Condensed Tannin Content Research Articles

Allelopathic Activity and Chemical Constituents of Extracts from Leaves and Stems of Kherchoun (Hertia cheirifolia)

Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. The aim of this study was to investigate the phytochemical screening of the various extracts of Kherchoun (Hertia cheirifolia) and the evaluation of antioxidant capacities, by the DPPH test (2, 2-diphenyl-1-picrylhydrazyl), and of their allelopathic effects, vis-à-vis the two species: Vetch (Vicia sativa L.) and triticale (Triticosecale wittm L.). Biochemical analysis results showed that the highest total lipid content was observed at the leaf level (9%). The aqueous extracts of the leaves are rich in polyphenols, with a rate of 268.67mg EAG/g MS, compared to the stems (242.67mg EAG/g MS). The levels of flavonoids are higher in the leaves (38.67mg EAG/g MS) but lower in the stems (24.75mg EAG/g MS). On the other hand, the highest total tannin content recorded at leaf level is 608.33 mg EAG/g MS and the lowest is recorded in the stems (505 mg EAG/g MS). In contrast, the aqueous extract of the stems has the highest condensed tannin content (0.049 mg EAG/g MS), compared to that of the leaves (0.036 mg EAG/g MS). The two extract .Both aqueous extracts of Hertia cheirifolia are endowed with good antioxidant abilities. CI50 =139.43 2.99a μg/mL at leaf level and CI50 =111.38 22.2a μg/mL at stem level.Concerning the allelopathic study, the results obtained showed that the two extracts (Leaves and stems) of Hertia cheirifolia exerted different effects on the germination parameters of weed seeds of vetch (Vicia sativa L.) and triticale (Triticosecale wittm L.). Indeed, the two extracts exerted very important inhibitory effects, vis-à-vis the two seeds tested, on the germination and development of the seedlings (length of the root and length of the aerial part), in a significant and dose-dependent way.

Environment and Genotype Influence Quantitative and Qualitative Variation in Condensed Tannins in Aspen.

Condensed tannins (CTs) are abundant, ecologically-relevant secondary metabolites in many plants, which respond to variables associated with anthropogenic environmental change. While many studies have reported how genetic and environmental factors affect CT concentrations, few have explored how they influence CT molecular structure. Here, using trembling aspen (Populus tremuloides) as a model organism, we report how foliar CT concentrations, polymer sizes, representation of procyanidins and prodelphinidins, and stereochemistry vary in response to changes in air temperature (warming and freeze damage), air composition (elevated CO2 and O3), soil quality (nutrients and microbiome), and herbivory (mammal and lepidopteran). Use of multiple aspen genotypes enabled assessment of genetic influences on aspen CTs. CT concentration and composition were analyzed by thiolysis-ultra high performance liquid chromatography/mass spectrometry in archived leaf samples from prior experiments. All environmental variables explored except for soil microbiome influenced both CT quantity and quality, with climate factors appearing to have larger effect magnitudes than herbivory. Climate, soil, and herbivory effects varied among genotypes, while air composition effects were consistent across genotypes. Considering that CT properties (concentrations and molecular structures) mediate functions at the organismal through ecosystem scales, intraspecific variation in responses of CT properties to environmental factors could provide a pathway through which environmental change exerts selective pressure on Populus populations. Future studies are needed to identify the molecular-level mechanisms by which environmental factors influence CT concentrations and structures, and to establish their ecological and evolutionary significance.

X-radiation of Lotus corniculatus L. seeds improves germination and initial seedling growth

Purpose Lotus corniculatus L. (bird’s foot trefoil, BFT) is a valuable perennial legume forage species due to its high nutritive value, persistence under grazing, and condensed tannin content that improves ruminant production and prevents bloating. However, it is less preferred by farmers compared with other perennial forage legumes such as alfalfa because of slow germination, slow establishment and low seedling vigor. This study was conducted to determine whether X-ray seed priming could improve these deficiencies. Materials and methods Seeds of L. corniculatus cv. ‘AC Langille’ were irradiated at 0, 100, and 300 Gy. Non-irradiated and irradiated seeds were sown on Murashige and Skoog/Gamborg medium under in vitro conditions and cultured for 21 days. Germination percentage, mean germination time (MGT), germination rate index, length of shoot and root, fresh and dry weight of shoot and root, dry matter ratios of shoot and root, water content of shoot and root, and seedling vigor index were measured. Results The results of this study demonstrated that X-ray seed priming significantly increased the germination percentage of L. corniculatus, increased the germination rate and thereby shortened the MGT, and improved seedling growth. However, X-ray pretreatment also decreased seedling shoot and root biomass. Conclusions In this study, it is reported for the first time that X-ray seed pretreatment has the potential to address important seedling establishment issues in L. corniculatus.

Fractionation, Phytochemical Screening and Antioxidant Activity of Different Sub-Fractions from Leaves and Flowers of Erica arborea L.

The purpose of this study was to prepare eight sub-fractions from leaves and flowers of Erica arborea L., characterize their phytochemicals constituents and investigate their potential antioxidant, in order to validate the beneficial medicinal properties of this shrub in Algeria folk medicine. Total polyphenols, flavonoids and condensed tannins contents were determined using Folin-Ciocalteu’s, aluminum chloride and vanillin reagents, respectively. The in vitro antioxidant activity was evaluated by using 2,2-diphenyl-l-picrylhydrazyl and reducing power assay. E. arborea L. contains various compounds such as polyphenols, flavonoids, tannins, quinones, anthraquinones, saponins and terpenoids in different sub-fractions. All the tested extracts showed an appreciable total phenolic, flavonoids and condensed tannins contents as well as strong antioxidant capacity. The highest total phenolic and flavonoids content was found in the ethyl acetate extracts ranging from 649.38 to 944.55 mg gallic acid equivalent/g dry extract and 65.31 to 67.15 mg quercetin equivalent/g dry extract, respectively. Whereas, the highest condensed tannins content was found in the crude extract for leaves and aqueous extracts for flowers. The ethyl acetate extract of the flowers and the crude extract of leaves exhibited the better antioxidant activity by DPPH assay (IC50 =17.72 µg/mL) and reducing power assays (IC50 = 2.91 µg/mL), respectively. Our findings indicate that leaves and flowers extracts are rich in natural antioxidant substances and have good qualities in antioxidant properties and may be beneficial against diver’s disorders related to free radicals.

Dates (Phoenix dactylifera L.) from the Adrar region of Algeria are rich in polyphenols, and ternary solvent extracts’ antioxidant activity correlates with condensed tannins content

Dates (Phoenix dactylifera L.) from the Adrar region of Algeria are rich in polyphenols, and ternary solvent extracts’ antioxidant activity correlates with condensed tannins content

Antioxidant and antimicrobial activities of four medicinal plants from Algeria

Medicinal plants are used in folk medicine to cure several human diseases. This work was designed to evaluate the antioxidant and antimicrobial activities of different extracts of Globularia alypum, Dittrichia viscosa, Juniperus oxycedrus, and Retama sphaerocarpa. The total phenolic content (TPC), the total flavonoid content (TFC), and the condensed tannin content (CTC) were determined spectrophotometrically. The antioxidant activity was tested using TAC, DPPH and reducing power assays. The agar diffusion method was used to determine antimicrobial activity against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa) and one fungus (Candida albicans). J. oxycedrus acetone extract showed the highest extraction yield (35.56±0.45%), TPC (504.96±14.82 mg GAE/g DE) and TFC (43.91±0.87 mg QE/g DE). The same extract exhibited the highest TAC (350.67±6.05 mg GAE/g DE) and was the most effective against the DPPH free radical (IC50 = 0.21±0.01 mg/mL). In contrast, the J. oxycedrus methanol extract showed the highest reducing power (A0.5 = 0.39 ± 0.09 mg/mL). All extracts tested showed antibacterial and anticandidal activities at different concentrations. The best antimicrobial effect was also observed with the acetone extract of J. oxycedrus against P. aeruginosa (26.77±0.06 mm), B. cereus (17.16±0.08 mm), E. coli (15.84±0.04 mm), and C. albicans (21.36±0.11 mm), while the ethanol extract of D. viscosa was the most active against S. aureus (24.54±0.03 mm). The results of this study provide a scientific basis for the traditional use of these local plants and demonstrate their potential as sources of natural antioxidant and antimicrobial bioactive compounds.

Evolution of Seed-Soluble and Insoluble Tannins during Grape Berry Maturation

Condensed tannins (CT) in wine are derived from the seeds and skins of grapes, and their composition and content contribute to the bitterness/astringency characteristics and ageing potential of the wine. Global warming has accelerated the ripening process of grape berries, making them out of sync with seed ripening. To understand the influence of berry ripening on the seed CT composition and content, we analyzed the changes in the soluble and insoluble CT in the seeds of 'Cabernet Sauvignon' grapes from two vineyards over two years. The results showed that the seed-soluble CT presented a slight downward trend in fluctuation during grape berry development, while the insoluble CT increased continuously before the véraison and remained at a high level afterwards. Relatively speaking, a lower sugar increment in developing grape berries favored the conversion of seed CT towards a higher degree of polymerization. The terminal unit of soluble CT was dominated by epigallocatechin gallate, the content of which decreased as the seeds matured. It is suggested that the seeds should be fully matured to reduce this bitter component in tannins. This study provides a reference for us to control the grape ripening process and produce high-quality grapes for wine making.

Interaction between life history parameters of Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) with physical and biochemical properties of legumes species

The cowpea beetle, Callosobruchus maculatus, is a highly damaging and destructive pest of pulse seeds, which is widely distributed in tropical and subtropical areas. In this research, the effects of the seeds of six pulse species (broad bean, cowpea, lentil, green gram, chickpea, and soybean) were assessed on life history and energy content of C. maculatus under controlled conditions, 27 ± 2 °C, 60 ± 5% relative humidity, and a photoperiod of 10:14 (L:D) h. Some biochemical (protein, starch, phenol, total anthocyanin, flavonoids and condensed tannin contents) and physical (humidity, seed volume and area) characteristics of legume seeds were measured and their interactions with population growth parameters of C. maculatus were assessed. The results showed that biological properties of C. maculatus were significantly different when fed on various legume seeds. The developmental time of cowpea beetle fed on broad bean (32.08 day) was longer compared with other seeds. The lowest immature survival rate was observed on broad bean. The pupal weight on cowpea, chickpea and green gram was significantly higher than on broad bean and lentil seeds. The lowest intrinsic rate of population increase (r) and net reproductive rate (R0) were recorded on soybean (r = 0.055 d−1, R0 = 14.02 offspring). The intrinsic rate of increase and the finite rate of increase (λ) of C. maculatus reared on cowpea (r = 0.145 d−1, λ = 1.16 d−1) and green gram (r = 0.144 d−1, λ = 1.15 d−1) seeds were significantly higher than those reared on other legumes. Significant correlations were detected between life history parameters of C. maculatus with biochemical and physical traits of legume seeds. The results showed that cowpea and green gram were relatively susceptible legume seeds and that soybean was a relatively resistant host for feeding of C. maculatus, which can be useful in the development or improvement of IPM programs for C. maculatus.

Assessment of Bioactive Profile of Sorghum Brans under the Effect of Growing Conditions and Nitrogen Fertilization

Sorghum bicolor (L.) Moench is an increasingly important crop grown in many countries as a food source due to its excellent nutritional value, drought and pest resistance, and gluten-free properties. In this study, the bioactive profiles and antioxidant potentials of brans of six sorghum varieties were evaluated using spectrophotometric methods. The effects of weather and environmental conditions and different nitrogen nutrition were also evaluated. The bran of red varieties contained a higher amount of polyphenols and tannins and exhibited higher antioxidant capacities than the bran of white varieties, with the exception of one red genotype. The highest total polyphenol contents were measured in samples from two red varieties (Zádor, Alföldi1) with 1084.52 ± 57.92 mg 100 g−1 GAE and 1802.51 ± 121.13 mg 100 g−1 GAE values, respectively, while condensed tannin content varied between 0.50 mg g−1 and 47.79 mg g−1 in sorghum brans. Red varieties showed higher antioxidant activities/capacities with 70–281 µmol TE g−1 and 71–145 µmol TE g−1 for DPPH and TEAC. Correlation analysis showed a strong interaction between DPPH, TEAC, and the amounts of polyphenols and tannins, but not with FRAP values. In conclusion, red-colored varieties are a good source of polyphenols, but seed color alone is not enough to determine the nutritional value of a genotype, and the environmental conditions greatly affect the bioactive profile of sorghum.

Phenolic Content, Antioxidant, Antibacterial, Antihyperglycemic, and α-Amylase Inhibitory Activities of Aqueous Extract of Salvia lavandulifolia Vahl

Salvia lavandulifolia Vahl essential oil is becoming more popular as a cognitive enhancer and treatment for memory loss. It is high in natural antioxidants and has spasmolytic, antiseptic, analgesic, sedative, and anti-inflammatory properties. Its aqueous extract has hypoglycemic activity and is used to treat diabetic hyperglycemia, but few studies have focused on it. The objective of this work is to evaluate the various biological and pharmacological powers of Salvia lavandulifolia Vahl leaf aqueous extract. Quality control of the plant material was first carried out. Followed by a phytochemical study on the aqueous extract of S. lavandulifolia leaves, namely phytochemical screening and determination of total polyphenols, flavonoids, and condensed tannins contents. Then, the biological activities were undertaken, in particular the antioxidant activity (total antioxidant activity and trapping of the DPPH° radical) and the antimicrobial activity. The chemical composition of this extract was also determined by HPLC-MS-ESI. Finally, the inhibitory effect of the α-amylase enzyme as well as the antihyperglycaemic effect was evaluated in vivo in normal rats overloaded with starch or D-glucose. The aqueous extract obtained by use of the decoction of leaves of S. lavandulifolia contains 246.51 ± 1.69 mg EQ of gallic acid/g DE, 23.80 ± 0.12 mg EQ quercetin/g DE, and 2.46 ± 0.08 mg EQ catechin /g DE. Its total antioxidant capacity is around 527.03 ± 5.95 mg EQ of ascorbic acid/g DE. At a concentration of 5.81 ± 0.23 µg/mL, our extract was able to inhibit 50% of DPPH° radicals. Moreover, it showed bactericidal effect against Proteus mirabilis, fungicidal against Aspergillus niger, Candida albicans, Candida tropicalis, and Saccharomyces cerevisiae, and fungistatic against Candida krusei. A marked antihyperglycemic activity (AUC = 54.84 ± 4.88 g/L/h), as well as a significant inhibitory effect of α-amylase in vitro (IC50 = 0.99 ± 0.00 mg/mL) and in vivo (AUC = 51.94 ± 1.29 g/L/h), is recorded in our extract. Furthermore, its chemical composition reveals the presence of 37.03% rosmarinic acid, 7.84% quercetin rhamnose, 5.57% diosmetin-rutinoside, 5.51% catechin dimer, and 4.57% gallocatechin as major compounds. The antihyperglycemic and α-amylase inhibitory activities, associated with the antioxidant properties of S. lavandulifolia, justify its use in the treatment of diabetes in traditional medicine and highlight its potential introduction into antidiabetic drugs.

Physical and Physicochemical Characteristics, Bioactive Compounds, and Antioxidant Activity of Cladodes from Erect Prickly Pear Opuntia stricta (Haw.) Haw.

Opuntia stricta (Haw.) Haw. is well adapted to arid and semiarid regions and has great potential for industrialisation. One- to four-year-old cladodes of this species harvested in Drâa-Tafilalet region in the southeast of Morocco, were characterised by examining physical and physicochemical parameters. Their bioactive compounds and antioxidant activity were also investigated. The cladode age had a significant impact on all the studied characteristics except some morphological parameters. Cladodes of different ages have a nutritional value comparable to a wide range of vegetables, particularly in terms of calcium, potassium, betalain, total polyphenol, and vitamin C contents. They are very rich in calcium (37.8–42.5 g/kg of dry matter (DM)) and have high betalain content. The content of phenolic compounds (133.9–165.0 mg gallic acid equivalent (GAE)/100 g DM) is especially noteworthy. These cladodes also contain very high amounts of vitamin C, especially the one-year-old cladodes (8.1–18.5 mg GAE/100 g DM). The recorded flavonoid contents vary from 3.8 to 7.6 mg of quercetin equivalent per 100 mL of cladodes mash. Condensed tannin contents range from 10.9 to 21.8 µg/100 mL of cladodes mash. Chlorophyll and carotenoid contents also vary from 5.55 to 23.76 and from 1.9 to 6.0 mg/100 g DM, respectively. One- and two-year-old cladodes are rich in total soluble solids (TSS) and ash with high total titratable acidity (TTA), compared to three- and four-year-old cladodes. Four-year-old cladodes have the highest TSS/TTA ratio, while two-year-old cladodes are the wealthiest in betalains with a dominance of indicaxanthins (yellow pigments). The oldest cladodes have the lowest inhibitory concentration (IC50) for antioxidant activity. Three-year-old cladodes have some traits significantly different, which may have resulted from physiological changes related to their great buds emission at this age. This study highlights the nutritional and functional potential of Opuntia stricta cladodes and the importance of their valorisation, particularly in agri-food and pharmaceutical industries.

HPLC/UV Analysis and In Vitro, Promising Antioxidant, Antidiabetic, Anti-Alzheimer, and Anti-Tyrosinase Potentials of the Algerian Pistacia atlantica Desf. Methanolic Extract

The main objective of this work is to evaluate the species Pistacia atlantica by analyzing the chemical composition of the methanolic extract of the plant leaves; then by determining its content on phenolic compounds, flavonoids and condensed tannins; and finally by testing its antioxidant and inhibitory activities against some enzymes involved in several diseases. To identify phenolic compounds, a high-performance liquid chromatography analysis with ultraviolet detector was used; Folin–Ciocalteu trichloroaluminum and vanillin methods were carried out for phenolic compounds, flavonoids, and condensed tannins quantification, respectively. The antioxidant effect was tested by five different methods. Acetylcholinesterase, butyrylcholinesterase, α-glucosidase, and tyrosinase were used to evaluate the inhibitory power of the plant against those enzymes. The results indicated the presence of phenolic compounds in the extract, including phenolic acids and flavonoids. The total phenolic compounds, flavonoids, and condensed tannins contents obtained, respectively, were equal to 36.089 ± 0.047 mg equivalent of galic acid per gram, 0.775 ± 0.01 mg equivalent of quercetin per gram, and 5.44 ± 0.5 mg of equivalent catechin per gram of dry plant. High antioxidant activity was observed and it was expressed by IC50 ranging from 3.50 ± 0.05 to 11.11 ± 4.03 μg/ml and concentrations at absorbance 0.5 from 0.84 ± 0.08 to 54.57 ± 0.24 μg/ml values. Strong antidiabetic effect was recorded which far exceeds the effect of acarbose, and interesting anti-Alzheimer and anti-tyrosinase effects were noted.

Evaluasi Tepung Kedele Terproteksi Tanin Kondensasi dari Ekstrak Daun Sengon (Albizia falcataria) terhadap Ketahanan Degradasi oleh Mikroba di Rumen

Soybean meal (SBM) is a quality feed with high protein and organic matter content but is easy to degrade by microbes in the rumen. A high degradation rate in the rumen causes potential protein loss as ammonia and energy in the form of fermentation heat, CO2 gas, and methane gas. This study aimed to determine the effect of SBM protected with condensed tannins (TK) from sengon leaves on its fermentability by rumen microbes. This study used a completely randomized design (CRD) consisting of four treatments and five replications. Treatments were of P1 = SBM unprotected with condensed tannin (CT) (control); P2 = SBM- protected 2% CT; P3 = SBM-protected 4% CT, and P4 = SBM- protected 6% CT. The amount of CT (0, 2, 4, 6%) was calculated and converted to the amount of sengon leaves equivalent to 0, 226.24, 452.49, and 678.72 g/kg SBM based on CT content in sengon leaves of 8.84%. SBM samples were weighed as much as 0.5 g, then put into a serum bottle with a capacity of 100 ml, added 40 ml of a mixture of rumen fluid and McDougall's buffer (1:4 v/v), closed with a rubber stopper, climb sealed using an aluminum seal, and incubated in an incubator for 3, 6, 9, 12, 24, and 48 hours. The variable measured was in vitro cumulative gas production (GP), methane production (CH4), dry matter degradation (DMD), organic matter degradation (OMD), metabolism energy (ME), and production of microbial protein (PMP). The results showed that the treatment of SBM protected with condensed tannins from sengon leaf extract had a significant effect (P<0.05) on reducing GP, CH4, DMD, OMD, ME, and PMP. The Treatment of P1 (control) was higher produced of GP, CH4, DMD, OMD, ME, and PMP (P<0.05) compared to P2, P3, and P4. But between P2, P3, and P4 were not significantly different (P>0.05). This study concluded that the use of condensed tannin at levelof 2% could be used to protect soybean meal from microbial degradation in the rumen.

Molecular studies of rust on European aspen suggest an autochthonous relationship shaped by genotype.

Forests are at increasing risk from pathogen outbreak. Climate change for example enhance the risk of local disease outbreaks, and naturalization of exotic pathogens may follow human activities, warranting robust pest surveillance routines to support forest management. Melampsora pinitorqua (pine twisting rust) is of concern in Swedish forestry, and here we evaluate the use of visible rust scores (VRS) on its obligate summer host, European aspen (Populus tremula) as a tool for quantification of the pathogen. With use of species-specific primers, we could detect the native rust, but we failed to detect two exotic rusts (M. medusae and M. larici-populina). We found that aspen genotype determined the presence of fungal genetic markers (amplifying the ITS2 region of the fungal rDNA sequence) as well as DNA sequences specific to M. pinitorqua. We correlated VRS with the amount of fungal DNA in the same leaf, and we related the findings to aspen genotype-specific parameters such as the ability to synthesize and store leaf condensed tannins (CT). At the genotype level both positive and negative relationships were observed between CTs, fungal markers, and rust infestations. However, at the population level, foliar CT concentrations correlated negatively with general fungal- and rust-specific marker abundances. Our results, therefore, do not support the use of VRS to assess Melampsora infestation in Aspen. They do, however, suggest that the relationship between European aspen and rust infestation may be characterized as autochthonous in northern Sweden.

Optimization of microwave-assisted extraction of phenolic compounds from chestnut processing waste using response surface methodology

Portugal is one of the world's top ten chestnut producers. The nut shells generated in the industrial processing have been discarded for use as soil conditioner or energy production. This waste material is rich in polyphenols, which can be used for various purposes, including well-established applications and new usages. Tannin-based coagulants/flocculants for water treatment are one of the emerging applications. Polyphenols extraction from vegetal sources is the initial step of the coagulant synthesis. In this work, tannin extraction from chestnut shell was accomplished in aqueous solution through different methods. After a preliminary assessment, microwave-assisted method (MAE) was selected to be optimized using Response Surface Methodology. The effect of extraction time, liquid:solid ratio, and temperature on the extraction yield and total phenolic content of the extracts was examined. The desirability function approach was applied to find the best extraction conditions leading to a quantitative extract with the highest phenolic content. The optimum conditions were determined as extraction time of 5 min, liquid-to-solid ratio of 50 mL g−1 and temperature 107 °C. In these optimized conditions, the expected extraction yield and phenolic content of the extract are 25 ± 3% and 344 ± 27 mg-GAE/g, respectively (values confirmed by experimental assays). The optimal extract presented a condensed tannin content of 1296 ± 68 mg-CE/g. This work showed that polyphenols can be quantitatively extracted from chestnut shells through a green approach and the generated extract has good features to be further used as a raw material for water treatment coagulants.

Characterization of Cosmos sulphureus Cav. (Asteraceae): Phytochemical Screening, Antioxidant Activity and Chromatography Analysis

Cosmos sulphureus Cav. (Asteraceae), and endemic plant of Mexico is used in herbal medicine. In this study, the phytochemical composition, phenolic content, and antioxidant activity of ethanolic and methanolic extracts from C. sulphureus leaves and flowers were determined. The phytochemical analysis showed the presence of compounds such as terpenoids, phenolic compounds, tannins, and flavonoids and the absence of alkaloids, saponins, glycosides, and anthraquinones. The experimental results showed that the extracts have high contents of phenolic, flavonoid, and condensed tannins contents. The phenolic compounds identified in the C. sulphureus extracts by high-performance thin-layer chromatography (HPTLC) include phenolic acids such as chlorogenic acid and caffeic acid as well flavonoids such as rutin and quercetin. The C. sulphureus extracts showed a relevant free radical scavenging activity, ferric-reducing antioxidant power, lipid peroxidation inhibition ability, and oxygen radical antioxidant capacity. This research highlights the phytochemical profile and antioxidant activity of phenolic compounds-rich extracts from C. sulphureus leaves and flowers.

Phytochemical Screening and In vitro Antioxidant, Antibacterial, and Antihemolytic Activities of Putoria calabrica Leaf Extracts

Background:: Putoria calabrica is a common Mediterranean plant used topically in folk medicine for medical purposes. The aim of this study is to evaluate the in vitro antioxidant, antibacterial, and antihemolytic properties of Putoria calabrica leaf extracts.Methods:Total phenol content (TPC), total flavonoid content (TFC), and condensed tannins content (CTC) were determined spectrophotometrically. The antioxidant activity was tested using TAC, DPPH, ABTS, and FRAP assays. Agar diffusion method was used to determine the antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. Anti-hemolytic activity was evaluated by the measurement of erythrocytes turbidity and extracellular hemoglobin concentration using AAPH method.Results:Methanol was the optimal solvent to extract the bioactive components with the highest extraction yield (30.11 ± 0.42%), TPC (142.11 ± 4.04 mg GAE/g dry extract) and TFC (29.16 ± 0.99 mg QrE/g dry extract). In terms of antioxidant activity, methanol extract was the most effective against ABTS free radical (IC50 = 5.02 ± 0.13 mg/ml) and FRAP (A0.5 = 2.91 ± 0.09 mg/ml). While, acetone extract showed the highest TAC (214.05 ± 8.74 mg GAE/g dry extract) and DPPH scavenging activity (IC50 = 1.94 ± 0.02 mg/ml). The strongest antimicrobial effect at a concentration of 10.24 mg/well was observed with acetone extract against P. aeruginosa (22.52 ± 0.60 mm) and C. albicans (17.33 ± 0.41 mm). While, methanol extract was the most active against S. aureus (17.31 ± 0.98 mm). Aqueous extract showed a good capacity to protect erythrocytes from oxidative damage by preventing their hemolysis and the oxidation of hemoglobin induced by AAPH.Conclusion:P. calabrica leaves could have a great importance as a source of therapeutic bioactive compounds.

Phytochemical Screening, Antioxidant Potential, and LC-ESI-MS Profiling of Ephedra alata and Ephedra altissima Seeds Naturally Growing in Tunisia.

Most Ephedra species are adapted to arid and desert conditions and are widely used in folk medicine to treat several disorders. The design of the current study was to determine the functional properties of seeds of two Ephedra species (E. alata and E. altissima) naturally growing in Tunisian arid zones by evaluating their mineral contents and bioactive compounds. The flame atomic absorption spectrometry revealed that seeds contained remarkable amounts of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn), and iron (Fe). The colorimetric investigation revealed high total polyphenol, flavonoid, and condensed tannin contents. Furthermore, by utilizing high-performance liquid chromatography-electrospray ionization-mass spectrometry method (HPLC-ESI/MS), a total of 11 phenolics were identified and quantified including 7 flavonoid compounds and 4 phenolic acids that were mostly predominated by gallic acid and quercetrin. Results so far have been very encouraging and proved that Ephedra seeds are a valuable source of natural bioactive compounds and minerals which could potentially be used for industrial and pharmaceutical purposes.

Chemical, Antioxidant and Biological Studies of Brassica incana subsp. raimondoi (Brassicaceae) Leaf Extract.

Brassica incana subsp. raimondoi is an endemic taxon present in a restricted area located on steep limestone cliffs at an altitude of about 500 m a.s.l. in eastern Sicily. In this research, for the first time, studies on the phytochemical profile, the antioxidant properties in cell-free and cell-based systems, the cytotoxicity on normal and cancer cells by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, and on Artemia salina Leach, were performed. The total phenolic, flavonoid, and condensed tannin contents of the leaf hydroalcoholic extract were spectrophotometrically determined. Ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) analysis highlighted the presence of several phenolic acids, flavonoids, and carotenoids, while High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) identified various kaempferol and isorhamnetin derivatives. The extract exhibited different antioxidant properties according to the five in vitro methods used. Cytotoxicity by MTT assay evidenced no impact on normal human fibroblasts (HFF-1) and prostate cancer cells (DU145), and cytotoxicity accompanied by necrotic cell death for colon cancer cells (CaCo-2) and hepatoma cells (HepG2), starting from 100 μg/mL and 500 μg/mL, respectively. No cytotoxic effects were detected by the A. salina lethality bioassay. In the H2O2-induced oxidative stress cell model, the extract counteracted cellular reactive oxygen species (ROS) production and preserved non-protein thiol groups (RSH) affected by H2O2 exposure in HepG2 cells. Results suggest the potential of B. incana subsp. raimondoi as a source of bioactive molecules.

Microwave-Assisted Extraction of Polyphenols from Eucalyptus Bark—A First Step for a Green Production of Tannin-Based Coagulants

Tannins are natural polyphenolic compounds widely found in plants. The production of natural coagulants for water treatment is one of their new applications. Polyphenols extraction is the first step for synthesizing tannin-based coagulants. Eucalyptus globulus bark (EGB), an abundant by-product of the pulp and paper industry, usually applied as fuel for energy production, was used in this work as a tannin source. The extraction of polyphenols from EGB was studied using water as a solvent. Extraction assays employing different extraction techniques were conducted. Microwave-assisted extraction showed superior performance and was further optimized. The influence of irradiation time, water-to-bark ratio, and temperature were evaluated using Response Surface Methodology. The extraction yield and the total phenolic content of the extract were modeled as function of the extraction conditions. The overall best conditions that maximize both responses were obtained through multi-response optimization. Optimized values (15% of extraction yield and a phenolic content of 354 mg of gallic acid equivalents per gram of extract) were predicted for an extraction time of 15 s, a liquid-to-solid ratio of 48.5 mL/g, and 141 °C. The extract generated under these conditions presented a condensed tannin content of 645 mg/g, expressed in terms of catechin equivalents. EGB presented good tannin-extractable contents to produce natural coagulants.