorogenic acid, caffeic acid, ferulic acid, vanillinic acid, p-coumaric acid, rosmarinic acid, trans-cinnamic acid, luteolin, apigenin, quercitrin and quercetin were identified in the extract. In the acute treatment, the extract was classified as safe (category 5), according to the OECD guide. In relation to the subacute study, females showed a reduction in AST (100, 200 and 400mg/kg), ALT (200mg/kg) and BUN (100 and 200mg/kg) levels, while male rats 400mg/kg presented an increase in AST levels. The Chol dosage significantly decreased in female rats in a dose-dependent manner, whereas for male rats this parameter showed no statistically significant reductions. No behavioral and histopathological changes were recorded.

CONCLUSIONS

Our results indicate that the hydroethanolic extract of Dolichandra unguis-cati leaves did not present relevant toxic effects when administered orally to male and female rats. The extract also showed a potential hypocholesterolemic activity.

Phenolics, antioxidant capacity and bioaccessibility of chicory varieties (Cichorium spp.) grown in Turkey

In this study, the changes in phenolics, anthocyanin, antioxidant capacity, and bioaccessibility of chicory varieties (Cichorium spp.) in Turkey were investigated. A total of 19 phenolic standards were screened in the chicory varieties studied and the most abundant compounds in the samples, extracted with methanol, were phenolic acids, syringic (2.54mg/kg) and trans-ferulic acid (1.85mg/kg), whilst (+)-catechin was the major flavanol. The highest flavanol content using either methanol or ethanol was determined in the green chicory samples (0.62mg/kg). The red chicory variety had higher anthocyanin (12.80mg/kg), and contained more phenolics, extractable (8855.50mg GAE/100g) and hydrolysable (7005.51mg GAE/100g), than the other varieties. Also, the antioxidant capacities in this variety, as measured using the CUPRAC assay (570.54 and 425.14μmol Trolox/g dw, respectively), had a wider range of difference than was found in the other assays used. Total phenolics were more bioaccessible from the white chicory variety (61.48%). However, the bioaccessibility of antioxidants was higher in the green chicory variety.

Cuscuta chinensis Lam.: A systematic review on ethnopharmacology, phytochemistry and pharmacology of an important traditional herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Cuscuta chinensis Lam. has found its use as a traditional medicine in China, Korea, Pakistan, Vietnam, India and Thailand. It is commonly used as an anti-aging agent, anti-inflammatory agent, pain reliever and aphrodisiac. To provide an overview of the ethnopharmacology, phytochemistry, pharmacokinetics, pharmacology and clinical applications of Cuscuta chinensis, as well as being an evidence base for further research works of the plant.

MATERIALS AND METHODS

The present review covers the literature available from 1985 to 2014. The information was collected from journals, books, theses and electronic search (Google Scholar, PubMed, ScienceDirect, ESBCO, Springerlink and CNKI). Literature abstracts and full-text articles were analyzed and included in the review.

RESULTS

Many phytochemicals have been isolated, identified and published to date, including: at least 18 flavonoids; 13 phenolic acids; 2 steroids; 1 hydroquinone; 10 volatile oils; 22 lignans; 9 polysaccharides; 2 resin glycosides; 16 fatty acids. These phytochemicals and plant extracts exhibit a range of pharmacological activities that include hepatoprotective, renoprotective, antiosteoporotic, antioxidant, anti-aging, antimutagenic, antidepressant, improve sexual function, abortifacient effects, etc.

CONCLUSION

This present review offers primary information for further studies of Cuscuta chinensis. The in vitro studies and in vivo models have provided a bioscientific explanation for its various ethnopharmacological uses and pharmacological activities (most notably antioxidant effects) especially in the prevention of hepatic disease and renal failure. It is necessary and important to do more pharmacokinetic and toxicological research works on human subjects in order to inform the possible active compounds in the body and validate its safety in clinical uses.