Design and development of orally disintegrating films: A platform based on hydroxypropyl methylcellulose and guar gum.

From a design of experiments (DOE) performed under four independent variables, with the filmogenicity conditions and shortest disintegration time as the answers, a new oral disintegrating film (ODF) based on hydroxypropyl methylcellulose (HPMC) and guar gum (GG) with the essential oil of Plectranthus amboinicus L. (EOPA) was developed. Sixteen formulations were tested for filmogenicity, homogeneity, and viability. The better selected ODF required 230.1 s for complete disintegration. The retention rate of the EOPA was quantified using the nuclear magnetic resonance hydrogen technique (H1 NMR), which identified the presence of 0.14 % carvacrol. The scanning electron microscopy showed a smooth and homogeneous surface with the presence of small white dots. Through the disk diffusion test, the EOPA was able to inhibit the growth of clinical strains of the Candida genus and gram-positive and gram-negative bacterial strains. This work opens new perspectives for the development of antimicrobial ODFS used in clinical practice.

Bis-nor-diterpene from Cnidoscolus quercifolius (Euphorbiaceae) induces tubulin depolymerization-mediated apoptosis in BRAF-mutated melanoma cells.

A phytochemical investigation of cytotoxic extract and fractions of Cnidoscolus quercifolius Pohl led to isolation of five terpenoids, including three lupane-type triterpenes (1-3) and two bis-nor-diterpenes (4-5). Compounds 4 (phyllacanthone) and 5 (favelanone) are commonly found in this species and have unique chemical structure. Although their cytotoxic activity against cancer cells has been previously reported, the anticancer potential of these molecules remains poorly explored. In this paper, the antimelanoma potential of phyllacanthone (PHY) was described for the first time. Cell viability assay showed a promising cytotoxic activity (IC50 = 40.9 µM) against chemoresistant human melanoma cells expressing the BRAF oncogenic mutation (A2058 cell line). After 72 h of treatment, PHY inhibited cell migration and induced apoptosis and cell cycle arrest (p < 0.05). Immunofluorescence assay showed that the pro-apoptotic effect of PHY is probably associated with tubulin depolymerization, resulting in cytoskeleton disruption of melanoma cells. Molecular docking investigation confirmed this hypothesis given that satisfactory interaction between PHY and tubulin was observed, particularly at the colchicine binding site. These results suggest PHY from C. quercifolius could be potential leader for the design of new antimelanoma drugs.

Corrigendum to: "Inclusion of vitexin in ß-cyclodextrin: preparation, characterization and expectorant/antitussive activities" [Heliyon 6 (12) (December 2020) e05461].

[This corrects the article DOI: 10.1016/j.heliyon.2020.e05461.].

Naphthoquinone-based Hydrazone Hybrids: Synthesis and Potent Activity Against Cancer Cell Lines.

BACKGROUND: Natural naphthoquinones have shown diversified biological activities including antibacterial, antifungal, antimalarial, and cytotoxic activities. However, they are also compounds with acute cytotoxicity, immunotoxicity, carcinogenesis, and cardio- and hepatotoxicity, and the modification at their redox center is an interesting strategy to overcome such harmful activity. OBJECTIVE: In this study, four novel semisynthetic hydrazones, derived from the isomers α- and ß- lapachones (α and ß, respectively) and coupled with the drugs hydralazine (HDZ) and isoniazid (ACIL), were prepared, evaluated by electrochemical methods and assayed for anticancer activity. METHODS: The semisynthetic hydrazones were obtained and had their molecular structures established by NMR, IR, and MS. Anticancer activity was evaluated by cell viability determined by reduction of 3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H-tetrazolium bromide (MTT). The electrochemical studies, mainly cyclic voltammetry, were performed, in aprotic and protic media. RESULTS: The study showed that the compounds 2, 3, and 4 were active against at least one of the cancer cell lines evaluated, compounds 3 and 4 being the most cytotoxic. Toward HL-60 cells, compound 3 was 20x more active than ß-lapachone, and 3x more cytotoxic than doxorubicin. Furthermore, 3 showed an SI value of 39.62 for HL-60 cells. Compound 4 was active against all cancer cells tested, with IC50 values in the range 2.90-12.40 µM. Electrochemical studies revealed a profile typical of self-protonation and reductive cleavage, dependent on the supporting electrolyte. CONCLUSION: These results therefore indicate that compounds 3 and 4 are strong candidates as prototypes of new antineoplastic drugs.

Jatropha mutabilis, a new source of vitexin: HPLC quantification and pharmacological evaluation.

Jatropha mutabilis (Pohl) Baill is an endemic species of the Caatinga biome, little studied in terms of chemical composition. The objective of this work was to develop an analytical methodology to quantify vitexin in the ethanolic extract of J. mutabilis and to evaluate the expectorant and antitussive activities in mice. The expectorant activity was performed by measuring the phenol red obtained from the bronchoalveolar fluid in animals and the antitussive activity was evaluated by the cough method induced by citric acid (0.4 M). The method developed by HPLC-DAD proved to be simple, linear, precise, accurate, robust and specific. Besides, both vitexin (0.2, 1 and 5 mg/kg) and the extract of J. mutabilis (20, 102, 510 mg/kg) showed efficacy in decrease cough and increase aqueous mucus in mice, but vitexin was more potent. Lastly, the identification of vitexin opens the possibility of new studies for J. mutabilis.

Inclusion of vitexin in ß-cyclodextrin: preparation, characterization and expectorant/antitussive activities.

The study aimed to include the isolated vitexin of Jatropha mutabilis in the ß-cyclodextrin cavity to improve the solubility of this flavone. Its characterization was performed by techniques such as 1H NMR/ROESY (Nuclear Magnetic Resonance Spectroscopy), FT-IR (Infrared Spectroscopy with Fourier Transform), SEM (Morphological analysis of IC by Scanning Electron Microscopy) and dissolution study in vitro. In addition, the following activities were evaluated in the animal models: expectorant, phenol red dosage in bronchoalveolar lavage and antitussive, cough induced by citric acid. In the characterization of the complex, interaction between hydrogens of ring B of vitexin and (H3) of ß-CD was observed, in addition to changes in morphology. In the dissolution test, an increase in the rate of dissolution of vitexin was observed in the first 30 min for the CI vitexin/ß-CD when compared with vitexin. Regarding the pharmacological activity, it was observed that the inclusion complex (IC) vitexin/ß-CD in the equivalent doses of 0.2, 1 and 5 mg/kg of flavone presented higher expectorant activity when compared to vitexin (p < 0.05), suggesting increased bioavailability. As for the antitussive activity, both vitexin and the complex had similar effects and were dose independent. In the toxicity test using Artemia salina, vitexin and IC vitexin/ß-CD were considered non-toxic. At last, the study efficacy of vitexin/ß-CD IC as an expectorant and of vitexin as antitussive. All of these data are being described for the first time.

Toxicological, chemopreventive, and cytotoxic potentialities of rare vegetal species and supporting findings for the Brazilian Unified Health System (SUS).

Caatinga flora which are found in a poor Brazilian region contain a substantial number of endemic taxa with biomedical and social importance for regional communities. This study examined the antioxidant and cytotoxic potential of 35 samples (extracts/fractions) from 12 Caatinga species and determined the antiproliferative and genotoxic action of dichloromethane fraction from Mimosa caesalpiniifolia stem bark (DC-Mca) on human and vegetal cells. Samples were assessed for chemopreventive ability, toxic effects on Artemia salina shrimp as well as cytotoxicity on tumor cell lines and erythrocytes. DC-Mca was also tested with respect to antiproliferative and genotoxic effects upon normal leukocytes and meristematic cells from A. cepa roots. Some extracts reduced free radical levels >95% and 7 samples exhibited a lethal concentration (LC) 50 < 100 µg/ml upon Artemia salina larvae. Eight samples displayed in vitro antitumor effects and three produced hemolysis. Data also demonstrated the pharmacological significance of bioactive extracts from Brazilian semi-arid region. There was no significant relationship between antioxidant, toxic, and antiproliferative activities, and that these properties were dependent upon the extractant. DC-Mca contained betulinic acid as main compound (approximately 70%), which showed higher (1) cytotoxic activity on cancer cell lines and dividing leukocytes, (2) reduced mitotic index of Allium cepa roots, and (3) induced cell cycle arrest and chromosomal bridges, thereby providing native promising sources for phytotherapy development. ABBREVIATIONS: ABTS: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); AcOH: ethyl acetate; ANOVA: analysis of variance; SUS: Brazilian Unified Health System; DC-Mca: dichloromethane fraction from Mimosa caesalpiniifolia stem bark; DMSO: dimethylsulfoxide; DPPH: 1,1-diphenyl-2-picrylhydrazyl; EC50: effective concentration 50%; EtOAc: ethyl acetate; FDA: Food and Drug Administration; GC-Qms: gas chromatograph quadrupole mass spectrometer; GI: genotoxic index; HCT-116: colon carcinoma line; HL-60: promyelocytic leukemia line; HPLC: high-performance liquid chromatography; HRAPCIMS: high resolution atmospheric pressure chemical ionization mass spectrum; IC50: inhibitory concentration 50%; LC50: lethal concentration 50%; MeOH = methyl alcohol; MI: mitotic index; MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide; MutI: mutagenic index; OVCAR-8 = ovarian carcinoma line; PBMC: peripheral blood mononuclear cells; RPMI-1640: Roswell Park Memorial Institute medium; SF-295: glioblastoma line; TEAC: trolox equivalent antioxidant capacity; TLC: thin-layer chromatography; Trolox: 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid.

Total content of kaurene diterpenes in Annona vepretorum stems via 1 H qNMR: A method for speeding the identification of bioactive extracts.

INTRODUCTION: Kaurene diterpenes (KDs) constitute a chemical class often found in the genus Annona with interesting biological activities. To date, chromatographic tools have been mostly used to determine KDs. Quantitative nuclear magnetic resonance (qNMR) has distinguished itself in quantitative estimation of natural products and is an interesting choice to assess total KD contents. OBJECTIVE: To establish a 1 H qNMR method for determining the total KD contents in extracts and fractions obtained from Annona vepretorum stems. METHODOLOGY: Stems were extracted with hexane and methanol, resulting in the hexane extract (HEX-E) and the methanol extract (MeOH-E). The former was partitioned with the acid-base method to obtain the total alkaloid fraction (TA-F) and the neutral dichloromethane fraction (NDM-F). 1 H qNMR measurements were performed on 400 MHz with samples solubilized in deuterated dimethyl sulfoxide. Quantification was carried out using the signals at 4.71 and 4.78 ppm related to hydrogens of the exocyclic double bond of the basic skeleton of KDs and gallic acid as the standard reference. The selectivity, intra- and inter-day precision, reproducibility, limit of detection, limit of quantification, and robustness of the methodology were evaluated. RESULTS: Using the newly developed method, the total KD contents (in µg/mg) were 653.80 ± 12.15 (HEX-E), 458.90 ± 25.94 (NDM-F), 375.60 ± 27.52 (TA-F), and 315.10 ± 19.20 (MeOH-E). For determining the most promising bioactive sample, the KD contents and the sample discriminations obtained by principal component analysis were correlated to the antibacterial activity. Such approach pointed out HEX-E as a potential source of KDs. CONCLUSION: The developed method offers a fast and simple way of determining total KD contents.

A Brief Review on the Neuroprotective Mechanisms of Vitexin.

The neural dysfunction is triggered by cellular and molecular events that provoke neurotoxicity and neural death. Currently, neurodegenerative diseases are increasingly common, and available treatments are focused on relieving symptoms. Based on the above, in this review we describe the participation of vitexin in the main events involved in the neurotoxicity and cell death process, as well as the use of vitexin as a therapeutic approach to suppress or attenuate neurodegenerative progress. Vitexin contributes to increasing neuroprotective factors and pathways and counteract the targets that induce neurodegeneration, such as redox imbalance, neuroinflammation, abnormal protein aggregation, and reduction of cognitive and/or motor impairment. The results obtained provide substantial evidence to support the scientific exploration of vitexin in these pathologies, since their effects are still little explored for this direction.

Dried extracts of Encholirium spectabile (Bromeliaceae) present antioxidant and photoprotective activities in vitro.

The antioxidant and photoprotective activities of dried extracts from the leaves of Encholirium spectabile were investigated. It was also evaluated the total phenolic and flavonoid contents by the Folin-Ciocalteu and aluminum chloride methods, respectively. Antioxidant activities of the extracts were evaluated by using of 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging and ß-carotene-linoleic acid bleaching and compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) used as reference compounds. The photoprotective effect was evaluated by the spectrophotometric method. The most significant total phenolic and flavonoid contents was of 188.50 ± 27.50 mg of gallic acid equivalent/g and 129.70 ± 4.59 mg of catechin equivalent/g, respectively, for chloroform fraction (Es-CHCl3). The Es-CHCl3 also presented the best antioxidant activity (IC50 25.35 ± 4.35 µg/ml) for DPPH scavenging. The ethanol extract (Es-EtOH), Es-CHCl3 and the fraction ethyl acetate (Es-AcOEt) showed characteristic absorption bands in regions UVB and UVA in a concentration-dependent manner. Es-CHCl3 presented the highest sun protection factor SPF (8.89 ± 2.11). It shows the possibility to use this extract as sunscreen in pharmaceutical preparations.

Antinociceptive activity of ethanol extract from Duguetia chrysocarpa Maas (Annonaceae).

The ethanol extract from the fruits of Duguetia chrysocarpa was evaluated for its antinociceptive activity in chemical and thermal models of nociception in mice. The intraperitoneal administration of the ethanol extract (100, 200, and 400 mg/kg body weight) showed a dose-dependent inhibition of acetic-acid-induced abdominal writhes. The extract also produced a significant inhibition of both phases of the formalin test in all doses tested and increased the reaction time in hot-plate test at dose of 200 mg/kg. The data obtained suggest that the antinociceptive effect of the extract may be mediated via both peripheral and central mechanisms. The phytochemical investigation yielded the isolation of the benzenoid derivative 3-methoxy-4-ethoxy benzoic acid which is being reported for the first time in this genus.

Cytotoxic abietane diterpenes from Hyptis martiusii Benth.

From roots of Hyptis martiusii Benth. two tanshinone diterpenes were isolated, the new 7beta-hydroxy-11,14-dioxoabieta-8,12-diene (1) in addition to the known 7alpha-acetoxy-12-hydroxy-11,14-dioxoabieta-8,12-diene (7alpha-acetoxyroyleanone) (2). Structures of 1 and 2 were established by spectroscopic means. The cytotoxic activity against five cancer cell lines was evaluated. Compounds 1 and 2 displayed considerable cytotoxic activity against several cancer cell lines with IC50 values in the range of 3.1 to 11.5 microg/ml and 0.9 to 7.6 microg/ml, respectively. The cytotoxic activity seemed to be related to inhibition of DNA synthesis, as revealed by the reduction of 5-bromo-2'-deoxyuridine incorporation and induction of apoptosis, as indicated by the acridine orange/ethidium bromide assay and morphological changes after 24 h of incubation in leukemic cells.

Spectral assignments of new diterpenes from Hyptis martiusii Benth.

The structural characterization of two new abietanes and a new spiro-fused tricyclic diterpene isolated from the roots of Hyptis martiusii is described. The first member of a new class of rearranged abietane diterpenoids designated martiusane was characterized by the use of 1D NMR and several 2D shift correlated NMR pulse sequences (1H,1H-COSY, HMQC, HMBC and NOESY). Unambiguous 1H and 13C chemical shift assignments for all compounds are reported.