Choline chloride-based deep eutectic solvents do not improve the ethanolic extraction of carotenoids from buriti fruit (Mauritia flexuosa L.)

The aim of the present study was to evaluate the effect of choline chloride-based deep eutectic solvents (DESs) as co-solvents for the ethanolic extraction of total carotenoids from buriti fruit (Mauritia flexuosa L.). Choline chloride-based DESs were synthesized by the heating method. The systems were prepared using ethanol and DESs as a co-solvent in concentrations of 0.5–70.0% (w/v). In addition, a control condition was performed using ethanol as the sole solvent. The total carotenoid concentration in the systems was determined by spectrophotometry at 450 nm. The results showed that the ethanol used without co-solvent obtained total carotenoid yields of 10.06 ± 0.03 mg/g for the buriti pulp and 10.43 ± 1.27 mg/g for the buriti peel. In turn, the use of choline chloride-based DESs as co-solvents did not increase the ethanolic extraction yield of carotenoids. However, it was observed that the buriti peel can be a rich source of carotenoids with yields comparable to the fruit. Thus, it is suggested that new green solvents be evaluated to increase the recovery of total carotenoids from buriti fruit using ecofriendly processes.     

Extraction and quantification of polyphenols from kinnow (Citrus reticulate L.) peel using ultrasound and maceration techniques

An investigation was carried out to extract polyphenols from the peel of kinnow (Citrus reticulate L.) by maceration and ultrasound-assisted extraction (UAE) techniques. The antioxidant potential of these polyphenols was evaluated using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide radical scavenging assays; and their antimicrobial activity was assessed against bacterial strains Staphyloccoccus aureus, Bacillus cereus, and Salmonella typhimurium. The highest extraction yield was obtained through the solvent ethanol at 80% concentration level, whereas UAE was a more efficient technique and yielded comparatively higher polyphenol contents than maceration. Maximum polyphenols were extracted with 80% methanol [32.48 mg gallic acid equivalent (GAE)/g extract] using UAE, whereas minimum phenolics (8.64 mg GAE/g extract) were obtained with 80% ethyl acetate through the maceration technique. Elevated antioxidant activity of kinnow peel extracts was exhibited in three antioxidant assays, where 80% methanolic extracts showed the highest antioxidant activity (27.67 ± 1.11mM/100 g for FRAP) and the highest scavenging activity, 72.83 ± 0.65% and 64.80 ± 0.91% for DPPH and superoxide anion radical assays, respectively. Strong correlations between total polyphenols and antioxidant activity were recorded. Eleven phenolic compounds—including five phenolic acids and six flavonoids—were identified and quantified by high performance liquid chromatography. Ferulic acid and hesperidin were the most abundant compounds whereas caffeic acid was the least abundant phenolic compound in kinnow peel extracts. Maximum inhibition zone was recorded against S. aureus (16.00 ± 0.58 mm) whereas minimum inhibition zone was noted against S. typhimurium (9.00 ± 1.16 mm). It was concluded that kinnow mandarin peels, being a potential source of phenolic compounds with antioxidant and antimicrobial properties, may be used as an ingredient for the preparation of functional foods.     

Comparative analysis of the antioxidant and DNA protection capacities of Anadenanthera colubrina, Libidibia ferrea and Pityrocarpa moniliformis fruits

This study aimed to explore the antioxidant and DNA protection abilities of hydroalcoholic extracts from fruits of Anadenanthera colubrina (ACHE), Libidibia ferrea (LFHE) and Pityrocarpa moniliformis (PMHE). These extracts were tested by five antioxidant methods (phosphomolibdenium and reducing power assays; superoxide, hydrogen peroxide and nitric oxide scavenging) and DNA protection capacity. Total phenolic content was measured by Folin-Ciocalteu method. ACHE exhibited the highest phenolic content (578 mg/g GAE), followed by LFHE (460 mg/g GAE) and PMHE (448 mg/g GAE). In phosphomolibdenium assay, ACHE showed 24.81% of activity in relation to ascorbic acid, whereas LFHE and PMHE had 21.08% and 18.05%, respectively. These plants showed high ability to inhibit reactive species tested with IC50 values ranged from 10.66 to 14.37 μg/mL for superoxide radical; 26.05 to 45.43 μg/mL for hydrogen peroxide; 178.42 to 182.98 μg/mL for reducing power; and 199.2 to 283 μg/mL for nitric oxide. Furthermore, these extracts had capacity to break the DNA damage induced by hydroxyl radicals. The antioxidant activity of these plants is related with their higher phenolic content and show that they may be used as source of bioactive compounds, relevant to the maintenance of oxidative stability of the food matrix, cosmetics and/or pharmaceutical preparations.     

Juniperus oxycedrus L. subsp. oxycedrus and Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. “berries” from Turkey: Comparative evaluation of phenolic profile,antioxidant, cytotoxic and antimicrobial activities

This work aimed to evaluate and compare the phenolic profile and some biological properties of the ripe “berries” methanol extracts of Juniperus oxycedrus L. subsp. oxycedrus (Joo) and Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. (Jom) from Turkey. The total phenolic content resulted about 3-fold higher in Jom (17.89 ± 0.23 mg GAE/g extract) than in Joo (5.14 ± 0.06 mg GAE/g extract). The HPLC–DAD–ESI–MS analysis revealed a similar flavonoid fingerprint in Joo and Jom, whereas a difference in their quantitative content was found (4632 μg/g extract and 12644 μg/g extract). In addition, three phenolic acids were detected in Jom only (5765 μg/g extract), and protocatechuic acid was the most abundant one. The antioxidant capacity of the extracts was evaluated by different in vitro assays: in the DPPH and in the TBA tests a stronger activity in Jom was highlighted, while Joo exhibited higher reducing power and metal chelating activity. Joo and Jom did not affect HepG2 cell viability and both extracts resulted virtually non-toxic against Artemia salina. The extracts were also studied for their antimicrobial potential, displaying efficacy against Gram-positive bacteria.     

Cytotoxic and bioactive properties of different color tulip flowers and degradation kinetic of tulip flower anthocyanins

This study was conducted to determine the potential use of anthocyanin-based extracts (ABEs) of wasted tulip flowers as food/drug colorants. For this aim, wasted tulip flowers were samples and analyzed for their bioactive properties and cytotoxicity. Total phenolic contents of the extracts of the claret red (126.55 mg of gallic acid equivalent (GAE)/g dry extract) and orange–red (113.76 mg GAE/g dry extract) flowers were the higher than those of the other tulip flowers. Total anthocyanin levels of the violet, orange–red, claret red and pink tulip flower extracts were determined as 265.04, 236.49, 839.08 and 404.45 mg pelargonidin 3-glucoside/kg dry extract, respectively and these levels were higher than those of the other flowers. The extracts were more effective for the inhibition of Listeria monocytogenes, Staphylococcus aureus and Yersinia enterocolitica compared to other tested bacteria. Additionally, the cytotoxic effects of five different tulip flower extracts on human breast adenocarcinoma (MCF-7) cell line were investigated. The results showed that the orange red, pink and violet extracts had no cytotoxic activity against MCF-7 cell lines while yellow and claret red extracts appeared to be toxic for the cells. Overall, the extracts of tulip flowers with different colors possess remarkable bioactive and cytotoxic properties.     

Malt and beer-related by-products as potential antioxidant skin-lightening agents for cosmetics

Malt and beer-related by-products, namely caramalt, aromatic malt, roasted malt, malt sprouts, dark beer spent grains, and wheat beer spent grains were extracted with water under moderate conditions to exploit the potential as sources of bioactive compounds. After characterizing the extracts in terms of carbohydrate, amino acid, and phenolic contents and composition, their antioxidant potential was assessed in vitro using keratinocyte cell cultures. Malt sprouts provided highest yields of glucose (50.1 mg g^-1) and fructose (38.4 mg g^-1), while the other materials gave up to 13.5 mg g^-1. Furthermore, malt sprouts gave a total amino acid content of 57.6 mg g^-1. Extracts of darker malts such as caramalt and roasted malt exhibited the highest yields of phenolic compounds of about 12.9 mg gallic acid equivalents (GAE) g^-1 and extracts from spent grains had the lowest total yield with 5.1 and 1.8 mg GAE g^-1 (dark beer and wheat beer spent grains), respectively. Phenolic compounds in caramalt extract inhibited the tyrosinase activity by 78% and 87%, when applying extract concentrations of 0.5% and 1%, respectively. Dark malt, roasted malt as well as the malt sprouts extracts achieved similar effects of 86% and 80% inhibition, when using a 1% extract. In contrast, extracts of spent grains showed low inhibitory effects. This study indicates the potential of malt and beer-related by-products as biological sources of ingredients for cosmeceutical products, for instance, in skin whitening.     

A novel strategy to improve the recovery of phenolic compounds from Pistacia lentiscus L. fruits using design-based statistical modeling for ultrasound-deep eutectic solvents extraction and the evaluation of their antioxidant potential

Recently, there has been increasing interest in using alternative green technologies for the isolation of bioactive metabolites from medicinal plants. This study was designed to select the optimal solvent for phenolic compounds (TPC) extraction from Pistacia lentiscus L. black fruits (PBF) and the development of an experimental model by response surface methodology using ultrasound-assisted deep eutectic solvents (UAE-DES). The characterization and the antioxidant capacity of PBF phytochemicals using a multi-test system in-vitro were investigated. The highest amount of phenolic compounds (TPC: 183.95 ± 0.01 mg GAE/Gdw) was obtained using choline chloride-acetic acid solvent DES, under the optimum extraction conditions: 28.3% of water percentage, 40 °C of extraction temperature, and 18 min of extraction time. Moreover, DES extract had a more important antioxidant capacity with no significant difference compared to the control (Ascorbic acid). Furthermore, HPLC-DAD and TLC analysis indicated the presence of rutin and Cyanidin-3-glycoside in fraction number 4 after fractionation using the HP-20 diaion resin column. This extraction media has proved to be an alternative approach for the extraction of bioactive compounds as a sustainable and safe extraction media for pharmaceutical and industrial applications.     

Flavonoid compositions and antioxidant activity of calamondin extracts prepared using different solvents

Calamondin has been demonstrated to exhibit antioxidant function and tyrosinase inhibitory activity, which might be attributed to its flavonoid compounds. To improve their application, the flavonoid compositions and antioxidant activity of calamondin extracts, prepared by different solvents, were investigated. The results showed that total phenolic and flavonoid contents of extracts from peel of calamondin were higher than that from pulp, except the flavonoid content in hot water extract. The flavonoids found in extracts of calamondin were 3′,5′-di-C-β-glucopyranosylphloretin (DGPP), naringin, hesperidin, nobiletin, tangeretin, and diosmin. DGPP exhibited the highest quantity, while naringin and hesperidin were the other two major flavonoids. The content of DGPP in hot water extract of peel was higher than in extracts of organic solvents, however, the contents of nobiletin and tangeretin were found only in extracts of organic solvents. The highest levels of total flavonoids and DGPP were obtained in hot water extract from peel at 90°C. The extracts of hot water and ethyl acetate showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging potency than that of ethanol and methanol. A positive relationship existed between total phenolic contents and DPPH scavenging potency (p < 0.01), while total flavonoid compositions also showed correlation (p < 0.05). Thus, DGPP, naringin, and hesperidin might contribute to antioxidant activity. Collectively, the hot water extract of calamondin peel might have potential for health food and cosmetic applications due to its good antioxidant activity and high level of DGPP.     

Bioactive microconstituents and antioxidant properties of wild edible mushrooms from the island of Lesvos,Greece

Crude composition, fatty acids, sterols, total phenolic content (TPC), individual polyphenols and terpenic acids were determined in five wild edible mushrooms species (Lactarius deliciosus, Lactarius sanguifluus, Lactarius semisanguifluus, Russula delica, Suillus bellinii) from Lesvos Island, Greece. In addition, the DPPH scavenging capacity, the ferric ion reducing power (FRAP) and the ferrous ion chelating activity of mushroom methanolic extracts were assessed. Among sterols, ergosterol predominated at concentrations 9.2–18.0 mg/100 g fw. Total phenolic content of mushroom extracts ranged from 6.0 to 20.8 mg GAE/100 g fw. Up to 19 simple polyphenols were determined in mushrooms extracts, the more abundant being p-OH-benzoic acid, p-OH-phenylacetic acid, o-coumaric acid, ferulic acid and chrysin. In addition, the triterpenic acids oleanolic and ursolic were detected for the first time in mushrooms. All species exerted antioxidant activity and ferrous ion chelating capacity. Principal component analysis revealed good correlations between TPC, DPPH and FRAP but not with metal chelating activity. It seems that mushrooms polyphenols exert antiradical and reducing activities, but they are not strong metal chelators, the observed chelating ability being probably due to other classes of compounds.To our knowledge, this is the first report on the bioactive microconstituents and antioxidant activity of wild Greek edible mushrooms.     

Anticancer,antioxidant and antibiotic activities of mushroom Ramaria flava

Ramaria flava is a species of edible mushroom with some bioactivity. The anticancer, antioxidant and antibiotic activities and chemical composition of R. flava ethanol extract (EE) were evaluated. The present study exhibited that the EE displayed the strongest inhibitory activity against tumor cell MDA-MB-231 with an IC₅₀ value of 66.54 μg/mL in three tested tumor cell lines, and the inhibition percent was 71.66% at the concentration of 200 μg/mL (MTT assay). The total phenolic compounds varied among four fractions of the EE from 6.66 to 61.01 mg gallic acid equivalent (GAE) per g dry weight. Water fraction exhibited high DPPH and OH radical-scavenging activities with low IC₅₀ values of 5.86 and 18.08 μg/mL, respectively. Meanwhile, three phenolic compounds from water fraction were also identified by HPLC. The antibiotic activities of the EE were evaluated against three microorganisms and three fungi strains by means of the agar well diffusion method and the poisoned medium technique, respectively. The EE also showed moderate antibiotic activities. These results suggest that R. flava could hold a good potential source for human health.     

Investigation of fruit peel extracts as sources for compounds with antioxidant and antiproliferative activities against human cell lines

The aim of this study was to evaluate antioxidant activity and cytotoxicity against human cell lines of fruit peel extracts from rambutan, mangosteen and coconut. The highest antioxidant activity was found from rambutan peel crude extract where the highest radical scavenging capacity via ABTS assay was from its ethyl acetate fraction with a TEAC value of 23.0 mM/mg and the highest ferric ion reduction activity via FRAP assay was from its methanol fraction with an EC value of 20.2 mM/mg. Importantly, using both assays, these fractions had a higher antioxidant activity than butylated hydroxyl toluene and vitamin E. It was shown that the ethyl acetate fraction of rambutan peel had the highest polyphenolic content with a gallic acid equivalent of 2.3 mg/mL. The results indicate that the polyphenolic compounds are responsible for the observed antioxidant activity of the extracts. Interestingly, the hexane fraction of coconut peel showed a potent cytotoxic effect on KB cell line by MTT assay (IC₅₀ = 7.7 μg/mL), and no detectable cytotoxicity toward normal cells. We concluded that the ethyl acetate fraction of rambutan peel is a promising resource for potential novel antioxidant agents whereas the hexane fraction of coconut peel may contain novel anticancer compounds.     

Passion fruit seed extract enriched in piceatannol obtained by microwave-assisted extraction

Apart from being food, passion fruit (Passiflora edulis Sims) offers seeds to be used as an oil source, and the residual seed cake from oil extraction contains piceatannol, a molecule that can prevent skin damages. In this work, microwave-assisted extraction (MAE) was evaluated as a technique for the preparation of piceatannol-rich seed cake extracts, and its performance was compared to the conventional Soxhlet extraction. MAE and Soxhlet exhibited different selectivities for the seed cake compounds. A sequential MAE at 87 °C, with 70% EtOH, for 30 min each cycle, provided a fine brown powder with 27.17 ± 0.9 μg of piceatannol per mg of the extract, while Soxhlet extraction for 120 min resulted in a dark lumpy extract containing 13.03 ± 0.4 μg mg^?1. Thus, MAE was shown to be a promising alternative to produce a passion fruit seed extract for cosmetic purposes, adding value to a residue from the passion fruit chain by providing a faster extraction and a more color friendly and easier-to-handle product with higher levels of piceatannol in comparison to the conventional method.     

In vitro anti-aging activities of extracts from leaves of Ma Kiang (Cleistocalyx nervosum var. paniala)

Abstract

Context: Cleistocalyx nervosum (DC.) Kosterm. var. paniala (Roxb.) J. Parn. & Chantaran. (Myrtaceae) or Ma Kiang contains high amounts of phenolic compounds. Antioxidant activity of its fruit and seed has been investigated. However, limited available information concerning the biological activities of its leaves has been reported.

Objective: To investigate the in vitro anti-aging potential of young and old leaves of Ma Kiang.

Materials and methods: Ma Kiang leaves were extracted using water, methanol, and chloroform as the solvents by cold (sonication) and hot (boiling) processes. The extracts were determined for total phenolic and flavonoid contents. The extracts (at 0.001–10?mg/ml) were tested for antioxidative and tyrosinase inhibition activities using a colorimetric method. The cytotoxicity of extracts (at 0.0001–1?mg/ml) was determined with human skin fibroblasts. Also, the extracts at 0.001, 0.01, and 0.1?mg/ml which showed no toxicity were tested for MMP-2 inhibition.

Results: The cold methanol extract of the old leaves showed the highest total phenolic and flavonoid contents of 511.44?±?18.23?μg GAE/mg and 262.96?±?2.98?μg QE/mg, respectively. This extract also gave high free radical scavenging, lipid peroxidation inhibition, and tyrosinase inhibition activities with SC₅₀, IPC₅₀, and IC₅₀ values of 0.02?±?0.004, 0.23?±?0.13, and 0.02?±?0.006?mg/ml, respectively. The extract at 0.1?mg/ml exhibited the highest MMP-2 inhibition of 91.14?±?1.67%.

Discussion and conclusion: The anti-aging potential of the cold methanol extract from old leaves of Ma Kiang can be further developed as an anti-aging agent.     

Inhibition of Cathepsin D protease activity by Punica granatum fruit peel extracts, isolates, and semisynthetic analogs

Crude extracts of Punica granatum fruit peel, its isolates, and semisynthetic analogs were investigated for their Cathepsin D protease reticence. Hexane extract (HE), chloroform extract (CE), and ethyl acetate extract (EAE) exhibited significant inhibition of Cathepsin D activity. The bioactivity-guided isolation of hexane- and chloroform-soluble fractions yielded piperine and ursolic acid as bioactive constituents. Upon semisynthetic modifications of ursolic acid, two of the analogs (7 and 8) exhibited higher inhibition of Cathepsin D activity: IC₅₀ at 12.87 and 9.40 μM, respectively. P. granatum fruit peel extracts may act as breast cancer chemopreventive agent.     

Beneficiation of eucalyptus tree barks in the context of an integrated biorefinery – Optimisation of accelerated solvent extraction (ASE) of polyphenolic compounds using response surface methodology

Bark from trees obtained from sustainably managed plantations used in the production of timber, pulp and paper is an under-utilised waste in many countries across the world. However, in the context of an integrated biorefinery, they may serve as a valuable feedstock for the production of high-value products for increased revenue generation and mitigation of environmental impacts for the ailing forestry, timber, pulp and paper industry. In this study, optimum accelerated solvent extraction conditions were established for the recovery of total polyphenolic compounds (TPC) and total extractive content (TEC) from barks obtained from four Eucalyptus tree species (E.dunnii, E.grandis, E.smithii and E.nitens). Using a response surface methodology and Box-Behnken experimental design, optimum extraction conditions found were an extraction temperature of 117 °C, three extraction cycles, and a milled bark particle size class of 500–850 μm. E. smithii showed the highest TEC at 21.9% and the highest TPC at 4.7 g/100 g gallic acid equivalents (GAE).     

Protection of DNA and erythrocytes from free radical induced oxidative damage by black gram (Vigna mungo L.) husk extract

Antioxidants present in various plant tissues exhibit health benefits by scavenging reactive oxygen species generated under various pathophysiological conditions. In the present study, bioactive compounds from black gram husk were extracted with water and the protection of black gram husk (BGH) extract against oxidative damage in DNA and erythrocytes were studied. BGH extract had total polyphenol content of 59 mg of gallic acid equivalents (GAE). The phenolic acids identified in the extract using RP-HPLC were gallic, protocatechuic, gentisic and ferulic acids. The extract showed good antioxidant properties. The IC₅₀ value for DPPH radical scavenging activity was found to be 3.92 μg of GAE. The BGH extract also showed α-glucosidase inhibition and the IC₅₀ value was found to be 2.78 μg of GAE. The oxidative hemolysis caused by hydrogen peroxide in rat erythrocytes was inhibited by BGH extract in a dose dependent manner. The IC₅₀ values for BGH extract and BHA for hemolysis were 11.5 and 14 μg of GAE, respectively. Morphological changes in erythrocyte membrane caused by hydrogen peroxide were protected by BGH extract. As BGH extract exhibited various antioxidant properties in different systems, it could be used as a functional food or nutraceutical product for health benefits.     

From agricultural waste to antioxidant-rich extracts: Green techniques in extraction of polyphenols from sugar beet leaves

Different conventional and “green” extraction techniques (solid/liquid extraction, microwave and ultrasound assisted extraction, pressurized liquid extraction and subcritical water extraction) were tested using different operating conditions in the recovery of valuable polyphenol compounds from sugar beet leaves. All tested extraction techniques provided considerable extraction yield in the range from 18.21% to 37.04%. Total phenolic content ranged from 0.4504 up to 1.7171 (g GAE/100 g DW) with the highest values obtained by using microwave and ultrasound assisted extraction. Extraction parameters had highly significant effect on the concentration of bioactive compounds recovered by pressurized liquid extraction and subcritical water extraction. Individual phenolic profile of sugar beet leaves extracts largely depended on the applied extraction technique, however, vitexin was the most abundant phenolic compound present in all extracts regardless of the extraction technique. Investigation of extracts antioxidant activity through DPPH, FRAP and ABTS values indicated the lowest antioxidant activity of extracts obtained by solid/liquid extraction compared to other extraction techniques.     

Antioxidant capacity and bioactive compounds of four Brazilian native fruits

The purpose of this study was to evaluate the bioactive compounds and antioxidant activity of extracts from araçá (Psidium cattleianum), butiá (Butia eriospatha), and pitanga (Eugenia uniflora) fruits with different flesh colors (i.e., purple, red, and orange), and blackberries (Rubus sp.; cv. Xavante and Cherokee) collected in the southern region of Brazil. The content of ascorbic acid, total carotenoids, and phenolics were determined. The profile of the phenolic compounds was assessed by high-performance liquid chromatography combined with diode array detection (HPLC-DAD). The antioxidant activity was determined using the ferric-reducing antioxidant power (FRAP) assay, 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) assay, total reactive antioxidant potential (TRAP) assay, and total antioxidant reactivity (TAR) assay. The Xavante blackberry and purple-fleshed pitanga showed the highest total phenolic content [816.50 mg gallic acid equivalents (GAE)/100g and 799.80 mg GAE/100g, respectively]. The araçá and red-fleshed pitanga showed the highest carotenoid content (6.27 ug β-carotene/g and 5.86 ug β-carotene/g, respectively). The fruits contained several phenolic compounds such as quercetin derivatives, quercitrin, isoquercitrin, and cyanidin derivatives, which may contribute differentially to the antioxidant capacity. The highest scavenging activity in the DPPH assay was found for purple-fleshed pitanga (IC₅₀ 36.78 mg/L), blackberries [IC₅₀ 44.70 (Xavante) and IC₅₀ 78.25 mg/L (Cherokee)], and araçá (IC₅₀ 48.05 mg/L), which also showed the highest FRAP, followed by orange- and red-fleshed pitanga. Our results revealed that some fruits grown in southern Brazil such as purple-fleshed pitanga, blackberries, and araçá are rich sources of phenolic compounds and have great antioxidant activity.     

Inhibitory effect of aqueous extract of different parts of unripe pawpaw (Carica papaya) fruit on Fe2+-induced oxidative stress in rat pancreas in vitro

Abstract

Context: Carica papaya L. (Caricaceae) is widespread throughout tropical Africa; it is cultivated for its fruits and it is eaten in various ways.

Objective: This study sought to investigate the inhibitory effect of the aqueous extract of different parts of unripe pawpaw fruit on Fe²⁺-induced lipid peroxidation in rat’s pancreas in vitro.

Materials and methods: The aqueous extract of the unripe pawpaw fruit parts; peel (PG), seed (SG), flesh (FG), flesh with peel (FPG) and a combination of equal amount of all parts (CG) were prepared, the total phenolic content and the antioxidant activities of the extracts were then evaluated using various spectrophotometric methods.

Result: PG had the highest total phenol content (1.24?mg GAE/g), flavonoid content (0.63?mg QUE/g), reducing power (7.07?mg AAE/g) and Fe²⁺ chelating ability while the SG had the highest 1,1-diphenyl-2-picrylhydrazyl radical scavenging ability. Furthermore, all the extracts caused a significant decrease (p?<?0.05) in the malondialdehyde contents in the pancreas with SG (IC₅₀?=?4.25?mg/mL) having the highest inhibitory effect on Fe²⁺-induced lipid peroxidation.

Discussion and conclusion: This protective effect of the extracts on Fe²⁺-induced lipid peroxidation in rat pancreas could be attributed to their phenolic compounds and, the possible mechanism may be through their antioxidant activities. However, the effect of combination of different parts of unripe pawpaw fruit in equal amount (w/w) on the inhibition of Fe²-induced lipid peroxidation in rat pancreas exhibited additive properties.     

The effects of Ficus carica on the activity of enzymes related to metabolic syndrome

The present study aimed to investigate the effects of the various parts of Ficus carica L. (figs) on antioxidant, antidiabetic, and antiobesogenic effects in vitro. Fruit, leaves, and stembark of the F. carica plant were sequentially extracted using organic and inorganic solvents and their total polyphenol and flavonoid contents were estimated. The effects of the extracts on antioxidative, antidiabetic (inhibition of α-amylase and α-glucosidase enzymes), and antiobesogenic (antilipase) activities were measured using several experimental models. The fruit ethanolic extract contained a high quantity of polyphenols and flavonoids (104.67 ± 5.51 μg/mL and 81.67 ± 4.00 μg/mL) compared with all other extracts. The activity of the ethanolic extract of F. carica fruit was significantly (p < 0.05) higher than all other extracts and parts of the plant in terms of antioxidative, antidiabetic, and antiobesogenic effects. The IC₅₀ values of the fruit ethanolic extract in terms of antioxidative (134.44 ± 18.43 μg/mL), and inhibition of α-glucosidase (255.57 ± 36.46 μg/mL), α-amylase (315.89 ± 3.83 μg/mL), and pancreatic lipase (230.475 ± 9.65 μg/mL) activity indicate that the activity of fruit ethanolic extract is better than all other extracts of the plant. The gas chromatography–mass spectroscopy analysis of the fruit ethanolic extract showed the presence of a number of bioactive compounds such as butyl butyrate, 5-hydroxymethyl furfural, 1-butoxy-1-isobutoxy butane, malic acid, tetradecanoic acid, phytol acetate, trans phytol, n-hexadecanoic acid, 9Z,12Z-octadecadienoic acid, stearic acid, sitosterol, 3,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one, and 2,4,5-trimethyl-2,4-dihydro-3H-pyrazol-3-one. The results of this study suggest that the ethanolic extract of the fruit of F. carica may have potential antidiabetic and antiobesogenic agents.