Acetogenins from Annona cornifolia and their antioxidant capacity

Therapeutic potential of traditional herbal plants and their polyphenols in alleviation of mercury toxicity

Mercury (Hg) is a major environmental contaminant significantly impacting human health. As a naturally occurring element, mercury has been extensively mobilized into aquatic and terrestrial ecosystems over thousands of years, largely due to anthropogenic activities such as mining and metal extraction. Acute mercury toxicity causes extensive physiological damage, affecting vital organs including the kidneys, heart, liver, brain, and skin. Phytochemicals, known for their diverse pharmacological properties, have shown promise in mitigating metal-induced toxicities, including mercury. These compounds exhibit protective effects against mercury-induced multi-organ damage through mechanisms such as reactive oxygen species (ROS) scavenging, cyclooxygenase (COX) inhibition, and anti-inflammatory activity. This review explores the therapeutic potential of traditional herbal plants and their phytoconstituents in alleviating mercury-induced toxicity. Key findings highlight several plants with hepatoprotective effects, mitigating necrosis and anatomical distortion in liver cells. Phytochemicals such as quercetin, rutin, salicylic acid, ferulic acid, 6-gingerol, and 6-shogaol play pivotal roles in downregulating molecular pathways activated by mercury exposure. Other bioactive compounds, including acetogenin and gallic acid, exhibit potent antioxidant properties, with mechanisms such as ROS scavenging and inhibition of lipid peroxidation. This review also highlights certain compounds, such as aloe-emodin and gentisic acid, which exhibit potential for mitigating mercury toxicity through mechanisms like inhibiting oxidative stress and enhancing cellular defense pathways. However, these compounds remain underexplored, with no significant studies conducted to evaluate their efficacy against mercury-induced toxicity, presenting a critical area for future research. These findings underscore the potential of phytochemicals as effective agents in combating mercury toxicity through antioxidant mechanisms, cellular signalling regulation, and heavy metal chelation.

Feature-based molecular networking and MS2LDA analysis for the dereplication of adjacent bis-tetrahydrofuran Annonaceous acetogenins

INTRODUCTION

Annonaceous acetogenins are a group of natural polyketide compounds possessing notable cytotoxic and antitumor properties. Mass spectrometry (MS) techniques can be used for the structural determination of these compounds, including the location of functional groups along the long alkyl chain.

OBJECTIVE

This study aims to develop a convenient liquid chromatography (LC)-MS-based method for the dereplication of acetogenins in plant extracts using a molecular networking approach.

METHODOLOGY

The LC-electrospray ionization (ESI)-MS/MS spectra of pure adjacent bis-tetrahydrofuran (THF) acetogenins isolated from Uvaria rufa (Annonaceae) were acquired, along with those of the crude ethyl acetate and hexanes fractions of the plant extract, followed by dereplication and molecular networking analysis using the Global Natural Products Social Molecular Networking (GNPS) platform.

RESULTS

A high level of fragmentation of the protonated molecules [M + H]+ was observed at collision energies of 37.5 and 25.0 eV. The application of feature-based molecular networking (FBMN) allowed for distinguishing diastereoisomers based on different retention times in the reversed-phase high-performance liquid chromatography method. The acetogenin possessing one or more additional OH groups on the methyl-terminal chain side of the OH-flanked bis-THF ring unit were grouped separately from those lacking such substructure. Furthermore, the MS2LDA analysis revealed shared Mass2Motifs among acetogenins, confirming the structural relations within the molecular network.

CONCLUSIONS

The ESI-MS/MS-based molecular networking method provided an effective strategy for the dereplication of acetogenins in plant extracts. It is anticipated that this molecular networking approach could be extended to other types of acetogenins to facilitate rapid identification of this class of compounds.

Economic, nutritional, and innovative aspects of non-conventional Brazilian fruits in the international novel foods market

Recent advances in fruit research have reignited interest in the market of tropical and unconventional fruit varieties, leading to increased investment in this sector. Additionally, consumers are currently seeking healthier food options to maintain the nutritional integrity of their diets and maximize health benefits, which has driven the demand for novel fruits and a deeper understanding of existing varieties. Despite this growing interest, knowledge of the full potential and diversity of these fruits remains insufficient for key stakeholders to reconcile sustainable production with the promotion of healthier diets within the global context. In this context, many endemic fruits from countries renowned for their rich biodiversity, such as Brazil, are still not produced and consumed regularly. Focusing on nutritional value, the distinctive composition of Brazilian fruits offers numerous health benefits, including essential vitamins, minerals, antioxidants, and anti-inflammatory compounds. This review delves into the economic implications of the Brazilian fruit industry, highlighting its capacity to penetrate the global market for novel foods. The introduction of new features, such as new flavors and textures, presents an excellent opportunity for product differentiation and market expansion. Furthermore, it discusses the importance of developing the fruit industry to promote a circular economy, reduce food insecurity, and generate income. This development can bring substantial social, economic, and environmental benefits to various regions around the globe.

Changes in the pasting and rheological properties of wheat, corn, water caltrop and lotus rhizome starches by the addition of Annona montana mucilage

Annona montana mucilage (AMM) is a novel mucilage with unique but limited information. This study investigated the effects of AMM addition on the pasting and rheological properties of wheat starch (WS), corn starch (CS), water caltrop starch (WCS), and lotus rhizome starch (LRS). The addition of AMM generally increased the pasting temperature and peak viscosity, but reduced the setback value of all starches to varying degrees, and the initiation of viscosity-increase for cereal starch/AMM systems during pasting occurred at lower temperatures, accompanied with a distinctive two-stage swelling process as well as lower peak and final hot paste viscosity at 50 °C. AMM significantly increased the pseudoplasticity and entanglement of the systems to varying degrees (LRS > WS > WCS > CS). Under a constant shear rate of 50 s-1, the consistency level was found to fall in honey-like for cereal starch/AMM groups, and honey-like to extremely thick levels for WCS and LRS/AMM groups. Except for the WCS/AMM systems, the storage and loss modulus as well as tan increased with increasing AMM concentration. Short-term retrogradation of starch at 4 °C was pronouncedly retarded by the addition of AMM for WS, CS and WCS groups, but was less affected for LRS group.

Acetogenins from the Stem of Uvaria rufa and Their Cytotoxic Activity

Four new adjacent bis-tetrahydrofuran acetogenins, bullacin C (7), uvarirufin (9), and uvariasolins III (12) and IV (13), along with 11 known acetogenins, were isolated from the stem of Uvaria rufa. Their structures were elucidated based on spectroscopic data analysis, including 1D and 2D NMR, HRESIMS, and MALDI-MS/MS of the lithium adducts. Absolute configurations were assigned using Mosher ester analysis and ECD measurements. Uvarirufin (9) possesses a unique C-39 skeleton among acetogenins. Most tested acetogenins exhibited cytotoxicity against human cancer cell lines (HCT 116, 22Rv1, MDA-MB-435, OVCAR3). Squamocin (8) and uvarirufin (9) were found to be the most potent, with an IC50 value of 1.2 μM for both in HCT 116 colon cancer cells. Additionally, a new application of Dragendorff's reagent is proposed herein for the TLC detection of acetogenins.

Polyphenol-Rich Leaf of Annona squamosa Stimulates Insulin Release from BRIN-BD11 Cells and Isolated Mouse Islets, Reduces (CH2O)n Digestion and Absorption, and Improves Glucose Tolerance and GLP-1 (7-36) Levels in High-Fat-Fed Rats

Annona squamosa, commonly known as custard apple, is traditionally used for the treatment of various diseases including diabetes, cardiovascular disease (CVD), and gastritis. This study was undertaken to investigate the effects of an ethanolic (80% v/v) extract of A. squamosa (EEAS) leaves in vitro on insulin secretion from clonal pancreatic BRIN BD11 β-cells and mouse islets, including mechanistic studies on the effect of EEAS on membrane potential and intracellular calcium ion concentration. Additional in vitro glucose-lowering actions were assessed. For in vivo studies, high-fat-fed (HFF) obese/normal rats were selected. EEAS increased insulin secretion in vitro in a dose-dependent manner. This effect was linked to β-cell membrane depolarisation and cytoplasmic Ca²⁺ influx. In the presence of isobutyl methylxanthine (IBMX), tolbutamide, or KCl, the insulin-releasing effect of EEAS was increased, suggesting its effect was also mediated via a K_ATP-independent pathways. EEAS inhibited insulin glycation, glucose absorption, and DPP-IV enzyme activity in vitro and enhanced glucose uptake and insulin action in 3T3L1 cells. In vivo, gut motility, food intake, glucose tolerance, plasma insulin, and active GLP-1 (7-36) levels were improved, whereas plasma DPP-IV levels were reduced in HFF rats. EEAS attenuated the absorption of sucrose and glucose as well as decreased serum glucose levels after sucrose loading and in situ intestinal perfusion in non-diabetic rats. Rutin, proanthocyanidin, and squafosacin G were putatively identified as the anti-hyperglycaemic phytomolecules in EEAS using HPLC followed by LC-MS analysis. This study illustrates the potential of A. squamosa and its phytoconstituents as a source of potential antidiabetic agents.

Extraction of Acetogenins Using Thermosonication-Assisted Extraction from Annona muricata Seeds and Their Antifungal Activity

The objective of this work was to find the optimal conditions by thermosonication-assisted extraction (TSAE) of the total acetogenin content (TAC) and yield from A. muricata seeds, assessing the effect of the temperature (40, 50, and 60 °C), sonication amplitude (80, 90, and 100%), and pulse-cycle (0.5, 0.7, and 1 s). In addition, optimal TSAE conditions of acetogenins (ACGs) were compared with extraction by ultrasound at 25 °C and the soxhlet method measuring TAC and antioxidant capacity. Moreover, solubility and identification of isolated ACGs were performed. Furthermore, the antifungal activity of ACGs crude extract and isolated ACGs was evaluated. Optimal TSAE conditions to extract the highest TAC (35.89 mg/g) and yield (3.6%) were 50 °C, 100% amplitude, and 0.5 s pulse-cycle. TSAE was 2.17-fold and 15.60-fold more effective than ultrasound at 25 °C and the Soxhlet method to extract ACGs with antioxidant capacity. Isolated ACGs were mostly soluble in acetone and methanol. Seven ACGs were identified, and pseudoannonacin was the most abundant. The inhibition of Candida albicans, Candida krusei, and Candida tropicalis was higher from isolated ACGs than crude extract. TSAE was effective to increase the yield in the ACGs extraction from A. muricata seeds and these ACGs have important antifungal activity.

Phytochemical Analysis of the Fruit Pulp Extracts from Annona crassiflora Mart. and Evaluation of Their Antioxidant and Antiproliferative Activities

Annona crassiflora Mart., the marolo fruit of the Cerrado biome, is one of the most frequently consumed species from the Brazilian Midwest. This study aimed to evaluate the chemical composition and the antioxidant and cytotoxic properties of the fruit pulp of A. crassiflora collected at Chapada das Mesas, Maranhão, Brazil. The volatile concentrate was identified as mainly ethyl octanoate, ethyl hexanoate, and methyl octanoate. From the ethanol (LFP-E) and ethyl acetate (LFP-A) extracts were identified phenolic acids (p-coumaric, gallic, quinic, and ferulic), flavones and derivatives (apigenin, epicatechin, 2′-5-dimethoxyflavone, 3′,7-dimethoxy-3-hydroxyflavone, kaempferol-3-O-glucoside and 3-O-rutinoside, quercetin-3-O-glucoside, procyanidin B2, and rutin), aporphine alkaloids (xylopine, stephagine, and romucosine), and acetogenin (annonacin). For the LFP-E and LFP-A extracts, the total phenolic compound values were 15.89 and 33.16 mg GAE/g, the flavonoid compound content values were 2.53 and 70.55 mg QE/g, the DPPH radical scavenging activity showed EC₅₀ values of 182.54 and 57.80 µg/mL, and the ABTS radical activity showed TEAC values of 94.66 and 192.61 µM TE/g. The LFP-E extract showed significant cytotoxicity and cell selectivity for the U251-glioma strain, presenting a GI₅₀ value of 21.34 µg/mL, which is close to doxorubicin (11.68 µg/mL), the standard chemotherapeutic drug. The marolo fruit seems to be a promising source for developing innovative and healthy products for the food industry.

Traditional Uses, Phytochemistry and Pharmacological Activities of Annonacae

In 1789, the Annonaceae family was catalogued by de Jussieu. It encompasses tropical and subtropical plants which are widespread in distribution across various continents such as Asia, South and Central America, Australia and Africa. The genus of Annona is one of 120 genera of the Annonaceae family and contains more than 119 species of trees and shrubs. Most species are found in tropical America, where over 105 species have been identified. Due to its edible fruits and medicinal properties, Annona is the most studied genus of Annonaceae family. To date, only a limited number of these species have economic value, including A. squamosa L. (sugar apple), A. cherimola Mill. (Cherimoya), A. muricata L. (guanabana or soursop), A. atemoya Mabb. (atemoya), a hybrid between A. cherimola and A. squamosa, A. reticulata L. (custard apple), A. glabra L. (pond-apple) and A. macroprophyllata Donn. Sm. (ilama). Phytochemically, several classes of secondary metabolites, including acetogenins, essential oils, alkaloids, terpenoids and flavonoids. The pharmacological activities of Annona species leaves and seeds include antibacterial, anticancer, antidiabetic and anti-inflammatory properties.

Antifungal activity screening of fractions from Annona cherimola Mill. leaf extract against Fusarium oxysporum

The antifungal effect of ethanolic extract fractions of Annona cherimola leaves against the mycelial growth of Fusarium oxysporum was studied. The ethanolic crude extract was solvent partitioned and the ethyl acetate phase was fractionated by column or preparative thin-layer chromatography. All fractions were developed on TLC and analyzed for acetogenins (ACG) with Kedde reagent. The antifungal effect assays were carried out in vitro by the diffusion method on PDA plates. The ethanolic extract of A. cherimola leaves was highly active against F. oxysporum growth; subfractions obtained from the antifungal screening had a significant effect (p < 0.05) on the F. oxysporum growth parameters. The screening showed that as the purification steps progressed, the inhibition of mycelial growth increased. Six bioactive ACG (Annomolon-B, 34-epi annomolon B, almunequin, cherimoline 1, cherimoline 2, and isocherimoline 1) were identified by LC-QTOF-MS/MS. These findings suggested that bioactive ACG from A. cherimola leaves could be an alternative resource of a promising botanical fungicide to control plant diseases caused by F. oxysporum.

Screening of antidiabetic and antioxidant potential along with phytochemicals of Annona genus: a review

Background

Annona species can be found in the subtropical and tropical parts of the world. Because of their medicinal capabilities and highly exotic edible fruits, they are one of the most important members of the Annonaceae family. Isoquinolines, pyrimidine-β-carboline alkaloids, lectins, acetogenins, and volatile oils are among the active metabolites found in this genus, all of which have been shown to have anti-diabetic and antioxidant activities.

Main body

The fundamental objective of this review was to summarize the antidiabetic and antioxidant activity based on reported secondary data from different plants of the genus Annona. These species include Annona cherimola, Annona squamosa, Annona macroprophyllata, Annona muricate, Annona reticulata, Annona carcans, Annona coriacea, Annona cornifolia, and Annona senegalensis. The Annona species investigated had significant antihyperglycemic and antioxidant properties.

Conclusion

The available evidence, both in vitro and in vivo, confirms the ability of Annona species to treat diabetes in addition to producing oxidative damage.

Biochemical investigation of the upstream anti-sickling mechanisms of soursop (Annona muricata): 15-acetyl guanacone as an inhibitor of deoxyhaemoglobin polymerisation

Current sickle cell disease (SCD) therapies are limited and inefficient. The ethnomedicinal values of Annona muricata in the treatment of SCD, leading to this present research. Leaves and fruits of Annona muricata were processed using solvent extraction and partitioning; aqueous, chloroform and ethyl acetate fractions. In vitro (anti-oxidant and anti-sickling), in silico, quantitative (amino acids) and kinetic simulation experiments were done. 15-acetyl guanacone, was used, in silico against 2,3-bisphosphoglycerate (2, 3-BPG) mutase and deoxyhaemoglobin. The ethyl acetate and chloroform fractions better NO^● scavengers, iron-chelators and ferric reducing. In vitro unsickling (UT₅₀) had ethyl acetate = 5 h and methanol = 7 h. Chloroform fraction had EC₅₀ 1.00 mg/mL (EC₅₀ = 546 mg/mL) to 10.00 mg/mL (EC₅₀ = 99 mg/mL). EC₅₀ and IC₅₀ of ethyl acetate fraction had steady-decrease. At higher concentration, chloroform fraction had higher Bmax (1.48 × 10²¹ U/mL) and higher Kd (3.66 × 10¹⁹ mg/mL), whereas, at a lower concentration, the ethyl acetate fraction demonstrated higher Bmax (7.23 × 10¹² U/mL) and lower Kd (2.12 × 10¹¹ mg/mL); The relative affinity (BP) of chloroform fraction increased progressively with concentration. The amino acid profile revealed rich concentrations glycine, valine, leucine, lysine, phenylalanine, histidine, arginine, and tryptophan. From the in silico experiments, 15-acetyl guanacone specifically targeted the A and B chains, with greater affinity for the beta subunit. This suggested that 15-acetyl guanacone might be able to prevent the polymerisation of deoxyHbSS, induce an allosteric conformational change that increases the oxygen affinity, and decrease the cellular 2, 3-BPG concentration.Communicated by Ramaswamy H. Sarma.

Acetogenins from Annonaceae family. Their potential biological applications

The aim of this contribution has been to continue with the knowledge about newly isolated acetogenins from Annonaceae family for the last fifteen years. This review will report classification, extraction, isolation, elucidation of the structure, biological activities and mechanism of action of such interesting natural products. In fact, out of the 532 compounds reviewed, 115 previously non-described annonaceous acetogenins have been added to the list of isolated compounds from 2005 to May 2019.

Antibiofilm, antiquorum sensing and antioxidant activity of secondary metabolites from seeds of Annona senegalensis, Persoon

The increasing resistance of bacteria to antibiotics has motivated the interest in potent natural compounds capable of disrupting bacterial cell-to-cell communication. Column chromatography of seed extract of Annona senegalensis afforded N-cerotoyltryptamine (1), asimicin (2) and ent-19-carbomethoxykauran-17-oic acid (3). The compounds were tested for their antimicrobial, antibiofilm, and anti-quorum sensing activities. The minimum inhibitory concentrations (MIC) values ranged from 50 μg/mL to 100 μg/mL for C. albicans ATCC 10239 and S. aureus ATCC 25923 E. coli ATCC 25922, C. violaceum CV026 and C. violaceum CV12472. All the compounds inhibited biofilm formations of all microorganisms tested in various percentages at MIC and MIC/2. Compound 2 also exhibited the highest antibiofilm activity against C. albicans (yeast) and E. coli with percentage inhibitions ranging from 6.3 ± 4.1 (MIC/4) to 37.9 ± 4.5 (MIC) for C. albicans and from 18.8 ± 1.1 (MIC/4) to 43.2 ± 0.5 (MIC) for E. coli. Compound 1, however, showed highest biofilm inhibition on S. aureus as the percentage inhibition varied from 26.7 ± 3.6 (MIC/4) to 43.8 ± 2.1 (MIC). Compound 2 showed highest percentage violacein inhibition on C. violaceum CV12472 ranging from 10.2 ± 0.5 (MIC/8), 65.76 ± 1.3 (MIC/2) and 100 (MIC). Compound 1 and 3 had percentage violacein formation inhibitions on C. violaceum CV12472 ranging from 9.66 ± 1.1 (MIC/4) to 100 (MIC), and from 17.4 ± 2.4 (MIC/4) to 100 (MIC), respectively. Swimming and swarming motility of P. aeruginosa PA01 strain was evaluated at three concentrations of 50, 75 and 100 μg/mL. The compounds inhibited the P. aeruginosa swimming and swarming motility at the three tested concentrations (50, 75 and 100 μg/ml) in a dose-dependent manner. The extents of inhibition of motility migration was relatively higher in the swimming model than in the swarming model for all compounds. Compound 1 exhibited the highest percentage inhibition of motility of 41.50 ± 3.5 and 39.73 ± 1.5 in swimming model and swarming model respectively at 100 μg/ml. Compound 3 showed the lowest percentage inhibition of 30.36 ± 2.0 and 23.50 ± 2.5 in swimming and swarming respectively at 100 μg/ml. At the lowest tested concentration of 50 μg/ml, it was compound 2 showing the highest inhibition of motility of 17.49 ± 0.5 and 14.29 ± 1.0 in swimming and swarming respectively. Compound 1 showed highest quorum sensing (QS) activity with QS inhibition zone of 20.0 ± 1.5 mm at MIC and 11.0 ± 1.0 mm at MIC/8 while compound 2 had the highest antimicrobial (AM) zone diameter amongst the compounds at MIC. Compound 3 was the QS inhibitory sample and did not show any QS inhibition at MIC/8 while showing its highest QS inhibition zone of 13.0 ± 1.6 mm at MIC. For antioxidant assays, no sample showed better activity than the standards. Compound 2 had highest activity with IC₅₀ values of 87.79 ± 2.70 and 42.77 ± 1.53 μg/mL in DPPH and β-carotene-linoleic acid assay respectively and was more active (IC₅₀ of 97.69 ± 1.40 μg/mL) than standard quercetin (IC₅₀ 250.09 ± 0.87 μg/mL) in metal chelation assay.

Potential therapeutic applications of the genus Annona: Local and traditional uses and pharmacology

ETHNO-PHARMACOLOGICAL RELEVANCE

Annona species (Annonaceae) have long been used as traditional herbal medicines by native peoples in tropical areas. In different countries they are used against a large variety of illnesses, such as parasitic and infectious diseases, cancer, diabetes, peptic ulcers, and mental disorders.

AIM OF THE STUDY

This review aims to achieve a comprehensive understanding of the research conducted so far on the local and traditional uses, pharmacological activities, mechanism of actions of active compounds, toxicity, and possible interactions with other drugs of the Annona species. Through analysis of these findings, evidences supporting their applications in ethno-medicines are described. We discuss the possible research opportunities and stand out the weak points in our knowledge that deserves further investigation.

MATERIAL AND METHODS

Information on ethno-medicinal uses and pharmacological activities of the Annona genus was collected. The main scientific biomedical literature databases (Cochrane, PubMed, Scopus, Lilacs, SeCiMed, Elsevier, SpringerLink, Google Scholar, SciFinder) were consulted. The search covered all the literature available until September 2017. National and regional databases of Herbal Medicine and Complementary and Alternative Medicine were also revised in order to explore further data. For a better understanding of the therapeutic importance of these species, we have classified the pharmacological activities within each group of disorders. The International Classification of Diseases (ICD), used from WHO Member States, was chosen as the reference classification.

RESULTS

From among the 27 species revised, four species are highlighted for their important pharmacological activities in most of the groups of illnesses: A. muricata, A. squamosa, A. senegalensis, and A. cherimola. Many investigations have been performed with extracts from the leaves, bark, fruit and seeds and have shown a wide range of pharmacological activities, such as antiprotozoal, antitumoural, antidiabetic, hepato-protective, anti-inflammatory and anxiolytic activities. The chemistry on the annonaceous acetogenins (ACGs) has been extensively investigated due to their potent antitumoural activity. Many of the assays were carried out with the isolated acetogenins in different lines of tumour culture cells and were found effective at very low doses even in multidrug-resistant tumours, and hence constitute promising compounds in the treatment of different types of cancers. No studies were found with extracts rich in acetogenins in the clinical field.

CONCLUSIONS

The experimental results from the pharmacological research enable the validation of their traditional uses in several of the groups of diseases in the countries of origin and reveal these plants to be a valuable source for therapeutic molecules. However, more toxicity assays and clinical trials would be necessary to establish optimal and safe doses of consumption on the application of these medicinal plants.

Antioxidant Activities and Phenolic Compounds of Several Tissues of Pawpaw (Asimina triloba [L.] Dunal) Grown in Korea

Pawpaw (Asimina triloba [L.] Dunal) possesses antioxidant compounds and strong inhibitors of cancer cells, and is widely cultivated in North America, Canada, and Korea. We analyzed the total phenolic and total flavonoid contents (TPC and TFC, respectively) of pawpaw plants grown in Korea and the antioxidant activities of their roots, twigs, leaves, and fruit with respect to 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis diammonium salt (ABTS) radical scavenging activity, ferrous (Fe²⁺ ) chelating ability, and nitrite scavenging activity. Pearson's correlation analyses revealed a linear correlation between TPC and antioxidant activities (r² >0.69). Root methanol extracts had higher TPC and antioxidant activities than other extracts, which was also consistent with those from the phenolic compounds found in those extracts. Therefore, antioxidant activities seem to depend on the TPC of each pawpaw tissue and pawpaw roots might be useful as a natural source of natural antioxidants.

Antifungal and antioxidant activity of fatty acid methyl esters from vegetable oils

Fatty acid methyl esters (FAMEs) were obtained from vegetable oils of soybean, corn and sunflower. The current study was focused on evaluating the antifungal activity of FAMEs mainly against Paracoccidioides spp., as well as testing the interaction of these compounds with commercial antifungal drugs and also their antioxidant potential. FAMEs presented small IC50 values (1.86-9.42 μg/mL). All three FAMEs tested showed antifungal activity against isolates of Paracoccidioides spp. with MIC values ranging from 15.6-500 µg/mL. Sunflower FAMEs exhibited antifungal activity that extended also to other genera, with an MIC of 15.6 μg/mL against Candida glabrata and C. krusei and 31.2 μg/mL against C. parapsilosis. FAMEs exhibited a synergetic effect with itraconazole. The antifungal activity of the FAMEs against isolates of Paracoccidioides spp. is likely due to the presence of methyl linoleate, the major compound present in all three FAMEs. The results obtained indicate the potential of FAMEs as sources for antifungal and antioxidant activity.

Desacetyluvaricin induces S phase arrest in SW480 colorectal cancer cells through superoxide overproduction

Annonaceous acetogenins (ACGs) are a group of fatty acid-derivatives with potent anticancer effects. In the present study, we found desacetyluvaricin (Dau) exhibited notable in vitro antiproliferative effect on SW480 human colorectal carcinoma cells with IC50 value of 14 nM. The studies on the underlying mechanisms revealed that Dau inhibited the cancer cell growth through induction of S phase cell cycle arrest from 11.3% (control) to 33.2% (160 nM Dau), which was evidenced by the decreased protein expression of cyclin A Overproduction of superoxide, intracellular DNA damage, and inhibition of MEK/ERK signaling pathway, were also found involved in cells exposed to Dau. Moreover, pre-treatment of the cells with ascorbic acid significantly prevented the Dau-induced overproduction of superoxide, DNA damage and cell cycle arrest. Taken together, our results suggest that Dau induces S phase arrest in cancer cells by firstly superoxide overproduction and subsequently the involvement of various signaling pathways.

Tropical Plant Extracts as Sources of Grain-Protectant Compounds Against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)

The toxicity of organic plant extracts to Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) was assessed for three tropical plant species: branches, leaves, and seeds of Annona montana (Annonaceae), branches of Aristolochia paulistana (Aristolochiaceae), and leaves and branches of Casearia sylvestris (Salicaceae). The screening assay resulted that the extracts of A. montana seeds obtained with hexane (LC50 = 534.75 mg kg(-1) and LT50 = 6.10 days) and with dichloromethane (LC50 = 424.67 mg kg(-1) and LT50 = 5.03 days) were the most promising treatments, followed by the extract prepared from A. montana leaves with hexane (LC50 = 837.70 mg kg(-1) and LT50 = 4.90 days). Moreover, extracts (at 1,500 mg kg(-1)) prepared from C. sylvestris branches with dichloromethane and A. paulistana with hexane caused significant mortality (37% and 41.5%, respectively) beyond sublethal effects on S. zeamais. Therefore, based on the biological assays, extraction yield, and evaluation of the chromatographic profile of the crude extracts by TLC, the hexane extract of A. montana seeds was selected and fractioned using liquid-liquid partitioning. The hydroalcoholic fraction caused mortality of 55.5%, significantly superior to dichloromethane fraction, which caused 35.5% of mortality. Chemical analyses ((1)H NMR, HPLC, and TLC) were performed, and the results showed the presence of alkaloids and acetogenins in both active fractions, which have been associated with bioactivity. Therefore, extracts prepared from A. montana seeds (especially) is an interesting source of new compounds with promising grain-protectant properties.

Nutritional and phytochemical composition of Annona cherimola Mill. fruits and by-products: Potential health benefits

Annona cherimola Mill., commonly known as cherimoya, is a tropical fruit well known due to its tasty flavour. In the present study the antioxidant activity of pulp, peel and seeds of four cultivars from A. cherimola Mill. from Madeira Island (Madeira, Funchal, Perry Vidal and Mateus II) was analysed. Moreover, nutritional composition (proximates and vitamins) and bioactive compounds content were determined. The peel of Madeira cultivar showed the highest antioxidant capacity, with an EC50 of 0.97mg/mL, and total flavonoids (44.7 epicatechin equivalents/100g). The most abundant carotenoid was lutein, with values ranging from 129 to 232μg/100g. The highest l-ascorbic acid content (4.41mg/100g) was found in the peel of Perry Vidal cultivar. These results highlight A. cherimola Mill. antioxidant properties, especially in its by-products and encourage their application in cosmetic, pharmaceutical and food processing industries, as added value natural extracts.

In vitro cytotoxic, antifungal, trypanocidal and leishmanicidal activities of acetogenins isolated from Annona cornifolia A. St. -Hil. (Annonaceae)

Annona cornifolia A. St. -Hil. is a small annual perennial tree found in the Brazilian savannah; their green fruit is popularly used in the treatment of ulcers. The acetogenins isolated from the seeds of Annona cornifolia previously showed to possess antioxidant activity. In continuation of our investigations on the biological activities of acetogenins, four binary mixtures and ten pure adjacent bis-tetrahydrofuran annonaceous acetogenins were evaluated: the cytotoxic (against three human tumor cell lines), antifungal (against Paracoccidioides brasiliensis), trypanocidal (against Trypanosoma cruzi) and leishmanicidal (against Leishmania amazonensis) activities. Acetogenins presented cytotoxic activity confirming their potential use in anti-cancer therapy. Regarding leishmanicidal and trypanocidal activities, an inhibition of 87% of L. amazonensis amastigotes and 100% of T. cruzi amastigotes and trypomastigotes was observed, when tested at the concentration of 20 µg mL–1. Moreover, six acetogenins showed more activity against all the three tested isolates of P. brasiliensis than trimethoprim-sulfamethoxazole, a drug used for treating paracoccidioidomycosis. Thus, acetogenins may be an alternative in treating a number of diseases that have a huge impact on millions of people worldwide. This paper reports for the first time the antifungal, leishmanicidal and trypanocidal activities for these acetogenins.

Anti-tumor activity of Annona squamosa seeds extract containing annonaceous acetogenin compounds

ETHNOPHARMACOLOGICAL RELEVANCE

Seeds of Annona squamosa L. have been used in the south of China as a folk remedy to treat "malignant sores" (cancer).

AIM OF THE STUDY

To investigate the chemical constituents and the anti-tumor activity of the standardized A. squamosa seeds extract in vitro and in vivo.

MATERIALS AND METHODS

Annonaceous acetogenin profiles of the standardized extract were determined by using Fourier transform infrared (FT-IR) and high performance liquid chromatography (HPLC) techniques. The anti-tumor activity of the extract was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cytotoxicity in vitro and H(22) hepatoma cells transplantation tumor model in vivo.

RESULTS

The FT-IR spectroscopy showed the presence of annonaceous acetogenin compounds in the extract. Two major annonaceous acetogenins: 12, 15-cis-squamostatin-A and bullatacin were identified and quantified by HPLC. The seed extract showed significant anti-tumor activity against four human tumor cell lines, especially for MCF-7 (IC(50). 0.25 μg/ml) and Hep G2 (IC(50). 0.36 μg/ml) cells in vitro. The extract inhibited the growth of H(22) tumor cells in mice with a maximum inhibitory rate of 69.55% by oral administration.

CONCLUSION

A. squamosa seed extract showed significant anti-tumor activities against human hepatoma cells in vitro and in vivo, indicating a potential for developing the extract as a novel anti-liver cancer drug.

Six cytotoxic annonaceous acetogenins from Annona squamosa seeds

Custard apple (Annona squamosa L.) is an edible tropical fruit, and its seeds had been used in south China as a folk medicine to treat "malignant sore" (cancer) and as an insecticide. Phytochemical investigation of the ethanol fraction of custard apple seeds led to the isolation of six new annonaceous acetogenins: annosquacins A-D (1-4), annosquatin A (5) and annosquatin B (6). Their structures were elucidated by spectroscopic analysis. Compounds 1-4 are adjacent bistetrahydrofuran annonaceous acetogenins. Compounds 5 and 6 are non-adjacent bistetrahydrofuran annonaceous acetogenins and the first examples in which the tetrahydrofuran ring system is located between C-9 and C-20. The absolute configurations of 1-6 were defined by the application of the Mosher method. Compounds 1-6 exhibited potent cytotoxic activity in vitro against five human tumour cell lines. Compounds 5 and 6 showed a high selectivity toward the MCF-7 and A-549 cell line respectively.

Antiproliferative acetogenins from a Uvaria sp. from the Madagascar dry forest

Investigation of the endemic Madagascan plant Uvaria sp. for antiproliferative activity against the A2780 ovarian cancer cell line led to the isolation of two new acetogenins. The structures of these two compounds were elucidated on the basis of analysis of their 1D and 2D NMR spectra, circular dichroism, and mass spectrometric data, together with chemical modification. The two acetogenins display weak antiproliferative activity against the A2780 ovarian cancer, the A2058 melanoma, and the H522 lung cancer cell lines.

Cytotoxic bistetrahydrofuran annonaceous acetogenins from the seeds of Annona squamosa

Three new bistetrahydrofuran annonaceous acetogenins (1-3) were isolated from a 95% EtOH extract of Annona squamosa seeds. Four known annonaceous acetogenins, uvarigrandin A (4), bullatacin (5), squamostatin-A (6), and squamostatin-D (7), were also isolated. Their structures were elucidated by spectroscopic analyses, and the absolute configurations of the carbinol centers of 1-3 were defined by application of the Mosher method. These compounds all exhibited significant cytotoxic activity in vitro against five human tumor cell lines.

Annonaceae: bio-resource for tomorrow's drug discovery

One of the rich sources of lead compounds is the Angiosperms. Many of these lead compounds are useful medicines naturally, whereas others have been used as the basis for synthetic agents. These are potent and effective compounds, which have been obtained from plants, including anti-cancer (cytotoxic) agents, anti-malaria (anti-protozoal) agents, and anti-bacterial agents. Today, the number of plant families that have been extensively studied is relatively very few and the vast majorities have not been studied at all. The Annonaceae is the largest family in the order Magnoliales. It includes tropical trees, bushes, and climbers, which are often used as traditional remedies in Southeast Asia. Members of the Annonaceae have the particularity to elaborate a broad spectrum of natural products that have displayed anti-bacterial, anti-fungal, and anti-protozoal effects and have been used for the treatment of medical conditions, such as skin diseases, intestinal worms, inflammation of the eyes, HIV, and cancer. These special effects and the vast range of variation in potent compounds make the Annonaceae unique from other similar families in the Magnoliales and the Angiosperms in general. This paper attempts to summarize some important information and discusses a series of hypotheses about the effects of Annonaceae compounds.