Condensed Tannin Content Research Articles

Reclamation of beneficial bioactivities of herbal antioxidant condensed tannin extracted from Euonymus laxiflorus

Natural condensed tannins (CT) have received great interest due to their vast beneficial bioactivities. Recently, Euonymus laxiflorus, an edible medicinal herb collected in the Central Highlands of Vietnam, was newly recognized as a natural source rich in antioxidant CT. The aim of this study is to scale up extraction and investigate various novel bioactivities of the isolated CT. The screening of the parts used rich in CT, such as heartwood, trunk bark, branch, and the leaves of EL, indicated that the EL trunk bark (ELTB) has the highest CT content. E. laxiflorus CT (ELCT) was extracted with high-level scale from ELTB via several techniques and then was qualified by NMR spectra and HPLC finger printing. A condensed tannin ELBT-3.1.d was isolated and showed its high molecular weight of ≥ 10 kDa and various in vitro bioactivities. ELBT-3.1.d demonstrated high antioxidant capacity (IC50 = 6.11 µg/mL), and potent enzymes inhibition targets in anti-diabetes, especially showing novel potential inhibition against human salivary α-amylase with IC50 value of 3.01 µg/mL. ELBT-3.1.d displayed no anti-NO effect but did show moderate to effective anticancer activities against A549, MCF-7, HepG2, and WiDr. Notably, condensed tannin ELBT-3.1.d displayed no toxicity to normal cells and a novel potential prebiotic effect on Lactobacillus paracasei BCRC14023 and Lactobacillus rhamnosus BCRC16000. In the animal test, ELCT demonstrated significant effect on reducing plasma glucose in mice at the doses of 50–100 mg/kg BW. The current study contributes to enrich the novel bioactivities of ELCT which may be suggested as functional food or drugs due to processing numerous beneficial bioactivities.

Solid state fermentation of fenugreek (Trigonella foenum-graecum): implications on bioactive compounds, mineral content and in vitro bioavailability.

In the present study, solid-state fermentation (SSF) of four fenugreek cultivars viz. HM-57, AFG-2, RMT-1 and RMT-303 were carried out using Aspergillus awamori and its effect on antioxidant properties, phenolic content and bioactive compounds were studied. Macro (Ca, K, and Na) as well as micro (Fe, Zn, and Cu) elements and in vitro bioavailability of the unfermented fenugreek (UFF) and Aspergillus-fermented fenugreek (AFF) samples were assessed with standard methods. On 5th day, total phenolic and condensed tannin contents showed significant (p ≤ 0.05) increase for all cultivars. Further, HPLC analysis confirmed formation of some new bioactive (vanillin, benzoic acid and catechin) compounds. Similarly, extracts from all AFF also showed an increase in the antioxidant potential such as inhibition of DPPH, hydroxyl free radical scavenging, reducing power, and total antioxidant capacity up to 5th day of SSF. Mineral in AFF were found with enhanced values when compared with respective UFF. In vitro bioavailability of Fe, Zn and Ca was also improved during SSF. Results from the present study may be helpful to food industry in developing new health foods and may provide a rational for development of functional ingredient in preparation of novel nutraceuticals.

Response of Ziziphus mucronata and Acacia nilotica saplings to increasing clipping intensity in a southern African savanna

Many woody plants respond to intense clipping through an increase in growth parameters and nutritive value. However, optimal clipping intensities that result in peak plant growth and nutritive value have not been determined. We studied the response of Ziziphus mucronata and Acacia nilotica saplings to four clipping intensities. Parts of the main stem and each lateral branch were removed to simulate 0%, 30%, 60%, and 90% clipping intensity. After four months of resprouting five sapling growth parameters were determined viz. height, basal stem diameter, length of the longest shoot, root length, and number of new shoots. In addition, foliar crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), total phenolic (TP), and condensed tannin (CT) concentrations were determined. Shoot clipping did not stimulate sapling height and basal diameter growth, while shoot length responded to an increase in clipping intensity with a weak hump-shape in both species. Ziziphus mucronata increased root growth in response to increasing clipping intensity, while A. nilotica showed no clear trend. The largest number of new shoots was produced at 60% and 30% clipping intensities for Z. mucronata and A. nilotica respectively. Ziziphus mucronata produced more new shoots than A. nilotica. The most severe (90%) clipping intensity produced the highest CP and lowest NDF content in the two species, reduced TP and CT content in A. nilotica, but not in Z. mucronata. We conclude that an increase in clipping intensity produced varying responses in sapling growth parameters and nutritive values in Z. mucronata and A. nilotica.

Nutritional, phytochemical, antioxidant, α-glucosidase and α-amylase inhibitory properties of Moringa oleifera seeds

The aim of this study was to analyze nutritional characteristics of Moringa oleifera seed and evaluate phytochemical compounds, as well as antioxidant and enzyme inhibitory activities, of such seeds. Results demonstrated that seed protein possessed 23.77% of indispensable amino acids, but lysine was the first limiting amino acid. Seed oil contained 78.44% of unsaturated fatty acids, with oleic acid (C18:1) greater than 70%. And seeds were rich in mineral elements, especially being a good source of Ca in the human diet. In addition, total saponins (146.92–169.82 mg GEs/g), total phenolics (37.07–40.75 mg GAEs/g), total flavonoids (6.85–8.43 mg REs/g), and condensed tannins contents (2.74–5.28 mg CEs/g) were identified in different extracts of Moringa oleifera seed. Seed extracts exhibited good antioxidant activities as assessed by different in vitro assays, including 2,2-azino-bis-3-ethylbenzothiazloine-6-sulfonic acid (ABTS), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, and ferric reducing antioxidant power assays. The α-glucosidase and α-amylase inhibitory activity were also investigated. Furthermore, ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was utilized to characterize the bioactive components in seed extracts. Thirty-three compounds were identified, mainly consisting of glucosides, phenolics (and derivatives), and flavonoids (and derivatives).

Florivory defence: are phenolic compounds distributed non-randomly within perianths?

Abstract Plants might allocate chemical defences unequally within attractive units of flowers including petals, sepals, and bracts because of variations in the probability of florivory. Based on optimal defence theory, which predicts that plants allocate higher chemical defences to tissues with higher probabilities of herbivore attack, we predicted that distal parts and sepals would have higher chemical defence allocations than proximal parts and petals. To test this prediction, we compared total phenolics and condensed tannins concentrations as well as presence of florivory within attractive units of ten angiosperm species. In agreement with the prediction, the overall results showed that the distal parts had higher total phenolics and condensed tannins than the proximal parts. On the other hand, contrary to the prediction, petals and sepals showed no tissue-specific variations. Florivory was more severe on the distal parts than the proximal parts, although statistical support for the variation was slightly weak, while the variations in presence of florivory between petals and sepals differed between the distal and proximal parts. These results may support the prediction of the optimal defence theory because distal parts of attractive units had higher presence of florivory and concentration of chemical defences.

Essential Oil and Hydrosol Extract Chemical Composition, Phytochemicals of Algerian Rhus pentaphylla Desf. and its Antioxidant Activity

Background: Rhus pentaphylla Desf. (Anacardiaceae) widely grown in Algeria, is an underutilized plant and remains poorly studied. To investigate for the first time, the chemical composition profile of essential oil and hydrosol extract; besides Total Phenolic (TPC), Flavonoid (TFC) and Condensed Tannins Contents (CTC) of fruits, leaves and roots, the fatty acid composition was assessed. The radical scavenging activity of R. pentaphylla extracts was then evaluated. Methods: Essential oil and hydrosol extract were isolated respectively by hydrodistillation and liquidliquid- extraction from the aerial parts of R. pentaphylla. The antioxidant activity was evaluated using 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) radical and ferric reducing antioxidant power (FRAP). Chemical compositions of various extracts were investigated using Gas Chromatography (GC) and GC-Mass Spectrometry (GC-MS). Results: The results of GC and GC-MS analysis revealed 83 components in essential oil and 75 components in hydrosol extract representing respectively 96.9% and 92.5% of the total extract composition. The main constituents were hexadecanoic acid (31.5%) followed by spathulenol (14.9%) in the oil while the higher amount present in the hydrosol extract was of spathulenol (14.2%). Otherwise, 13 and 18 fatty acids were identified in roots and fruits respectively. The highest levels of TPC and CTC were found in roots extracts while the highest quantity of TFC has been recorded in the leaves extract. Besides, hydrosol extract was able to scavenge DPPH and FRAP free radicals more efficiently than essential oil. Conclusion: R. pentaphylla contains bioactive substances that could be used as a new promising source of antioxidant compounds in different applications.

Effects of dietary grapeseed extract on performance, energy and nitrogen balance as well as methane and nitrogen losses of lambs and goat kids.

The influence of phenol-rich dietary grapeseed extract on performance, energy and N balance and methane production was determined in sixteen lambs and thirteen goat kids (body weight 20·5 and 19·0 kg, 2 months of age, day 1 of study). Half of the animals received a concentrate containing grapeseed extract, and the others received concentrate without grapeseed extract (total extractable phenols analysed 27 v. 9 g/kg dietary DM; concentrate and hay 1:1). Diets were fed for 7 weeks with 1 week for determining intake, excretion and gaseous exchange in metabolism crates and respiration chambers. Overall, there was an adverse effect of the phenolic diet on apparent N digestibility and body N retention. Faecal N loss as proportion of N intake increased while urinary N loss declined. Relative to N intake, total N excretion was higher and body N retention lower in goat kids than lambs. Diets and animal species had no effect on methane emissions. The saliva of the goat kids had a higher binding capacity for condensed tannins (CT). Goat kids on the phenolic diet had higher CT concentrations in faeces and excreted more CT compared with the lambs (interaction species × diet P < 0·001). The lambs had overall higher (P < 0·001) urinary phenol concentrations than the goat kids (2·19 v. 1·48 g/l). The negative effect on body N retention and lack of effect on methane emissions make the use of the extract in the dosage applied not appealing. Species differences need to be considered in future studies.

Factors Affecting the Color of Herbaceous Peony

Herbaceous peony (Paeonia lactiflora Pall.) is a well-known ornamental plant with abundant flower colors. However, our understanding of the underlying mechanisms of flower color formation is limited. In this study, a wild sample of herbaceous peony (collected from Heze, China) and eight cultivars with different colors were selected for experimental investigation. The Royal Horticultural Society Color Chart was used to determine flower color, and the anatomic structure; cell sap pH value; moisture content (MC); condensed tannin content (Ct); soluble sugar and soluble protein content of the petals; and content and composition of anthocyanin, flavonoids, and carotenoids in the petals were examined. 1) In the white, pinkish white, pale purple, purplish pink, and reddish purple cultivars, deeper color was associated with greater total amounts of anthocyanin (TA). Hypochromic effects were observed for kaempferol-7-O-glucoside (Km7G), myricetin-3-rhamnoside (My3R), and luteolin-7-O-glucoside (Lu7G). The accumulation of quercetin-3-O-glucoside (Qu3G) and lutein affected yellow color formation in the petals. 2) There are papillate epidermal cells in the petals of the wild P. lactiflora sample, ‘Lanyucangjin’, and ‘Dongjingnvlang’. 3) Cell sap pH and MC of the petals of white, pinkish white, pale purple, and purplish pink cultivars were greater than those of the purplish red and most of the reddish purple cultivars. 4) The Ct was greatest in the purplish red cultivars, whereas no condensed tannins were detected in the white, pinkish white, and pale purple cultivars. 5) There were no significant correlations among soluble sugar content, soluble protein content, and the other physiological indications.

Phytochemical Analysis of Ampelopteris Prolifera (Retzius) Copeland

The fronds of Ampelopteris prolifera are used in stomach ache as well as vegetable. Dried and powdered fronds of A. prolifera was extracted successively with hexane, chloroform, ethyl acetate, methanol and 50% aqueous methanol. The results of phytochemical screening revealed that alkaloids were absent in all extracts. Hexane extract showed the absence of all the tested phytochemicals while chloroform extract showed the presence of only terpenoids and quinones. Ethylacetate extract showed the presence of all tested phytochemicals except quinones and saponins.Methanol and 50% aqueous methanol extracts showed the presence of phenolics, flavonoids, terpenoids, glycosides, tannins, quinones and saponins. The total content of phenolics, flavonoids, tannins and sugars as well as antioxidant activity were determined in ethyl acetate, methanol and 50% aqueous methanol extracts. Total phenolic content was measured spectrophotometrically by using Folin-Ciocalteu, total flavonoid content by using aluminium chloride, total hydrolyzable tannin content by using Folin-Ciocalteu, total condensed tannin content using vanillin-HCl and total sugar content by using anthrone reagent. Gallic acid was used as the standard for the calibration of phenolics, catechin for flavonoids and condensed tannins, tannic acid for hydrolyzable tannins and glucose for carbohydrates. The highest amount of phenolic was detected in 50% methanol extract (114.27±10.37 mg GAE/g). The highest amount of flavonoid was detected in ethylacetate extract (151.47±3.57 mg CE/g extract). The highest amount of hydrolyzable tannin was detected in 50% methanol extract (31.21±2.14 mg TAE/g extract). The highest amount of condensed tannin was detected in ethylacetate extract (337.50±5.00 mg CE/g extract), and the highest amount of sugar was detected in methanol extract (809.74±7.86 mg GE/g). The antioxidant activity was determined by using DPPH free radical and IC50 value was determined. All the tested extracts showed only weak antioxidant activity. Among the tested extracts, 50% aqueous methanol extract showed better activity with an IC50 value of 185.03μg/mL. The HPLC-ESI-MS analysis of methanol extract allowed the tentative identification of peganine, 1-methyltryptophan and rutin. The study thus demonstrates the potential value of A. proliferain the medicinal application.

Assessment of the use of cooked Araucaria angustifolia seed coats extract as food for brine shrimp

The use of vegetable waste and its screening for potential cytotoxicity is of utmost importance to ensure its safe use in the feed industry for fish and other animals. We evaluated aqueous and ethanolic extracts of cooked Araucaria angustifolia seed coats. The Stiasny index for the aqueous and ethanolic extracts was 2.87% ± 0.03% and 60.53% ± 4.79%, respectively. Condensed tannins were 11-fold higher in the ethanolic extract than the aqueous extract. The flavonoid and polyphenol contents were 1.7- and 1.8-fold higher in the ethanolic extract than in the aqueous extract, respectively. The 36 h EC50 for brine shrimp hatchability was 300.32 µg/mL for the aqueous extract, and 76.60 µg/mL for the ethanolic extract. The 24 h LC50 was 1405.96 µg/mL for the aqueous extract, and it was 356.32 µg/mL for the ethanolic extract. The aqueous extract was nontoxic to A. salina nauplii, and therefore, it can be used as a possible food additive in fish feed. The results also demonstrated that the different solvents used in the extraction affected the yield and the total phenolic, total flavonoid, and condensed tannin content. Further in vivo and cell line cytotoxicity testing is recommended to substantiate these findings.

Tortilla chips made with white sorghum and corn: Comparison of sensory and physicochemical characteristics with corn‐made commercial products

Tortilla chips made with mixtures of white sorghum and corn were compared with two commercial products made from corn to determine their physicochemical, sensory characteristics, and acceptance. A higher content of white sorghum generated products with dark-red tones, but which were equally fracturable and exhibited the same hardness, when compared to commercial tortilla chips. The total phenolic content ranged from 50 to 75 mgGAE/100g, and the condensed tannins content was higher as the white sorghum content in products increased (559–1,100 µgCE/g), but there was no difference in the antioxidant activity (900–1,250 µMAEAA/g) among the products. Two groups of consumers who were identified rated commercial products best for overall liking, although Group 1 (n = 102 subjects) rated products made entirely with sorghum as second best, and Group 2 (n = 116 subjects) considered that treatment as the worst. The white sorghum content in products did not affect taste and aroma, but affected its appearance and acceptance for some consumers. Practical applications Tortilla chips are snacks that are widely consumed around the world. Developing foods with health potential to consumers are a current trend in the market. Sorghum grains contain compounds that could provide health benefits, although its tannins content could impart negative visual or astringent effects to products made from them. Tortilla chips made entirely with white sorghum contain a higher amount of condensed tannins than products made with corn, these modifies the appearance of chips affecting the liking of consumers. Despite this, a segment of consumers considered that those products were almost as good as commercial corn made tortilla chips.

Extraction and Characterization of Polyphenols from Artocarpus heterophyllus and Its Effect on Oxidative Stability of Peanut Oil

ABSTRACT The present study deals with the extraction and characterization of Jackfruit seed polyphenol (JSP) and its application in the stabilization of peanut oil. The optimized extract was obtained at condition of 95% ethanol for 30 min by using conventional solvent extraction method. The extract exhibited a total phenolic content of 120.5 µg GAE/mL, flavonoid content of 0.43 mg CE/ml, condensed tannin content of 0.34 mg CE/ml and DPPH scavenging EC50 value of 14.22 µg/ml. The characterization of extract by LC-ESI-Q-TOF-MS/MS revealed the presence of phenolic acid, flavonoids, and stilbenes. The JSP extract in the presence of synthetic antioxidants such as butylated hydroxytoluene (BHT) and α-Tocopherol-acetate (vitamin-E acetate) were tested for the stabilization of cold-pressed peanut oil. Furthermore, natural antioxidant mediated stabilization of cold-pressed peanut oil was also investigated using α-Tocopherol (vitamin E) and curcumin. The JSP extract and curcumin significantly retarded lipid oxidation in peanut oil under Schaal oven test conditions of 60°C for a week, as compared to BHT, α-Tocopherol, and α-Tocopherol acetate. Also, the JSP extract and curcumin showed better antioxidant effects on the oxidative stability of oil at frying temperature of 150–180°C for 2 hr and thus can prove potential in ensuring the retardation of oil oxidation process. Hence, JSP extract and curcumin can have industrial application of serving as a natural preservative in oil.

Banana condensed tannins scavenge glyphosate in aqueous solution through non-covalent interactions

The protective effects of polyphenols against glyphosate-induced toxicity in animals are generally considered to be associated with their antioxidant properties. Recently, some researchers put forward that the direct interactions of polyphenols with molecules may also play roles in their biological activities. However, there is little information about the direct interactions between polyphenols and glyphosate. Bananas are demonstrated to be rich in phenolic compounds (especially condensed tannins) at the unripe stage. To provide a possible new mechanism of protection by polyphenols against glyphosate intoxication, the direct interaction of banana condensed tannins (BCT) with glyphosate was characterized by different techniques for the first time. Our results showed that glyphosate could be effectively precipitated by BCT in aqueous solution, and the glyphosate scavenging ability of BCT (10.30–59.14%) significantly increased with the rising condensed tannin concentration (0.25–1.0 mg proanthocyanidin B2 equivalent/mL). Notably, the glyphosate scavenging ability of BCT was closely related to the electrostatic interactions, hydrogen-bond interactions and hydrophobic interactions between BCT and glyphosate. In addition, the interaction of glyphosate with BCT was further confirmed by characterizing the BCT-glyphosate coprecipitates using spectroscopic methods and morphological analysis. Therefore, the precipitation of glyphosate by BCT might reduce the toxicity of glyphosate through affecting its gastrointestinal absorption.

Effect of Acacia purified tannins extract and polyethylene glycol treatment on in vitro ruminal fermentation pattern and methane production

Condensed tannins are polyphenolic compounds which can exert beneficial effects in ruminants. They have the ability to bind proteins and decrease their degradation. They have also been reported to reduce methanogenesis and improve ruminants performances. The present work aimed to study the effect of purified condensed tannins from Acacia horrida extract on fermentation parameters, gas and methane production. In this context, seven substrates were selected: four Acacia species (Acacia pycnantha, Acacia dealbata, Acacia horrida and Acacia cyanophylla) and three plant by-products (date palm leaves, grenade peel and artichoke stems). Biological activity of tannins was evaluated by the incubation of the substrates in vitro with Polyethylene glycol (PEG). Tannins decreased concentration of all fermentation parameters (gas (p &lt; 0.0001), methane (CH4) (p= 0.0983), ammonia (N-NH3) (p= 0.0382), Volatile Fatty Acids (VFA) (p= 0.0009), acetate (p &lt;0.0001), propionate (p= 0.1024), butyrate (p= 0.0373), isobutyrate (p= 0.0046), valerate (p &lt; 0.0001), isovalerate (p= 0.0032)). Substrates were also characterized by their content in main nutrients (dry matter (DM), organic matter (OM), ash, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) ,acid detergent lignin (ADL)) and in secondary metabolites (total phenols (TP), total tannins (TT) and condensed tannins (CT) ). All substrates presented high CP content except by-products (&gt; 100 g/kg DM) and moderate cell-wall components. CT content was comprised between 120.5 and 680.4 g/kg DM in plants and between 23.1 and 170.4 g/kg DM in plant by-products. A. horrida presented the highest biological activity. Thus, their CT were extracted and purified on a sephadex LH-20 column. Purified tannins from A. horrida were incubated with two different forages alfalfa hay and barley straw at three different concentrations: 50, 100, 150 mg/g DM. Results showed that purified tannins from A. horrida had no effect on fermentation parameters (P &gt; 0.05). The effects of A. horrida tannins may be strongly linked to their structure and their molecular weight more than to their concentration. For this reason, it is interesting that this work may be completed by physical characterization of these tannins.

Invasive red oak (Quercus rubra L.) modifies soil physicochemical properties and forest understory vegetation

This study assessed the effects of invasive Quercus rubra on soil physicochemical properties and understory vegetation in native plant communities. Chemical properties of senesced tree leaves were also analysed. The study was performed at paired invaded-native plots in managed forests in southern Poland. Freshly fallen senesced leaves were characterized in terms of C, Ca, K, Mg, N, P, total phenolics and condensed tannins concentrations. Soil physicochemical parameters, namely bulk soil density, moisture, water holding capacity (WHC), pH, organic C, total Ca, K, Mg, N, P, exchangeable Ca, K, Mg, N-NH4, N-NO3, P-PO4, and total phenolics were analysed in organic and mineral soil horizons, and condensed tannins were analysed in organic soil horizon. The diversity, cover and composition of understory vegetation were assessed. Although, senesced leaves of Q. rubra and native trees, Quercus robur, Fagus sylvatica, Carpinus betulus and Acer pseudoplatanus among others, differed only in total K, N and C/N ratio, we observed considerable differences in soil physicochemical parameters between the plot types. Soil beneath Q. rubra was characterised by significantly lower WHC, organic C, total Mg, N, P, exchangeable Ca, Mg, N-NH4, N-NO3, total phenolics and higher moisture in organic and mineral soil horizons as well as lower content of P-PO4 and condensed tannins in organic soil horizon relative to native plant communities. Q. rubra negatively influenced species richness and cover of understory vegetation. The changes in soil physicochemical parameters and understory vegetation under Q. rubra may be associated with low quality (low N, high C/N) litter that decomposes slowly and generates a physical barrier, limiting seed germination and seedling growth. The changes in soil properties and vegetation under invasive Q. rubra indicate that this species may alter the structure and function of forest ecosystems and should be avoided in forest management practices.

Ruminal fermentation and enteric methane production of legumes containing condensed tannins fed in continuous culture

A continuous-culture fermentor study was conducted to assess nutrient digestibilities, volatile fatty acid (VFA) concentrations, microbial protein synthesis, bacterial nitrogen (N) efficiency, and enteric methane (CH4) production of four 50:50 grass-legume diets, randomly assigned in a 4 × 4 Latin square design. Four legumes with different concentrations of condensed tannins (CT) were tested: alfalfa [ALF; Medicago sativa L., non-CT legume]; birdsfoot trefoil [BFT; Lotus corniculatus L., low-CT legume]; crown vetch [CV; Securigera varia (L.) Lassen, moderate-CT legume]; and sericea lespedeza [SL; Lespedeza cuneata (Dum. Cours.) G. Don, high-CT legume]. Orchardgrass (Dactylis glomerata L.) was the common forage used in all diets. Four fermentors were evaluated over four 10-d periods by feeding 82 g of dry matter (DM)/d in 4 equal feedings. Methane output was recorded every 10 min. Effluent samples were collected during the last 3 d of the experiment, composited by fermentor and period, and analyzed for pH and VFA, as well as DM, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber for determination of apparent and true nutrient digestibilities. Microbial protein synthesis and bacterial efficiency were estimated by analysis of N flows and purines. The CT concentrations were 3, 21, 38 and 76 g/kg of DM for ALF, BFT, CV, and SL diets, respectively. The SL diet had decreased fiber digestibilities and total VFA concentrations compared with the other diets. This resulted in the least total CH4 production in the SL diet. Bacterial N efficiency per kilogram of organic matter truly digested was lower in the SL diet than in the BFT and CV diets. The lowest CH4 production per unit of digestible nutrients was also found in the SL diet. Further work should be conducted to find optimal diets (by testing other legumes, rations, and sources of CT) for reducing CH4 emissions without negatively affecting ruminal digestion to maintain or improve productivity.

Ethanol extracts from Cinnamomum camphora seed kernel: Potential bioactivities as affected by alkaline hydrolysis and simulated gastrointestinal digestion

The aim of the study was to evaluate the changes of potential bioactivities of ethanol extracts (EE) from Cinnamomum camphora seed kernel (CCSK) after alkaline hydrolysis and simulated gastrointestinal digestion. A total of 13 compounds in EE, mainly phenolics and saponins were tentatively identified using HPLC-ESI-QTOF-MS2 analysis. The total phenolic and total flavonoid contents in EE decreased by 30.6%, 1%, 33% and 11.8% after hydrolysis and digestion, respectively. The total saponins content decreased by 17% after hydrolysis while increased by 48% after digestion. The total condensed tannin contents increased by 70.3% and 17.2% after hydrolysis and digestion, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), cupric ion reducing activity (CUPRAC), ferric reducing antioxidant power (FRAP) and metal chelating activity (MCA) were used to determine antioxidant activity. Overall, the changes of antioxidant activities by hydrolysis and digestion were consistent with the changes of their total phenolic and flavonoid contents. The α-amylase and α-glucosidase inhibitory activities in EE increased by 817% and 33.3% after digestion while decreased by 12.3% and 19% after hydrolysis, respectively. Although the inhibitory activities of cholinesterase, tyrosinase and xanthine oxidase were decreased by hydrolysis and digestion, most of these activities were retained. These results showed that CCSK ethanol extracts had strong bioactivities and were reasonably stable to alkali and digestive enzymes.

Phenolic composition and antioxidant activities of thirteen Eucalyptus species cultivated in North East of Tunisia

This study aimed to determine the chemical composition of methanolic extracts of thirteen Eucalyptus species leaves cultivated in north east of Tunisia and their antioxidant activity was also investigated. Some of them were investigated for the first time. The total phenol and total condensed tannin contents varied significantly among species, E. lehmannii had the highest values. Significant difference was also found in total flavonoid contents and the highest one was observed in E. astringens. The HPLC analysis indicated that the main phenolic compounds were the flavonoid rutin in some species such as E. maidenii and acid gallic acid in other species as E. lehmanii. Different assays were used to evaluate the antioxidant activities; Total antioxidant activity test, DPPH radical scavenging, ABTS scavenging activity, reducing power, and β-carotene-linoleic acid bleaching. All these tests showed a high influence of the interspecific variation. However, all species exhibited interesting antioxidant activities, and DPPH radical scavenging was the most remarkable one whose all extracts were more active than the positive control. E. erythrocorys has the strongest activity with IC50 = 5.07 ± 0.54 µg/mL. All results confirmed that the secondary metabolites of these studied species could be used as a source of natural antioxidants.

Phytochemical Analysis, Antioxidant Activity, Antimicrobial Activity, and Cytotoxicity of Chaptalia nutans Leaves.

Objective This work was to evaluate the chemical constitution of the hydromethanolic (30/70 methanol-water) macerating extract obtained from the leaves of C. nutans, as well as to study the antioxidant, antimicrobial, cytotoxic, and genotoxic activity of the species. Materials and methods. Phytochemical screening, antioxidant activity (total phenolic, total flavonoid, condensed tannins content, DPPH radical, and FRAP), antibacterial activity (P. aeruginosa, B. cereus, E. epidermidis, E. coli, S. aureus, E. faecalis, P. mirabilis, Candida glabrata (clinical isolate), Candida tropicalis (clinical isolate), C. krusei (clinical isolate), and C. albicans (clinical isolate)), and oxidative stress parameters (TBARS, carbonyl protein, and DCFH) were analyzed according to the literature. Toxicity of C. nutans was evaluated using an alternative method, D. melanogaster, as well as a locomotor assay. Results The phytochemical screening test of methanolic leaves extract revealed the presence of alkaloids, coumarins, quaternary bases, phenolics, flavonoids, tannins, and free steroids. A quantitative phytochemical study indicated the total phenol (30.17 ± 1.44 mg/g), flavonoid (21.64 ± 0.66 mg/g), and condensed tannins (9.58 ± 0.99 mg/g). DPPH (345.41 ± 5.35 μg/mL) and FRAP (379.98 ± 39.25 μM FeSO4/mg sample) show to extract of C. nutans leaves an intermediate value, indicating moderate antioxidant activity of the extract. Antibacterial results revealed only a positive result (antimicrobial activity) for the hexane fraction which significantly inhibited the microorganisms E. epidermidis, C. tropicalis, C. glabrata, and C. krusei at a concentration of 1000 μg/mL. TBARS, carbonyl protein, and DCFH demonstrate that the extract has the ability to protect the cell from protein and lipid damage, as well as the inhibition of oxygen-derived radicals at the three concentrations tested: 0.1, 1, and 10 mg/mL. Regarding the toxicity of C. nutans extract against D. melanogaster, it was found that until the concentration of 15 mg/mL, the extract showed no toxicity and that the LC50 obtained was 24 mg/mL. Results show that the C. nutans extract leaves used to prevent PQ damage were effective in reducing flies' mortality and improving locomotor capacity. Conclusion Our studies demonstrated for the first time that C. nutans crude leaf extract has high antioxidant capacity both in vitro and in vivo through different analysis techniques. These results make it possible to infer future applications in the pharmacological area, evidenced by the low toxicity observed in D. melanogatser, as well as the ability to neutralize different sources of RONS.

Optimisation of microwave effect on bioactives contents and colour attributes of aqueous green tea extracts by central composite design

The aim of the present study was to investigate the effects of microwave-assisted extraction parameters on total phenolic content (TPC), total flavonoid content (TFC), condensed tannins content (CTC), DPPH-scavenging activity, and colour attributes of aqueous green tea extracts and to optimise the microwaving conditions using response surface methodology. Microwave power (120–360–600 W) and irradiation time (1–3–5 min) were selected as independent variables. Statistical analysis revealed that all responses were significantly affected by extraction parameters. The optimum microwave-assisted extraction conditions were 350.65 W microwave power and 5 min irradiation time to maximise TPC, TFC, CTC, DPPH-scavenging activity, and L* values and to minimise a* and b* values of aqueous green tea extracts. The predicted TPC was 116.58 mg gallic acid equivalents/g (GAE/g), TFC was 49.33 mg catechin equivalents/g (CE/g), CTC was 9.89 mg catechin equivalents/g (CE/g), DPPH-scavenging activity (IC50) was 294.46 µg/mL, L* value was 12.31, a* value was 2.61 and b* value was 7.02 under optimum microwave-assisted extraction conditions. This study revealed that microwave extraction conditions should be controlled to obtain aqueous green tea extracts with both high bioactivity and acceptable colour quality.