Preparation of Ethanol Extract of Propolis Loaded Niosome Formulation and Evaluation of Effects on Different Cancer Cell Lines

Propolis is a candidate for cancer treatment with its activity against different tumor cells and, has a wide spectrum of biological and pharmacological activities due to the diversity of its components. In this study, antitumorigenic activities of ethanol extract of propolis (EEP) and ethanol extract of propolis loaded niosome (PLN) were compared using 2D and 3D cell culture. Niosome formulations were prepared by thin film hydration technique. Cell viability of EEP and PLN was analyzed on MCF7, A549, MDA-MB-231, SK-MEL, SK-BR-3, DU145 and L-929 cell lines using MTT assay. L929, MCF7 and A549 cells were cultured using the 3D petri dish technique and their spherical forms were obtained after 142 h. After 24 h, PLN and EEP application, cell viability analysis was performed on 3D cultures with WST assay. As a result, niosome formulations containing EEP showed higher activity than ethanol extract of propolis in cancer cells. While a slow decrease was observed in cell viability in EEP treated cancer cells, it was observed that the percentage viability rates decreased in a shorter time in PLN treated cancer cells. Also, PLN can be used as an anticancer activity drug such as Doxorubicin, but this is not the case for EEP.

Cytotoxicity screening of supercritical fluid extracted seaweeds and phenylpropanoids

Detached leaves of Posidonia oceanica and Zostera marina creating nuisance at the shores were extracted by means of supercritical CO2 enriched with a co-solvent, compared with that of soxhlet extraction. The extracts and their active compounds which are phenylpropanoids (chicoric, p-coumaric, rosmarinic, benzoic, ferulic and caffeic acids) were screened for cytotoxicity in cancer cell lines including human breast adenocarcinoma (MCF-7, MDA-MB-231, SK-BR-3), human colon adenocarcinoma (HT-29), human cervix adenocarcinoma (HeLa), human prostate adenocarcinoma (PC-3), Mus musculus neuroblastoma (Neuro 2A) cell lines and African green monkey kidney (VERO) as healthy cell line. Supercritical CO2 extracts proved to be more active than soxhlet counterparts. Particularly, Zostera marina extract obtained by supercritical CO2 at 250 bar, 80 °C, 20% co-solvent and a total flow rate of 15 g/min revealed the best IC50 values of 25, 20, 8 μg/ml in neuroblastoma, colon and cervix cancer cell lines. Among the major compounds tested, p-coumaric acid exhibited the highest cytotoxic against colon and cervix cell lines by with IC50 values of 25, 11 μg/ml. As for the effects on healthy cells, the extract was not cytotoxic indicating a selective cytotoxicity. Obtained supercritical CO2 extracts can be utilized as a supplement for preventive purposes.

A novel niosome formulation for encapsulation of anthocyanins and modelling intestinal transport

The bioavailability of drugs can be improved by regulating the structural properties, particularly lipoid systems, such as niosomes, can increase cellular uptake. Herein, we optimized double emulsion and niosomal formulations for encapsulating anthocyanin-rich black carrot extract. Nanoparticles obtained by selected formulation were characterized in terms of morphology, particle size, drug encapsulation efficiency, in vitro release and cytotoxicity. The optimum conditions for niosomal formulation were elicited as 30 mg of cholesterol, 150 mg of Tween 20 and feeding time of 1 min at a stirring rate of 900 rpm yielding the lowest average particle size of 130 nm. In vitro release data showed the majority of the encapsulated anthocyanins were released at the end of 10 h. A mathematical model was developed to estimate the absorption of anthocyanins released from niosomes and cytotoxicity was assessed against neuroblastoma. Overall, these findings suggest that niosomal vesicles might be suitable delivery systems for anthocyanins.

Extracts from black carrot tissue culture as potent anticancer agents

Black carrots contain anthocyanins possessing enhanced physiological activities. Explants of young black carrot shoots were cultured in Murashige and Skoog (MS) medium for callus initiation and were transferred to new MS medium supplemented with four different combinations of 2,4-dichlorophenoxyacetic acid and kinetin. Subsequently, the lyophilized calli and black carrot harvested from fields were subjected to ultrasound extraction with ethanol at a ratio of 1:15 (w:v). Obtained extracts were applied to various human cancer cell lines including MCF-7 SK-BR-3 and MDA-MB-231 (human breast adenocarcinomas), HT-29 (human colon adenocarcinoma), PC-3 (human prostate adenocarcinoma), Neuro 2A (Musmusculus neuroblastoma) cancer cell lines and VERO (African green monkey kidney) normal cell line by MTT assay. The highest cytotoxic activity was achieved against Neuro-2A cell lines exhibiting viability of 38-46% at 6.25 μg/ml concentration for all calli and natural extracts. However, a significantly high IC50 value of 170.13 μg/ml was attained in normal cell line VERO indicating that its natural counterpart is an ideal candidate for treatment of brain cancer without causing negative effects to normal healthy cells.

ALCAPs induce mitochondrial apoptosis and activate DNA damage response by generating ROS and inhibiting topoisomerase I enzyme activity in K562 leukemia cell line

Endemic Alkanna cappadocica was used to isolate novel antitumor molecules from Turkish landscapes in our previous studies. In this study, deoxyalkannin (ALCAP1), β,β-dimethylacrylalkannin (ALCAP2), acetylalkannin (ALCAP3), and alkannin (ALCAP4) as well as the novel isolated compounds 5-methoxydeoxyalkannin (ALCAP5), 8-methoxydeoxyalkannin (ALCAP6), 5-methoxyacetylalkannin (ALCAP7), 5-methoxy-β,β-dimethylacrylalkannin (ALCAP8) were characterized. The topoisomerase I (topo I) inhibitory activity of ALCAPs was investigated using in vitro plasmid relaxation assay and found that ALCAP2, 3, 4 and 7 were potent inhibitors at 2-6μM concentrations. Further, DNA damage response to ALCAP treatments was also studied by measuring the H2AX((S139)) and ATM((S1981)) phosphorylations. ALCAP2, 7 and 8 induced the DNA damage and apoptosis, consistently resulted in PARP cleavage at nanomolar concentrations in K562 leukemia cells. Moreover, when the free radical (ROS) generating capacity of the compounds was studied by 2',7'-dichlorofluorescein-diacetate assay using flow cytometry, we found that a known antioxidant N-acetyl-cysteine almost completely abrogated the H2AX((S139)) phosphorylations and the caspase 3 cleavage and activation. Thus, γH2AX((S139)) foci formation remained higher than the control, and an increase in CHK2((T68)) phosphorylation was observed by ALCAP2 and 7 treatments suggested that, these compounds can be potential therapeutics against tumor cell growth because of their unique DNA damaging abilities additional to enzyme inhibition similar to those of doxorubicin.

Cytotoxic naphthoquinones from Alkanna cappadocica ( perpendicular)

In a continuing program to discover new anticancer agents from plants, especially naphthoquinones from the Alkanna genus, Alkanna cappadocica was investigated. Bioassay-guided fractionation of a dichloromethane/methanol (1:1) extract of the roots led to the isolation of four new and four known naphthoquinones. The known compounds are 11-deoxyalkannin (1), beta,beta-dimethylacrylalkannin (2), 11-O-acetylalkannin (3), and alkannin (4). The new compounds 5-O-methyl-11-deoxyalkannin (5), 8-O-methyl-11-deoxyalkannin (6), 5-O-methyl-11-O-acetylalkannin (7), and 5-O-methyl-beta,beta-dimethylacrylalkannin (8) were characterized by spectroscopic analyses (LC-ESIMS, 1D and 2D NMR). Cytotoxicity of the isolated compounds was evaluated versus 12 human cancer cell lines, HT-29, MDA-MB-231, PC-3, AU565, Hep G2, LNCaP, MCF7, HeLa, SK-BR-3, DU 145, Saos-2, and Hep 3B together with two normal cell lines, VERO and 3T3, by using the MTT assay. Compound 7 showed remarkable cytotoxicity with IC(50) values between 0.09 and 14.07 muM. It was more potent than the other compounds in six out of 12 cancer cell lines and the positive controls doxorubicin and etoposide. The mono-O-methylated alkannin derivatives and their cytotoxicities are reported for the first time.