Physiological components of kiwifruits with in vitro antioxidant and acetylcholinesterase inhibitory activities

Comprehensive evaluation of twelve kiwifruit (Actinidia) varieties on the winemaking adaptability based on multi-criteria decision-making method

As one of the deep processing products of kiwifruit, kiwifruit wine (KW) has shown good commercial development prospects. In this paper, the wine-making adaptability and quality characteristics of 12 kiwifruit varieties with three pulp colors were systematically evaluated from the aspects of basic physicochemical, functional and sensory qualities. The results of the study showed that the ratio of sugar to acid of Hongyang wine was 0.81, which was significantly higher than other varieties. In terms of functional quality, the vitamin C content of Puyu wine was 214.43 mg/100 g, which was significantly higher than that of other varieties. Hongshi No.2 wine is the variety with the highest content of total polyphenols and flavonoid, the contents are 51.64 mg/100 g and 18.86 mg/100 g, respectively. The antioxidant activity of the wines in descending order was red-fleshed, yellow-fleshed and green-fleshed. The results of the color characterization showed that the brightness of all the wines was higher than 80, indicating that the KW were relatively clear and transparent. The result of artificial sensory evaluation showed that the Hongshi No.2 wine was more popular overall. Based on principal component analysis, optimal solution based ranking approach and gray relevance analysis models, Hongshi No.2 wine ranks first overall due to its rich nutritional content, sweet taste, and rich fruity aroma. This study involves the kiwifruit varieties with the largest planting area in the world, and the quality characteristics of their corresponding KW varieties were preliminary analyzed and compared. It provides a theoretical basis with strong pertinence and wide coverage for the production of various KW types, so as to contribute to the sustainable development of KW industry.

Effects of Green and Gold Kiwifruit Varieties on Antioxidant Neuroprotective Potential in Pigs as a Model for Human Adults

Kiwifruit (KF) has shown neuroprotective potential in cell-based and rodent models by augmenting the capacity of endogenous antioxidant systems. This study aimed to determine whether KF consumption modulates the antioxidant capacity of plasma and brain tissue in growing pigs. Eighteen male pigs were divided equally into three groups: (1) bread, (2) bread + Actinidia deliciosa cv. 'Hayward' (green-fleshed), and (3) bread + A. chinensis cv. 'Hort16A' (yellow-fleshed). Following consumption of the diets for eight days, plasma and brain tissue (brain stem, corpus striatum, hippocampus, and prefrontal cortex) were collected and measured for biomarkers of antioxidant capacity, enzyme activity, and protein expression assessments. Green KF significantly increased ferric-reducing antioxidant potential (FRAP) in plasma and all brain regions compared with the bread-only diet. Gold KF increased plasma ascorbate concentration and trended towards reducing acetylcholinesterase activity in the brain compared with the bread-only diet. Pearson correlation analysis revealed a significant positive correlation between FRAP in the brain stem, prefrontal cortex, and hippocampus with the total polyphenol concentration of dietary interventions. These findings provide exploratory evidence for the benefits of KF constituents in augmenting the brain's antioxidant capacity that may support neurological homeostasis during oxidative stress.

In vitro anticholinergic and antiglycaemic properties of frost-hardy Actinidia fruit extracts and their polyphenol profile, L-ascorbic acid content and antioxidant capacity

The aim of this study was to investigate the inhibitory effects of Actinidia arguta ('Weiki', 'Skarlet September Kiwi') and Actinidia kolomikta ('Lande') fruit extracts against advanced glycation end-products (AGEs) formation and acetylcholinesterase (AChE) activity. The extracts were also tested regarding polyphenol profile and Lascorbic acid content (UHPLC-DAD-MS), and antioxidant capacity (DPPH, ABTS). 'Scarlet September Kiwi' showed the strongest anti-AGEs activity studied with BSAGLU (IC50 = 2.68) and BSA-MGO (IC50 = 18.06) models. The highest anti-AChE activity was found for the 'Lande' extract (IC50 = 4.56). 'Lande' showed the highest L-ascorbic acid content (8271.96 µg/g dw), ABTS (312.42 µmol TE/g dw) and DPPH (282.01 µmol TE/g dw) values. 'Scarlet September Kiwi' revealed the highest individual phenolics concentration (2321.43 µg/g dw). The contents of (+)-catechin and L-ascorbic acid were significantly correlated with anti-AChE activity. This research sheds new light on the bioactivity of Actinidia arguta and Actinidia kolomikta fruit elucidating the role of (+)-catechin and L-ascorbic acid in prevention of Alzheimer's disease.

Kombucha Fermentation of Olympus Mountain Tea (Sideritis scardica) Sweetened with Thyme Honey: Physicochemical Analysis and Evaluation of Functional Properties

This study implemented kombucha fermentation of Olympus Mountain tea (Sideritis scardica) sweetened with honey (OMTWH) in order to investigate the potential for producing a novel beverage with functional properties. The increase in the total count of bacteria and yeast suggests that the OMTWH acts as a viable substrate for supporting the proliferation of the microorganisms of the Kombucha symbiotic culture. The fermentation resulted in a reduction in pH and increased total titratable acidity. After fermentation, a statistically significant increase in the vitamins C, B1, B2, B6, B7, and B12 content was observed (p < 0.05). Total phenolics and antioxidant activity of the fermented beverage was significantly enhanced, as assessed by the method of Folin-Ciocalteu and ABTS assay, respectively. Results revealed that OMTWH had a potent inhibitory activity of α-amylase, α-glucosidase, acetylcholinesterase, and butyrylcholinesterase; OMTWH fermented with a kombucha consortium exhibited even higher inhibition. Hence, the process of kombucha fermentation can convert OMTWH into a novel beverage with enhanced functional properties.

Polyphenol Profiling by LC QTOF/ESI-MS and Biological Activity of Purple Passion Fruit Epicarp Extract

A polyphenolic preparation in the form of the passion fruit epicarp extract was analyzed to identify and quantify the polyphenolic compounds using LC QTOF/ESI-MS and UPLC-PDA-FL. The analyzed parameters included antidiabetic activity (α-amylase, α-glucosidase, and pancreatic lipase), inhibitory activity toward cholinesterase (AChE, BuChE), anti-inflammatory activity (COX-1, COX-2, 15-LOX) and antioxidant activity based on ORAC and ABTS. The polyphenolic preparation of the passion fruit epicarp extract contained 51 polyphenolic compounds representing five groups-flavones (25 compounds; 52% of total polyphenolic), flavonols (8; 16%), flavan-3-ols (6; 7%), phenolic acids (4; 3%), and anthocyanins (7; 21%), with derivatives of luteolin (13 derivatives) and apigenin (8 derivatives) as dominant compounds. The preparation was characterized by an antioxidant activity of 160.7 (ORAC) and 1004.4 mmol Trolox/100 mL (ABTS+o). The inhibitory activity toward α-amylase, α-glucosidase, and pancreatic lipase reached IC50 of 7.99, 12.80, and 0.42, respectively. The inhibition of cholinesterases (IC50) was 18.29 for AChE and 14.22 for BuChE. Anti-inflammatory activity as IC50 was 6.0 for COX-1, 0.9 for COX-2, and 4.9 for 15-LOX. Food enriched with passion fruit epicarp extract has a potentially therapeutic effect.

Antioxidative Properties and Phenolic Profile of the Core, Pulp and Peel of Commercialized Kiwifruit by LC-ESI-QTOF-MS/MS

The kiwifruit is cultivated globally due to its diversity of phytochemicals, especially phenolic compounds, which have antioxidant, anti-inflammatory and anti-cancer medical effects. However, only the pulp of the kiwifruit is consumed, while the peels and cores—which are also rich in phytochemicals—are usually wasted. Meanwhile, detailed information on the comparison among the three parts is still limited. In this study, the antioxidant potentials in the core, pulp, and peel of the three most commercialized kiwifruit cultivars (Australian-grown Hayward kiwifruit, New Zealand-grown Zesy002 kiwifruit, and New Zealand-grown organic Hayward kiwifruit) were selected. Their antioxidant capacities were tested, and their phenolic profiles were identified and characterized by liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS). The antioxidant results showed that the peel of New Zealand-grown organic Hayward kiwifruit contained the highest total phenolic content (9.65 mg gallic acid equivalent (GAE) mg/g) and total antioxidant capacity (4.43 mg ascorbic acid equivalent (AAE) mg/g), respectively. In addition, the antioxidant capacity of the peel is generally higher than that of the pulp and cores in all species, especially ABTS (2,2-Azino-bis-3ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging ability), ranging from 13.25 mg AAE/g to 18.31 mg AAE/g. The LC-ESI-QTOF-MS/MS tentatively identified the phenolic compounds present in the three kiwifruit species, including 118 unique compounds in kiwifruit peel, 12 unique compounds in the kiwifruit cores, and three unique compounds in kiwifruit pulp. The comprehensive characterization of the phenolics in the kiwifruits’ parts indicates the importance of their waste part as a promising source of phenolics with antioxidant properties. Therefore, this study can guide the industry with meaningful information on kiwifruit waste, and can provide it with the utilization of food and pharmacological aspects.

Fermentation of kiwifruit juice from two cultivars by probiotic bacteria: Bioactive phenolics, antioxidant activities and flavor volatiles

Three commercial lactic acid bacteria (LAB), namely Lactobacillus acidophilus 85 (La85), Lactobacillus helveticus 76 (Lh76) and Lactobacillus plantarum 90 (Lp90), were employed to investigate the effects on the phenolic compounds, antioxidant capacities and flavor volatiles of kiwifruit juices prepared from two cultivars (Actinidia deliciosa cv. Xuxiang and Actinidia chinensis cv. Hongyang). Results showed that both kiwifruit juices were favorable matrices for LAB growth and the colony counts remained above 9.0 log CFU/mL after fermentation. Total phenolics and flavonoids in Xuxiang and Hongyang juices were increased dramatically by Lh76. Correspondingly, antioxidant capacities based on DPPH, ABTS and FRAP methods were improved significantly and positively correlated with protocatechuic acid and catechin contents (p < 0.05), two newly formed phytochemicals in fermented kiwifruit juices. Furthermore, results of hierarchical cluster analysis revealed that flavor profiles were improved significantly by LAB, and there were noticeable differences between fermented Xuxiang and Hongyang juices.

Characterization of free, conjugated, and bound phenolics in early and late ripening kiwifruit cultivars

BACKGROUND

Kiwifruit (Actinidia) has long been called the 'king of fruits' because of its unique flavor and the wide range of bioactive compounds which contains ascorbic acid, phenolics and minerals. These bioactivities are influenced by species and cultivar. However, to date few studies are concerned with the effect of ripening time on fruit quality. Here, early and late ripening kiwifruits were investigated to determine their content of ascorbic acid, organic acid, and phenolic compounds.

RESULTS

Early ripening cultivars contained higher quinic acid and malic acid, while citric acid were found in large amounts in late ripening kiwifruits. Most of the early ripening cultivars contained higher free phenolic fractions than the late ripening fruits, mainly due to the high levels of epicatechin. However, conjugated phenolics, mainly including caffeic and 2,3,4-trihydroxybenzoic acid, achieved higher levels in the late ripening cultivars. Free phenolics were higher than conjugated phenolics in the early ripening cultivars. Principal component analysis revealed some key compounds that differentiated the kiwifruits, and all the kiwifruits were divided into two subgroups as early and late ripening cultivars.

CONCLUSION

Ripening time had a great impact on the accumulation of bioactive compounds. The early ripening cultivars, compared to the late ripening ones, were characterized by higher levels of free neochlorogenic acid and epicatechin, while the late ripening kiwifruits contained higher amounts of conjugated phenolics. Results from this study provide further insights into the health-promoting phenolic compounds in kiwifruit, and also provide good evidence to aid consumer selection. © 2021 Society of Chemical Industry.

Effect of Thermal Processing on Color, Phenolic Compounds, and Antioxidant Activity of Faba Bean (Vicia faba L.) Leaves and Seeds

The leaves and seeds of the faba bean are good sources of L-3,4-dihydroxyphenylalanin (L-dopa), and are usually eaten with thermal cooking methods. However, little information is available on the effect of thermal treatments on their nutritional value. We compared the changes in color, contents of L-dopa, vitamin C (Vc), total phenolics (TP), total flavonoids (TF) and antioxidant activity after dry heating or steaming faba bean leaves and seeds. The young leaves provided higher values of all the estimate factors, regardless of the thermal treatment. Steaming significantly degraded nutritional values of the leaves, but less changed in seeds, whereas dry heat maintained these attributes. The contents of L-dopa, Vc, TP and TF were shown to have strongly positive correlations with antioxidant activity in the leaves, whereas only L-dopa content was positively correlated with antioxidant activity of the seeds. Faba leaves contained relatively high L-dopa which possessed strong antioxidant activity compared to the Vc. As L-dopa is an important contributor to the antioxidant activity of faba leaves and seeds, consuming L-dopa from leaves may provide beneficial effects not only regarding Parkinson's Disease.

Antioxidant Contributors in Seed, Seed Coat, and Cotyledon of γ-ray-Induced Soybean Mutant Lines with Different Seed Coat Colors

The development of soybean with high antioxidant activities for use in the food and cosmetics industries is a target of breeding programs. In soybean, antioxidants are associated with seed color, although the metabolic basis for seed coloration remains incompletely understood. We selected six γ-ray-induced mutant lines that exhibited black, partially black, brown, partially brown, or yellowish-white pigmentation in the seed coat. Antioxidant activity and contents of anthocyanins, flavan-3-ols, and isoflavones were evaluated in the seed coat and cotyledons. The lines with black or brown seeds showed the highest antioxidant activities. The cotyledons showed no significant differences in seed coat components or antioxidant activities among lines. Black and brown seed coat components showed the highest antioxidant activities. The black seed coat contained five anthocyanins, whereas seed coats of brown- and yellow-seeded lines entirely lacked anthocyanins. Both black and brown seeds were rich in flavan-3-ols, including catechin and epicatechin, which were the predominant antioxidant contributors in brown seeds. Isoflavone contents showed weaker correlations with antioxidant activity than anthocyanins and flavan-3-ols. These results demonstrated that antioxidant activities were determined by anthocyanins in black seeds and flavan-3-ols in brown and black seeds, whereas relatively low antioxidant activities in yellow seeds reflected their high isoflavone contents.

Actinidia arguta Sprout as a Natural Antioxidant: Ameliorating Effect on Lipopolysaccharide-Induced Cognitive Impairment

Here, we investigated the prebiotic and antioxidant effects of Actinidia arguta sprout water extract (AASWE) on lipopolysaccharide (LPS)-induced cognitive deficit mice. AASWE increased viable cell count, titratable acidity, and acetic acid production in Lactobacillus reuteri strain and showed a cytoprotective effect on LPS-induced inflammation in HT-29 cells. We assessed the behavior of LPSinduced cognitive deficit mice using Y-maze, passive avoidance and Morris water maze tests and found that administration of AASWE significantly improved learning and memory function. The AASWE group showed antioxidant activity through downregulation of malondialdehyde levels and upregulation of superoxide dismutase levels in brain tissue. In addition, the AASWE group exhibited activation of the cholinergic system with decreased acetylcholinesterase activity in brain tissue. Furthermore, AASWE effectively downregulated inflammatory mediators such as phosphorylated- JNK, phosphorylated-NF-κB, TNF-α and interleukin-6. The major bioactive compounds of AASWE were identified as quercetin-3-O-arabinopyranosyl(1→2)-rhamnopyranosyl(1→6)-glucopyranose, quercetin-3-O-apiosyl(1→2)-galactoside, rutin, and 3-caffeoylquinic acid. Based on these results, we suggest that AASWE not only increases the growth of beneficial bacteria in the intestines, but also shows an ameliorating effect on LPS-induced cognitive impairment.

The impact of high-pressure processing on the polyphenol profile and anti-glycaemic, anti-hypertensive and anti-cholinergic activities of extracts obtained from kiwiberry (Actinidia arguta) fruits

This study analysed the impact of high pressure processing (HHP) on the inhibitory effects (IC₅₀) of kiwiberries (cv. 'Weiki'), on the formation of advanced glycation end-products (AGEs) and the activity of angiotenisn-converting enzyme (ACE) and the enzyme acetylcholinesterase (AChE). The polyphenol profile (HPLC-MS/MS) and antioxidant capacity (PCL_ACW, ABTS, FRAP) were also studied. HHP-treated 'Weiki' (450 MPa/5 min and 650 MPa/5 min) was the most potent inhibitor of AGEs in the BSA-GLU model (6.52 mg/mL on average) relative to other materials (12.09-7.21 mg/mL). Among all samples assayed in the BSA-MGO model (61.97-14.48 mg/mL), HHP-treated 'Weiki' (450 MPa/5 min) showed the highest anti-AGE activity (12.37 mg/mL). Pressurization (450 MPa/5 min) significantly enhanced the anti-ACE (14.09 mg/mL) and anti-AChE (16.95 mg/mL) potentials of the tested extract relative to the other materials (23.75-14.50 mg/mL and 37.88-19.69 mg/mL, respectively). Pressurization increased polyphenol content and antioxidant capacity of the samples analysed.

Dynamic Changes of Phenolic Compounds and Their Associated Gene Expression Profiles Occurring during Fruit Development and Ripening of the Donghong Kiwifruit

The newly released Donghong kiwifruit is a promising commercial cultivar. The dynamic changes of major phenolic compounds (flavonols, flavanols, phenolic acids, and anthocyanins) during the representative stages of fruit development and ripening of the Donghong kiwifruit were determined by high-performance liquid chromatography. The corresponding time-course transcriptional changes were evaluated using the combined analysis of RNA-Seq and qRT-PCR. The most predominant phenolic compound in the Donghong kiwifruit was epicatechin. Cyanidin 3-O-[2-O-(β-xylosyl)-β-galactoside] and cyanidin 3-O-β-galactoside were two essential anthocyanins detected. Candidate genes and pathways involved in phenolic compounds biosynthesis were highlighted. The structural genes (AcLDOX2, Ac5GGT1, and Ac5AT2) and the transcription factor (bHLH74-2) were strongly associated with anthocyanin biosynthesis. AcMYB4-1 may be a novel transcription factor that reduces anthocyanin accumulation. Results from the study may be a very useful supplement to current knowledge of molecular mechanisms to elucidate coloration in the red-fleshed kiwifruit and could help breeders modify the kiwifruit germplasm.

Changes in phenolics, soluble solids, vitamin C, and antioxidant capacity of various cultivars of hardy kiwifruits during cold storage

Hardy kiwifruits (Actinidia arguta) contain various bioactive compounds such as vitamin C and phenolics and can withstand cold temperatures. Changes in soluble solid, vitamin C, total phenolic, and total flavonoid content, and antioxidant capacity of three cultivars of hardy kiwifruits (A. arguta × A. deliciosa cv. Mansu, A. arguta cv. Haeyeon, and A. arguta cv. Chiak) were comparatively evaluated for 8 weeks of storage at 1 ± 0.5 °C. After the 8 weeks of storage, soluble solid content of three cultivars increased, whereas their vitamin C content decreased. Throughout this storage period, total phenolic and flavonoid content of cv. Mansu and cv. Haeyeon remained the same, while antioxidant capacity of these two cultivars also remained similar but with slightly more variations. Cv. Chiak, however, showed a decrease in total phenolic and flavonoid content and antioxidant capacity. These results suggest that cold storage of the hardy kiwifruits maintains levels of bioactive compounds.

Comparison of the nutritional properties and biological activities of kiwifruit (Actinidia) and their different forms of products: towards making kiwifruit more nutritious and functional

The nutritional properties and biological activities of kiwifruit and their different products made from same raw kiwifruit were investigated. Compared with the more common Hayward variety, three new kiwifruit varieties, namely Qinmei, Hongyang and Huayou, showed better nutritional properties and biological activities. After processing into different products, the nutritional properties and biological activities of kiwifruit changed substantially but still showed a correlation with the variety's characteristics. Processing kiwifruit into juice, wine and vinegar retained a higher vitamin C and polyphenol content than dried slices and jam and demonstrated better biological activities, while dried slices and jam provided more mineral elements than the three liquid products. In addition, the fermentation products wine and vinegar showed a similar nutritional composition that were present at a higher concentration than in juice, which indicated that fermentation helps in the dissolution of nutrient substances, while the thermal processing products dried slices and jam showed a similar nutritional composition. Consuming original kiwifruit supplies a more comprehensive nutritional composition than from any kiwifruit products.

Phenolic compounds and antioxidant activity in red- and in green-fleshed kiwifruits

Red-fleshed kiwifruits are receiving increasing attention because of their high phenolic contents. However, detailed information on their phenolic compounds and antioxidant capacities remains scarce. Here, six red-fleshed and six green-fleshed kiwifruits were investigated to determine their contents of phenolic compounds and their antioxidant capacities. The results showed chlorogenic acid, p-coumaric acid and ferulic acid were the main phenolic compounds found in kiwifruit. Most of red-fleshed kiwifruits contain higher amounts of total phenolics and anthocyanins, as well as higher activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). Moreover, they exhibited stronger antioxidant capacities than green-fleshed kiwifruits in ABTS, DPPH and FRAP assays. Furthermore, the reactive oxygen species (ROS) inhibition assay showed the phenolics extracted from red-fleshed kiwifruit can better protect tobacco leaves against hydrogen peroxide (H2O2)-induced oxidative damage. This is because of their abundant anthocyanins which in vitro contribute more to H2O2 scavenging than the other phenolic compounds. Based on these findings, it is fair to conclude the red-fleshed kiwifruits are promising sources of antioxidants in human nutrition.

Correction: Comparison of the nutritional properties and biological activities of kiwifruit (Actinidia) and their different forms of products: towards making kiwifruit more nutritious and functional

Correction for ‘Comparison of the nutritional properties and biological activities of kiwifruit (Actinidia) and their different forms of products: towards making kiwifruit more nutritious and functional’ by Tingting Ma et al., Food Funct., 2019, 10, 1317–1329.

The nutritional and health attributes of kiwifruit: a review

PURPOSE

To describe the nutritional and health attributes of kiwifruit and the benefits relating to improved nutritional status, digestive, immune and metabolic health. The review includes a brief history of green and gold varieties of kiwifruit from an ornamental curiosity from China in the 19th century to a crop of international economic importance in the 21st century; comparative data on their nutritional composition, particularly the high and distinctive amount of vitamin C; and an update on the latest available scientific evidence from well-designed and executed human studies on the multiple beneficial physiological effects. Of particular interest are the digestive benefits for healthy individuals as well as for those with constipation and other gastrointestinal disorders, including symptoms of irritable bowel syndrome. The mechanisms of action behind the gastrointestinal effects, such as changes in faecal (stool) consistency, decrease in transit time and reduction of abdominal discomfort, relate to the water retention capacity of kiwifruit fibre, favourable changes in the human colonic microbial community and primary metabolites, as well as the naturally present proteolytic enzyme actinidin, which aids protein digestion both in the stomach and the small intestine. The effects of kiwifruit on metabolic markers of cardiovascular disease and diabetes are also investigated, including studies on glucose and insulin balance, bodyweight maintenance and energy homeostasis.

CONCLUSIONS

The increased research data and growing consumer awareness of the health benefits of kiwifruit provide logical motivation for their regular consumption as part of a balanced diet. Kiwifruit should be considered as part of a natural and effective dietary strategy to tackle some of the major health and wellness concerns around the world.

Phenolic Profiles, Antioxidant Capacities, and Inhibitory Effects on Digestive Enzymes of Different Kiwifruits

In order to obtain high-quality kiwifruits with health-promoting characteristics, physicochemical properties, phenolic profiles, antioxidant capacities, and inhibitory effects on digestive enzymes (pancreatic lipase and α-glucosidase), of fourteen different types of kiwifruit obtained from China were systematically investigated and compared. Noticeable variations in the fruits’ physicochemical properties and phenolic profiles were observed among them. The total phenolic content of Actinidia chinensis cv. Hongshi, A. chinensis cv. Jinshi, and A. chinensis cv. Jinlong were 16.52 ± 0.26 mg GAE/g DW (dry weight), 13.38 ± 0.20 mg GAE/g DW, and 11.02 ± 0.05 mg GAE/g DW, respectively, which were much higher than those of the other tested kiwifruits. According to high performance liquid chromatography (HPLC) analysis, phenolic compounds, including procyanidin B1, procyanidin B2, (−)-epicatechin, chlorogenic acid, gallic acid, and quercetin-3-rhamnoside, were found to be the major compounds in kiwifruits, while procyanidin B1, procyanidin B2, and chlorogenic acid were the most abundant phenolic compounds. Furthermore, all the tested kiwifruits exerted remarkable antioxidant capacities and inhibitory effects on pancreatic lipase and α-glucosidase. Indeed, A. chinensis cv. Hongshi, Actinidia chinensis cv. Jinshi, and Actinidia chinensis cv. Jinlong exhibited much better antioxidant capacities and inhibitory effects on digestive enzymes than those of the other tested kiwifruits. Particularly, A. polygama showed the highest inhibitory activity on α-glucosidase. Therefore, Actinidia chinensis cv. Hongshi, Actinidia chinensis cv. Jinshi, and Actinidia chinensis cv. Jinlong, as well as A. polygama could be important dietary sources of natural antioxidants and natural inhibitors against pancreatic lipase and α-glucosidase, which is helpful for meeting the growing demand for high-quality kiwifruits with health-promoting characteristics in China.

Anti-amyloidogenic properties of an ethyl acetate fraction from Actinidia arguta in Aβ1-42-induced ICR mice

This study aimed to investigate the ameliorating effect of an ethyl acetate fraction from the fruit Actinidia arguta (EFAA) on amyloid beta (Aβ)-induced neurotoxicity and cognitive deficits in ICR mice. EFAA showed potent protective effects against Aβ-induced neurotoxicity through 2',7'-dichlorofluorescein diacetate (DCF-DA), 2',3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release into the assay medium. EFAA treatment reduced the intracellular ROS level and lactate dehydrogenase (LDH) release in the mitochondria, and increased cell viability in Aβ-induced neuroblastoma MC-IXC cells. The administration of EFAA significantly attenuated Aβ-induced learning and memory deficits, which were evaluated by Y-maze, passive avoidance, and Morris water maze tests. Furthermore, EFAA showed the ameliorating effect of cholinergic functions by increasing acetylcholine (ACh) levels and decreasing acetylcholinesterase (AChE) activity, and protected antioxidant systems by increasing superoxide dismutase (SOD) and decreasing the oxidized glutathione (GSH)/total GSH and malondialdehyde (MDA) in the brain. Finally, EFAA prevented mitochondrial dysfunction via regulating apoptotic signaling molecules including phosphorylated Akt (p-Akt), phosphorylated tau (p-tau), Bax, and cytochrome c in the brain tissues. Therefore, the present study suggests that EFAA might be a potential source of natural antioxidants with the ability to ameliorate Aβ-induced amnesia.

Kiwifruit of Actinidia eriantha cv. Bidan has in vitro antioxidative, anti-inflammatory and immunomodulatory effects on macrophages and splenocytes isolated from male BALB/c mice

Kiwifruit is known to contain considerable amount of antioxidative phenolics. The objective of this study was to evaluate the antioxidative, anti-inflammatory and immunomodulatory effects of Actinidia eriantha cv. Bidan and A. deliciosa cv. Hayward kiwifruits. The antioxidant capacity of kiwifruit was measured with the DPPH, ABTS and ORAC assays, and was significantly (p < 0.05) higher in cv. Bidan than in cv. Hayward. The production of proinflammatory cytokines interleukin-6, interleukin-12 and tumor necrosis factor-α by peritoneal macrophages from male BALB/c mice was significantly (p < 0.05) lower following treatment of cv. Bidan extracts than after treatment with lipopolysaccharide alone. Cv. Bidan extracts significantly (p < 0.05) increased the proliferation of splenocytes stimulated with an anti-CD3 antibody and significantly (p < 0.05) reduced their interferon-γ secretion. Taken together, these findings suggest that cv. Bidan kiwifruit is rich in antioxidants and may be a source of anti-inflammatory and immunomodulatory agents.

Effects of freeze-drying on antioxidant and anticholinesterase activities in various cultivars of kiwifruit (Actinidia spp.)

Oxidative stress contributes to neurodegenerative disorders such as Alzheimer's disease. Phenolic antioxidants can efficiently reduce oxidative stress. In this study, we evaluated the effects of the freeze-drying process on phenolics, antioxidants, and cholinesterase inhibition in five cultivars of kiwifruits grown in Korea, Actinidia chinensis cv. Hort16A, cv. Happygold, and cv. Haegeum; A. deliciosa cv. Hayward; and A. eriantha cv. Bidan, by comparing them with their fresh counterparts. Among the five cultivars of both fresh and freeze-dried kiwifruits tested in this study, cv. Bidan had the highest levels of total phenolics, total flavonoids, and antioxidants, and cv. Hayward had the lowest. Freezedried kiwifruits inhibited acetylcholinesterase and butyrylcholinesterase that catalyze the breakdown of acetylcholine (neurotransmitter). On sensory evaluation, cv. Happygold had the highest overall preference scores among the freeze-dried kiwifruits. The results suggest that freeze-dried kiwifruit could serve as a good source of antioxidants and cholinesterase inhibitors.

Antiamnesic Effect of Actinidia arguta Extract Intake in a Mouse Model of TMT-Induced Learning and Memory Dysfunction

The antiamnesic effects of ethyl acetate fraction from Actinidia arguta (EFAA) on trimethyltin- (TMT-) induced memory impairment were investigated to find the possibility of functional food substances. EFAA showed a potent AChE inhibitory effect (IC₅₀ = 53 μg/mL) and efficient neuroprotection against H₂O₂-induced oxidative stress. The administration of EFAA significantly decreased TMT-induced cognitive deficit in Y-maze, passive avoidance, and Morris water maze (MWM) tests. After the behavioral tests, the antioxidant activities were confirmed using mice brain tissues. EFAA not only showed the inhibition of AChE activity and the decline of malondialdehyde (MDA) level as a sign of lipid peroxidation but also presented the increase of the superoxide dismutase (SOD) level and the decrease of the oxidized glutathione (GSSG)/total glutathione (GSH + GSSG) ratio. Finally, the phenolics in EFAA were identified using liquid chromatography coupled with hybrid triple quadrupole-linear ion trap mass spectrometry, and four main phenolics, such as quinic acid, chlorogenic acid, caffeoyl hexose, and quercetin-3-glucoside, were identified. These results suggest that EFAA containing physiological phenolics might enhance drug-induced amnesia through AChE inhibition and neuroprotection.

Evaluation of Antioxidant, Antidiabetic and Anticholinesterase Activities of Smallanthus sonchifolius Landraces and Correlation with Their Phytochemical Profiles

The present study aimed to investigate the phytochemical profile of leaf methanol extracts of fourteen Smallanthus sonchifolius (yacon) landraces and their antioxidant, anticholinesterase and antidiabetic activities that could lead to the finding of more effective agents for the treatment and management of Alzheimer's disease and diabetes. For this purpose, antioxidant activity was assessed using different tests: ferric reducing ability power (FRAP), 2,2-diphenyl-1-picryl hydrazyl (DPPH), nitric oxide (˙NO) and superoxide (O2˙-) scavenging and lipid peroxidation inhibition assays. Anticholinesterase activity was investigated by quantifying the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, whereas antidiabetic activity was investigated by α-amylase and α-glucosidase inhibition tests. To understand the contribution of metabolites, phytochemical screening was also performed by high performance liquid chromatography-diode array detector (HPLC-DAD) system. Among all, methanol extract of PER09, PER04 and ECU44 landraces exhibited the highest relative antioxidant capacity index (RACI). ECU44 was found to be rich in 4,5-di-O-caffeoylquinic acid (CQA) and 3,5-di-O-CQA and displayed a good α-amylase and α-glucosidase inhibition, showing the lowest IC50 values. Flavonoids, instead, seem to be involved in the AChE and BChE inhibition. The results of this study revealed that the bioactive compound content differences could be determinant for the medicinal properties of this plant especially for antioxidant and antidiabetic activities.