New Source Of Natural Antioxidants Research Articles

Phytochemical screening and antimicrobial activities of Periploca aphylla Decne, Persian walnut (Juglans regia L.) and oleander (Nerium indicum Mill.) Leaf extracts

Natural phenolic acids and their derivatives in plant extracts in addition to wide use in food industry, have also medicinal properties. In the present study, the antioxidant and antimicrobial activities of ethanol and water extracts of Periploca aphylla, Persian walnut and oleander leaves were evaluated using assays of 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, hydrogen peroxide scavenging activity and ferric-reducing capacity. In addition, total phenolic compounds, total flavonoids and anthocyanins content of the extracts were determined. The plants extracts showed different levels of antioxidant properties in various assays. The ethanol extracts, which have the highest amount of total phenolics and flavonoids, showed the highest antioxidant and antimicrobial activities in all assays, compared with water extracts. The extracts of P. aphylla were found to have the highest antioxidant potential, followed by Persian walnut and oleander extracts. The highest antimicrobial activity was found for both ethanol and aqueous extracts of P. aphylla, which showed the greatest effect on Gram-positive bacteria. The results suggest that the leaves of these plants specifically P. aphylla can be considered as a new source of natural antioxidant.

Microwave‐assisted extraction of phenolic compounds from Morus nigra leaves: optimization and characterization of the antioxidant activity and phenolic composition

AbstractBACKGROUNDMorus nigra (mulberry) fruit has been reported as a source of bioactive compounds, although information about their leaves is very limited. Usually, they are considered wastes and have been traditionally used only for tea preparation. The main objective of this work was to explore the valorization of mulberry leaves by polyphenols microwave‐assisted extraction (MAE) and characterization of their antioxidant activity and phenolic composition. A 23 factorial design combined with response surface methodology were applied to characterize the effect of main microwave parameters on total phenolic content (TPC).RESULTSThe optimized MAE conditions were 20 mL of ethanol:water (1:1; v/v), 120 °C, 28 min, 0.414 g and medium stirring speed. Under these conditions, TPC was 19.7 ± 2.0 mg gallic acid equivalents (GAE) g‐1 dry plant (DP), and antioxidant activity was 15.3 ± 1.0 mg ascorbic acid (AA) g‐1 DP (ferric reduction activity power –FRAP– assay), 18.6 ± 1.3 mg Trolox equivalents (TE) g‐1 DP (2,2‐diphenyl‐1‐picrylhydrazyl –DPPH– assay) and 186 ± 15 mg TE g‐1 DP (oxygen radical absorbance capacity –ORAC– assay). When compared with ultrasound extraction and Pharmacopeia reference method, MAE was more efficient, representing a valuable technology. Of the 13 compounds identified by HPLC, the most abundant were rutin, chlorogenic, β‐resorcylic and caffeic acids.CONCLUSIONThese results indicate that mulberry leaves are of potential interest for agro‐food industries as a new source of natural antioxidants. © 2017 Society of Chemical Industry

Diketopiperazines and 2H-pyran-2-ones with antioxidant activity from the rice fermented with Aspergillus luchuensis

Aspergillus luchuensis is widely used as a starter of saccharification in the koji industry, but no secondary metabolites have been reported from this fungus. Herein, we report the isolation and identification of four new diketopiperazine derivatives (1–4), one new methyl 4-(3-acetyl-2, 6-dihydroxyphenyl)-2-methoxybutanoate (5), and six known compounds (6–11) from the rice koji of A. luchuensis. The structures of 1–5 were determined by extensive spectral analysis including 1D and 2D NMR, HRESIMS, and CD, and ECD calculation. In antioxidant assays, compound 10 displayed moderate DPPH scavenging activity with an EC50 value of 60.8μM; compounds 1–4, 10 and 11 showed reducing ability with EC50 values ranging from 8.73 to 176.39μM. Compounds 1–11 showed no cytotoxicity against cell lines A549, K562, ASPC, and H460 at 200μM. Our current reports support the safety of A. luchuensis in food chemistry and confirm this fungus to be a new source of natural antioxidants.

Cistus incanus from Strandja Mountain as a Source of Bioactive Antioxidants.

The purpose of the present study is to survey the extraction conditions and explore the antioxidant potential of the wild herb Cistus incanus, which is non-traditional in Bulgarian ethnomedicine and widespread in the Strandja Mountain. The influence of the extraction time (0–500 min) and solvent composition (0–50% ethanol in water) on the polyphenols, flavonoid yields and on the antioxidant capacity of the extracts of leaves, stalks (wood parts) and bud mixture were studied. The antioxidant capacity (AOC) was evaluated by use of scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Total polyphenol and flavonoid contents were quantified using UV–vis (ultraviolet-visible) spectrophotometry. The optimal yield of the desired components was obtained with 30% ethanol in water solvent at the 390th min of extraction time. In addition, the influence of seasonality (winter and summer Cistus incanus), and of the different aerial parts—hard-coated seeds, buds, and a mixture of leaves and stalks of the wild plant—on the presence of polyphenols, flavonoids, and AOC were investigated. The present work revealed that the high values of polyphenols, flavonoids and the high AOC occurred not only in the summer leaves, but were also found in the winter leaves, hard-coated seeds, buds, and stalks. Based on the obtained results, the Cistus incanus from Strandja Mountain could be an excellent new source of natural antioxidants in food and for the pharmaceutical industries.

In-vitro radical scavenging activity of Daucus carota L. extracts

Background and objective Antioxidants play a vital role against the harmful effect caused by oxidative stress. The aim of the current study was to assess the antioxidant potential of methanol extracts of Daucus carota L. callus addend with an amino acid precursor, l-phenylalanine, under light and dark conditions. Materials and methods Callus cultures of petiole, stem, and root explants of D. carota L. in-vitro seedlings were implanted on calli maintenance medium fortified with 500 and 1000 mg/l l-phenylalanine as an amino acid precursor and then were incubated under light and dark conditions. The various prepared concentrations of D. carota L. callus crude extracts of petiole, stem, and root explants by maceration with 85% methanol were screened for possible antioxidant activity using 2, 2′-diphenyl 1-picrylhydrazyl radical scavenging test. Results and conclusion The present study re-cultured the induced calli from petiole, stem, and root explants of D. carota L. on the best selected medium [MS-medium supplemented with 1 mg/l benzylaminopurine (BAP)+2 mg/l naphthaleneaceticacid (NAA)] for callus cultures added with l-phenylalanine. The different concentrations (2, 4, 6, 8, 10, 12, 14, 16, and 18 mg/ml) of the prepared callus cultures extracts of stem, root, and petiole explants of D. carota L. have been tested for antioxidant effects. The results revealed that, under dark condition, 12 mg of petiole extract concentration exhibited the least concentration of methanol crude extract recording the greatest antioxidant activity (124.71%) on medium containing 1000 mg/l phenylalanine in comparison with other callus extracts. The results of this investigation revealed that calli of D. carota L. petiole explant should be incubated under dark condition, and their methanol crude extract ought to be used at a concentration of 12 mg. Hence, D. carota L. extract should be considered as a new source of natural antioxidant.

Antioxidant capacities and total phenolic contents of 30 flowers

In order to find new sources of natural antioxidants, total phenolic content (TPC) and total flavonoid content (TFC) of 30 flowers in their free, esterified and insoluble-bound forms were determined. Rosa rugosa Thunb (pink) showed the highest TPC, and Osmanthus fragrans had the highest TFC. The antioxidant activities of 30 flowers were determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), ferric reducing antioxidant power (FRAP), and trolox equivalent antioxidant capacity (TEAC) assays. Rosa rugosa Thunb (purple) and Rosa rugosa Thunb (pink) had the highest DPPH (612.79 and 544.75μmol Trolox/g DW), FRAP (273.10 and 301.14μmol Trolox/g DW) and TEAC (1013.71 and 937.19μmol Trolox/g DW) value. Furthermore, several phenolic compounds were detected using ultra performance liquid chromatography (UPLC) technique, and (+)-catechin, ferulic acid, isoquercitrin, and quercitrin were widely found in these flowers. The results implied that the flowers were important natural sources of bioactive components with higher antioxidant capacities for use in the food and pharmaceutical industries.

Cellular Antioxidant and Antiproliferative Activities of <i>Morchella conica</i> Pers. Polyphenols <i>in</i> <i>vitro</i>

This study analyzed the cellular antioxidant and antiproliferative activities, as well as the phenolic composition of three Morchella conica Pers. cultures. Results showed that the free phenolic contents of the three Morchella conica Pers. ranged from 4.928 to 6.157 mg GAE/g DW and their bound phenolic contents ranged from 0.188 to 0.250 mg GAE/g DW. Polyphenols in M. conica Pers. were dominated by phenolic acids, particularly for gallic acid. The free phenolic extracts exhibited higher cellular antioxidant activity than the bound phenolic extracts. Free phenolics in M. conica Pers. cultured from Yunnan China showed the highest antiproliferative activity against HepG2 cells, whereas bound phenolics in M. conica cultured from Tibet China showed the highest antiproliferative activity. Results confirmed that Morchella conica Pers. (growing in Yunnan China especially) could be a new source of natural antioxidant and a potential inhibitor for the growth of HepG2 cells.

Characterization of a novel polysaccharide isolated from Rosa roxburghii Tratt fruit and assessment of its antioxidant in vitro and in vivo

In this study, a novel water-soluble polysaccharide (RRTP1-1) was obtained from Rosa roxburghii Tratt fruit through the ultrasonic-assisted extraction followed by anion-exchange and size-exclusion chromatography purification. The primary structure of RRTP1-1 was investigated by UV, FT-IR, HPLC, GC−MS, 1H and 13C NMR spectroscopy. Chemical composition analysis revealed that RRTP1-1 had an average molecular weight of 97.58kDa and consisted of Man, Rha, GlcA, GalA, Glc, Gal, Ara and Xyl in a molar ratio of 2.88:1.39:2.83:1.00:69.11:3.04:2.52:3.41. This polysaccharide was proven to be a kind of glucan, owning a backbone structure of →6)-α-d-Glcp-(1→6)-α-d-Glcp-(1→. Congo red test indicated that RRTP1-1 had no triple helix structure. Antioxidation tests performed in vitro revealed that RRTP1-1 possessed obviously DPPH, hydroxyl and superoxide radicals scavenging activities. Furthermore, antioxidant assays in vivo showed that RRTP1-1 at 200 or 400mg/kg dose could significantly enhance the activities of antioxidant enzymes (CAT, SOD, and GSH-Px), increase TAOC values, and decrease the LPO and MDA levels in different degrees in the serum of D-Gal aging-induced mice. The present results suggested that RRTP1-1 could be a new source of natural antioxidants for applications in functional foods and dietary supplemental products.

Phytochemical, antimicrobial and antioxidant preliminary screening of a traditional Palestinian medicinal plant, Ononis pubescens L.

IntroductionAntibiotic resistance has become a serious global concern, and the discovery of novel antimicrobial herbal constituents may provide valuable solutions to overcome this problem. It is important to identify new sources of natural antioxidants and antimicrobials. The present study describes for the first time the antioxidant, and antibacterial activities of various fractions of Ononis pubescens L., a traditional Palestinian medicinal plant. MethodsAntimicrobial activity was tested against selected strains from American Type Culture Collection (ATCC) and clinical isolates including Shigella sonnie, Staphylococcus aureus, Entrococuss feacium, Escherichia coli, Pseudomonas aeruginosa, Methicillin Resistant Staphylococcus aureus (MRSA), Candida albicans and Epidermatophyto flacosum using minimum inhibitory concentration (MIC) assay, while antioxidant activity was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. ResultsA mixture of phytochemicals was found in all of the studied fractions of O. pubescens, which also showed remarkable potential with antioxidant and antimicrobial activities. ConclusionThe current study provides initial data that justify the use and importance of Ononis species in Palestinian folkloric medicine. Our results showed that Ononis pubescens n-hexane fraction has powerful antibacterial bioactivity against Staphylococcus aureus, as well as the acetone, n-hexane and methanol fractions which showed excellent potential against Epidermatophyto flacosum fungi, while the acetone fraction showed the highest antioxidant activity among other fractions. Further investigations are needed to identify and characterize these constituents.

ANTIOXIDANT ACTIVITIES OF MYCELIA AND BROTH FILTRATE EXTRACTS OF ASPERGILLUS SPP

The antioxidant activities of mycelia and broth filtrate ethyl acetate extracts produced from the cultures of 12 Aspergillus spp. were investigated. Extracts showed a concentration-dependent antioxidant activity by inhibiting DPPH radicals. Broth filtrate extracts showed higher activity than mycelia filtrate extracts. A. fumigatus showed the best activity (with 92.5% inhibition at the concentration of 0.8 mg ml-1). The extracts exhibited potent nitric oxide-scavenging activity. Broth filtrate extract of A. fumigatus showed the best activity (with 79.6 % inhibition at 1.6 mg ml-1) followed by the A. ostianus and A. terreus. Reducing powers of extracts also increased with the increases in their concentrations. Two broth filtrate extracts, A. terreus and A. fumigatus, have shown potent reducing power. In chelating ability, mycelia filtrate extracts showed higher activity. A. flavus showed the best activity (with 49.1% inhibition at 1.6 mg ml-1). The present study demonstrates the potential of soil fungi to have antioxidant activity similar to plants and represent them as new sources of natural antioxidants.

Potato and Ginger Peels: A potential new source of natural antioxidants

Potato and Ginger Peels: A potential new source of natural antioxidants

Jackfruit (Artocarpus heterophyllus Lam.) peel: A better source of antioxidants and a-glucosidase inhibitors than pulp, flake and seed, and phytochemical profile by HPLC-QTOF-MS/MS

Jackfruit (Artocarpus heterophyllus Lam.) peel is an underutilized by-product in both, the production and processing of jackfruit. This research compared the antioxidant and hypoglycemic potential of jackfruit peel with jackfruit pulp, flake and seed for the first time. The phytochemical profile of peel extract was characterized with HPLC-QTOF-MS/MS. Results revealed that peel extract exhibited the highest total phenolic and total flavonoid content, and the phenolics was 4.65, 4.12 and 4.95 times higher than that of pulp, flake and seed extract, respectively. The strongest DPPH and ABTS+ scavenging ability, α-glucosidase inhibition were also found in peel extract, and the α-glucosidase inhibition was about 11.8-fold of that of acarbose. The HPLC-QTOF-MS/MS analysis led to the tentative identification of 53 compounds, prenylflavonoids, hydroxycinnamic acids and glycosides are the predominant bioactive compounds. Above results reveal promising potential of jackfruit peel as a new source of natural antioxidants and hypoglycemic agents.

Effects of microwaves, hot air and freeze-drying on the phenolic compounds, antioxidant capacity, enzyme activity and microstructure of cacao pod husks (Theobroma cacao L.)

Abstract The cacao pod husk (CPH) is the primary waste byproduct of the chocolate industry. One ton of cacao beans generate approximately ten times that amount of fresh CPH. The husk is rich in phenolic compounds. The aim of this study is to determine the effects of microwaves, hot air and freeze-drying on the phenolic compound content, antioxidant capacity, enzyme activity and microstructure of CPH. The results showed that fresh CPH contain 323.7 ± 26.5 mg gallic acid equivalents (GAE)/100 g dry mass (d.m.) of total phenolic compounds, and dehydration had a positive effect on the CPH phenolic content and antioxidant capacity. Catechin, quercetin, and (−)-epicatechin and gallic, coumaric and protocatechuic acids were identified in fresh and dried CPH. Drying the material using a microwave and freeze-drying preserved the husk microstructure. The results showed that microwave drying was a better drying method than hot air and as good as freeze-drying. Industrial relevance The food industry is currently searching for new sources of natural antioxidants. The cacao pod husk (CPH) is a good source of phenolic compounds that can function as antioxidants and could be used as ingredients in functional foods. However, due to their high water content, fresh CPH are perishable products, and for this reason, the first step would be dry the pod husk to improve its shelf life. The findings of this study showed that the use of microwaves to dry CPH may release polyphenols, thereby enhancing the antioxidant capacity and decreasing the polyphenol oxidase (PPO) activity while maintaining the microstructure. Thus, microwave drying could be of interest as a method for enhancing the extractability of phenolic compounds from CPH.

Antioxidant and free radical scavenging activities of taxoquinone, a diterpenoid isolated from Metasequoia glyptostroboides

Nowadays, there is an upsurge of interest on finding effective phyto-constituents as new sources of natural antioxidants for using in food and pharmaceutical preparations. However, this study was carried out to investigate the antioxidant and free radical scavenging efficacy of a biologically active diterpenoid compound taxoquinone isolated from Metasequoia glyptostroboides in various antioxidant models. An abietane type diterpenoid taxoquinone, isolated from ethyl acetate cone extract of Metasequoia glyptostroboides, was analyzed for its antioxidant efficacy as reducing power ability and its ability to scavenge free radicals such as 1,1-diphenyl-2-picryl hydrazyl (DPPH), nitric oxide, superoxide and hydroxyl radicals. As a result, taxoquinone showed significant and concentration-dependent antioxidant and free radical scavenging activities of DPPH, nitric oxide, superoxide and hydroxyl free radicals by 78.83%, 72.42%, 72.99% and 85.04%, as compared to standard compounds ascorbic acid (81.69%, 74.62%, 73% and 73.79%) and α-tocopherol/butylated hydroxyanisole (84.09%, 78.61%, 74.45% and 70.02%), respectively. These findings justify the biological and traditional uses of M. glyptostroboides or its secondary metabolite taxoquinone as confirmed by its promising antioxidant and free radical scavenging activities.

Antioxidant content and activity in different parts of pomelo [Citrus grandis (L.) Osbeck] by-products

This study aimed to investigate the total antioxidant content and activity in different parts of pomelo by-products, namely flavedo, albedo and segment membrane. Total phenolic content (TPC) was determined using Folin-Ciocalteu method while total flavonoid content (TFC) was determined using aluminium chloride colorimetric method. The total antioxidant activity was determined by performing DPPH free radical scavenging assay and ferric ion reducing antioxidant power (FRAP) assay. Albedo possessed the highest TPC and TFC while flavedo demonstrated the highest antioxidant activity in both assays as compared to other tissues. Pearson correlation tests revealed that there were no correlations between TPC and EC50 as well as FRAP value. There was also a lack of relationship between TFC and antioxidant activity as determined in DPPH and FRAP assays. The pomelo by-products of 'Ledang' possessed higher antioxidant properties than previous studies and therefore can be considered as a new source of natural antioxidants.

Antioxidant activity of three microalgae Dunaliella salina, Tetraselmis chuii and Isochrysis galbana clone Tahiti

Natural alternatives antioxidant source has become a trending topic in the past decades to replace synthetic antioxidant. Microalgae have been mentioned to show interesting bioactive properties and one of them is its antioxidant activity. This study aims to evaluate the potential of three microalgae Dunaliella salina, Tetraselmis chuii and Isochrysis galbanaas new source of natural antioxidant. Proximate analysis and total phenolic content of D. salina, T. chuii and I. galbanas were determined. Antioxidant activity of methanolic extracts of these three species prepared in different concentration (50, 100, 250, 500, and 1000 ppm) was performed through DPPH assay. I. galbana clone Tahiti demonstrated a highest antioxidant potential with 61.64 of inhibition at 50 ppm followed by D. salina with 58.45 % of inhibition and T. chuii with 52.58 % of inhibition. I. galbana clone Tahiti was the best antioxidant with total phenol content of 17.798 mg GAE g-1 extract at 50 ppm; followed by T. chuii 16.868 mg GAE g-1 extract and the lowest was D. salina with 4.672 mg GAE g-1 extract. Results suggest that these microalgae posses antioxidant potential which could be considered for future applications in medicine, dietary supplements, cosmetics or food industries.

Quantification of Antioxidant Phenolic Compounds in a New Chrysanthemum Cultivar by High-Performance Liquid Chromatography with Diode Array Detection and Electrospray Ionization Mass Spectrometry.

The flowers of Chrysanthemum morifolium Ramat. have been used as an herbal tea and in traditional medicine, and the plant has been developed to produce horticultural cultivars of various colors and shapes. In this study, a new chrysanthemum cultivar with dark purple petals (C. morifolium cv. ARTI-Dark Chocolate; ADC) was developed by radiation-induced mutation breeding of its original cultivar with purple striped white petals (C. morifolium cv. Noble Wine, NW). The phenolic profile and antioxidant property of ADC were investigated and compared with NW and the commercially available medicinal herb, C. morifolium with yellow petals (CM), in order to find a scientific support to produce a new source of natural antioxidant. Flavonoid and phenolic acid profiles of the ethanol extracts of the three flowers were analyzed by high-performance liquid chromatography-diode array detector-electrospray ionization mass spectrometry (HPLC-DAD-ESIMS), while antioxidant properties were evaluated using the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay. Among the tested flowers, ADC possessed the strongest antioxidant capacity and the highest phenolic contents. Flavonoids (acacetin, apigenin, luteolin, acacetin-7-O-β-glucoside, apigenin-7-O-β-glucoside, luteolin-7-O-β-glucoside, and linarin) and phenolic acids (chlorogenic acid and mixture of 1,4-, 1,5-, and 3,5-dicaffeoylquinic acids) were identified and quantified.

Phytochemical, Antioxidant and Photo-Protective Activity Study of Bunga Kantan (Etlingera elatior) Essential Oil

The three main objectives of this study were to evaluate the extracted essential oil in terms of total phenolic and flavonoids contents, radical scavenging activity and sun protection factor. The antioxidant activity of the essential oil was determined by using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity while the content of total phenol was determined by using Folin-Ciocalteu reagent. Aluminium chloride colorimetric method was used for flavonoid content determination while photo-protective potential was determined by using Mansur’s sun protection factor (SPF) value. The extracted essential oil was found to contain low levels of total phenolic contents (2.30±0.003 µg/g as garlic acid equivalent) and total flavonoid contents (254.99±0.64 µg/g as quercetin equivalent) respectively. DPPH free radical scavenging activity of the essential oil was 40.73%±1.32 at 200µg/ml. The Mansur’s equation of sun protective factor showed that the essential oil possesses some sun protective potentials. This study suggests that the essential oil from Etlingera elatior could be potentially used as a new source of natural antioxidant and ingredient that can be incorporated into the sunscreen cosmetic products.

Antioxidant potential, tannin and polyphenol contents of seed and pericarp of three Coffea species.

To investigate the antioxidant activity, total phenolic and total tannin content of the pericarp and the seed of Coffea benghalensis (C.benghalensis) and Coffea liberica compared to Coffea arabica (C.arabica). The antioxidant potential, total tannin and polyphenol contents of the immature and mature seed and pericarp of C.benghalensis and Coffea liberica were quantified and compared to C.arabica. Enhanced chemiluminescence (ECL), 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity, Folin-Ciocalteau method and total tannin content assays were used. Trolox equivalent (TE/g plant material) values obtained by ECL and DPPH methods showed loose correlation (r(2)=0.587) while those measured by oxygen radical absorbance capacity assay were higher without correlation in each plant. A closer correlation was detected between the ECL method and the percentage antioxidant activity of the DPPH technique (r(2)=0.610 7) in each species, however the immature pericarp of C.benghalensis showed much higher DPPH scavenging potential than was seen in the ECL assay. The immature pericarp of C.benghalensis expressed the highest tannin and polyphenol content, and a high polyphenol level was also detected in the immature seed of C.arabica. The immature pericarp of Bengal and Liberian coffees showed the largest amount of phenolic contents. The obtained data highlight the potential role of C.benghalensis as a new source of natural antioxidants and polyphenols compared to C.arabica.

Phenolic acid content, antioxidant and cytotoxic activities of four Kalanchoë species.

Phenolic acid composition, antioxidant, and cytotoxic activities in leaves of four Kalanchoe (Crassulaceae) species were evaluated. Determination of phenolic acid contents were conducted by an optimized LC–ESI-MS/MS method. The results show that Kalanchoe daigremontiana Raym.-Hamet & H. Perrier (using ASE extraction) and Kalanchoe pinnata (Lam.) Pers. contain the highest amounts of phenolic acids, while Kalanchoe nyikae Engl. the lowest ones. Among phenolic acids ferulic, caffeic and protocatechuic acids were occurring in the highest quantities in the analysed species. The greatest amounts of ferulic and protocatechuic acids were found in K. daigremontiana and K. pinnata. Moreover, the antiradical and cytotoxic activities of Kalanchoe extracts were investigated. All tested extracts possessed antioxidant activity. The obtained IC50 values (μg/mL) ranged from 49.9 μg/mL to 1410 μg/mL, indicating a large variation of the activity of the analysed extracts. Cytotoxicity assays revealed dose-dependent effects in the cells lines tested. Only K. pinnata extract showed a high cytotoxicity against the H-9 human T cell line. Other extracts (K. daigremontiana, Kalanchoe milloti, K. nyikae) showed more pronounced cytotoxicity towards J45.01 cells (human acute lymphoblastic leukaemia T cells).The present study demonstrated that Kalanchoe extracts have significant antioxidant and cytotoxic effects. This suggests that these species can be used as new sources of natural antioxidants and potential anticancer compounds.