Edgar Caamal-Fuentes

Screening of plants used in Mayan traditional medicine to treat cancer-like symptoms

AIM OF THE STUDY To investigate the potential of plants used in Mayan traditional medicine to treat cancer-like symptoms using the Mayan ethnobotany literature, and evaluate their organic extracts for in vitro cytotoxic activity on cancer cell lines. MATERIALS AND METHODS The selection of the plants studied in this investigation was based on the Mayan ethnobotanical information provided by different literature sources. Extracts were obtained by maceration with methanol for 72 h of each plant part used and evaporated in vacuo to give the corresponding dried extract. Each methanol extract was tested for its cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay performed in 96-well tissue plates on seven cancer cell lines, lung carcinoma (A549), cervix adenocarcinoma (HeLa), laryngeal carcinoma (Hep-2), nasopharynx carcinoma (KB), breast adenocarcinoma (MCF-7), prostate adenocarcinoma (PC-3), and cervix squamous carcinoma cells (SiHa), as well as normal human embryonic kidney cell line (HEK-293). Cell proliferation/viability was spectrophotometrically assessed at 540 nm after addition of MTT. RESULTS 51 plants were found in the literature to be used for the treatment of symptoms suggestive of cancer, 21 were chosen to evaluate the cytotoxic activity. Aeschynomene fascicularis root bark extract showed a pronounced cytotoxic activity on Hela and KB cell lines and Bonellia macrocarpa stem and root bark extracts showed similar prominent activities on KB cells. CONCLUSION 21 plants were selected according to their use in the treatment of cancer-like symptoms recorded in the ethnobotanical literature. Plant extracts prepared from Aeschynomene fascicularis root bark and Bonellia macrocarpa stem and root bark have been selected for extensive studies leading to the isolation of the active constituents.

Isolation and Identification of Cytotoxic Compounds from Aeschynomene fascicularis, a Mayan Medicinal Plant

The plant Aeschynomene fascicularis (Fabaceae) has been used in Mayan traditional medicine in the Yucatan peninsula. However, the compounds present in the plant responsible for its curative properties have not yet been investigated. Aeschynomene fascicularis root bark was extracted with 100% methanol to obtain a crude extract. The methanol extract was partitioned successively with solvents with increasing polarity to obtain the corresponding hexane (Hx), dichloromethane (DCM) and ethyl acetate fractions (EtOAc), as well as a residual water-alcoholic fraction. These fractions were tested for their cytotoxic activities using an MTT assay against Hep-2 cancer cell lines. The Hx fraction led to the isolation of spinochalcone C (1), spinochalcone A (2), isocordoin (3) and secundiflorol G (4). Their structures were identified based on spectroscopic evidence and chemical properties. All compounds were subjected to cytotoxicity and antiproliferative assays against a panel of seven cell lines, including one normal-type cell line. Spinochalcone A (2) exhibited cytotoxic activity against DU-145 cell line and antiproliferative activity against the KB cell line. Secundiflorol G (4) showed strong cytotoxic activity towards KB and Hep-2 cell lines. In addition, isocordoin (3) showed moderate activity on KB, Hep-2 and DU-145 cell lines. The active Compounds 2, 3 and 4 are potential therapeutic entities against cancer.

Cytotoxic and antiproliferative constituents from Dictyota ciliolata, Padina sanctae-crucis and Turbinaria tricostata.

Abstract Context: The hexane extracts of Dictyota ciliolata Sonder ex Kützing (Dictyotaceae), Padina sanctae-crucis Børgesen (Dictyotaceae), and Turbinaria tricostata E.S. Barton (Sargassaceae) were found to exhibit cytotoxic and antiproliferative activities in vitro. Bioactive compounds responsible for these activities have not been studied in detail for these species and phytochemical studies are very limited. Objective: Isolate, evaluate, and elucidate the bioactive constituents of D. ciliolata, P. sanctae-crucis, and T. tricostata. Materials and methods: Bioassay-guided cytotoxicity fractionations using the Hep-2 cell line of the hexane extracts from these brown algae were analyzed using various chromatographic techniques. Cytotoxic and antiproliferative activities of all isolated compounds were also evaluated on a panel of cell lines (KB, Hep-2, MCF-7, and SiHa). Furthermore, their selectivity index, the ratio of cytotoxicity on normal cells to cancer cells, was evaluated using the HEK-293 cell line. Results: Four compounds were isolated from studied species: two sterol, fucosterol (1) and 24ξ-hydroperoxy-24-vinylcholesterol (2); and two diterpenes, pachydictyol A (3) and dictyol B acetate (4). The major bioactive components of the hexane extracts of T. tricostata and P. sanctae-crucis were compounds 1 and 2 (with CC50 varying around 3.1–25.6 µg/mL) on cell lines tested. Whereas compounds 1, 3, and 4 showed cytotoxic activity against cancer cell lines (CC50 varying between 14.8 and 41.2 µg/mL) and were major bioactive constituents of hexane extract of D. ciliolata. Compounds 1 and 4 showed antiproliferative activity on MCF-7 (IC50 = 43.3 µg/mL for compound 1 and 38.3 µg/mL for compound 2) and SiHa (IC50 = 43.3 µg/mL for compound 1 and 38.3 µg/mL for compound 2) cell lines. Conclusion: This study is the first investigation on the bioactive components of D. ciliolata, P. sanctae-crucis, and T. tricostata. Although compounds 1–3 were described previously, the pharmacological activity of compound 4 is presented here for the first time.

Bonellia albiflora: A Mayan Medicinal Plant That Induces Apoptosis in Cancer Cells

Few studies have been carried out on the medical flora of Mexicos Yucatan Peninsula in search for new therapeutic agents, in particular against cancer. In this paper, we evaluated the cytotoxic potential of the extract of Bonellia albiflora, a plant utilized in the traditional Mayan medicine for treatment of chronic injuries of the mouth. We carried out the methanolic extracts of different parts of the plant by means of extraction with the Soxhlet equipment. We conducted liquid-liquid fractions on each extract with solvents of increasing polarity. All extracts and fractions were evaluated for cytotoxic activity versus four human cancer cell lines and one normal cell line through a tetrazolium dye reduction (MTT) assay in 96-well cell culture plates. The methanolic root-bark extract possessed much greater cytotoxic activity in the human oropharyngeal cancer cell line (KB); its hexanic fraction concentrated the active metabolites and induced apoptosis with the activation of caspases 3 and 8. The results demonstrate the cytotoxic potential of the B. albiflora hexanic fraction and substantiate the importance of the study of the traditional Mayan medicinal plants.

Lipid characterization of red alga Rhodymenia pseudopalmata (Rhodymeniales, Rhodophyta)

Rhodymenia pseudopalmata is a red alga that grows at the Caribbean coast of the Yucatan Peninsula and has been proven successful in cultivation. In this study we present the lipid composition of R. pseudopalmata collected from wild populations during three different seasons of 2013. Cultured material was also analyzed and compared in order to evaluate its value as feedstock for biotechnological uses. Thin layer chromatography, 1 H and 13 C NMR spectroscopy and gas chromatography‐mass spectrometry were used to assess variations in their lipid composition. Our results showed that the dominant lipid classes were phospholipids both in wild and cultured materials. The phospholipids phosphatidylcholine and phosphatidylglycerol and the glycolipid monogalactosyldiacylglycerol were present in both wild and cultured R. pseudopalmata, whereas the phospholipid lysophosphatidylcholine was only found in wild material. Fatty acids (FAs) showed a high monounsaturated FAs (MUFAs) content with oleic acid (C18:1ω9) as the dominant compound (78 and 94% of the MUFAs for wild and culture materials, respectively). Saturated FAs (SFAs) represented approximately 90% of the total fatty acid content, with palmitic acid (C16:0) reaching approximately 83% of the SFA content. Rhodymenia pseudopalmata was low in polyunsaturated FAs when compared to other red algae. Other compounds such as 1‐heptadecene, 1‐hexadecene, 15‐heptadecenal, 3‐eicosene 6,10,14‐trimethyl‐2‐pentadecanone, phytol, and heptadecane were also found. Lipid composition differences between the wild and cultured algae suggest that light and nutrients can be manipulated to modify lipid composition. Based on its lipid composition and cultivation feasibility, R. pseudopalmata could be a potential source for nutraceuticals and biofuels production.

Antiproliferative and Antiestrogenic Activities of Bonediol an Alkyl Catechol from Bonellia macrocarpa

The purpose of this study was to investigate antiproliferative activity of bonediol, an alkyl catechol isolated from the Mayan medicinal plant Bonellia macrocarpa. Bonediol was assessed for growth inhibition of androgen-sensitive (LNCaP), androgen-insensitive (PC-3), and metastatic androgen-insensitive (PC-3M) human prostate tumor cells; toxicity on normal cell line (HEK 293) was also evaluated. Hedgehog pathway was evaluated and competitive 3H-estradiol ligand binding assay was performed. Additionally, antioxidant activity on Nrf2-ARE pathway was evaluated. Bonediol induced a growth inhibition on prostate cancer cell lines (IC50 from 8.5 to 20.6 µM). Interestingly, bonediol binds to both estrogen receptors (ERα (2.5 µM) and ERβ (2.1 µM)) and displaces the native ligand E2 (17β-estradiol). No significant activity was found in the Hedgehog pathway. Additionally, activity of bonediol on Nrf2-ARE pathway suggested that bonediol could induce oxidative stress and activation of detoxification enzymes at 1 µM (3.8-fold). We propose that the compound bonediol may serve as a potential chemopreventive treatment with therapeutic potential against prostate cancer.

Growth, biochemical and antioxidant content of Rhodymenia pseudopalmata (Rhodymeniales, Rhodophyta) cultivated under salinity and irradiance treatments

Growth, biochemical composition and antioxidant capacity of Rhodymenia pseudopalmata were studied under controlled laboratory conditions. Cultures were exposed to five salinities ranging from 20, 25, 30, 35 and 40 psu under three photosynthetic active radiations (PAR) 50, 100 and 200 μmol photons m-2s-1. Rhodymenia pseudopalmata daily growth rates were significantly higher at 20 psu and high PAR, and decreased at 40 psu and low PAR. Chl a and PE contents were lower at high PAR. The carbohydrate content increased up to 54 % DW-1 under high PAR and 20 psu. Protein ranged from 4.9 to 10.5 % DW-1. Sixteen amino acids were detected in R. pseudopalmata under the experimental conditions tested. Glutamic acid, proline and methionine may act as osmolytes, while histidine, methionine and tyrosine may be involved in R. pseudopalmata antioxidant capacity. Rhodymenia pseudopalmata grown under high PAR and 20 psu had the highest increase in total phenolic compounds. Moreover, DPPH radical scavenging activity increased at 20, 25 and 40 psu under low PAR, and at 20 psu under high PAR. These results may partly explain the ability of R. pseudopalmata to grow under extreme conditions at the intertidal and its acclimation for mariculture.