Greatest Total Phenolic Content Research Articles

Effect of pullulan and pullulan-chitosan composite coating on the antioxidant activity, texture, color and shelf-life of a local cultivar of sweet cherry

This study explored the effects of pullulan and pullulan-chitosan composite edible coatings on the post-harvest quality of sweet cherries over 20 days of storage. We evaluated weight loss, total soluble solids (TSS), decay percentage, color value, texture and biochemical content, including ascorbic acid, total phenolic content (TPC), flavonoids, anthocyanins, antioxidant activity and enzyme activity. The results revealed that cherries with 3 % pullulan coating presented the lowest weight loss (25 % vs 26.33 % in the control) and decay percentage (25 % vs 47 % in the control) and maintained superior texture and stability compared with those of the control and other coatings. TSS increased less in the coated cherries than in the control cherries, with 3 % pullulan-treated cherries showing the least increase, indicating slower ripening. Pullulan coatings effectively reduced color changes, with the 3 % coating delaying darkening in cherries more than the other treatments did. Additionally, the pullulan coating preserved higher levels of ascorbic acid, phenolic compounds (TPC) and flavonoids and delayed the decrease in antioxidant activity. Notably, the 3 % pullulan-treated cherries maintained the highest antioxidant activity (88.97 %) and had the greatest TPC (2.79 mg GAE/g FW) at the end of storage. The activity of enzymes, particularly peroxidase (POD), increased less in coated cherries, highlighting the role of coatings in delaying oxidative stress. Overall, the pullulan coatings, especially at a 3 % concentration, were the most effective at extending the shelf-life and maintaining the quality of the sweet cherries. These findings suggest that the use of a pullulan-based coating is a promising approach for preserving fruit quality during storage, thereby extending shelf-life. These coatings can contribute to a reduction in food waste, improved consumer acceptability and improved economic gains by reducing postharvest losses and maintaining quality. To optimize pullulan-based coatings for commercial application, future research can focus on optimizing the formulation, consumer acceptability and scalability. Moreover, field trials to assess the effectiveness of these coatings in preserving the quality of cherry can be performed. By addressing these areas, future research can contribute to the development of sustainable options for preserving the quality and extending the shelf life of sweet cherries and other fruits.

Effects of drying conditions on physical properties, bioactive compounds and antioxidant activity of Andrographis paniculata leaves

Andrographis paniculata (Burm. f.) Wall. ex Nees (AP) is a medicinal plant widely used in the tropical area of Asia. The effects of drying temperature and time on the andrographolide (AG) content, total phenolic content (TPC), 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical scavenging activity and ferric ion reducing antioxidant power (FRAP) activity were investigated. A 3×4 factorial completely randomized design was performed. Sun drying and hot-air drying at different temperatures (50℃, 60℃ and 70℃) and different drying times (5 hrs, 6 hrs and 7 hrs) were investigated. The results demonstrated that a higher drying temperature and a longer time decreased the AG content, the TPC, the DPPH radical scavenging activity and the FRAP activity. Dried AP leaves at 50℃ for 5 hrs had the highest AG content. However, sun drying for 5 hrs resulted in the greatest TPC, DPPH radical scavenging activity and FRAP activity. Therefore, the recommended options for the optimum drying of AP to maintain active ingredients were 50℃ for 5 hrs, while sun drying was recommended to maintain antioxidant activity. These results provided the basis for further development of dried Andrographis paniculata leaf products containing high contents of bioactive and antioxidant activity as functional or nutraceutical foods in the future.

Biochemical Dynamics and Quality Attributes of Strawberry Fruits across Maturity Stages with Respect to Different Preservation Methods

Strawberry is nutritious but perishable, and it is susceptible to quality flaws and infections after harvest. Objective: To examine strawberry biochemical changes with harvest maturity and preservation methods. Methods: The experiment was factorial with a completely randomized design (CRD). Strawberry cv. Chandler fruit was harvested at three color-based maturation phases (M1: 0% red, M2: 50% red, and M3: 100% red), frozen, and freeze-dried and analyzed for quality. Total soluble solids (TSS), titratable acidity (TA), vitamin C, total phenolic content (TPC), total antioxidant capacity, SOD, POD, CAT, and organoleptic characteristics were assessed for quality. Results: Due to harvest maturity, completely ripe strawberries displayed higher biochemical properties such as total soluble solids (TSS), titratable acidity (TA), and TSS/TA than 50% and 0% of red strawberries. 100% red strawberries also had greater TPC and POD. Compared to strawberries picked during the green stage (0% red color), strawberries harvested at 100% and 50% red color had better aroma, color, and flavor. TSS, TSS/TA, Vitamin C, antioxidants, total phenolic content, and peroxidase were better in freeze-dried strawberries than frozen strawberries. Conclusions: The superior fruit aroma and color rating made frozen strawberries more popular than freeze-dried ones. The preserved fruit retained these qualities better for 7 months in dried storage. This study found that strawberry fruit should be harvested at 100% red and freeze-dried for commercial use.

Antioxidant Activity in Melon (Cucumis melo L. 'Gama Melon Parfum') AS Antiaging Cream Formulation

Antiaging cosmetics are becoming increasingly popular among the general public. Melon (Cucumis melo L.) Gama Melon Parfum cultivars ('GMP') are one of the plants that can be utilized as a basic ingredient in the production of antiaging cosmetics. 'GMP' melon has cucurbitacin compounds that can be utilized as antiaging and contains flavonoid, saponin, and terpenoid compounds that have antioxidant properties. This research aims to analyze the difference in antioxidant activity of 'GMP' melon extract and 'GMP' melon cosmetic cream preparation cultivated in Yogyakarta with 'GMP' melon cultivated in Bandung, analyze extract standardization parameters, and determine the phenolic and flavonoid contents of each melon extract contains. The activity of antioxidants was determined by the DPPH method, the Folin-Ciocelteu method to measure phenolics, and the AlCl3 solution-based colorimetric approach to measuring flavonoid content. It was revealed that the highest % RSA of antioxidant activity is in ‘GMP’ melon extract cultivated in Bandung. The results of the standardization of 'GMP' melon extract met the requirements of standard parameters. The greatest total phenolic content is derived from the extract of ‘GMP’ melon in Bandung, while the highest total flavonoid content in 'GMP' melon extracts is cultivated in Yogyakarta. The highest to lowest antioxidant activity of ‘GMP’ melon cream was formula IV (‘GMP’ melon extract 30% cultivated in Bandung), formula III (‘GMP’ melon extract 20% grown in Bandung), formula II (‘GMP’ melon extract 30% cultivated in Yogyakarta), formula I (‘GMP’ melon extract 20% cultivated in Yogyakarta), and the lowest is in K- with formula without ‘GMP’ melon extract.

Quality attributes and antioxidant activity of three wild plums from Prunus spinosa and Prunus domestica species

In this study, the quality and antioxidant properties of three plum cultivars wildly grown in Turkey including Blackthorn (Prunus spinosa), Karaca (Prunus domestica var. karaca) and Üryani (Prunus domestica var. uryani) were investigated. For the outer shell, the lowest L*, a* and b* values were found in blackthorn (15.47, 2.59 and 1.77, respectively), while the highest values were obtained in Üryani (27.58, 7.04 and 6.55, respectively). For the pulp, the highest L*(31.26), a* (7.46) and b* (14.59) were found in Üryani, Karaca and Üryani, respectively. Although Blackthorn displayed higher values of dry matter, total soluble solids, pH, total acidity, formol number, total sugar, reduced sugar, unreduced sugar, dietary fiber and ash, the studied plums showed no significant difference in terms of the physico-chemical properties. The protein content was higher in Üryani (1.26%), followed by Blackthorn (0.99%) and Karaca (0.87%), respectively. The greatest total phenolic content (TPC), total anthocyanin content (TAC) and ferric reducing antioxidant power (FRAP) were determined in Blackthorn while the greatest radical scavenging activity (EC50) was identified in Karaca. The studied plums contained sorbitol, glucose and fructose. These plums contain reasonable amounts of micronutrients. Karaca, Üryani and particularly Blackthorn have great nutritional and antioxidant properties and their consumption can prevent many diseases.

Chemical Composition and Biological Activities of Lavandula coronopifolia Poir Extracts: A Comparison between Callus Culture and Native Plant

Nowadays, according to the development and high functions of in vitro cultivation, one of the questions that researchers are looking for is whether the characteristics and compositions of the obtained product meet the needs of the society or not. Therefore, this research was done aimed to compare the bioactive characteristics of callus and native plant aqueous extracts of Lavandula coronopifolia Poir. Thus, two different culture media were utilized for calluses’ growth. Extracts from these calluses and native plants were obtained using the sequential ultrasound-microwave assisted extraction (SUMAE) method. The extraction conditions were a constant temperature of 70°C ultrasound in 20 min at 250 W and 8 minutes at 800 W for microwave at 85°C. At first, results revealed that callus cultures were not able to produce any significant amounts of essential oil. Therefore, aqueous extracts obtained from calluses as well as the natural plant were examined in terms of antioxidant activity, total phenolic content, total flavonoid content, and antimicrobial activity. Moreover, their volatile components were detected with GC-MS. Both DPPH and FRAP techniques demonstrated that the callus on MS + Auxin had stronger antioxidant activity than the other callus and native plant. It also had the greatest total phenolic content. In terms of total flavonoid content, the native plant has the highest value. Generally, it can be concluded that the extract of callus on MS + Auxin has shown significant activity against the tested microorganisms than the other samples.

Bioactive compounds extraction from oak chips into rice spirit: New application of ultrasound

AbstractThis research proposed using power ultrasound to produce a phenolic‐rich rice spirit from oak chips. Independent parameters were ultrasound power (0, 275, and 550 W), oak–spirit ratio (1.00:1.25, 1.00:2.50, and 1.00:5.00), and time (1 h to 14 days). Dependent factors were color parameters (L*, a*, b*, C*, and ΔE), pH, alcohol content, total acidity (TA), total phenolic content (TPC), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) value, total energy consumption, and specific energy consumption (SEC). Furthermore, oak chips were analyzed using a scanning electron microscopy (SEM) to elaborate on the extraction mechanism. Results showed that ultrasound enhanced ΔE, C*, TPC, and DPPH. TA ranged between 0.008% and 0.014% and was not affected by sonication. Alcohol content and pH decreased by increasing the sonication time. Also, increasing ultrasound power and time, as well as the oak–spirit ratio, enhanced the phenolic content. The greatest TPC was 138.95 ± 2.21 mg gallic acid equivalent per L which was achieved at 550 W/136 min/oak–spirit ratio of 1.0:2.5. Besides, ultrasound saved more than 99% of processing time. Moreover, decreasing the oak–spirit ratio and increasing input power increased the SEC. SEM revealed that the sonication power significantly affected the surface of oak chips, and 550 W treatment caused the highest damage to the oaks, converting the surface from smooth to cracked porous. This study provided a scalable platform for an innovative product enriched with antioxidants and phenolic compounds.Practical ApplicationUltrasound treatment yielded a potentially health‐promoting rice spirit from oak chips, and essential information regarding the effects of processing parameters on product quality parameters and energy consumption was revealed. For example, it was found that alcohol content and pH values decreased by increasing sonication time. On the other hand, increasing sonication power, time, and the oak–spirit ratio increased phenolics. Sonication saved more than 99% of processing time and altered the oak surface. Besides, specific energy consumption increased by decreasing oak–spirit ratios and increasing input power. This study was performed in collaboration with a winery in Taiwan, and the technology was transferred and implemented in the industry.

Chemical Compositions of Clove (Syzygium aromaticum (L.) Merr. & L.) Extracts and Their Potentials in Suppressing SARS-CoV-2 Spike Protein-ACE2 Binding, Inhibiting ACE2, and Scavenging Free Radicals.

COVID-19 is initiated by binding the SARS-CoV-2 spike protein to angiotensin-converting enzyme 2 (ACE2) on host cells. Food factors capable of suppressing the binding between the SARS-CoV-2 spike protein and ACE2 or reducing the ACE2 availability through ACE2 inhibitions may potentially reduce the risk of SARS-CoV-2 infection and COVID-19. In this study, the chemical compositions of clove water and ethanol extracts were investigated, along with their potentials in suppressing SARS-CoV-2 spike protein-ACE2 binding, reducing ACE2 availability, and scavenging free radicals. Thirty-four compounds were tentatively identified in the clove water and ethanol extracts, with six reported in clove for the first time. Clove water and ethanol extracts dose-dependently suppressed SARS-CoV-2 spike protein binding to ACE2 and inhibited ACE2 activity. The water extract had stronger inhibitory effects than the ethanol extract on a dry weight basis. The clove water extract also had more potent free radical scavenging activities against DPPH• and ABTS•+ (536.9 and 3525.06 μmol TE/g, respectively) than the ethanol extract (58.44 and 2298.01 μmol TE/g, respectively). In contrast, the ethanol extract had greater total phenolic content (TPC) and relative HO• scavenging capacity (HOSC) values (180.03 mg GAE/g and 2181.08 μmol TE/g, respectively) than the water extract (120.12 mg GAE/g and 1483.02 μmol TE/g, respectively). The present study demonstrated the potential of clove in reducing the risk of SARS-CoV-2 infection and COVID-19 development.

Influence of Nitrogen Fertilizer on the Antioxidative Potential of Basil Varieties (Ocimum basilicum L.).

Total phenolic content (TPC) in extracts of basil depended on the cultivar and type of fertilization used in cultivation. TPC was determined spectrophotometrically with the Folin–Ciocalteu reagent. The antioxidant activity of extracts was analyzed by scavenging of DPPH and ABTS radicals, on the basis of metal chelating ability (MetChel) and ferric reducing antioxidant power (FRAP). The greatest TPC was determined in the purple cultivars—141.35 and 165.44 mg gallic acid/g d.m. for fertilized with ammonium nitrate (NH4NO3) and ammonium sulfate ((NH4)2SO4), respectively. Their extracts had the greatest antioxidant capacity in the majority of the methods used. The results varied depending on the modelling system used. The amount of polyphenols in individual basil cultivars differed significantly (p < 0.05) depending on the fertilization used in the culture. Regarding TPC, DPPH, ABTS, FRAP, and MetChel variables, we observed a significant effect for the applied cultivation. In the case of MetChel factor, lower results of all investigated basil species were observed for cultivation with ammonium sulfate. PCA demonstrated in the present study shows that Sweet and Cinnamon Basil samples cultivated with ammonium nitrate create a separated group. We recommend cultivation with ammonium sulfate fertilizers for these varieties of basil. The high content of phenolic compounds demonstrated in Sweet and Cinnamon Basil cultivated with ammonium sulfate, and thus associated antioxidant activity, indicates that it can constitute a valuable source for bioactive compounds in a balanced diet.

Does water addition during the industrial milling phase affect the chemical-sensory quality of olive oils? The case of cv. Arbequina oils

At olive oil industrial extraction, water addition is a practice overcoming the formation of thick pastes. The effect of water addition (0 to 6.2%, kgadded water/kgolives), during the industrial milling of cv. Arbequina olives, on the oils’ chemical-sensory quality, was evaluated. Despite the extra virgin olive oil classification, compared with the water incorporation (1.2–6.2%), extraction without water addition resulted into oils that showed less primary oxidation (lower peroxide values and K232), greater total phenolic content (+12–22%) and higher oxidative stability (+22–31%). No water addition increased the oils secoiridoids content (+5–13%), mainly oleacein (+27–79%). Oils extracted without water addition had a more intense ripe fruity sensation (≥ +11%) but lower fruit intensities (at least −4%). Thus, the quality and stability of the cv. Arbequina oils can be favoured if extracted without adding water during the olives industrial milling.

The influence of different light spectra on physiological responses, antioxidant capacity and chemical compositions in two holy basil cultivars

Light-emitting diodes (LEDs) are an artificial light source used in indoor cultivation to influence plant growth, photosynthesis performance and secondary metabolite synthesis. Holy basil plants (Ocimum tenuiflorum) were cultivated under fully controlled environmental conditions with different red (R) and blue (B) light intensity ratios (3R:1B, 1R:1B and 1R:3B), along with combined green (G) LED (2R:1G:2B). The photosynthetic activities of both cultivars were maximal under 3R:1B. However, the highest fresh (FW) and dry (DW) weight values of green holy basil were recorded under 3R:1B and 2R:1G:2B, significantly higher than those under alternative light conditions. For red holy basil, the highest FW and DW were recorded under 1R:3B. Moreover, 2R:1G:2B treatment promoted pigment (chlorophyll and carotenoid) accumulation in green holy basil, while red holy basil was found to be rich in both pigments under 3R:1B. Antioxidant capacity was also influenced by light spectrum, resulting in greater total phenolic content (TPC) and DPPH accumulation in both cultivars under 1R:3B. The highest content of flavonoid in green holy basil was detected under 1R:1B; meanwhile, 1R:3B treatment significantly promoted flavonoid content in red holy basil. In addition, anthocyanin content increased in red holy basil under 1R:3B conditions. Gas chromatography coupled with mass spectrometry (GC–MS/MS) analysis of chemical composition showed higher proportional accumulation in Methyleugenol and Caryophyllene of two cultivars grown under all light spectrum ratios at two developmental stages. Overall, specific light spectrum ratios induced different chemical composition responses in each cultivar and at each developmental stage. These results suggest that 3R:1B was favorable for biomass accumulation and photosynthetic responses in green holy basil, while 1R:3B provided antioxidant accumulation. For red holy basil cultivation, 1R:3B provided optimal growing conditions, promoting improvements in plant biomass, and physiological and antioxidant capacities.

Antioxidant properties of lipote (Syzygium polycephaloides (C.B. Rob.) Merr.) flesh and seeds as affected by maturity and processing method

Lipote (Syzygium polycephaloides (C. B. Rob.) Merr.) is a Philippine endemic tree whose berries have a potential for functional food development. This study aimed to investigate the effect of the maturity stage (unripe, half-ripe or fully ripe) and processing (blanching at 90±5°C for 2 mins and steaming at 105±5°C for 5 mins) on the antioxidant content (total phenolic content (TPC), total flavonoid content (TFC), and total anthocyanin content (TAC)) and antioxidant activity by DPPH, ABTS, and FRAP assays, of lipote flesh and skin (referred herein as flesh) and seeds. Results showed that maturity and processing significantly affect the antioxidant contents and activities of fresh lipote flesh and seeds. Blanched lipote flesh generally had higher TPC, TFC, and antioxidant activities than their unprocessed and steamed counterparts. Blanched unripe flesh had the highest TPC (33.57±0.27 mg gallic acid equivalents [GAE]/g) and antioxidant activity measured by ABTS, FRAP, and DPPH assay (92.31±1.28 mg Trolox equivalents [TE]/g, 123.83±0.86 mg TE/g, and 74.02±0.33 mg TE/g, respectively) while blanched fully ripe flesh had the highest TFC (27.98±0.08 mg quercetin equivalents [QE]/g) and TAC (18.11±0.11 mg cyanidin-3-glucoside equivalents [C3GE]/g). Lipote seeds, especially unripe ones, have appreciable antioxidant contents and antioxidant activity, even greater than that of lipote flesh. Unprocessed unripe seeds had the greatest TPC, TFC and antioxidant activity by DPPH assay (123.56±0.94 mg GAE/g, 111.90±0.14 mg QE/g and 465.89±1.86 mg TE/g, respectively). It is recommended that blanching be used as a processing step to increase the antioxidant content of lipote flesh while lipote seeds should be investigated further for nutraceutical applications due to their high antioxidant properties.

Effect of Ethanol and Methanol on the Total Phenolic Content and Antioxidant Capacity of Chia Seeds (Salvia hispanica L.)

The use of methanol and ethanol for the extraction of antioxidant compounds in Chia Seed (Salvia hispanica L.) is studied, but only the effect of a single concentration of these solvents was evaluated. However, factors such as the nature and the concentration of the solvents determines the content of phenolic compounds, the antioxidant capacity and the possible use of the extract. For this reason, it is necessary to have a detailed study of different extraction conditions to find the optimum. The objective of this work was to evaluate the effect of different concentrations of ethanol and methanol and the hexane treatment on the extraction of phenolic compounds and the antioxidant capacity of the Chia Seeds extracts. The greatest total phenolic content was obtained in the 50% aqueous ethanol and methanol extracts. Nevertheless, all the extracts showed a high DPPH scavenging activity. With exception of 100% ethanol extract, no significant differences were found between the extracts treated with and without hexane. No significant differences were found in the extraction yields of the 80% aqueous ethanol and methanol extracts, but the aqueous methanol extract presented lower IC50. The FTIR and UV-VIS spectra of the aqueous ethanol and methanol Chia extracts suggest differences in the composition of the extracts. It is possible to extract the phenolic compounds from the Chia Seeds with different concentration of ethanol and methanol, which will allow to select the appropriate extraction conditions according to the application of the extract.

Effect of Traditional Fermentation Time on Total Phenolic Content and In vitro Antioxidant Activity of Kocho: Ethiopian Fermented Food from Enset (Ensete ventricusum welw. Chessman)

Ensete ventricusum, locally known as Enset, is the main crop of a sustainable food source that ensures food security in Central ,South and South West Ethiopia. It has been used as a food and local medicine for thousands of years. Kocho is a product of matured Enset prepared traditionally by fermenting (for few weeks to some months) a mixture of pulverized pseudostem and corm in pit. The objective of this study was to evaluate the effect of traditional fermentation period on the total phenolic content and antioxidant activity of Kocho . The sample was fermented in the pit for 15, 30, 45, 60, 75, 90, 105 and 120 days. Oven dried Kocho powder was extracted with methanol followed by water. Total phenolic content of the extract was determined by the Folinciocalteu method. Antioxidant activities of the extracts were evaluated with 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and total antioxidant activity using phosphomolybdenum assay. The results revealed that Kocho showed greater total phenolic content and antioxidant activities than unfermented product. Methanol extract of Kocho fermented for 45 days showed the highest amount of total phenolic content (9.27 ± 0.44 milligram of gallic acid equivalent per gram of dried extract). In comparison of DPPH scavenging and total antioxidant, methanol extracts were also superior to aqueous extracts. Methanol extract of Kocho fermented for 60 days exhibited the strongest DPPH scavenging activity (IC 50 = 0.15 ± 0.02 mg/mL) and total antioxidant activity (0.43 ± 0.04 milligram of ascorbic acid equivalent per gram of dried extract). Thus fermentation offers a tool to further increase the bioactive compounds and antioxidant potential of Kocho. Keywords: antioxidant activity, Ensete ventricusun , , fermentation, Kocho, total phenolic DOI : 10.7176/FSQM/91-05 Publication date :October 31 st 2019

Chemical compositions of chrysanthemum teas and their anti-inflammatory and antioxidant properties

Seventeen commercial chrysanthemum teas (Chrysanthemum morifolium and Coreopsis tinctoria) were extracted with hot-H2O, and examined and compared to the 75% methanol extracts for their chemical compositions using UPLC/Q-TOF-MS analysis. For the first time, 6, 8-C,C-diglucosylapigenin and eriodicyol-7-O-glucoside were detected in the Snow chrysanthemum, and acetylmarein was detected in HangJu, GongJu and HuaiJu. The extracts were also examined for their radical scavenging and anti-inflammatory activities in vitro. The hot-H2O extract of Kunlunmiju 1 had the greatest total phenolic content, and relative DPPH and oxygen radical absorbance capacity values of 12.72 mg gallic acid equivalents/g, 105.48 and 1222.50 μmol Trolox equivalents/g, respectively. In addition, all the hot-H2O extracts suppressed the lipopolysaccharide-induced interleukin-6, IL-1β and cyclooxygenase-2 mRNA expressions, and H2O2-induced intracellular reactive oxygen species production in cultured cells. The results from this research may be used to promote the consumption of chrysanthemum as a functional tea.

Drying characteristics and quality evaluation in convective drying of Cissus quadrangularis Linn.

This study aimed to investigate the effect of drying temperature (40, 60, 80, and 100°C) on drying characteristics of Cissus quadrangularis Linn. (CQ) undergoing convective drying. Physical properties and phytochemicals of the dried CQ were also evaluated. CQ with the thickness of 5 mm was dried from about 10 to 0.1 g water/g dry matter. The results showed that increasing drying temperature increased drying rate (DR) and effective moisture diffusivity (Deff) and consequently decreased drying time. The drying time, maximum DR, and Deff were in the ranges of 85-1920 min, 0.0059-0.0248 g water/g dry matter·min, and 0.7302-9.1281×10-9 m2/s, respectively. Lower drying temperature could preserve quality of the dried CQ. Decreasing drying temperature resulted in greener and lower bulk density and shrinkage. The greatest total phenolic content (TPC) and quercetin content were obtained by drying the CQ at 60°C.

Evaluation of Phenolic Phytochemical Enriched Commercial Plant Extracts on the In Vitro Inhibition of α-Glucosidase.

Green tea (GT), cranberry (CR), and tart cherry extracts were evaluated for their ability to inhibit yeast α-glucosidase, relevant to glucose uptake. The total phenolic content (TPC), antioxidant activity, and in vitro inhibitory activity of yeast α-glucosidase were examined for the extracts in the present study. GT had higher TPC and antioxidant activity, but CR demonstrated a greater α-glucosidase inhibitory activity, on phenolic basis. CR was fractionated using LH-20 column chromatography into two fractions: 30% methanol (CME) and 70% acetone (CAE). TPC, antioxidant activity, and yeast α-glucosidase inhibitory activity were determined for the fractions. CAE had a greater TPC and antioxidant activity than CME, but the two fractions had a synergistic effect when inhibiting yeast α-glucosidase. Our findings suggest that CR has the greatest potential to possibly manage post-prandial blood glucose levels via the inhibition of α-glucosidase, and that the effect is through synergistic activity of the extract’s phenolic compounds.

The relationship between metal composition, phenolic acid and flavonoid content in Imleria badia from non-polluted and polluted areas

ABSTRACTThe aim of this study was to determine the elemental composition, phenolic content and composition and antioxidant properties of Imleria badia (Fr.) Vizzini (former names Boletus badius (Fr.) Fr., and Xerocomus badius (Fr.) E.-J. Gilbert) fruiting bodies collected from sites with different levels of pollution. Imleria badia was relatively tolerant to soil contamination with toxic elements and was able to grow in As, Cd, Hg and Pb concentrations exceeding 15, 2.9, 0.4 and 77 mg kg−1, respectively. The concentration of elements in soil was reflected in the element content in I. badia. The fruiting bodies from polluted sites exhibited significantly higher content of all the analyzed elements. Among 21 individual phenolic compounds only protocatechiuc and caffeic acids, and quercetin were determined in fruiting bodies of I. badia. The differences between the concentration of the quantified phenolic compounds and the total flavonoid content in fruiting bodies of I. badia from unpolluted and polluted sites were not significant. However, the greatest total phenolic content was found in fruiting bodies from the polluted areas. The antioxidative capacity of mushrooms collected from heavily polluted sites was lower than those growing in unpolluted areas. The concentrations of some metals in soil and fruiting soil were positively correlated with phenolic content and IC50.

Phenolic antioxidant profiles in the whole fruit, flesh and peel of apple cultivars grown in Lithuania

In this study total phenolic content (TPC), total ferric reducing antioxidant power, individual phenolics and their contributed antioxidant activity were determined by Folin-Ciocalteu, FRAP and HPLC-DAD coupled to FRAP post-column assays in the whole fruit, flesh and peel of six Lithuanian grown apple cultivars. The greatest TPC and total antioxidant activity were determined in ‘Aldas’ and ‘Auksis’ cultivars. Significant amounts of flavonols were determined in peels, while flavan-3-ols in apple parts varied. (−)-Epicatechin, procyanidins B2, C1 and chlorogenic acid were predominant reducing compounds in whole apple fruits. Hyperoside, avicularin and quercitrin were significant reducing compounds in peels. The cultivars with highly expressed flavan-3-ol fraction could be used in preparation of highly antioxidant active natural products.

Propolis extracts from the northern region of Thailand suppress cancer cell growth through induction of apoptosis pathways

The continual increase in mortality rates and number of cancer cases is a matter of serious concern in developing countries. The incorporation of natural products into classical cancer treatment approaches is a promising direction. The mechanisms of A549 and HeLa cancer cell death induction by ethanolic extracts of propolis samples from Phayao, Chiang Mai, and Nan provinces in northern Thailand were investigated in this study. The propolis extract from Chiang Mai showed the highest antioxidant activity and the greatest total phenolic content. The propolis extract from Nan also exhibited the highest total flavonoid content. The proliferation of A549 and HeLa cells grown in the presence of the propolis extracts was suppressed in a dose- and time-dependent manner. Moreover, treatment of both cancer cells with the propolis extracts showed DNA fragmentation and significantly increased the number of the apoptotic cells. On A549 cells, the extrinsic and intrinsic pathways of caspase enzymes were activated by the propolis extracts from Phayao and Chiang Mai. In the case of the propolis extract from Nan, the mechanisms involved apoptosis on the A549 cells were caspase-independent pathway. The extrinsic pathway of the caspase enzyme was triggered by all of the propolis extracts on HeLa cells. Finally, oral administration of the propolis granule produced from the propolis extract from Nan resulted in extended survival of tumour-bearing mice. Therefore, propolis extracts from the northern region of Thailand demonstrated pharmacological properties, both antioxidant and anticancer activities. From these findings, it is evident that propolis extracts can be considered as a naturally obtained agent extremely useful in cancer treatment.