Paw paw and cancer: annonaceous acetogenins from discovery to commercial products

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.

Annonaceae acetogenins: A potential treatment for gynecological and breast cancer

Breast and gynecological cancers are major health concerns due to their increasing incidence rates, and in some cases, their low survival probability. In recent years, multiple compounds of natural origin have been analyzed as alternative treatments for this disease. For instance, Acetogenins are plant secondary metabolites from the Annonaceae family, and its potential anticancer activity has been reported against a wide range of cancer cells both in vitro and in vivo. Several studies have demonstrated promising results of Acetogenins' antitumor capacity, given their selective activity of cellular inhibition at low concentrations. This review outlines the origin, structure, and antineoplastic activities in vitro and in vivo of Acetogenins from Annonaceae against breast cancer and gynecological cancers reported to date. Here, we also provide a systematic summary of the activity and possible mechanisms of action of Acetogenins against these types of cancer and provide references for developing future therapies based on Acetogenins and nanotechnologies.

Ethnomedicine, phytochemistry, and pharmacological activities of Uvaria chamae P. Beauv.: A comprehensive review

The use of medicinal plants as food and medicine has been a common practice in the world, especially in tropical African countries. One such plant in West Africa is Uvaria chamae, also known as Bush banana, renowned for its diverse ethnomedicinal applications and, more recently, for its pharmacological activities attributed to a rich array of phytochemical constituents. Various parts of the plant have been traditionally employed for the treatment of diverse health issues such as digestive disorders, fever, dysmenorrhea, cancer, wound healing, and many more. To unravel the bioactive compounds responsible for these medicinal properties, a comprehensive phytochemical analysis has been undertaken. Notable isolates include chamanetin, dichamanetin, uvaretin, and uvarinol from different parts of the plant. The pharmacological evaluation of these compounds has revealed significant anticancer and antimicrobial properties. Therefore, this review provides a thorough examination of the phytochemicals derived from Uvaria chamae, detailing their associated pharmacological activities both in vitro and in vivo. The review emphasizes the potential of Uvaria chamae as a valuable source of lead compounds for cancer chemotherapy and antimicrobial drug discovery.

Total Synthesis of (+)-Muricatetrocin B via a Late-Stage Co-Catalyzed Hartung-Mukaiyama Cyclization

Convergent total synthesis of (+)-muricatetrocin B, a tetrahydrofuran-containing acetogenin with potent and selective cytotoxicity against the HT-29 human colon adenocarcinoma cell line, was achieved in 13 steps. Our synthesis is highlighted by a late-stage sequential olefin cross-metathesis/Hartung-Mukaiyama cyclization for convergent assembly of the 2,5-trans-substituted tetrahydrofuran ring.

Targeting Carbohydrate Mimetics of Tetrahydrofuran-Containing Acetogenins to Prostate Cancer

The high potency of the tetrahydrofuran-containing acetogenins (THF-ACGs) against a broad range of human cancer cell lines has stimulated interest in structurally simpler mimetics. In this context, we have previously reported THF-ACG mimetics in which the THF and butenolide moieties of a mono-THF-ACG were replaced with carbohydrate and thiophene residues, respectively. In the present study, towards the targeting of these carbohydrate analogues to prostate cancer (PCa), we synthesized prodrugs in which a parent thiophene or butenolide congener was conjugated through a self-immolative linker to 2-[3-(1,3-dicarboxypropyl)ureido] pentanedioic acid (DUPA), a highly specific ligand for prostate-specific membrane antigen (PSMA), which is overexpressed on prostate tumors. Both prodrugs were found to be more active against receptor positive LNCaP than receptor-negative PC-3 cells, with 2.5 and 12 times greater selectivity for the more potent thiophene analog and the less active butenolide congener, respectively. This selectivity for LNCaP over PC-3 contrasted with the behavior of the parent drugs, which showed similar or significantly higher activity for PC-3 compared to LNCaP. These data support the notion that higher activity of these DUPA-derived prodrugs against LNCaP cells is connected to their binding to PSMA and suggest that the conjugation of PSMA ligands to this family of cytotoxic agents may be effective for targeting them to PCa.

Effects of Pawpaw (Asimina triloba) Seed Extract on the Differentiation and Fat Accumulation of 3T3-L1 Cells under Different Glucose Conditions

Asimina triloba (pawpaw) contains various bioactive alkaloids and acetogenins. In the present study, the effects of pawpaw seed extract (PSE) on adipocyte differentiation and fat accumulation were investigated in 3T3-L1 cells under different glucose conditions. Treatment of undifferentiated cells with 10 ng/mL PSE increased lactic acid production, suggesting enhanced anaerobic glycolysis. PSE treatment also suppressed cell proliferation and decreased the nicotinamide adenine dinucleotide (NAD)⁺/NADH ratio in low-glucose medium; however, this effect was not observed in high-glucose medium. Additionally, PSE treatment under low-glucose conditions resulted in reduced accumulation of triglycerides and decreased expression of peroxisome proliferator-activated receptor (PPAR)-γ, CAAT/enhancer-binding protein (C/EBP)-α, and sterol regulatory element binding protein (SREBP)-1c in adipocyte-differentiated cells. PSE exerted greater effects on adipocyte differentiation and triglyceride content in 3T3-L1 cells under low-glucose conditions than under high-glucose conditions. These findings indicate that PSE enhances anaerobic glycolysis and inhibits adipocyte differentiation and fat accumulation in 3T3-L1 cells under glucose-restricted conditions.

Genotoxic and chemopreventive potentials of ethanol leaves extract of Annona muricata on N-Ethyl-N-Nitrosourea-induced pro-leukaemia carcinogen in mice model by bone marrow micronucleus assay

Background. Studies have proven the effect of several agents, including natural products, to induce, prevent and treat genotoxicity through experimental models and clinical trials. In this study, the genotoxic preventive potential of Annona muricata ethanol extract on N-Ethyl-N-Nitrosourea (ENU)-induced pro-leukaemia in mice models using micronuclei formation in bone marrow was assessed. Materials and methods. Forty-eight mice weighing 18-24g were randomly divided into six groups of eight mice. The mice were intravenously administered 20mg/kg of NEU 48 hourly 3 times, 80mg/kg of NEU 48 hourly 3 times. The negative control was fed with feed and water only. We introduced 0.2ml (0.1g/ml) ethanolic extract of Annona muricata for 3 weeks prior to NEU low dosage administration, 0.2ml (0.1g/ml) ethanolic extract of Annona muricata for 3 weeks prior to ENU high dosage and Annona muricata (ethanolic extract) administration, and gave commercial diet to the adverse/ toxicity group.  The bone marrow was harvested, smeared and stained using MayGrumwald. The procedure enabled the determination of micronucleus polychromatic erythrocytes (MNPCEs) microscopically. Results. Groups exposed to various dosages of the ENU yielded significantly increased MNPCEs, with group B producing higher MNPCEs. The groups treated with the extract displayed a significant reduction in the MNPCEs despite prior exposure to concentrations of NEU. The adverse group displayed no difference in MNPCEs compared with the negative control. Conclusion. The ENU induced genotoxicity depending on its concentration. The extract displayed a profound capacity to prevent genotoxicity and alleviate leukaemia with good tolerance.

Acetogenins from the stems of Uvaria micrantha showing antiproliferative effects on HepG2 liver cancer cells

Five mono-tetrahydrofuran acetogenins: uvamicranins A-E and three known mono-tetrahydrofuran acetogenins; reticulatacin, calamistrin A, and uvarigrin, were isolated from the stems of Uvaria micrantha (Annonaceae). Their structures were elucidated by 2D NMR and high-resolution mass spectral analysis. The absolute configurations of uvamicranins A and B were determined by modified Mosher's method. Evaluation of antiproliferative activity of the isolated compounds showed that they were more potent towards the human hepatocellular carcinoma cell line HepG2, compared to the five other tested cell lines. Among the tested compounds, uvamicranin B (UvB) and uvarigrin (Uv) possessed strong antiproliferative activity with IC50 values of 2.89 ± 0.71 μM and 0.37 ± 0.06 μM, respectively. The antiproliferative mechanism of UvB and Uv, was investigated in HepG2 cell line showing that both compounds marginally induced apoptotic cell death, but exhibited cytostatic effect through induction of cell cycle arrest at the G2/M phase.

Synthesis of carbohydrate analogues of the THF-acetogenin 4-deoxyannomontacin and their cytotoxicity against human prostate cancer cell lines

The THF containing acetogenin 4-deoxyannonmontacin (4-DAN) has attracted interest for its potent cytotoxicity against a broad range of human tumor cell lines, and relatively simple structure. Herein is described the synthesis and cytotoxicity of C-10 epimers of 4-DAN and analogues thereof comprising carbohydrate and thiophene substitutes for the THF and butenolide moieties respectively. The key synthetic ploy was the union of THF and butenolide segments or their substitutes, via an alkene cross metathesis. The different analogues showed cytotoxicity in the low micromolar to nanomolar range against the human prostate cancer cell lines LNCaP and PC3. A relatively simple mannose-linked thiophene analog was found to be similar in activity to 4-DAN.

Binding of Natural Inhibitors to Respiratory Complex I

NADH:ubiquinone oxidoreductase (respiratory complex I) is a redox-driven proton pump with a central role in mitochondrial oxidative phosphorylation. The ubiquinone reduction site of complex I is located in the matrix arm of this large protein complex and connected to the membrane via a tunnel. A variety of chemically diverse compounds are known to inhibit ubiquinone reduction by complex I. Rotenone, piericidin A, and annonaceous acetogenins are representatives of complex I inhibitors from biological sources. The structure of complex I is determined at high resolution, and inhibitor binding sites are described in detail. In this review, we summarize the state of knowledge of how natural inhibitors bind in the Q reduction site and the Q access pathway and how their inhibitory mechanisms compare with that of a synthetic anti-cancer agent.

Carica papaya L. Leaves: Deciphering Its Antioxidant Bioactives, Biological Activities, Innovative Products, and Safety Aspects

The prevalence of viral infections, cancer, and diabetes is increasing at an alarming rate around the world, and these diseases are now considered to be the most serious risks to human well-being in the modern period. There is a widespread practice in Asian countries of using papaya leaves (C. papaya L.) as herbal medicine, either alone or in combination with prescribed medications, to treat a variety of ailments. The importance of conducting the necessary descriptive studies in order to determine the safety of papaya leaf consumption is also emphasized in the context of their application in the healthcare sector. Electronic databases such as Google Scholar, Scopus, and PubMed were used to gather information on papaya leaves, their therapeutic potential, and clinical evidence-based studies. The literature was gathered from publications on papaya leaves, their therapeutic potential, and clinical evidence-based studies. The antidengue, anticancer, antidiabetic, neuroprotective, and anti-inflammatory effects of papaya leaves discussed in this article are supported by evidence from preclinical, in vivo, in vitro, and clinical trial studies, as well as from other sources. Leaves have been investigated for their mechanism of action as well as their potential to be used in the development of novel herbal products for the health business. According to the reports gathered, only a small number of research demonstrated that leaf extract at high concentrations was hazardous to certain organs. The collective literature reviewed in this review provides insights into the use of papaya leaves as a cure for epidemic diseases, highlighting the phytochemical composition and pharmacological attributes of papaya leaves, as well as the results of various preclinical and clinical studies that have been conducted so far on the subject. The review clearly demonstrates the successful medical evidence for the use of papaya leaf extracts in the healthcare system as a supplemental herbal medication in a variety of clinical settings.

Annonaceous Acetogenin Mimic AA005 Inhibits the Growth of TNBC MDA-MB-468 Cells by Altering Cell Energy Metabolism

Triple-negative breast cancer (TNBC) is a serious health issue for women worldwide and there is still no suitable treatment option. AA005, a structurally simplified mimic of natural Annonaceous acetogenins, presents outstanding properties with impressive cytotoxicity and cell-type selective actions. The present study was aimed at evaluating the potential of AA005 as a therapeutic agent for TNBC. AA005 potently inhibited the growth of TNBC cells at 50 nM level. Inspired by the finding of the phosphatase and tensin homologue (PTEN) tumor suppressor, the effect of AA005 on aerobic glycolysis was investigated in TNBC MDA-MB-468 cells. A short-term AA005 exposure markedly suppressed mitochondrial function in MDA-MB-468 cells, thus activating the aerobic glycolysis to lessen the risk of decreased ATP generation in mitochondria. Prolonging the incubation time of AA005 clearly weakened the aerobic glycolysis in the cells. This was in part attributed to the PI3K-AKT pathway inactivation and subsequent declined glucose uptake. As a consequence, the energy supply was completely cut from the two major energy-producing pathways. Further experiments showed that AA005 resulted in irreversible damage on cell activity including cell cycle and growth, inducing mitochondrial oxidative stress and ultimately leading to cell death. In addition, the in vivo therapeutic efficacy of AA005 was proved on 4T1 xenograft tumor mice model. Our data demonstrate that AA005 exhibited a great potential for future clinical applications in TNBC therapy.

Photothermal combined with intratumoral injection of annonaceous acetogenin nanoparticles for breast cancer therapy

ACGs (annonaceous acetogenins) possess excellent antitumor activity, but their serious accompanying toxicity has prevented their application in the clinic. To address this problem, we therefore constructed an intratumoral drug delivery system integrating chemotherapy and photothermal therapy. The PEGylation of polydopamine nanoparticles (PDA-PEG NPs) possessed an excellent biocompatibility with size of 70.96 ± 2.55 nm, thus can be used as good photothermal materials in the body. Moreover, PDA-PEG NPs can kill half of cancer cells under NIR (near-infrared) laser irradiation, and the survival rate of 4T1 cells is only 1% when ACG NPs and PDA-PEG NPs are combined. In vivo distribution studies showed that the 0.1 mg/kg ACGs NPs + PDA-PEG NPs + NIR group had the highest tumor inhibition rate, which was significantly superior to that of the 0.1 mg/kg ACGs NPs intratumoral injection group (82.65% vs. 59.08%). Altogether, the combination of PDA-PEG NPs + NIR with chemotherapy drugs may provide a feasible and effective strategy for the treatment of superficial tumors.

A Review on the Nutraceutical Anti-Metastatic Importance of Annona Muricata Crude Extract (AMCE) and its Coping Mechanism Against Breast Cancer

Background:

Annona Muricata is used as a folkloric herbal medicine as it has anticancer, antiproliferative and anti-tumorigenic properties. The extracts from various parts of the plant are considered therapeutic due to Annonaceous Acetogenin compounds which are an absolute boon to the versatility of the plant, paving the mechanistic pathways for its therapeutic potential.

Method:

Google Scholar and PubMed databases were reviewed with the main focus on availing information on Annona muricata and its anticancer effect on breast cancer.

Results and Discussion:

- An array of clinical investigations on the dosage of extracts on cell lines, animal models, and human trials provide confirmatory insights of A. muricata as a preventive and therapeutic measure for cancer. The extract when administered at different dosages shows a high cytotoxic effect on the cancer cells, mostly accounting for an IC50 of less than 1000µg/mL which is of significance.

Conclusion -:

Although high efficacy has been conclusive, assurance of the safety prior to commercialization is of significance. Investigations are required to define the origin and magnitude of side effects along with long-term safety for the enhancement of efficacy and optimum utilization of potential chemo-preventive properties of the plant for the curation of a nutraceutical intervention for cancer that surpasses the traditional medicine.

Biomedical Effects of the Phytonutrients Turmeric, Garlic, Cinnamon, Graviola, and Oregano: A Comprehensive Review

Phytonutrients are plant foods that contain many natural bioactive compounds, called phytochemicals, which show specific biological activities. These phytonutrients and their phytochemicals may play an important role in health care maintaining normal organism functions (as preventives) and fighting against diseases (as therapeutics). Phytonutrients’ components are the primary metabolites (i.e., proteins, carbohydrates, and lipids) and phytochemicals or secondary metabolites (i.e., phenolics, alkaloids, organosulfides, and terpenes). For years, several phytonutrients and their phytochemicals have demonstrated specific pharmacological and therapeutic effects in human health such as anticancer, antioxidant, antiviral, anti-inflammatory, antibacterial, antifungal, and immune response. This review summarizes the effects of the most studied or the most popular phytonutrients (i.e., turmeric, garlic, cinnamon, graviola, and oregano) and any reported contraindications. This article also presents the calculated physicochemical properties of the main phytochemicals in the selected phytonutrients using Lipinski’s, Veber’s, and Ghose’s rules. Based on our revisions for this article, all these phytonutrients have consistently shown great potential as preventives and therapeutics on many diseases in vitro, in vivo, and clinical studies.

A prospective observational study on oral administration of Ellagic Acid and Annona Muricata in patients affected by non-muscle invasive bladder cancer not undergoing maintenance after 6-week intravesical prophylaxis

INTRODUCTION

BCG and MMC shortage and Covid-19 pandemic, more recently, limit accessibility to maintenance regimen in intravesical prophylaxis against recurrence of non-muscle invasive bladder cancer (NMIBC). Ellagic acid (EA) and Annona muricata (AM) exert antitumor activity against different human tumours. An observational prospective study on the prophylactic effect of oral administration of EA+AM in patients avoiding maintenance regimen is presented.

MATERIALS AND METHODS

Patients affected by NMIBC and not undergoing maintenance after a 6-week course of intravesical prophylaxis with MMC or BCG were entered. Tis and very high-risk tumours were excluded. After informed consent, the patients were subdivided in relation to the oral assumption or not of EA (100 mg) plus AM (100 mg), daily for 6 months. All patients were submitted to 3-month cytology and cystoscopy.

RESULTS

162 (90%) of 180 entered patients are evaluable, 90 and 72 receiving or not EA+AM. No difference emerged in patients' characteristics between the two groups. BCG was given in 86 (54%) and chemotherapy in 74 (46%) patients. The recurrence free rate at 3, 6 and 12 months in patients assuming or not EA was 96.5% versus 84.6% (p = 0.003), 85.4% versus 64.8% (p = 0.005) and 74.2% versus 60.6% (p = 0.246), respectively. The recurrence free survival at 12 months in patients assuming or not EA was 63.0% versus 34.5% (p < 0.0001).

DISCUSSION AND CONCLUSIONS

Our study suffers several limits: not randomized trial although prospective, limited number of patients and short follow-up, nevertheless it shows the prophylactic effect of oral EA+AM in absence of maintenance after intravesical chemotherapy or immunotherapy induction.

Leaf and Fruit Methanolic Extracts of Azadirachta indica Exhibit Antifertility Activity on Rats' Sperm Quality and Testicular Histology

BACKGROUND

The world's population is still growing, having an impact on the environment and the economic growth of developing countries; so that, there is a particular interest in the development of new fertility control methods, focused on male contraception.

OBJECTIVE

The objective of this study was to evaluate the effect of methanolic extracts of leaf and fruit of Azadirachta indica on sperm quality and testicular histology of Long Evans rats.

METHODS

Antifertility effects of a methanolic leaf and fruit extracts of A. indica on 24 male rats were investigated. The animals were randomly divided into two control groups and four treatment groups (n=4). Doses of the leaf and fruit extract were given at concentrations of 100 and 200 μg mL-1.

RESULTS

A significant decrease in the viability of sperm cells was observed. The leaf extract at a concentration of 200 μg mL-1 inhibited cell viability compared to the negative control (p< 0.001). The percentage of abnormal cells in leaf extract was shown in 100 and 200 μg mL-1, the conditions at which a higher percentage of morphological irregularities of observed (15% and 16% respectively). The results show that there was cellular detachment in the seminiferous epithelium in the experimental groups treated with methanolic extracts. Sperm death was observed without decreasing the number of sperm.

CONCLUSION

The methanolic extracts of Azadirachta indica have a modulating effect on the spermatogenesis of experimental rats through sperm morphological alterations.

In vitro studies of Annona muricata L. extract-loaded electrospun scaffolds for localized treatment of breast cancer

This paper presents in vitro studies of the sustained release of Annona muricata leaf extracts (AME) from hybrid electrospun fibers for breast cancer treatment. Electrospun hybrid scaffolds were fabricated from crude AME extracts, poly(lactic-co-glycolic acid)/gelatin (PLGA/Ge) and pluronic F127. The physicochemical properties of the AME extract and scaffolds were studied. The antiproliferative effects of the scaffolds were also assessed on breast cancer (MCF-7 and MDA-MB-231) and non-tumorigenic breast (MCF10A) cell lines. Scanning electron microscope micrographs revealed a random network of micro- and submicron fibers. In vitro drug release profiles, governed by quasi-Fickian diffusion at pH 7.4 and non-Fickian super case II at pH 6.7, showed initial burst AME release from the PLGA/Ge-AME and PLGA/Ge-F127/AME fibers at pH 7.4, and burst release from PLGA/Ge-F127/AME (not observed from PLGA/Ge-AME) at pH 6.7. Then, a slower, sustained release of the remaining AME from the fibers, attributed to the onset of degradation of the PLGA/Ge backbone, was observed for the next 72 hr. The cumulative release of AME was 89.33 ± 0.73% (PLGA/Ge-AME) and 51.17 ± 7.96% (PLGA/Ge-F127/AME) at pH 7.4, and 9.27 ± 2.3% and 73.5 ± 4.5%, respectively, at pH 6.7. Pluronic F127 addition increased the drug loading capacity and prolonged the sustained AME release from the fibers. The released AME significantly inhibited the in vitro growth of the breast cancer cells more than the non-tumorigenic cells, due to the induction of apoptosis, providing evidence for using pluronic F127-containing electrospun fibers for sustained and localized AME delivery to breast cancer cells.

Effects of Annona muricata Extract on Triple-Negative Breast Cancer Cells Mediated Through EGFR Signaling

Purpose

To evaluate the antiproliferative activity and the mechanisms of action of Annona muricata ethyl acetate (AMEA) extract and one of its active fractions on BT-20 TNBC cells.

Methods

The triple-negative human breast cancer BT-20 cells were used. After the preparation and extraction of Annona muricata ethyl acetate (AMEA), the ethyl acetate extract was exposed to a preparative thin layer chromatography (TLC) plate. From this preparative TLC plate, eight individual bands were collected. Each band was scraped and removed from the plate and soaked in ethyl acetate. After filtration, all eight fractions were then tested on the BT-20 TNBC cells using the MTS cell viability assay. The expressions of EGFR, p-EGFR, AKT, p-AKT, MAPK, p-MAPK, cyclin D1, and NF-κB p65 were measured using Western blot analysis.

Results

The AMEA showed a significant decrease in NF-κB p65 protein expression and BT-20 cell viability, as determined via the MTS assay. Furthermore, the AMEA was subjected to preparative thin layer chromatography (TLC), and eight fractions were obtained. From the eight fractions, only fraction 4 (F4) showed a significant reduction in cell viability in the MTS assay. Immunoblotting analysis revealed that AMEA and F4 formed an antiproliferative effect. These effects were complemented by a downregulation of cyclin D1 assembly, causing cell-cycle arrest at the G1/S phase. Furthermore, NF-κB was measured because of its involvement in the progression of cancers.

Conclusion

The antiproliferative influence is produced through EGFR-mediated signaling pathways, which include AKT, MAPK, NF-κB, and cyclin D1 inhibition. Further studies will be required to demonstrate the possible applications of this natural product in breast cancer therapy.

Synthesis and Cytotoxic Property of Annonaceous Acetogenin Glycoconjugates

Background

Annonaceous acetogenins (ACGs) are secondary metabolites produced by the Annonaceae family and display potent anticancer activity against various cancer cell lines. Squamocin and bullatacin are two examples of ACGs that show promising antitumor activity; however, preclinical data are not sufficient partly due to their being highly lipophilic and poorly soluble in water. These compounds also display high toxicity to normal cells. Due to these disadvantageous properties, the therapeutic potential of squamocin and bullatacin as antitumor agents has not been fully evaluated.

Methods

In order to enhance their water solubility and potentially improve their cancer targeting, squamocin and bullatacin were conjugated to a glucose or galactose to yield glycosylated derivatives by direct glycosylation or the Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction (the click reaction). The synthesized compounds were evaluated for their anticancer property against HeLa, A549 and HepG2 cancer cell lines using MTT assay.

Results

Nine glycosyl derivatives were synthesized and structurally characterized. Most of them show comparable in vitro cytotoxicity against HeLa, A549 and HepG2 cancer cell lines as their parent compounds squamocin and bullatacin. It appears that the type of sugar residue (glucose or galactose), the position at which the sugar residue is attached, and whether or not a linking spacer is present do not affect the potency of these derivatives much. The solubility of galactosylated squamocin 13 in phosphate buffer saline (PBS, pH = 7) is greatly improved (1.37 mg/mL) in comparison to squamocin (not detected in PBS).

Conclusion

The conjugation of a glucose or galactose to squamocin and bullatacin yields glycosyl derivatives with similar level of anticancer activity in tested cell lines. Further studies are needed to demonstrate whether or not these compounds show reduced toxicity to normal cells and their therapeutic potential as antitumor agents.

Risk assessment regarding the use of Annona muricata in food supplements

The current risk assessment was performed in the context of the European Food Risk Assessment Fellowship Programme (EU-FORA) supported by EFSA and was intended to evaluate possible health risks associated with the consumption of Annona muricata L. (Annonaceae) and derived food supplements. A. muricata grows as a tree and is native to the Caribbean and Central America. Preparations made from different plant parts of A. muricata (i.e. fruit, leaves, bark, roots) have been used as herbal medicine and are also marketed worldwide as over-the-counter food supplements that have been purported to support general health or to treat a wide range of health conditions, particularly cancer and parasitic infections. However, open questions remain regarding the safety of A. muricata-based food supplements, since Annonaceae have been reported to contain potentially neurotoxic compounds, i.e. acetogenins. The assessment conducted within the present fellowship programme shows that substantial uncertainties exist regarding the safe use of A. muricata-based supplements. The available data provide indications of neurotoxic potential of certain A. muricata preparations. The paucity of adequate studies, particularly related to long-term use of A. muricata supplements, currently does not allow the establishment of a safe intake level. Within this technical report a workflow of the project is presented.

Bio-Guided Isolation of Acetogenins from Annona cherimola Deciduous Leaves: Production of Nanocarriers to Boost the Bioavailability Properties

Annonaceous acetogenins (ACGs) are lipophilic polyketides isolated exclusively from Annonaceae. They are considered to be amongst the most potent antitumor compounds. Nevertheless, their applications are limited by their poor solubility. The isolation of ACGs from Annona cherimola leaves, an agricultural waste, has not been reported to date. Molvizarin (1) cherimolin-1 (2), motrilin (3), annonacin (4) and annonisin (5) are isolated for the first time from A. cherimola deciduous leaves. Annonacin was found to be four- and two-times more potent in tumoral cells (HeLa, 23.6% live cells; IGROV-1, 40.8% live cells for 24 h) than in HEK-293 at 50 µM (24 h, 87.2% live cells). Supramolecular polymer micelles (SMPMs) were synthesized to encapsulate the major ACG isolated, annonacin, in order to improve its solubility in aqueous media. The bioavailability of this compound was increased by a factor of 13 in a simulated human digestive system when compared with free annonacin and an encapsulation efficiency of 35% was achieved. In addition, the cytotoxic activity of SMPMs that hosted annonacin (100 µM, 24 h, 5.8% live cells) was increased compared with free annonacin in water (100 µM, 24 h, 92% live cells). These results highlight the use of by-products of A. cherimola, and their pure compounds, as a promising source of anticancer agents. The use of SMPMs as nanocarriers of ACGs could be an alternative for their application in food field as nutraceutical to enhance the administration and efficacy.

Total Synthesis of (+)-Petromyroxol, (-)-iso-Petromyroxol, and Possible Diastereomers

The total synthesis of (+)-petromyroxol (1) and its seven diastereomers including the (-)-iso-petromyroxol (2) is described. The employed strategy involves the use of easily available C5-epimeric epoxides 5 and 5' and nonselective anomeric C1-allylation, proceeding with or without inversion at C2, thereby giving the possibility of synthesizing all possible diastereomers. Extensive two-dimensional (2D) NMR analyses of all eight diastereomers have been carried out to assign the chemical shifts of the central carbons and the corresponding attached hydrogens and to learn how the C/H-chemical shifts of the tetrahydrofuran ring were influenced by the adjacent centers.

Modulation of inflammatory pathways, medicinal uses and toxicities of Uvaria species: potential role in the prevention and treatment of inflammation

The therapeutic efficacy of the contemporary anti-inflammatory drugs are well established; however, prolonged use of such can often lead to serious and life-threatening side effects. Natural product-based anti-inflammatory compounds with superior efficacy and minimum toxicity can serve as possible therapeutic alternatives in this scenario. Genus Uvaria is a part of Annonaceae family, while the majority of its species are widely distributed in tropical rain forest regions of South East Asia. Uvaria species have been used extensively used as traditional medicine for treating all sorts of inflammatory diseases including catarrhal inflammation, rheumatism, acute allergic reactions, hemorrhoids, inflammatory liver disease and inflamed joints. Phytochemical analysis of Uvaria species has revealed flavones, flavonoids, tannins, saponins, polyoxygenated cyclohexene and phenolic compounds as major phyto-constituents. This review is an attempt to highlight the anti-inflammatory activity of Uvaria species by conducting a critical appraisal of the published literature. The ethnopharmacological relevance of Uvaria species in the light of toxicological studies is also discussed herein. An extensive and relevant literature on anti-inflammatory activity of Uvaria species was collected from available books, journals and electronic databases including PubMed, ScienceDirect, Scopus, Proquest and Ovid. Extracts and isolates of Uvaria species exhibited significant anti-inflammatory activity through various mechanisms of action. 6,7-di-O-Methyl-baicalein, flexuvarol B, chrysin, (-)-zeylenol, 6-hydroxy-5,7-dimethoxy-flavone, and pinocembrin were the most potent anti-inflammatory compounds with comparable IC₅₀ with positive controls. Therefore, it is suggested that further research should be carried out to determine the pharmacokinetics, pharmacodynamics and toxicity of these therapeutically significant compounds, to convert the pre-clinical results into clinical data for drug development and design.

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.

Phytochemical, Antioxidant and Mitochondrial Permeability Transition Studies on Fruit-Skin Ethanol Extract of Annona muricata

Uncontrolled cell proliferation hallmarks cancer and most cancer cells have developed multiple resistance to the drugs employed for their treatment. The study examined the phytochemical and antioxidant properties of the fruit-skin ethanol extract of Annona muricata Linn. (ESA) and its effect on rat liver mitochondrial membrane permeability transition (MMPT). Qualitative phytochemical study and antioxidant assays were carried out following established protocols while the opening of the MMPT pore in the presence of varying concentrations of the extract was assayed spectrophotometrically under succinate-energized conditions. Calcium chloride (CaCl₂) and spermine were used to trigger and inhibit pore opening respectively. Cytochrome c release was assayed for using ELISA kit. Terpenoids, steroids, phenols among other phytochemicals were found present in ESA and the extract showed very low antioxidant properties at the tested concentrations based on the diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity assay. Lipid peroxidation was induced in a concentration-dependent manner on both the cytosolic and mitochondrial hepatocyte fractions in vitro. In the absence of CaCl₂ 0.84 mg/mL concentration of ESA induced MMPT pore opening by 129% while the extracts showed no inhibitory activity in its presence. The induction fold corresponded with the concentrations of cytochrome c released. The fruit-skin ethanol extract of Annona muricata at certain concentrations may possibly contain bioactive compounds that induce apoptosis.

Bioguided Fractionation, and Antioxidant, Antiproliferative, and Anti-Inflammatory Activity of Annona cacans Warm

This study evaluated to determine the phenolic and flavonoids contents, and antioxidant, anti-inflammatory, and antiproliferative activity of the hydromethanolic extracts of the leaves, pulp, and seeds of Annona cacans. The isolation and structural identification of the constituent acetogenin, phenolic acid, and flavonoids were also reported. Antioxidant capacity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), ethylbenzothiazoline-6-sulfonic acid (ABTS), and β-carotene/linoleic acid methods. Cell proliferation was determined by spectrophotometric quantification of the cellular protein content using a sulforhodamine B assay. Anti-inflammatory activity was evaluated in paw edema model, to myeloperoxidase (MPO) activity induced by carrageenan in mice. Fractionation resulted in the isolation of one acetogenin (annoreticuin-9-one), two flavonoids (quercetin-3-O-β-glucoside-6-O-α-rhamnoside and kaempferol-3-O-β-glucoside), and one phenolic acid (p-coumaric acid). The pulp extract presented potent antioxidant activities by the DPPH (IC₅₀ = 44.08 μg/mL) and ABTS (IC₅₀ = 39.32 μg/mL) methods, as well as high contents of phenols (618.95 mg GA/g) and flavonoids (477.35 mg QE/g). The bioguided fractionation demonstrated that the ethyl acetate fraction of the pulp extract and annoreticuin-9-one showed potent antiproliferative activity against ovarian cancer (GI₅₀ = 6.4 μg/mL). The anti-inflammatory activity demonstrated significant inhibition of edema compared to the control group in 2 and 4 h; in addition, the extracts inhibited the increase in MPO activity after 6 h, when compared to the DEX and control groups. For the first time, this study demonstrated antioxidant, anti-inflammatory, and antiproliferative activity, as well as compounds isolated, suggesting that A. cacans could also be potential sources for prevention of cancer and other diseases associated with oxidative stress.

Modulation of cancer signalling pathway(s) in two -stage mouse skin tumorigenesis by annonacin

Background

Annonacin, an annonaceous acetogenin isolated from Annona muricata has been reported to be strongly cytotoxic against various cell lines, in vitro. Nevertheless, its effect against in vivo tumor promoting activity has not been reported yet. Therefore, this study was aimed to investigate antitumor-promoting activity of annonacin via in vivo two-stage mouse skin tumorigenesis model and its molecular pathways involved.

Methods

Mice were initiated with single dose of 7,12-dimethylbenz[α]anthracene (DMBA) (390 nmol/100 μL) followed by, in subsequent week, repeated promotion (twice weekly; 22 weeks) with 12-O-tetradecanoylphorbol-13-acetate (TPA) (1.7 nmol/100 μL). Annonacin (85 nM) and curcumin (10 mg/kg; reference) were, respectively, applied topically to DMBA/TPA-induced mice 30 min before each TPA application for 22 weeks. Upon termination, histopathological examination of skin, liver and kidney as well as genes and proteins expression analysis were conducted to elucidate the potential mechanism of annonacin.

Results

With comparison to the carcinogen control, Annonacin significantly increased the tumor latency period and reduced the tumor incidence, tumor burden and tumor volume, respectively. In addition, it also suppressed tumorigenesis manifested by significant reduction of hyperkeratosis, dermal papillae and number of keratin pearls on skin tissues. Annonacin also appeared to be non-toxic to liver and kidney. Significant modulation of both AKT, ERK, mTOR, p38, PTEN and Src genes and proteins were also observed in annonacin-targeted signaling pathway(s) against tumorigenesis.

Conclusions

Collectively, results of this study indicate that annonacin is a potential therapeutic compound targeting tumor promoting stage in skin tumorigenesis by modulating multiple gene and protein in cancer signaling pathways without apparent toxicity.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2650-1) contains supplementary material, which is available to authorized users.

Droplet probe: coupling chromatography to the in situ evaluation of the chemistry of nature

Covering: up to 2019The chemistry of nature can be beautiful, inspiring, beneficial and poisonous, depending on perspective. Since the isolation of the first secondary metabolites roughly two centuries ago, much of the chemical research on natural products has been both reductionist and static. Typically, compounds were isolated and characterized from the extract of an entire organism from a single time point. While there could be subtexts to that approach, the general premise has been to determine the chemistry with very little in the way of tools to differentiate spatial and/or temporal changes in secondary metabolite profiles. However, the past decade has seen exponential advances in our ability to observe, measure, and visualize the chemistry of nature in situ. Many of those techniques have been reviewed in this journal, and most are tapping into the power of mass spectrometry to analyze a plethora of sample types. In nearly all of the other techniques used to study chemistry in situ, the element of chromatography has been eliminated, instead using various ionization sources to coax ions of the secondary metabolites directly into the mass spectrometer as a mixture. Much of that science has been driven by the great advances in ambient ionization techniques used with a suite of mass spectrometry platforms, including the alphabet soup from DESI to LAESI to MALDI. This review discusses the one in situ analysis technique that incorporates chromatography, being the droplet-liquid microjunction-surface sampling probe, which is more easily termed "droplet probe". In addition to comparing and contrasting the droplet probe with other techniques, we provide perspective on why scientists, particularly those steeped in natural products chemistry training, may want to include chromatography in in situ analyses. Moreover, we provide justification for droplet sampling, especially for samples with delicate and/or non-uniform topographies. Furthermore, while the droplet probe has been used the most in the analysis of fungal cultures, we digest a variety of other applications, ranging from cyanobacteria, to plant parts, and even delicate documents, such as herbarium specimens.

The graviola impact on human astroglioma cells: functional significance of MUDENG

Graviola (Annona muricate) is a coveted tropical plant that has been found to be effective against many human cancers. Malignant glioblastoma multiformes are the most common and aggressive malignant forms of astrocytoma in the central nervous system. MUDENG (Mu-2-related death-inducing gene, MuD) is involved in cell death signaling. In this study, we investigated the impact of extracts from graviola leaves (from Korea and Africa), fruits and seeds against human astroglioma cells. Interestingly, graviola leaf extract-Korea (GLE-K), graviola leaf extract-Africa (GLE-A) and graviola fruit extract-Africa (GFE-A) exhibited significant cytotoxic effects on the cell proliferation in a dose-dependent manner and altered the MuD expression pattern. Cell cycle analyses revealed that GLE-A and GLE-K triggered no significant induction of apoptosis at concentrations up to 5% in U251-MG cells, while in GLE-K treated cells at 10% concentrations, there were much fewer apoptotic cells (33.64%) compared to those in GLE-A (73.55%) treated cells. In the case of GFE-A treated cells, 5% graviola extract (GE) concentration resulted in predominant cells entering the apoptotic phase (59.31%), whereas almost no significant increase in apoptotic cells was observed in GSE-A treated cells (1.38%) even up to 25% of graviola extract (GE) concentration. While using stable transfectants knock-out (KO)(-)-and overexpressing (OE)-MuD(+), significant and consistent differences in the cell viability (enhanced anti-astroglioma effect of GEs) were observed in KO-MuD(-) cells. This validated the functional consequence of MuD in the anti-astroglioma activity of GEs. Our results confirmed that GFE-A possesses the highest anti-astroglioma activity followed by the leaf extracts (GLE-A/K). This is the first report that highlights the MuD aspect of GEs.

In vitro anticancer activity Annona squamosa extract nanoparticle on WiDr cells

This study aimed to prepare Annona squamosa leaf extract-loaded chitosan nanoparticles (nano-ASLE) against human colon cancer (WiDr) cells. Nano-ASLE was made with ionic gelation method. Four concentrations of the nano-ASLE (50, 100, 200, and 400 μg/mL) in dimethyl sulfoxide were prepared on WiDr cells to determine the IC₅₀ value using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Then, it was divided into three groups of concentration of IC₅₀, 2IC₅₀, and 4IC₅₀ and continued with analysis of caspase-3 expression and cell cycle arrest. The results of particles size were obtained 535.1 nm and showed potent cytotoxicity with IC₅₀ 292.39 μg/mL. The expression of caspase-3 increased significantly and caused cell cycle arrest at the G2/M phase and induced apoptosis on WiDr cells. Further studies are needed to obtain the loading efficiency, release of drug concentration, and in vivo study of nano-ASLE to suppress WiDr cells.

Antiangiogenic Activity and Chemical Derivatization of the Neurotoxic Acetogenin Annonacin Isolated from Asimina triloba

Annonacin (1) was isolated from the North American pawpaw ( Asimina triloba), as reported earlier from these laboratories. Natural 1 was submitted to the rat aortic ring bioassay for evaluation of antiangiogenic activity and was found to inhibit microvessel growth (IC₅₀ value of 3 μM). 4,10,15,20-Tetraazido derivatives of 1 were prepared by permesylation followed by azide displacement or by iodination followed by azide displacement. The tetraazide derived from mesylation/azidation was antiangiogenic, while that derived from iodination/azidation exhibited no appreciable activity. The membrane permeability of natural 1 was evaluated using the parallel artificial membrane permeability assay and was found to be marginally permeable as compared to several clinically relevant compounds.

Anticancer Properties of Graviola (Annona muricata): A Comprehensive Mechanistic Review

Graviola (Annona muricata) is a small deciduous tropical evergreen fruit tree, belonging to the Annonaceae family, and is widely grown and distributed in tropical and subtropical regions around the world. The aerial parts of graviola have several functions: the fruits have been widely used as food confectionaries, while several preparations, especially decoctions of the bark, fruits, leaves, pericarp, seeds, and roots, have been extensively used in traditional medicine to treat multiple ailments including cancers by local communities in tropical Africa and South America. The reported therapeutic benefits of graviola against various human tumors and disease agents in in vitro culture and preclinical animal model systems are typically tested for their ability to specifically target the disease, while exerting little or no effect on normal cell viability. Over 212 phytochemical ingredients have been reported in graviola extracts prepared from different plant parts. The specific bioactive constituents responsible for the major anticancer, antioxidant, anti-inflammatory, antimicrobial, and other health benefits of graviola include different classes of annonaceous acetogenins (metabolites and products of the polyketide pathway), alkaloids, flavonoids, sterols, and others. This review summarizes the current understanding of the anticancer effects of A. muricata and its constituents on diverse cancer types and disease states, as well as efficacy and safety concerns. It also includes discussion of our current understanding of possible mechanisms of action, with the hope of further stimulating the development of improved and affordable therapies for a variety of ailments.

Targeted and non-targeted analysis of annonaceous alkaloids and acetogenins from Asimina and Annona species using UHPLC-QToF-MS

In current work, targeted and non-targeted analysis of alkaloids and acetogenins from methanolic extracts of Asimina, Annona species and dietary supplements have been performed using UHPLC-QToF in positive ion mode. Thirty-five standard compounds (twelve alkaloids and twenty-three acetogenins) were used for the analysis. The fragment ions produced by collision induced dissociation (CID) revealed the characteristic cleavage and provided structural information. Aporphine alkaloids and acetogenins are the major groups found in Asimina and Annona species. An untargeted analysis based on high-resolution mass spectrometry was carried out to profile the alkaloids and acetogenins from Asimina species (As. triloba, As. parviflora). Magnoflorine, being a major alkaloid from twigs of As. triloba samples, was used as an example to discuss the fragmentation patterns. In (+)-ESI-MS, magnoflorine gave [M]⁺ ions at m/z 342.1705. The fragment ions at m/z 297.1127 [M-(CH₃)₂NH]⁺, 282.0886 [M-(CH₃)₃NH]⁺, 265.0865 [M-(CH₃)₂NH-CH₃OH]⁺, 237.0916 [M-(CH₃)₂NH-CH₃OH-CO]⁺, and 222.0681 [M-(CH₃)₂NH-CH₃OH-CO-CH₃]⁺ resulted from the [M]⁺ molecular ion. One dietary supplement claiming to contain paw paw (As. triloba) was also analyzed and showed a similar profile to twigs of As. triloba. A total of 131 compounds including standard compounds were identified from the different parts of As. triloba and As. parviflora samples. These compounds can be used to distinguish Asimina species. However, for definite identification of these unknown components, further investigation is required. This may provide a model for the rapid screening and structural characterization of bioactive constituents from plant extracts in a single analysis.

Annonacin promotes selective cancer cell death via NKA-dependent and SERCA-dependent pathways

In the healthcare sector, phytocompounds are known to be beneficial by contributing or alleviating a variety of diseases. Studies have demonstrated the progressive effects of phytocompounds on immune-related diseases and to exhibit anticancer effects. Graviola tree is an evergreen tree with its extracts (leafs and seeds) been reported having anticancer properties, but the precise target of action is not clear. Using an in silico approach, we predicted that annonacin, an Acetogenin, the active agent found in Graviola leaf extract (GLE) to potentially act as a novel inhibitor of both sodium/potassium (NKA) and sarcoplasmic reticulum (SERCA) ATPase pumps. We were able to validate and confirm the in silico studies by showing that GLE inhibited NKA and SERCA activity in intact cells. In the present study, we also demonstrated the antiproliferative and anticancer effects of GLE in a variety of cancer cell lines with limited toxic effects on non-transformed cells. Moreover, our results revealed that known inhibitors of both NKA and SERCA pumps could also promote cell death in several cancer cell lines. In addition, a mouse xenograft cancer model showed GLE as able to reduce tumor size and progression. Finally, bioprofiling studies indicated a strong correlation between overexpression of both NKA and SERCA gene expression vs. survival rates. Overall, our results demonstrated that GLE can promote selective cancer cell death via inhibiting NKA and SERCA, and thus can be considered as a potential novel treatment for cancer. After molecular analysis of GLE by liquid chromatography–mass spectrometry and ESI–QTOF–MS analysis, it was found that the MS spectrum of the high abundant chromatographic peak purified sample highly consisted of annonacin.