Mycotoxin Production in Liquid Culture and on Plants Infected with Alternaria spp. Isolated from Rocket and Cabbage

Fungi belonging to the genus Alternaria are common pathogens of fruit and vegetables with some species able to produce secondary metabolites dangerous to human health. Twenty-eight Alternaria isolates from rocket and cabbage were investigated for their mycotoxin production. Five different Alternaria toxins were extracted from synthetic liquid media and from plant material (cabbage, cultivated rocket, cauliflower). A modified Czapek-Dox medium was used for the in vitro assay. Under these conditions, more than 80% of the isolates showed the ability to produce at least one mycotoxin, generally with higher levels for tenuazonic acid. However, the same isolates analyzed in vivo seemed to lose their ability to produce tenuazonic acid. For the other mycotoxins; alternariol, alternariol monomethyl ether, altenuene and tentoxin a good correlation between in vitro and in vivo production was observed. In vitro assay is a useful tool to predict the possible mycotoxin contamination under field and greenhouse conditions.     

Mycotoxin Profile and Phylogeny of Pathogenic Alternaria Species Isolated from Symptomatic Tomato Plants in Lebanon

The tomato is one of the most consumed agri-food products in Lebanon. Several fungal pathogens, including Alternaria species, can infect tomato plants during the whole growing cycle. Alternaria infections cause severe production and economic losses in field and during storage. In addition, Alternaria species represent a serious toxicological risk since they are able to produce a wide range of mycotoxins, associated with different toxic activities on human and animal health. Several Alternaria species were detected on tomatoes, among which the most important are A. solani, A. alternata, and A. arborescens. A set of 49 Alternaria strains isolated from leaves and stems of diseased tomato plants were characterised by using a polyphasic approach. All strains were included in the recently defined phylogenetic Alternaria section and grouped in three well-separated sub-clades, namely A. alternata (24 out of 49), A. arborescens (12 out of 49), and A. mali morpho-species (12 out of 49). One strain showed high genetic similarity with an A. limoniasperae reference strain. Chemical analyses showed that most of the Alternaria strains, cultured on rice, were able to produce alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT) and tenuazonic acid (TA), with values up to 5634, 16,006, 5156, and 4507 mg kg⁻¹, respectively. In addition, 66% of the strains were able to co-produce simultaneously the four mycotoxins investigated. The pathogenicity test carried out on 10 Alternaria strains, representative of phylogenetic sub-clades, revealed that they were all pathogenic on tomato fruits. No significant difference among strains was observed, although A. alternata and A. arborescens strains were slightly more aggressive than A. mali morpho-species strains. This paper reports new insights on mycotoxin profiles, genetic variability, and pathogenicity of Alternaria species on tomatoes.     

Isolation and characterization of ellagic acid derivatives isolated from Casearia sylvestris SW aqueous extract with anti-PLA2 activity

The Casearia sylvestris SW (Flacourtiaceae) is utilized in folk medicine (Brazil and all Latin American) to treat several pathologic processes as inflammation, cancer, microbial infection and snake bites. Studies showed that C. sylvestris aqueous extract can inhibit many toxic effects caused by snake venoms (or caused by phospholipase A₂ isolated) from different species, mainly of Bothrops genus. Inhibition of enzymatic and myotoxic activities, decrease of edema formation and increase of the survival rate of rats injected with lethal doses of bothropic venoms are some toxic effects inhibited by C. sylvestris. In this study, four ellagic acid derivatives from aqueous extracts of C. sylvestris were isolated, characterized, and tested against effects from both total venom and PLA₂ (Asp 49 BthTX-II) from the venom of Bothrops jararacussu. The isolated compounds were as follows: ellagic acid (A), 3′-O-methyl ellagic acid (B), 3,3′-di-O-methyl ellagic acid (C), 3-O-methyl-3′,4′-methylenedioxy ellagic acid (D). The inhibition constant values (Ki) for enzymatic activity, as well the IC₅₀ values found in the edematogenic and myotoxic activities, indicate that the ellagic acid is the best inhibitor of these activities, while compounds C and D are the substances with lowest capacity on inhibiting these same effects. Our results show that the presence of hydroxyls at position 3 or 3′ (compounds A and B) increases the capacity of these derivatives on inhibiting these toxic effects. However, the presence of methoxyl groups at position 3 or 3′ reduced, but did not completely inhibit the capacity of compounds C and D on inhibiting all the toxic effects studied.     

Presence of phthalate derivatives in the essential oils of a medicinal plant Achillea tenuifolia

Background

Phthalate, esters of phthalic acid, are mainly applied as plasticizers and cause several human health and environment hazards. The essential oils of Achillea species have attracted a great concern, since several biological activities have been reported from varieties of these medicinal species. On the other side, due to the problems regarding the waste disposal in developing countries, phthalate derivatives can easily release from waste disposal to the water and soil resulting in probable absorption and accumulation by medicinal and dietary plants. As a matter of fact, although the toxicity of phthalate derivatives in human is well-known, food crops and medicinal plants have been exposing to phthalates that can be detected in their extracts and essential oils. Achillea tenuifolia (Compositea) is one of these herbaceous plants with traditional applications which widely growing in Iran.

Finding

The plant root was subjected to hydro-distillation for 4 h using Clevenger type apparatus to obtain its essential oil before and after acid treatment. Both of the hydro-distilled essential oils were analysed by GC-MS method resulted in recognition of their constituent. Phthalate contamination as (1, 2-benzenedicarboxylic acid, bis (2-methylpropyl) ester (5.4%) and phthalic acid (4.5%), were identified in the first and second extracted oils, respectively.

Conclusion

As a warning, due to the potential role of phthalates to cause reproductive toxicity, disturb of endocrine system and causing cancers, medicinal plants have to be considered through quality control for detection of these compounds.     

Echinacea and its alkylamides: Effects on the influenza A-induced secretion of cytokines,chemokines, and PGE2 from RAW 264.7 macrophage-like cells

The goal of this study was to determine whether extracts and isolated alkylamides from Echinacea purpurea would be useful for prevention of the inflammatory response that accompanies infections with H1N1 influenza A. Seventeen extracts and 4 alkylamides were tested for the ability to inhibit production of cytokines, chemokines, and PGE₂ from RAW 264.7 macrophage-like cells infected with the H1N1 influenza A strain PR/8/34. The alkylamides undeca-2Z,4E-diene-8,10-diynic acid isobutylamide, dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamide, dodeca-2E,4E-dienoic acid isobutylamide, and undeca-2E-ene-8,10-diynoic acid isobutylamide suppressed production of TNF-α and PGE₂ from infected cells. Dodeca-2E,4E-dienoic acid isobutylamide was especially effective at inhibiting production of these mediators and also strongly inhibited production of G-CSF, CCL2/MCP-1, CCL3/MIP-1α and CCL5/RANTES. In contrast, the ethanol extracts (75%), which were prepared from dormant roots of E. purpurea grown in different locations throughout North Carolina, displayed a range of effects from suppression to stimulation of mediator production. Precipitation of the extracts with ethanol removed the stimulatory activity, however, even after precipitation; many of the extracts did not display any suppressive activity. Analysis of the extracts revealed slight variations in concentration of alkylamides, caftaric acid, and cichoric acid, but the activity of the extracts did not strongly correlate with concentrations of these compounds. Our in vitro experiments suggest that E. purpurea extracts have the potential for use in alleviating the symptoms and pathology associated with infections with influenza A; however, further study will be necessary to define procedures necessary to unmask the alkylamide activity in crude extracts.     

Determination of breviflavone A and B in Epimedium herbs with liquid chromatography–tandem mass spectrometry

Two new types of minor flavonoids, breviflavone A and B, have been recently isolated and identified from Epimedium brevicornu in our previous research. Breviflavone B is a novel flavonoid with potent and specific estrogen receptor (ER) bioactivity. Its positional isomer, breviflavone A, is not ER active. Therefore, it is important to determine the two minor components, breviflavone A and B, in Epimedium herbs. In this report, a robust method for measurement of the two breviflavones in Epimedium ethanolic extracts has been developed by using liquid chromatography tandem mass spectrometry via selected-reaction monitoring (m/z 437 → m/z 367 for breviflavone A and m/z 437 → m/z 351 for breviflavone B) under negative electrospray ionization mode. This method has been successfully used to determine the two breviflavones in ethanolic herbal extracts of five major Epimedium species (E. brevicornu, E. koreanum, E. pubescens, E. sagittatum, and E. wushanese) from various sources. The contents of the two breviflavones range from 0.0181 to 0.1791% for breviflavone A and 0.0026 to 0.0252% for breviflavone B in the dried ethanolic extracts of those Epimedium herbal samples.     

Toxic dinoflagellates (Dinophyceae) from Rarotonga, Cook Islands

Dinoflagellate species isolated from the green calcareous seaweed, Halimeda sp. J.V. Lamouroux, growing in Rarotongan lagoons, included Gambierdiscus australes Faust & Chinain, Coolia monotis Meunier, Amphidinium carterae Hulburth, Prorocentrum lima (Ehrenberg) Dodge, P. cf. maculosum Faust and species in the genus Ostreopsis Schmidt. Isolates were identified to species level by scanning electron microscopy and/or DNA sequence analysis. Culture extracts of G. australes isolate CAWD149 gave a response of 0.04 pg P-CTX-1 equiv. per cell by an N2A cytotoxicity assay (equivalent to ca 0.4 pg CTX-3C cell⁻¹). However, ciguatoxins were not detected by LC-MS/MS. Partitioned fractions of the cell extracts potentially containing maitotoxin were found to be very toxic to mice after intraperitoneal (i.p.) injection. A. carterae was also of interest as extracts of mass cultures caused respiratory paralysis in mice at high doses, both by i.p. injection and by oral administration. The Rarotongan isolate fell into a different clade to New Zealand A. carterae isolates, based on DNA sequence analysis, and also had a different toxin profile. As A. carterae co-occurred with G. australes, it may contribute to human poisonings attributed to CTX and warrants further investigation. A crude extract of C. monotis was of low toxicity to mice by i.p. injection, and an extract of Ostreopsis sp. was negative in the palytoxin haemolysis neutralisation assay.     

Inhibition of Lung Inflammation by Acanthopanax divaricatus var. Albeofructus and Its Constituents

In order to find potential therapeutic agents on lung inflammatory conditions, the extracts of Acanthopanax divaricatus var. albeofructus were prepared and its constituents were isolated. They include lignans such as (+)-syringaresinol (1), acanthoside B (2), salvadoraside (3) and acanthoside D (4), lariciresinol-9-O-β-D-glucopyranoside (5) and phenylpropanoids such as 4-[(1E)-3-methoxy-1-propenyl]phenol (6), coniferin (7), and methyl caffeate (8). The extracts and several constituents such as compound 1, 6 and 8 inhibited the production of inflammatory markers, IL-6 and nitric oxide, from IL-1β-treated lung epithelial cells and lipopolysaccharide (LPS)-treated alveolar macrophages. Furthermore, the extracts and compound 4 significantly inhibited lung inflammation in lipolysaccharide-treated acute lung injury in mice by oral administration. Thus it is suggested that A. divaricatus var. albeofructus and its several constituents may be effective against lung inflammation.     

A New Flavonoid C-Glycoside from Celtis australis L. and Celtis occidentalis L. Leaves and Potential Antioxidant and Cytotoxic Activities

A major development over the past two decades has been the realization that free radical induced lipid peroxidation and DNA damage are associated with major health problems, e.g. cancer and ageing. Plant-derived antioxidants are increasingly found beneficial in protecting against these diseases. Celtis australis L. and Celtis occidentalis L. are two plants that have a variety of uses in folk medicine but have not been evaluated before for their antioxidant and cytotoxic properties. Therefore, the extracts of both plants’ leaves were investigated for these activities, as well as isolation of the bioactive compounds responsible for the activities. Molecular structures of the compounds were elucidated by UV, HRESIMS, 1D (¹H and ¹³C) and 2D (¹H-¹³C HSQC and ¹H-¹³C HMBC) NMR analyses. The ethanolic and aqueous extracts, n-butanol fractions and the isolated major compound were tested for their antioxidant activity using DPPH radical scavenging assay, xanthine oxidase-induced generation of superoxide radical and lipid peroxidation assay by thiobarbituric acid-reactive substances (TBARS) method using rat tissue homogenates. Cytotoxic activities were studied using standard MTT assay. A novel flavonoid C-triglycoside, 4‴-α-rhamnopyranosyl-2″-O-β-d-galactopyranosylvitexin, was isolated from both plants’ leaves, together with seven known flavonoids. The n-butanol fractions and the major compound 2″-O-β-galactopyranosylvitexin showed significant antioxidant activities, more pronounced than the tested standards BHT and dl-α-tocopherol in most tests. All extracts showed variable cytotoxic activities. This study provides strong evidence for the antioxidant and cytotoxic activities of the extracts of Celtis australis L. and Celtis occidentalis L. leaves, which were attributed to the polar n-butanol fractions and the major isolated flavonoid 2″-galactosylvitexin.     

Liquid chromatography/tandem mass spectrometry study of anti-inflammatory activity of Plantain (Plantago L.) species

To evaluate anti-inflammatory activity of selected Plantago species (P. lanceolata L. and P. major L.) an optimized in vitro test for determination of cyclooxygenase-1 (COX-1) and 12-lipoxygenase (12-LOX) inhibition potency was undertaken. By using intact cell system (platelets) as a source of COX-1 and 12-LOX enzymes and highly sensitive and specific LC–MS/MS technique for detection of main arachidonic acid metabolites formed by COX-1 and 12-LOX, this test provides efficient method for evaluation of anti-inflammatory potential of plant extracts and isolated compounds. Our results validated the well-known COX-1 inhibitory activity of P. lanceolata and P. major methanol extracts (concentration required for 50% inhibition (IC₅₀) was 2.00 and 0.65 mg/ml, respectively). Furthermore, 12-LOX inhibitory activity of examined extracts was reported for the first time (IC₅₀ = 0.75 and 1.73 mg/ml for P. lanceolata and P. major, respectively). Although renowned inhibitors, such as acetylsalicylic acid and quercetin showed higher activity, this study verifies P. lanceolata and P. major as considerable anti-inflammatory agents.     

Toxicity assessment of crude and partially purified extracts of marine Synechocystis and Synechococcus cyanobacterial strains in marine invertebrates

Among the Cyanoprokaryota, the genera Synechocystis and Synechococcus have rarely been studied with respect to potential toxicity. This is particularly true with marine environments where studies about the toxicity of cyanobacteria are restricted to filamentous forms at the warmer temperate and tropical regions and also to filamentous forms at cold seas such as the Baltic Sea. In this study, we describe the effects of cyanobacterial strains of the Synechocystis and Synechococcus genera isolated from the marine coast of Portugal, on marine invertebrates. Crude and partially purified extracts at a concentration of 100 mg/ml of freeze-dried material of the marine strains were tested for acute toxicity in nauplii of the brine shrimp Artemia salina, in the rotifer Brachionus plicatillis and in embryos of the sea urchin Paracentrotus lividus and the mussel Mytilus galloprovincialis. The cyanobacterial extracts, especially the crude extract, had an impact on A. salina nauplii. No significant toxic effects were registered against the rotifer. A negative impact of all strains was recorded on the embryonic development of the sea urchin, with toxic effects resulting in an inhibition of embryogenesis or development of smaller larvae. To the mussel embryos, the effects of cyanobacterial extracts resulted in a complete inhibition of embryogenesis. The results of all assays indicate that Synechocystis and Synechococcus marine strains contained toxic compounds to marine invertebrates.     

Evaluation of cytotoxic and apoptotic effects of the extracts and phenolic compounds of Astragalus globosus Vahl and Astragalus breviflorus DC

Astragalus L. is a genus member of the Fabaceae family, representing about 3,000 species all over the world and 380 species in Turkey. Astragalus species have been used in traditional medicine for many years. Astragalus globosus Vahl, known as “top geven”, is a dwarf, scapose, perennial herb, Astragalus breviflorus DC., known as “yünlü geven”, is an extremely spiny dwarf shrub. These endemic species grow in the Turkish cities of Erzurum, Kars, and Van. This is the first phytochemical and cytotoxic investigation of Astragalus globosus Vahl and Astragalus breviflorus DC. The main extracts and sub-fractions from the plants were evaluated for in vitro cytotoxic and apoptotic activities. The IC₅₀ values of dichloromethane, n-butanol, and water extracts of the aerial parts of A. globosus against the MCF-7 cell line were determined as 28.39, 868.60, and 1753.00 µg/mL. The values for the MDA-MB-231 cell line were 264.00, 620.30, and 1300.50 µg/mL, respectively. From A. globosus, the following were isolated: a flavone glycoside, diosmetin-7-O-rutinoside (1); and two flavonol glycosides, isorhamnetin-3-O-rutinoside (2) and quercetin-3-O-galactoside (3). From A. breviflorus, two phenolic acids, caffeic acid (4) and chlorogenic acid (5), and a flavan-3-ol, catechin (6), were isolated. Diosmetin-7-O-rutinoside was isolated from Astragalus species for the first time and showed the highest cytotoxic activities on the MCF-7 and MDA-MB-231 breast cancer cell lines with IC₅₀ values of 13.65 and 12.89 μg/mL, respectively. Moreover, we observed that diosmin exerts cytotoxic effects by causing cell necrosis.     

Toxicity evaluation of some traditional African spices on breast cancer cells and isolated rat hepatic mitochondria

Background

Fagara leprieuri (FL), Fagara xanthoxyloïdes (FX), Mondia whitei (MW) and Xylopia aethiopica (XA) are used in many African countries as food spices or in traditional medicine to treat several maladies. In this work, we (a) investigate whether the crude spice extracts present selective cytotoxicity for breast cancer cell lines and (b) investigate whether the same extracts affect the bioenergetics and calcium susceptibility of isolated liver mitochondrial fractions.

Results

All extracts were cytotoxic to the cell lines studied, with the exception of MW, which was less toxic for a normal cell line. Interestingly, some of the extracts did not depolarize mitochondria in intact breast cancer MCF-7 cells, although this effect was observed in a normal breast cancer cell line (MCF-12A). All extracts increased hepatic mitochondrial state 2/4 respiration and decreased the respiratory control ratio and the transmembrane electric potential. Also, the extracts induced the mitochondrial permeability transition (MPT).

Conclusions

Mitochondrial toxicity may be part of the mechanism by which the spices tested cause inhibition of proliferation and death in the cell lines tested. This study also warrants caution in the excessive use of these spices for human consumption.     

Antioxidant Activity in the Extracts of Two Edible Aroids

Two neglected species of Araceae, Alocasia macrorhiza (Linn.) G. Don and Alocasia fornicata (Roxb.) Schott are important as food and ethno medicine in Asia and Africa. Their bioefficacy is documented in the Ayurveda. The solvent extracts of different edible parts of these two species like rhizomes, leaves, roots and stolons were screened for in vitro antioxidant properties using standard procedures. The successive extracts in hexane, benzene, toluene, chloroform, diethyl ether, ethyl acetate and water fraction exhibited IC₅₀ values in the following order, roots>rhizome>leaves for Alocasia macrorhiza and leaves>stolon for Alocasia fornicate, respectively in 2,2-diphenyl-1-picryl hydrazyl antioxidant inhibition assay. Maximum antioxidant activity was observed in diethyl ether extracts for both species. The IC₅₀ values were comparable with those of quercetine and ascorbic acid as standards. These results suggest that the two aroid species have antioxidant activity in their edible parts and should be extracted using diethyl ether solvent.     

Evaluation of Antitumor and Antioxidant Activity of Melothria heterophylla (Lour.) Cogn

Melothria heterophylla (Lour.) Cogn., (family-Cucurbitaceae) popularly known as kundari, has been shown to exhibit antioxidant effects. The main objective was to isolate active constituents of the plant extract. In this study, the ability of M. heterophylla to induce apoptosis was studied in Ehrlich ascites carcinoma cells. Treatment of the Ehrlich ascites carcinoma cells with a variety of concentrations of the ethanol extracts of M. heterophylla and gallic acid (100-1000 μM), to determine the sequences of events marked by apoptosis, assayed by the spectrofluorometric method. Gallic acid and rutin were isolated from plant extract which were quantified by high-performance liquid chromatography. Our results indicate that ethanol extracts of M. heterophylla and gallic acid-induced apoptotic cell death in a dose dependent manner could be due to the generation of reactive oxygen species, especially H₂O₂, which is confirmed by caspase 3 activation. Treatment of Ehrlich ascites carcinoma bearing Swiss albino mice with varied doses (200 and 400 mg/kg, b.w.) of plant extract significantly reduced tumor volume and viable tumor cell count and improved hemoglobin content, RBC count, mean survival time, tumor inhibition, and percentage life span. The enhanced antioxidant status in extract-treated animals were evident from the decline in the levels of lipid peroxidation and increased levels of glutathione, catalase, and superoxide dismutase. The data suggest that M. heterophylla exerts anticancer activity, valuable for application in food and drug products.     

Quercus infectoria. Oliv.

Abstract

Bacterial resistance to antibiotics is enhanced by unrestricted use of such drugs. In addition, stimulating effects of certain antibiotics on the production of verocytotoxin by enterohemorrhagic Escherichia coli. have been reported. The aim of this communication was to report a medicinal plant species that is effective against a broad range of bacteria of clinical importance including Acinetobacter baumannii., Bacillus cereus., Enterobacter faecalis., Escherichia coli., Helicobacter pylori., Klebsiella pneumoniae., Listeria monocytogenes., Pseudomonas aeruginosa., Salmonella. spp., Shigella flexneri., Staphylococcus aureus., Streptococcus mutans., and Streptococcus pyogenes.. Ethanol extracts of Quercus infectoria. Oliv. (Fagaceae) demonstrate a broad spectrum of activity against all bacterial species tested. Detailed studies were carried out on clinical isolates of pathogens commonly presenting problems with the use of antibiotics, including enterohemorrhagic Escherichia coli. (EHEC), methicillin-resistant Staphylococcus aureus. (MRSA), multidrug-resistant Klebsiella pneumoniae., multidrug-resistant Helicobacter pylori., and Salmonella.spp. The extracts of Quercus infectoria. displayed remarkable activity against MRSA with MICs ranging from 0.02 to 0.4 mg/mL, and MBCs ranging from 0.4 to 1.6 mg/mL. More importantly, this plant species could exhibit strong antibacterial activity against all Gram-Negative organisms. Its significant activity was shown with EHEC, with MICs of 0.05 to 0.1 mg/mL and MBCs of 0.8 to 1.6 mg/mL. The results from this study indicate that Quercus infectoria. is potentially a good source of antibacterial substances with broad spectrum of activities against antibiotic-resistant bacteria.     

New azaspiracids in Amphidomataceae (Dinophyceae)

Azaspiracids (AZAs) are a group of lipophilic polyether toxins implicated in incidents of shellfish poisoning in humans, particularly in northern Europe, which are produced by the small marine dinoflagellate Azadinium spinosum. Other related species/strains of the Amphidomataceae have not been proven to date to contain any of the known azaspiracids. Closer analyses of these species/strains by triple quadrupole mass spectrometry in the precursor and product ion mode now revealed four new compounds with high similarity to azaspiracids, all of them with a characteristic m/z 348 fragment but with absence of the m/z 362 fragment. These compounds were detected in three species/strains, i.e. in North Sea isolates of Azadinium poporum (molecular mass: 845.5 Da), in a Korean isolate which has been designated as A. cf. poporum (molecular mass: 857.5 Da) and in Amphidoma languida isolated from Bantry Bay, Ireland (molecular masses: 815.5 and 829.5 Da). Cell quotas of roughly 2-20 fg per cell were in the same range as found for AZA-1/-2 in A. spinosum. Structures for all compounds were proposed by interpretation of fragmentation patterns and high resolution mass measurements using Fourier transform ion cyclotron resonance-mass spectrometry (FTICR-MS).     

Antitumor constituents from Annona squamosa fruit pericarp

Pharmacologically safe compounds that can inhibit the proliferation of tumor cells have potential as anticancer agents. Annonaceae seems to be one of the least chemically as well as pharmacologically known families compared with its large size. Earlier studies on Annona species have showed that this family is a potent source of a wide variety of secondary metabolites belonging to several categories. The chemistry and anti-inflammatory effects of the seed oils of Annona species have been studied and published. Several antibacterial and anti-inflammatory kaurane-type diterpenes were isolated and identified, and biological evaluations were also carried out and published. The pesticidal activity of various extracts has been reported and their formulations have been tested against a wide spectrum of pests of national importance. Flowers of some Annonaceae are used in perfumery and many members of this family are used in folk medicine of some tropical countries to treat various types of cancers and tumors. In the present study we used various solvent extracts of Annona squamosa fruit pericarp to test for cytotoxic activity using in vitro cultures of Dalton’s lymphoma cells as well as HeLa cells. Cytotoxicity was detected by the Trypan blue exclusion test and induction of apoptosis was evaluated by [3-(4,5-Dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide] assay (MTS assay) and DNA ladder assay. The chloroform extract of Annona squamosa pericarp was found to be cytotoxic to the different cell lines tested. The inhibitory concentration required for 50% cytotoxicity (IC₅₀) was also determined. The bioactivity-directed isolation yielded two kaurane-type diterpenes, (-)-ent-kaur-16-en-19-oic acid and 16α,17-dihydroxy-ent-kauran-19-oic acid. This study suggests the potential of Annonna squamosa fruit pericarp for the development of modern medicine for the treatment of cancers.