Screening of growth inhibitors for epithelial-mesenchymal transition-induced cells by TGF-ß from plant-based sources identified the active compound hydroxychavicol from Piper bitle.

Epithelial-mesenchymal transition (EMT) has recently been associated with cancer invasion, metastasis, and resistance. In our previous study, we discovered nanaomycin K, a natural growth inhibitor for EMT-induced Madin Darby canine kidney (MDCK) cells, from the cultured broth of actinomycetes. However, the screening method was undeveloped, because the activity of nanaomycin K was discovered accidentally. In this study, we established a screening method by analyzing the characteristics of nanaomycin K in MDCK cells. Nanaomycin K showed the characteristic growth inhibitory activity on MDCK cells cultured under four conditions: medium containing dimethyl sulfoxide, SB431542, TGF-ß, and a mixture of SB431542 and TGF-ß. The activity was stronger in TGF-ß-treated cells than in DMSO-treated cells. In the mixture of SB431542 and TGF-ß-treated cells, the activity of nanaomycin K was suppressed. The anti-cancer agents, mitomycin C, cisplatin, and staurosporine, lacked the characteristics as that of nanaomycin K for these four treatment conditions. Since these four conditions distinguish between the effects of nanaomycin K and other anti-cancer agents in EMT-induced cells, the screening method was established. Among the 13,427 plant extracts tested, Piper betle leaf extract displayed growth inhibitory activity against EMT-induced cells. Through the purification of the extract via bio-guided fractionation, hydroxychavicol was isolated as an active compound. The cytotoxic activity of hydroxychavicol was stronger in EMT-induced MDCK cells than in control cells. However, its cytotoxic activity was suppressed in EMT-inhibited cells. Furthermore, hydroxychavicol exhibited same activity against SAS cells (human squamous cell carcinoma of the tongue). Thus, we have successfully established a screening method for growth inhibitors of EMT-induced cells and have discovered an inhibitor from plant-based sources.

Efficacy of quorum sensing and growth inhibitors alone and in combination against avian pathogenic Escherichia coli infection in chickens.

Avian pathogenic E. coli (APEC), a causative agent of colibacillosis, is associated with high mortality and morbidity which results in severe economic losses to the poultry industry worldwide. APEC can be transmitted to humans through the consumption of contaminated poultry products. The limited effect of the current vaccines and the advent of drug-resistant strains have necessitated the development of alternative therapies. Previously, we identified 2 small molecules (SMs; [quorum sensing inhibitor; QSI-5] and [growth inhibitor; GI-7]) with high efficacy in vitro and in chickens subcutaneously challenged with APEC O78. Here, we optimized the oral challenge dose of APEC O78 in chickens to mimic the infection in the natural settings, evaluated the efficacy of the GI-7, QSI-5, and combination of GI-7 and QSI-5 (GI7+ QSI-5) in chickens orally infected with APEC, and compared their efficacy to sulfadimethoxine (SDM), an antibiotic currently used to treat APEC. Using the optimized dose of each SM in drinking water, GI-7, QSI-5, GI7+ QSI-5, and SDM were evaluated in chickens challenged with the optimized dose of APEC O78 (1 × 109 CFU/chicken; orally; d 2 of age) and grown on built-up floor litter. Reduction in mortality was 90, 80, 80, and 70% in QSI-5, GI-7+QSI-5, GI-7, and SDM treated groups compared to the positive control (PC), respectively. GI-7, QSI-5, GI-7+QSI-5, and SDM reduced the APEC load in the cecum by 2.2, 2.3, 1.6, and 0.6 logs and in the internal organs by 1.3, 1.2, 1.4, and 0.4 logs compared to PC (P < 0.05), respectively. The cumulative pathological lesions scores were 0.51, 0.24, 0.0, 0.53, and 1.53 in GI-7, QSI-5, GI-7+QSI-5, SDM, and PC groups, respectively. Overall, GI-7 and QSI-5 individually have promising effects as a potential antibiotic-independent approach to control APEC infections in chickens.

Enhanced tolerance of Cupriavidus necator NCIMB 11599 to lignocellulosic derived inhibitors by inserting NAD salvage pathway genes.

Polyhydroxybutyrate (PHB) is a bio-based, biodegradable and biocompatible plastic that has the potential to replace petroleum-based plastics. Lignocellulosic biomass is a promising feedstock for industrial fermentation to produce bioproducts such as polyhydroxybutyrate (PHB). However, the pretreatment processes of lignocellulosic biomass lead to the generation of toxic byproducts, such as furfural, 5-HMF, vanillin, and acetate, which affect microbial growth and productivity. In this study, to reduce furfural toxicity during PHB production from lignocellulosic hydrolysates, we genetically engineered Cupriavidus necator NCIMB 11599, by inserting the nicotine amide salvage pathway genes pncB and nadE to increase the NAD(P)H pool. We found that the expression of pncB was the most effective in improving tolerance to inhibitors, cell growth, PHB production and sugar consumption rate. In addition, the engineered strain harboring pncB showed higher PHB production using lignocellulosic hydrolysates than the wild-type strain. Therefore, the application of NAD salvage pathway genes improves the tolerance of Cupriavidus necator to lignocellulosic-derived inhibitors and should be used to optimize PHB production.

Myrsinane-type diterpenes from Euphorbia gedrosiaca with cell growth inhibitory activity and apoptotic effects on melanoma cancer cells.

Phytochemical analysis of Euphorbia gedrosiaca Rech.f., Aellen & Esfand., an Iranian endemic spurge, afforded the isolation of four myrsinane types diterpene polyesters. Two new compounds (1-2) were based on a myrsinane skeleton while the others (3-4) were known diterpenes based on a cyclomyrsinane backbone. Their chemical structures were elucidated by spectroscopic methods, including 1D and 2D NMR and HRESIMS. The isolated compounds were tested to evaluate their cell growth inhibitory activity and apoptotic effects on melanoma cell lines, B16F10 and A375. The IC50 values for compounds 1-4 were 58.45, 55.43, 86.52 and 82.27 µM, respectively, on B16F10, and 20.66, 21.88, 36.21 and 39.87 µM, respectively, on A375 cells. Non-treated cells were used as negative control (100% cell growth) and 5 nM Taxol were considered as a positive control.

Computer-assisted screening of mycobacterial growth inhibitors: Exclusion of frequent hitters with the assistance of the multiple target screening method.

Background: The emergence of frequent hitters (FHs) remains a challenge in drug discovery. We have previously used in silico structure-based drug screening (SBDS) to identify antimycobacterial candidates. However, excluding FHs has not been integrated into the SBDS system. Methods: A dataset comprising 15,000 docking score (protein-compound affinity matrix) was constructed by multiple target screening (MTS): DOCK-GOLD two-step docking simulations with 154,118 compounds versus the 30 target proteins essential for mycobacterial survival. After extraction of 141 compounds from the protein-compound affinity matrix, compounds determined to be FHs or false positives were excluded. Antimycobacterial properties of the top nine compounds selected through SBDS were experimentally evaluated. Results: Nine compounds designated KS1-KS9 were selected for experimental evaluation. Among the selected compounds, KS3, identified as adenosylhomocysteinase inhibitor, showed a potent inhibitory effect on antimycobacterial growth (inhibitory concentration [IC]50 = 1.2 M). However, the compound also showed potent cytotoxicity. Conclusion: The MTS method is applicable in SBDS for the identification of enzyme-specific inhibitors.

Lignans and Neolignans with Antioxidant and Human Cancer Cell Proliferation Inhibitory Activities from Cinnamomum bejolghota Confirm Its Functional Food Property.

In the aim to evaluate the functional food property of Cinnamomum bejolghota, seven new lignans and neolignans, bejolghotins A-G (1-4 and 9-11), along with 14 known ones (5-8 and 12-21), were isolated and their structures including absolute configurations were elucidated by extensive spectroscopic data and electronic circular dichroism (ECD) analyses. All of the isolates were tested for antioxidant and human cancer cell proliferation inhibitory activities. Twenty compounds showed comparable antioxidant activity to the positive controls, and three significantly inhibited the growth of three cancer cell lines HCT-116, A549, and MDA-MB-231 with IC50 values of 0.78-2.93 µM, which confirmed its health benefits.

Peptide-lipid nanoconstructs act site-specifically towards glioblastoma growth impairment.

Ultra-small nanostructured lipid carriers (usNLCs) have been hypothesized to promote site-specific glioblastoma (GB) drug delivery. Envisioning a multitarget purpose towards tumor cells and microenvironment, a surface-bioconjugated usNLC prototype is herein presented. The comeback of co-delivery by repurposing atorvastatin and curcumin, as complementary therapy, was unveiled and characterized, considering colloidal properties, stability, and drug release behavior. Specifically, the impact of the surface modification of usNLCs with hyaluronic acid (HA) conjugates bearing the cRGDfK and H7k(R2)2 peptides, and folic acid (FA) on GB cells was sequentially evaluated, in terms of cytotoxicity, internalization, uptake mechanism and hemolytic character. As proof-of-principle, the biodistribution, tolerability, and efficacy of the nanocarriers were assessed, the latter in GB-bearing mice through magnetic resonance imaging and spectroscopy. The hierarchical modification of the usNLCs promotes a preferential targeting behavior to the brain, while simultaneously sparing the elimination by clearance organs. Moreover, usNLCs were found to be well tolerated by mice and able to impair tumor growth in an orthotopic xenograft model, whereas for mice administered with the non-encapsulated therapeutic compounds, tumor growth exceeded 181% in the same period. Relevant biomarkers extracted from metabolic spectroscopy were ultimately identified as a potential tumor signature.

Cell Growth Inhibition of Saponin XII from Dipsacus japonicus Miq. on Acute Myeloid Leukemia Cells.

In previous studies, we isolated the known compound saponin XII from the roots of Dipsacus japonicus Miq. Here, we show that this compound reduced the number of acute myeloid leukemia OCI-AML3 cells as evaluated by a hemocytometer. Flow cytometry analyses demonstrated that the reported activity was associated with a significant increase of apoptosis and of cells in the G0/G1 phase of the cell cycle, with a decrease of cells in the S and G2/M phases. Thus, the inhibition of cell growth in OCI-AML3 cells was due to antiproliferative and pro-apoptotic effects. Interestingly, the bioactivity of saponin XII exerted its effect at a concentration as low as 1 µg/mL.

Comparison of phenolics, antioxidant, and antiproliferative activities of two Hypsizygus marmoreus varieties.

Phenolics, antioxidant activities, and antiproliferative properties of brown Hypsizygus marmoreus (brown HM) and white Hypsizygus marmoreus (white HM) were compared. The results showed that the contents of (+)-catechin, gallic acid, and protocatechuic acid of brown HM were higher than those of white HM. Moreover, brown HM had greater cellular antioxidant activity (CAA), peroxyl radical scavenging capacity (PSC), and oxygen radical absorbance capacity (ORAC) values than white HM, which demonstrated that brown HM presented a stronger antioxidant capacity. Both of brown HM and white HM showed remarkable antiproliferative activities against HepG2 cells and brown HM was proven to be the more effective. The flow cytometry results revealed that both of brown HM and white HM could induce G1 arrest and cell apoptotics in a dose-dependent manner. In addition, CyclinD1, CDK4, and Bcl-2 mRNA expression levels were downregulated with the treatment of brown HM or white HM. Taken together, our study revealed that brown HM afforded better antioxidant and antiproliferative activities than white HM and laid the foundation for potential application of Hypsizygus marmoreus as source of nutraceuticals and functional food products. PRACTICAL APPLICATION: A systematic assessment of the potential differences of phenolics, antioxidant, and antiproliferative activities between different Hypsizygus marmoreus varieties was carried out in the present study. Furthermore, our findings would present possible antiproliferative mechanism of extracts of different Hypsizygus marmoreus varieties, which may provide theoretical basis for further development and utilization of Hypsizygus marmoreus.

Combination of Resveratrol and Quercetin Causes Cell Growth Inhibition, DNA Damage, Cell Cycle Arrest, and Apoptosis in Oral Cancer Cells.

Resveratrol and quercetin alone are well reported to have anticancer potential, but their combination studies are very inadequate. We have examined their combination in Cal-33 and SCC-15 oral cancer cells (OCCs) and noncancerous HEK-293 cells. Combination of 10 µM concentration of each resveratrol and quercetin brought additive effect on cellular growth, DNA damage, S-phase cell cycle arrest, and cell death in Cal-33 cells but not in the HEK-293 cells. Augmentation of the cell cycle regulatory protein, Cyclin E, and downregulation of Cyclin A possibly caused S-phase arrest in Cal-33 cancer cells. Comet formation and presence of gamma-H2AX foci confirmed DNA damage, and cleavage of PARP1 and upregulation in Bax level specified apoptosis after combined treatment. Ratio of transcription activation and repression histone marks was found increased after alone as well as combined treatment. Histone deacetylase (HDAC)1, HDAC3, and HDAC8 were downregulated by resveratrol alone and combined treatment. Conclusively, combination of resveratrol and quercetin brings cell growth inhibition, DNA damage, and cell cycle arrest in OCCs but not in normal cells. Additionally, combined treatment causes downregulation of HDACs and apoptosis in cancer cells and it could be an incisive strategy against oral cancer.

Optimization of 2-(1H-imidazo-2-yl)piperazines series of Trypanosoma brucei growth inhibitors as potential treatment for the second stage of HAT.

A previous publication from our laboratory reported the identification of a new class of 2-(1H-imidazo-2-yl)piperazines as potent T. brucei growth inhibitors as potential treatment for Human African Trypanosomiasis (HAT). This work describes the structure-activity relationship (SAR) around the hit compound 1, which led to the identification of the optimized compound 18, a single digit nanomolar inhibitor (EC50 7 nM), not cytotoxic and with optimal in vivo profile that made it a suitable candidate for efficacy studies in a mouse model mimicking the second stage of disease.

Biocatalytic Production of a Potent Inhibitor of Adipocyte Differentiation from Phloretin Using Engineered CYP102A1.

In this study, we investigated an efficient enzymatic strategy for producing potentially valuable phloretin metabolites from phlorizin, a glucoside of phloretin that is rich in apple pomace. Almond ß-glucosidase efficiently removed phlorizin's glucose moiety to produce phloretin. CYP102A1 engineered by site-directed mutagenesis, domain swapping, and random mutagenesis catalyzed the highly regioselective C-hydroxylation of phloretin into 3-OH phloretin with high conversion yields. Under the optimal hydroxylation conditions of 15 g cells L-1 and a 20 mM substrate for whole-cell biocatalysis, phloretin was regioselectively hydroxylated into 3.1 mM 3-OH phloretin each hour. Furthermore, differentiation of 3T3-L1 preadipocytes into adipocytes and lipid accumulation were dramatically inhibited by 3-OH phloretin but promoted by phloretin. Consistent with these inhibitory effects, the expression of adipogenic regulator genes was downregulated by 3-OH phloretin. We propose a platform for the sustainable production and value creation of phloretin metabolites from apple pomace capable of inhibiting adipogenesis.

Leishmania donovani Growth Inhibitors from Pathogen Box Compounds of Medicine for Malaria Venture.

INTRODUCTION: Leishmaniasis is a collective term used to describe various pathological conditions caused by an obligate intracellular protozoan of the genus Leishmania. It is one of the neglected diseases and has been given minimal attention by drug discovery and development stakeholders to narrow the safety and efficacy gaps of the drugs currently used to treat leishmaniasis. The challenge is further exacerbated by the emergence of drug resistance by the parasites. METHODS: Aiming to look for potential anti-leishmanial hits and leads, we screened Medicines for Malaria Venture (MMV) Pathogen Box compounds against clinically isolated Leishmania donovani strain. In this medium-throughput primary screening assay, the compounds were screened against promastigotes, and then against amastigote stages. RESULTS: From the total 400 compounds screened, 35 compounds showed >50% inhibitory activity on promastigotes in the initial screen (1 µM). Out of these compounds, nine showed >70% inhibition, with median inhibitory concentration (IC50) ranging from 12 to 491 nM using the anti-promastigote assay, and from 53 to 704 nM using the intracellular amastigote assay. Identified compounds demonstrated acceptable safety profiles on THP-1 cell lines and sheep red blood cells, and had appropriate physicochemical properties suitable for further drug development. Two compounds (MMV690102 and MMV688262) were identified as leads. The anti-tubercular agent MMV688262 (delamanid) showed a synergistic effect with amphotericin B, indicating the prospect of using this compound for combination therapy. CONCLUSION: The current study indicates the presence of additional hits which may hold promise as starting points for anti-leishmanial drug discovery and in-depth structure-activity relationship studies.

Screening of new cell cycle suppressive compounds from marine-derived microorganisms in Chinese hamster ovary cells.

Monoclonal antibodies (mAbs) are active pharmaceutical ingredients in antibody drugs, produced mainly using recombinant Chinese hamster ovary (CHO) cells. The regulation of recombinant CHO cell proliferation can improve the productivity of heterologous proteins. Chemical compound approaches for cell cycle regulation have the advantages of simplicity and ease of use in industrial processes. However, CHO cells have genetic and phenotypic diversity, and the effects of such compounds might depend on cell line and culture conditions. Increasing the variety of cell cycle inhibitors is a promising strategy to overcome the dependency. Marine microorganisms are a vast and largely undeveloped source of secondary metabolites with physiological activity. In this study, we focused on secondary metabolites of marine microorganisms and evaluated their effectiveness as cell cycle inhibitory compounds. Of 720 extracts from microorganisms (400 actinomycetes and 320 filamentous fungi) collected from the Okinawan Sea, we identified nine extracts that decreased the specific growth rate and increased the specific production rate without reducing cell viability. After fractionating the extracts, the components of active fractions were estimated using time-of-flight mass spectrometry analysis. Then, four compounds, including staurosporine and undecylprodigiosin were deduced to be active compounds. These compounds have been reported to exert a cell cycle inhibitory effect on mammalian cells. These compounds might serve as additives to improve mAb production in CHO cells. This study indicates that secondary metabolites of marine microorganisms are a useful source for new cell cycle inhibitory compounds that can increase mAb production in CHO cells.

Selective cytotoxicity of epidithiodiketopiperazine DC1149B, produced by marine-derived Trichoderma lixii on the cancer cells adapted to glucose starvation.

The core of solid tumors is characterized by hypoxia and a nutrient-starved microenvironment and has gained much attention as targets of anti-cancer drugs. In the course of search for selective growth inhibitors against the cancer cells adapted to nutrient starvation, epidithiodiketopiperazine DC1149B (1) together with structurally related compounds, trichodermamide A (2) and aspergillazine A (3), were isolated from culture extract of marine-derived Trichoderma lixii. Compounds 1 exhibited potent selective cytotoxic activity against human pancreatic carcinoma PANC-1 cells cultured under glucose-starved conditions with IC50 values of 0.02 µM. The selective index of the compound 1 was found to be 35,500-fold higher for cells cultured under glucose-starved conditions than those under the general culture conditions. The mechanistic analysis indicated that compound 1 inhibited the response of the ER stress signaling. In addition, these effects of compound 1 could be mediated by inhibiting complex II in the mitochondrial electron transport chain.

Chemical composition, antioxidant and cytotoxic activity of Artemisia gmelinii essential oil growing wild in Kashmir valley.

The present study was carried to observe the phytochemical profile of aromatic constituents of Artemisia gmelinni essential oil using GC-FID, GC-MS and 13C NMR and to evalute anticancer and antioxidant activities. Twenty chemical constituents were detected from EO accounting 92.05% of total oil composition. Oxygenated monoterpenes (73.64%) were dominant class of compounds. The major constituents are isoascaridol (29.70%), alpha-terpinolene (25.37%), phellandrene (9.26%) and ascaridole (4.17%). Ascaridole and isoascaridole are first time identified to be the constituents of this essential oil. The essential oil effectively inhibit the growth of cancer cells and showed maximum anti-proliferative activity at 125µg/mL concentration, but highest inhibition in cell growth was found in A-549 cell line. Our study revealed that EO was effective in restricting the migration of A-549 cells up to 15% than control at 125 µg/mL concentration. The essential oil also showed moderate antioxidant activity.

An Evaluation of the DNA-Protective Effects of Extracts from Menyanthes trifoliata L. Plants Derived from In Vitro Culture Associated with Redox Balance and Other Biological Activities.

Menyanthes trifoliata L. is a valuable medical plant found in Europe, North America, and Asia, which grows on peat bogs and swamps. It has long been used in folk medicine as a remedy for various ailments. This is the first report to demonstrate the protective antioxidant and anti-inflammatory properties of aqueous methanolic extracts derived from the aerial parts (MtAPV) and roots (MtRV) of in vitro grown plants on human umbilical vein endothelial cells (HUVECs). It describes the influence of the tested extracts on the expression of antioxidant (HO-1, NQO1, NRF2, kEAP1, and GCLC) and inflammation-related genes (IL-1α, IL-1ß, IL-6, TNF-α, and IFN-γ) in cells stimulated with H2O2 or LPS, respectively. In addition, M. trifoliata extracts were found to moderately affect the growth of certain bacterial and fungal pathogens, with the strongest antibacterial effect found against Pseudomonas aeruginosa and Enterococcus faecalis. M. trifoliata extracts demonstrated protective effects against mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) damage caused by ROS, decreasing the numbers of mtDNA lesions in the ND1 and ND2 genes and nDNA damage in the TP53 and HPRT1 genes and reducing cleavage in PARP1- and γ-H2A.X-positive cells. The root extract of in vitro M. trifoliata (MtRV) appears to have better anti-inflammatory, antioxidant, antimicrobial, and protective properties than the extract from the aerial part (MtAPV). These differences in biological properties may result from the higher content of selected phenolic compounds and betulinic acid in the MtRV than in the MtAPV extract.

Amazon Fruits Inhibit Growth and Promote Pro-apoptotic Effects on Human Ovarian Carcinoma Cell Lines.

Murici (Byrsonima crassifolia (L.) Kunth and B. verbascifolia (L.) DC.) and tapereba (Spondias mombin) are Amazonian fruits that contain bioactive compounds. Biochemical and molecular characterization of these fruits can reveal their potential use in preventing diseases, including cancer. The extracts were characterized regarding the presence and profile of carotenoids by high-performance liquid chromatography (HPLC), total phenolic content by the Folin-Ciocalteu assay, and antioxidant activity by antioxidant value 2,2-diphenyl-1-picrylhydrazyl (DPPH) content analysis, 22,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) content analysis, Ferric-Reducing Ability of Plasma (FRAP), and Oxygen Radical Absorbance Capacity (ORAC) analysis. The extracts of tapereba and murici studied were important sources of total carotenoids and lutein, respectively. The extracts were then tested for their effect on the viability of the A2780 ovarian cancer (OC) cell line and its cisplatin (CDDP)-resistant derived cell line, called ACRP, by using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays. Their influence on cell cycle and apoptosis were analyzed by using flow cytometry. Murici and tapereba cell extracts exhibited a strong bioactivity by inhibiting A2780 and ACRP cell viability by 76.37% and 78.37%, respectively, besides modulating the cell cycle and inducing apoptotic cell death. Our results open new perspectives for the development of innovative therapeutic strategies using these Amazon fruit extracts to sensitize ovarian cancer cells to current chemotherapeutic options.

Glycation affects differently the main soybean Bowman-Birk isoinhibitors, IBB1 and IBBD2, altering their antiproliferative properties against HT29 colon cancer cells.

Naturally-occurring serine protease inhibitors of the Bowman-Birk family, particularly abundant in legume seeds, exert their potential chemopreventive and/or therapeutic properties via protease inhibition. Processing of legume seeds, including soybeans, has been proposed as a major cause for their loss of bioactivity due to glycation. In order to assess how glycation affected the protease inhibitory activities of major soybean Bowman-Birk isoinhibitors (BBI) and their antiproliferative properties, IBB1 and IBBD2 were purified and subjected to glycation under controlled conditions using glucose at high temperature. Both soybean isoinhibitors showed remarkable heat stability. In the presence of glucose, IBBD2 lost most of its trypsin inhibitory activity while IBB1 maintains similar trypsin and chymotrypsin inhibitory activities as in the absence of sugar. Glycation patterns of both BBI proteins were assessed by MALDI-TOF spectrometry. Our results show that the glycation process affects IBBD2, losing partially its antiproliferative activity against HT29 colon cancer cells, while glycated-IBB1 was unaffected.

Comparative assessment of phytochemical profiles and antioxidant and antiproliferative activities of kiwifruit (Actinidia deliciosa) cultivars.

The present study was designed to analyze and compare phytochemical activities of four different cultivars of kiwifruit. Among all investigated varieties, Hua You (HY) and Cui Xiang (CUX) displayed the maximum concentration of phytochemical content, and the highest total phenolic results were observed in HY and CUX cultivars with 220.20 ± 1.12 mg GAE/100 g and 218.04 ± 1.11 mg GAE/100 g FW, respectively. Likewise, the richest total flavonoids results were estimated in red kiwifruit (RKF) and CUX varieties with 49.082 ± 0.14 mg CE/100 g FW and 48.327 ± 0.14 mg CE/100 g FW, respectively. Moreover, tests for oxygen radical scavenging capacity (ORAC) and peroxyl radical scavenging capacity (PSC) were observed maximum in RKF cultivar showing 131.229 ± 5.91 µM Trolox equivalent/g FW and 85.957 ± 11.75 µM vitamin C equivalent/g FW, respectively. Furthermore, the highest cellular antioxidant activity (CAA) with No PBS wash protocol was depicted in RKF 237.544 ± 4.12 µM QE equivalent/g FW with the lowest EC50 0.0128 mg/ml. In addition, high-performance liquid chromatography (HPLC) analysis confirmed the presence of ferulic acid, naringin, gallic acid, syringic acid, caffeic acid, rutin, protocatechuic acid, salicylic acid, and catechin in kiwifruit. Catechin as one main content in our study is consistent with the recent reports. The result suggested that the phytochemical profile and bioactivities were significantly affected by the type of cultivars. PRACTICAL APPLICATIONS: Kiwifruit is widely consumed over the world for its rich nutritious and medicinal values. Currently, phytochemicals are considered as one of the main bioactive components of kiwifruits, which are responsible for lots of bioactivities, such as antitumor, anti-inflammatory, antioxidant, hypoglycemic, and hypolipidemic activities. There are varieties of kiwifruits, and the bioactive components and bioactivities are greatly affected by the cultivars. But there have been no comparative studies on the phytochemicals from different varieties. This study aimed to make a comprehensive assessments of the free, bound, and total phenolics and flavonoids, as well as the chemical-based and cell-based antioxidant activities of four different subspecies of kiwifruit. This work would be beneficial to elucidate the function differences of different kiwifruit phytochemicals, promote its further research, as well as provide a basis for selecting cultivars.