Leociley Rocha Alencar Menezes

Antitumour Activity of the Microencapsulation of Annona vepretorum Essential Oil

Annona vepretorum Mart. (Annonaceae), popularly known as ‘bruteira’, has nutritional and medicinal uses. This study investigated the chemical composition and antitumour potential of the essential oil of A. vepretorum leaf alone and complexed with β‐cyclodextrin in a microencapsulation. The essential oil was obtained by hydrodistillation using a Clevenger‐type apparatus and analysed using GC‐MS and GC‐FID. In vitro cytotoxicity of the essential oil and some of its major constituents in tumour cell lines from different histotypes was evaluated using the alamar blue assay. Furthermore, the in vivo efficacy of essential oil was demonstrated in mice inoculated with B16‐F10 mouse melanoma. The essential oil included bicyclogermacrene (35.71%), spathulenol (18.89%), (E)‐β‐ocimene (12.46%), α‐phellandrene (8.08%), o‐cymene (6.24%), germacrene D (3.27%) and α‐pinene (2.18%) as major constituents. The essential oil and spathulenol exhibited promising cytotoxicity. In vivo tumour growth was inhibited by the treatment with the essential oil (inhibition of 34.46%). Importantly, microencapsulation of the essential oil increased in vivo tumour growth inhibition (inhibition of 62.66%).

Chemical composition of essential oils from Annona vepretorum Mart. and Annona squamosa L. (Annonaceae) leaves and their antimalarial and trypanocidal activities

Here, we describe the trypanocidal and antimalarial activities from essential oils extracted from Annona vepretorum (AVOE) and Annona squamosa (ASOE) (Annonaceae) leaves. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography–mass spectrometry (GC–MS) and GC–flame ionization detection (GC–FID). A total of twenty-one compounds were identified in AVOE and twenty-three in ASOE. The sesquiterpenes are more abundant in the both essential oils. ASOE contained significant quantities of (E)-caryophyllene (27.4%), germacrene D (17.1%) and bicyclogermacrene (10.8%). The major compounds in AVOE were bicyclogermacrene (39.0%), spathulenol (14.0%) and α-phellandrene (11.5%). The essential oils demonstrated potent trypanocidal and antimalarial activities with values of ic50 lower than 20 μg/mL, and a strong inhibition of the proliferation of amastigotes, the clinically relevant forms of Trypanosoma cruzi. In addition, through ultrastructural studies and flow cytometry analysis with trypomastigotes of T. cruzi, we identified significant ultrastructural alterations induced by the essential oils, especially in the cell membrane and mitochondria, which ultimately results in necrotic parasite death.

Biological activities of the essential oil from the leaves of Xylopia laevigata (Annonaceae)

The essential oil from the leaves of Xylopia laevigata was obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and GC/flame ionization detector (GC/FID). Thirty-six compounds representing 97.48% of the crude essential oil were identified. The major compounds identified were -muurolene (17.99%), -cadinene (13.45%), germacrene D (9.09%), bicyclogermacrene (7.00%), -copaene (5.98%), and (E)-caryophyllene (5.43%). The biological activities of the essential oil against Trypanosoma cruzi epimastigote forms, yeast, bacteria, Aedes aegypti larvae, antioxidant properties and antiproliferative activity against tumor cell lines were investigated. The essential oil showed trypanocidal activity with IC50 value of 93.9±2.6 μg/mL. For antibacterial and antifungal activities, the best results were observed against Staphylococcus aureus (ATCC14458), Staphylococcus epidermidis (ATCC1228) and Candida tropicalis (ATCC 157), all with a minimal inhibitory concentration value of 100 μg/mL. The essential oil showed antioxidant capacity of 1468.96 μmol of TE/g in the oxygen radical absorbance capacity (ORACFL) assay. The oil showed moderate larvicidal activity with LC50 value of 632.36 μg/mL. The essential oil exhibited potent antiproliferative activity against all cell lines evaluated with total growth inhibition (TGI) value <40 μg/mL, exception for K562 cell line (TGI>250 μg/mL). The highest activity was observed against cell lines of UACC-62, NCI-ADR/RES and NCI-H460, with TGI values of 4.03, 4.26 and 8.37 μg/mL, respectively. For the VERO cell (non-cancer cell line), the TGI value was of 15.94 μg/mL.

Cytotoxic Alkaloids from the Stem of Xylopia laevigata

Xylopia laevigata (Annonaceae), known locally as “meiú” or “pindaíba”, is widely used in folk medicine in Northeastern Brazil. In the present work, we performed phytochemical analyses of the stem of X. laevigata, which led to the isolation of 19 alkaloids: (−)-roemerine, (+)-anonaine, lanuginosine, (+)-glaucine, (+)-xylopine, oxoglaucine, (+)-norglaucine, asimilobine, (−)-xylopinine, (+)-norpurpureine, (+)-N-methyllaurotetanine, (+)-norpredicentrine, (+)-discretine, (+)-calycinine, (+)-laurotetanine, (+)-reticuline, (−)-corytenchine, (+)-discretamine and (+)-flavinantine. The in vitro cytotoxic activity toward the tumor cell lines B16-F10 (mouse melanoma), HepG2 (human hepatocellular carcinoma), K562 (human chronic myelocytic leukemia) and HL-60 (human promyelocytic leukemia) and non-tumor peripheral blood mononuclear cells (PBMCs) was tested using the Alamar Blue assay. Lanuginosine, (+)-xylopine and (+)-norglaucine had the highest cytotoxic activity. Additionally, the pro-apoptotic effects of lanuginosine and (+)-xylopine were investigated in HepG2 cells using light and fluorescence microscopies and flow cytometry-based assays. Cell morphology consistent with apoptosis and a marked phosphatidylserine externalization were observed in lanuginosine- and (+)-xylopine-treated cells, suggesting induction of apoptotic cell death. In addition, (+)-xylopine treatment caused G2/M cell cycle arrest in HepG2 cells. These data suggest that X. laevigata is a potential source for cytotoxic alkaloids.

Xylopine Induces Oxidative Stress and Causes G2/M Phase Arrest, Triggering Caspase-Mediated Apoptosis by p53-Independent Pathway in HCT116 Cells

Xylopine is an aporphine alkaloid that has cytotoxic activity to cancer cells. In this study, the underlying mechanism of xylopine cytotoxicity was assessed in human colon carcinoma HCT116 cells. Xylopine displayed potent cytotoxicity in different cancer cell lines in monolayer cultures and in a 3D model of cancer multicellular spheroids formed from HCT116 cells. Typical morphology of apoptosis, cell cycle arrest in the G2/M phase, increased internucleosomal DNA fragmentation, loss of the mitochondrial transmembrane potential, and increased phosphatidylserine externalization and caspase-3 activation were observed in xylopine-treated HCT116 cells. Moreover, pretreatment with a caspase-3 inhibitor (Z-DEVD-FMK), but not with a p53 inhibitor (cyclic pifithrin-α), reduced xylopine-induced apoptosis, indicating induction of caspase-mediated apoptosis by the p53-independent pathway. Treatment with xylopine also caused an increase in the production of reactive oxygen/nitrogen species (ROS/RNS), including hydrogen peroxide and nitric oxide, but not superoxide anion, and reduced glutathione levels were decreased in xylopine-treated HCT116 cells. Application of the antioxidant N-acetylcysteine reduced the ROS levels and xylopine-induced apoptosis, indicating activation of ROS-mediated apoptosis pathway. In conclusion, xylopine has potent cytotoxicity to different cancer cell lines and is able to induce oxidative stress and G2/M phase arrest, triggering caspase-mediated apoptosis by the p53-independent pathway in HCT116 cells.

Chemical composition and antiparasitic activity of essential oils from leaves of Guatteria friesiana and Guatteria pogonopus (Annonaceae)

Abstract Natural products represent a valuable source for discovery of antiparasitic agents. Here, we describe the antiparasitic activity from essential oils extracted from leaves of Guatteria friesiana (EOGF) and Guatteria pogonopus (EOGP) (Annonaceae). The essential oils were obtained by hydrodistillation and analyzed by GC/MS and GC-FID. The sesquiterpenes are more abundant in both essential oils. G. friesiana are dominated by β-eudesmol (51.9%), γ-eudesmol (18.9%) andα-eudesmol (12.6%). The major compounds identified for EOGP were spathulenol (24.8%), γ-amorphene (14.7%) and germacrene D (11.8%). The essential oils demonstrated potent trypanocidal and antimalarial activities with values of IC50 lower than 41.3 μg/mL. EOGF also inhibits the proliferation of amastigotes. In addition, we identified significant ultrastructural alterations induced by the essential oils, especially in the cell membrane, Golgi complex, endoplasmatic reticulum and mitochondria. The results presented herein reinforce the potential of other members of this family for search of antiparasitic compounds.

Physicochemical Characterization and Antinociceptive Effect of β- cyclodextrin/Lippia pedunculosa Essential Oil in Mice

BACKGROUND Some research studies have shown that Lippia pedunculosa essential oil (EOLP) has interesting biological activities. However, its low water solubility is the main challenge to achieve its therapeutic potential. In this context, Cyclodextrins (CDs) have been widely used in order to overcome this problem due to your capability to improve the physicochemical properties of drugs. OBJECTIVE In this perspective, the main goal of this study was to investigate how the improvement of the physicochemical properties of inclusion complexes (EOLP and β-CD) enhance the antinociceptive effect in mice. METHODS To achieve that, we prepared samples by Physical Mixture (PM), Paste Complexation (PC) and Slurry Complexation (SC) methods, followed by their physicochemical characterization. In addition, it was evaluated if the use of β-CD enhances the antinociceptive effect of EOLP in mice. RESULTS The analysis showed that rotundifolone (72.02%) was the major compound of EOLP and we found out based on DSC results that β-CD protected it from oxidation. In addition, TG techniques demonstrated that the best inclusion methods were PC and SC, due to their greater weight loss (10.8 and 11.6%, respectively) in the second stage (171-312°C), indicating that more complexed oil was released at the higher temperature than oil free. Other characteristics, such as changes in the typical crystalline form, and reduced particle size were observed by SEM and laser diffraction, respectively. The SC was the most effective complexation method, once the presence of rotundifolone was detected by FTIR. Based on that, SC method was used in all mice tests. In this regard, the number of paw licks was reduced for both compounds (all doses), but EOLP was more effective in reducing the nociceptive behavior. CONCLUSION Therefore, CDs seem not to be a good tool to enhance the pharmacological properties of EOs rich in peroxide compounds such as rotundifolone.