NMR Metabolic Profiling of Sargassum Species Under Different Stabilization/Extraction Processes.

The genus Sargassum is well represented by benthic and pelagic species, some of which form massive aggregates that can travel long distances due to the force of the ocean currents. Although they constitute an essential habitat for fish and invertebrate species, large accumulations of Sargassum in coastal areas generate several economic, environmental, and health impacts. It is important to recognize the species forming these aggregates, and identify the metabolites they produce, allowing for its exploitation, and therefore, better management practices. NMR metabolic profiling is a technique that can discriminate samples while detecting their unique or differential chemical features, and has been successfully used in the study and classification of several algal species. The present investigation studied the metabolic profiling of Sargassum species found on strandings at Puerto Morelos (Quintana Roo) east coast of the Mexican Caribbean. PCA of the 1 H-NMR profiles corresponding to S. natans, S. natans (morphotype VIII), S. fluitans, and a benthic Sargassum buxifolium allowed the discrimination of samples amongst them. Furthermore, discrimination between the two forms of S. natans was also possible. The PCA loading plot revealed that glutamine and glutamate have the highest influence in the clustering of the benthic Sargassum, while a high abundance of lactate, Myo-inositol, and trimethylamine is a unique feature from the S. natans morphotype VIII. Additional PLS-DA models showed that a heat-drying process improved the extraction of metabolites. Maceration and microwave-assisted extraction with water-ethanol led to similar profiles and thus any of them could be used in future investigations.

Anti-giardia activity and acute toxicity of a methanol extract of Senna racemosa bark.

ETHNOPHARMACOLOGICAL RELEVANCE: Senna racemosa (Mill.) H.S. Irwin & Barneby (syn. Cassia racemosa Mill.) is a plant used in traditional Mayamedicinal practices to treat diarrhea. A methanol extract of S. racemosa bark has been shown to have in vitro activity against Giardia intestinalis. No studies of its efficacy and toxicity in in vivo models have been done. The present study objective was to analyze the activity of this methanol extract of S. racemosa bark against Giardia intestinalis trophozoites in experimentally infected mice, and evaluate its toxicological effects in rats. MATERIAL AND METHODS: S. racemosa was collected in Merida, Yucatan, Mexico (21°58'N, 89°36'W) in June 2005. The bark methanol extract was obtained and high performance liquid chromatography (HPLC-DAD) was used to generate a constituent profile. In vivo anti-giardia activity was assayed with an experimental model of G. intestinalis infection in neonatal CD-1 mice. Nine doses ranging from 0.25-15mg extract/kg body weight were tested to determine the dose required to kill 50% of the trophozoites (ED50). An acute toxicity assay was run in which one of four single doses (200, 1000, 2000 and3000mg/kg body weight) was orally administered to adult Wistar rats. Animal weight, death rates, toxic effects and behavioral parameters were observed over a 14-d period. They were then euthanized and a necropsy performed. RESULTS: The S. racemosa bark extract inhibited growth of G. intestinalis (ED50=1.14mg/Kg) in neonatal CD-1 mice. No toxic or lethal effects were observed even at the highest dosage (3000mg/Kg), and neither were signs of toxicity observed in internal organs. The active compounds chrysophanol and physcion were present in the extract at a 1.76 ratio. CONCLUSIONS: The results strongly support traditional use of S. racemosa bark for treatment of diarrhea caused by Giardia intestinalis infection.

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 ERß (2.1 µM)) and displaces the native ligand E2 (17ß-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.

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.

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.

Pterocarpans from the root bark of Aeschynomene fascicularis.

A new pterocarpan, aeschynocarpin (1), and the known pterocarpan 2-methoxymedicarpin (2) were isolated for the first time from Aeschynomene fascicularis (Fabaceae) and their structures elucidated by means of spectroscopic {UV/Vis, IR, and NMR (1H, 13C, COSY, HMQC,and HMBC)} andmass spectrometric (EI-MS and HRCIMS) techniques. Both compounds were tested in vitro for their cytotoxic and antiproliferative activities against a panel of cancer cell lines. This is the first report on the presence of pterocarpans in the genus Aeschynomene.

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

Few studies have been carried out on the medical flora of Mexico's 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.

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.