Ricinodendron heudelotii (Euphorbiaceae) seed oil prevents DMBA-induced breast cancer under menopause-like conditions in Wistar rats

Despite efforts, breast cancer remains associated with a high incidence and mortality rate. Ricinodendron heudelotii also known as "Njansang," is a plant used for cancer treatment. While several reports on the anticancer potential of its leaves exist, little is known about its seed oil. This study aimed to evaluate the in vitro and in vivo anti-breast cancer activity of "Njansang" seed oil. The inhibitory effect of "Njansang" seed oil was determined using MTT and CCK-8 dye reduction assays. Breast cancer was induced with DMBA and promoted with E2V (1 mg/kg) for 4 weeks in ovariectomized rats (menopausal condition). Evaluated parameters included tumor incidence, tumor mass and volume, histopathology, breast cancer biomarker CA 15-3, antioxidant status (CAT, GSH, MDA, NO, SOD), TNF-α and INFγ levels, lipid profile (total cholesterol, LDL-cholesterol, triglycerides and HDL-cholesterol), as well as toxicity parameters (ALT, AST, creatinine). "Njansang" oil significantly reduced the growth of ER+ (MCF-7) and triple negative (MDA-MB 231) adenocarcinoma cells in vitro as well as tumor incidence, tumor mass and CA 15-3 levels in vivo. It exhibited antioxidant activity, characterized by an increase in SOD and catalase activities, GSH levels and decreased MDA levels compared to the DMBA group. TNF-α and INF-γ levels were reduced following oil treatment, while total cholesterol, LDL-cholesterol and triglyceride levels were reduced. The aforementioned findings confirm the protective effects of "Njansang" oil on induced breast cancer in ovariectomized rats.

Dietary supplementation with seeds of Sesamum indicum L. (pedaliaceae) mitigates the 7,12-dimethylbenz(a)anthracene-induced breast tumor burden in rats

OBJECTIVES

Sesamum indicum L. seeds; rich in zinc and lignans are endowed with antioxidant and immunomodulatory properties which attract research on their anticancer potential. Although many studies have reported the in vitro antitumor potential of S. indicum and its phytoconstituents, much is yet to be known about its in vivo effects. To fill this gap, the effects of dietary supplementation with seeds of S. indicum in 7,12-dimethylbenz(a)anthracene-exposed rats was assessed.

METHODS

42 rats aged 30-35 days were randomized into six groups (n=6) as follows: the normal (NOR) and negative (DMBA) control groups were fed with standard diet; the positive control group (DMBA + Zinc) was fed with standard diet supplemented with commercial zinc (0.01 %); the test groups were fed with standard diet supplemented with S. indicum seeds in different proportions (6.25 , 12.5 and 25 %). Breast cancer was induced by a single administration of DMBA (50 mg/kg BW, s.c.) diluted in corn oil. The experiment lasted 20 weeks and afterward, tumor incidence; tumor burden, tumor volume, tumor micro-architecture and some biochemical parameters were evaluated.

RESULTS

As salient result, 100 % of rats in the DMBA group developed tumors, while rats feed with rat chow supplemented with S. indicum seeds (25 %) had a reduced incidence of tumors (33.3 %) and tumor volume (2.71 cm3 in sesame 25 % vs. 4.69 cm3 in the DMBA group, p˂0.01). The seeds (25 %) also slowed DMBA-induced neoplasm expansion in mammary ducts as compared to rats of DMBA group.

CONCLUSIONS

In summary, supplementation with S. indicum seeds slowed breast tumorigenesis via its antioxidant capacity.

Dunaliella β-Carotene Productivity Comparison Under In Vitro Conditions

Some species of Dunaliella produce high levels of β-carotene, which is the largest natural Vitamin A source. β-carotene production in Dunaliella is expensive due to low yields obtained under culture conditions used. Since three decades ago synthetic β-carotene has dominated 98% of world market, even when synthetic is less bioactive than Dunaliella β-carotene molecule. In vitro experiments have been performed to increase β-carotene productivity in Dunaliella and some useful results have been obtained. In this review, culture conditions used in those experiments were compared to identify parameters that improved β-carotene productivity in Dunaliella. Comparison results show that β-carotene in vitro production can be increased regulating some specific culture conditions.

Ameliorative effects of Dunaliella salina microalgae on nanoparticle (ZnO NPs)-induced toxicity in fish

Dunaliella salina (D. salina) is a well-known microalga that contains considerable amounts of nutritious and medicinal bioactive components. This work studied the modulatory role of D. salina against zinc oxide nanoparticle (ZnO NPs)-induced neurotoxic effects in adult zebrafish. Fishes were subjected to 0.69 mg L-1 (1/5th 96-h LC50) for 4 weeks; then, fishes were supplemented with D. salina in the diet for 2 weeks at two levels (15 and 30%). Exposure to ZnO NPs induced a significant increase in the levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OH-dG) while accompanied with downregulation of antioxidant genes in the brain of exposed fishes. Brain neurochemistry and enzyme activities were also altered following ZnO NP exposure. ZnO NPs significantly reduced the neurotransmitters and acetylcholinesterase (AchE) activity while increasing Alzheimer's disease-related proteins and inflammatory response via upregulation of tumor necrosis factor (TNF-α). Additionally, ZnO NPs increased the indices of brain's DNA oxidative damage, increasing brain tissue's metallothionein (MT) and zinc residues. ZnO NPs upregulated the transcription patterns of apoptosis-related genes (casp3 and p53). D. salina dietary co-supplementation with ZnO NPs alleviated the ZnO NPsZnO NP-induced neuro-oxidative damages by lowering the lipid, DNA damage, and inflammatory biomarkers. Besides, D. salina alleviating responses were linked with increasing the levels of the assessed antioxidants. Conclusively, D. salina dietary supplementation induced potential alleviating effects of the ZnO NP-induced neurotoxicity in adult zebrafish.

Comparative anticancer effects of Annona muricata Linn (Annonaceae) leaves and fruits on DMBA-induced breast cancer in female rats

BACKGROUND

Numerous studies have reported the anti-cancer effects of different parts of Annona muricata Linn, however ; most of them focused on the in vitro evaluation of isolates. In vivo evidence on which part is best suited for breast cancer chemoprevention remains to be demonstrated. This is a comparative study of the effects of A. muricata fruit and leaves extracts on DMBA induced-breast cancer in rats.

METHODS

Rats exposed to DMBA (50 mg/kg, s.c.), were treated with A. muricata fruit aqueous extract at 200 mg/kg BW (3 days/week or daily) and A. muricata Linn leaves ethanolic extract at 200 mg/kg daily. Positive control group received tamoxifen at 3.3 mg/kg, while the normal and diseased controls received vehicle. After 20 weeks of treatment, the tumor incidence, tumor burden, tumor volume, histopathology, protein and CA 15 - 3 levels as well as antioxidant status, pro-inflammatory cytokines were assessed.

RESULTS

Thus, 100% of diseased rats presented cribriform ductal carcinoma of SBR grade III. A. muricata extracts (leaves and fruit) and tamoxifen significantly reduced death and tumor incidences, volume and weight of the tumors, total protein and CA15-3 levels compared to the DMBA group. They exhibited antioxidant activity, through an increase in the GSH level and SOD and catalase activities with reduced levels of MDA compared to DMBA group. TNF-α, IL-6 and INF-γ levels reduced with regards to A. muricata treatment.

CONCLUSION

These results confirm the anti-breast cancer effect of A. muricata, however, the aqueous fruit extract was more potent than the ethanolic leaves extract.

Breast cancer cell growth arrest and chemopreventive effects of Passiflora edulis Sims (Passifloraceae) ethanolic leaves extract on a rat model of mammary carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Despite various prevention and treatment measures, the incidence and mortality due to breast cancer has been increasing globally. Passiflora edulis Sims is a plant used for the treatment of various diseases in traditional medicine, including cancers.

AIM OF THE STUDY

To assess the anti-breast cancer activity of the ethanolic extract of P. edulis leaves in vitro and in vivo.

MATERIAL AND METHODS

In vitro, the cell growth and proliferation were determined based on the MTT and BrdU assays. The flow cytometry was used to analyze the cell death mechanism while, cell migration, cell adhesion and chemotaxis were assayed for anti-metastatic potential. In vivo, 56 female Wistar rats aged 45-50 days (∼75 g) were exposed to 7,12-dimethylbenz(a)anthracene-DMBA except the normal group. Negative control group (DMBA) received solvent dilution throughout the study; standards groups (tamoxifen - 3.3 mg/kg BW and letrozole - 1 mg/kg BW) as well as P. edulis leaves ethanolic extract groups (50, 100 and 200 mg/kg) treated for 20 weeks. Tumor incidence, tumor burden and volume, CA 15-3 serum' level, antioxidant, inflammatory status and histopathology were assessed.

RESULTS

P. edulis extract showed a significant and concentration-dependent inhibition of MCF-7 and MDA-MB 231 cells growth at 100 μg/mL. It inhibited cell proliferation and clones' formation and induced apoptosis in MDA-MB 231 cells. The migration of cell into the zone freed of cells and the number of invading cells after the 48 and 72 h were significantly diminished while, it increased their adherence to collagen and fibronectin extracellular matrix as does Doxorubicin. In vivo, all rats in the DMBA group exhibited a significant (p < 0.001) increase in tumor volume, tumor burden and grade (adenocarcinoma of SBR III) and pro-inflammatory cytokine levels (TNF-α, INF-γ, IL-6 and IL-12). P. edulis extract at all tested doses significantly inhibited the DMBA-induced increase in tumor incidence, tumor burden and grade (SBR I) as well as pro-inflammatory cytokines. Moreover, it increased enzymatic and non-enzymatic antioxidants (SOD, catalase, and GSH) and decreased MDA levels although a greater effect was observed with Tamoxifen and Letrozole. P. edulis has medium content on polyphenols, flavonoids and tannins.

CONCLUSION

P. edulis has chemo-preventive effects against DMBA-induced breast cancer in rats probably through its antioxidative, anti-inflammatory and apoptosis-inducing potentials.

Dunaliella salina Microalga Restores the Metabolic Equilibrium and Ameliorates the Hepatic Inflammatory Response Induced by Zinc Oxide Nanoparticles (ZnO-NPs) in Male Zebrafish

Microalgae are rich in bioactive compounds including pigments, proteins, lipids, polyunsaturated fatty acids, carbohydrates, and vitamins. Due to their non-toxic and nutritious characteristics, these are suggested as important food for many aquatic animals. Dunaliella salina is a well-known microalga that accumulates valuable amounts of carotenoids. We investigated whether it could restore the metabolic equilibrium and mitigate the hepatic inflammation induced by zinc oxide nanoparticles (ZnO-NPs) using male zebrafish which were exposed to 1/5^th 96 h-LC₅₀ for 4 weeks, followed by dietary supplementation with D. salina at two concentrations (15% and 30%) for 2 weeks. Collectively, ZnO-NPs affected fish appetite, whole body composition, hepatic glycogen and lipid contents, intestinal bacterial and Aeromonas counts, as well as hepatic tumor necrosis factor- α (TNF-α). In addition, the mRNA expression of genes related to gluconeogenesis (pck1, gys2, and g6pc3), lipogenesis (srepf1, acaca, fasn, and cd36), and inflammatory response (tnf-α, tnf-β, nf-kb2) were modulated. D. salina reduced the body burden of zinc residues, restored the fish appetite and normal liver architecture, and mitigated the toxic impacts of ZnO-NPs on whole-body composition, intestinal bacteria, energy metabolism, and hepatic inflammatory markers. Our results revealed that the administration of D. salina might be effective in neutralizing the hepatotoxic effects of ZnO-NPs in the zebrafish model.

A Comparative Study on Inhibition of Breast Cancer Cells and Tumors in Mice by Carotenoid Extract and Nanoemulsion Prepared from Sweet Potato (Ipomoea batatas L.) Peel

The objectives of this study were to determine carotenoid composition in sweet potato (TNG66) peel and prepare carotenoid nanoemulsion to study its inhibition effect on breast cancer cells MCF-7 and tumors in mice. Results showed that a total of 10 carotenoids were separated within 30 min by employing a YMC C30 column and a gradient mobile phase of methanol/acetonitrile/water (74:14:12, v/v/v) and dichloromethane (B) with a flow rate of 1 mL/min, column temperature of 25 °C, and detection wavelength of 450 nm. Following quantitation, all-trans-β-carotene was present in the highest amount (663.8 μg/g). The method validation data demonstrated a high accuracy and precision of this method. The carotenoid nanoemulsion was prepared by mixing an appropriate proportion of carotenoid extract, Tween 80, PEG 400, soybean oil and deionized water with the mean particle size being 15.7 nm (transmission electron microscope (TEM)), polydispersity index 0.238, encapsulation efficiency 97% and zeta potential −69.8 mV. A high stability of carotenoid nanoemulsion was shown over a 90-day storage period at 25 °C and during heating at 100 °C for 2 h. The release percentage of total carotenoids from carotenoid nanoemulsion under gastric and intestinal condition was 18.3% and 49.1%, respectively. An antiproliferation study revealed that carotenoid nanoemulsion was more effective than carotenoid extract in inhibiting the growth of human breast cancer cells MCF-7. Following treatments of paclitaxel (10 μg/mL), carotenoid nanoemulsion (20 and 10 μg/mL) and carotenoid extract (20 and 10 μg/mL), the tumor weight of mice respectively decreased by 77.4, 56.2, 40.3, 36.1 and 18.7%, as well as tumor volume of mice by 75.4, 65.0, 49.7, 46.7 and 26.5%. Also, both carotenoid extract and nanoemulsion could reduce the levels of epidermal growth factor (EGF) and (vascular endothelial growth factor (VEGF) in serum, with the latter being more effective. This finding suggested that carotenoid nanoemulsion was more effective than carotenoid extract in inhibiting tumor growth in mice.

Effects of Hibiscus sabdariffa Calyxes Aqueous Extract on Antioxidant Status and Histopathology in Mammary Tumor-Induced in Rats

Breast cancer is a major threat worldwide. Hibiscus sabdariffa is widely consumed as beverage in sub-Saharan Africa for its anticancer potential. The present study therefore aimed at scientifically verifying its anticancer effect in rats. For this, 48 Wistar rats (∼55 days) were treated either with tamoxifen at 3.3 mg/kg BW (standard) or with a decoction of H. sabdariffa (125, 250, and 500 mg/kg BW) or distilled water (vehicle). Breast cancer was induced by a single dose of 50 mg/kg of 7,12-dimethylbenz(a)anthracene (DMBA). At the end of the 21 weeks of treatment, the tumor incidence, tumor morphology, histopathology, as well as some biochemical parameters in the tumors were assessed. As a result, 86% of DMBA's rats developed mammary tumors. The H. sabdariffa extract (125 and 250 mg/kg) reduced tumor incidence by 63% and 75%, respectively; inhibited tumor burden by 84.86% and 38.78%, respectively, and decreased tumor volume by more than 72% compared to the DMBA group. It also protected rats against DMBA-induced diffuse breast neoplasia, and the optimal effect was recorded at 125 mg/kg. Furthermore, it significantly increases the SOD activity and decreases the MDA level. In summary, H. sabdariffa has antibreast tumor and antioxidant properties in rats, which could justify its common use to treat cancer.

Microalgae for high-value products: A way towards green nutraceutical and pharmaceutical compounds

Microalgae is a renewable bioresource with the potential to replace the conventional fossil-based industrial production of organic chemicals and pharmaceuticals. Moreover, the microalgal biomass contains carotenoids, vitamins, and other biomolecules that are widely used as food supplements. However, the microalgal biomass production, their composition variations, energy-intensive harvesting methods, optimized bio-refinery routes, and lack of techno-economic analysis are the major bottleneck for the life-sized commercialization of this nascent bio-industry. This review discusses the microalgae-derived key bioactive compounds and their applications in different sectors for human health. Furthermore, this review proposes advanced strategies to enhance the productivity of bioactive compounds and highlight the key challenges associated with a safety issue for use of microalgae biomass. It also provides a detailed global scenario and market demand of microalgal bioproducts. In conclusion, this review will provide the concept of microalgal biorefinery to produce bioactive compounds at industrial scale platform for their application in the nutraceutical and pharmaceutical sector considering their current and future market trends.

Recent Updates on Marine Cancer-Preventive Compounds

The natural compounds derived from marine organisms often exhibit unique chemical structures and potent biological activities. Cancer-preventive activity is one of the rather new activities that has emerged and been extensively studied over the last decades. This review summarizes the recent updates on the marine chemopreventive compounds covering the relevant literature published in 2013-2021 and following the previous comprehensive review by Stonik and Fedorov (Marine Drugs 2014, 12, 636-671). In the current article, only the molecules having an effect on malignant transformation (or related pathway and molecules), cancer stem cells, or carcinogen-induced in vivo tumor development were considered to be "true" cancer-preventive compounds and were, therefore, reviewed. Additionally, particular attention has been given to the molecular mechanisms of chemoprevention, executed by the reported marine compounds.

Preventive Effect of Combined Zingiber officinale and Terminalia chebula against DMBA-Induced Breast Cancer Rats via mTOR Inhibition

Zingiber officinale (ZO) and Terminalia chebula (TC) are plants used for the treatment of diverse illnesses in traditional medicine. The present study investigates the preventive effect of Zingiber officinale-Terminalia chebula extract (ZOTC) against DMBA-induced breast cancer in a rat model. Bioactive compounds from ZO (6-gingerol, 6-shogaol) and TC (gallic acid, ellagic acid, corilagin, chebulinic acid, and chebulagic acid) were detected using high-performance liquid chromatography. Mammary carcinogenesis was induced in rats with a single subcutaneous injection of 7,12-Dimethylbenz[a]anthracene (DMBA). Oral administration of ZOTC ameliorated the antioxidant status in mammary tissues, serum lipid levels, and serum cytokines. Histological analysis of the mammary tissue (normal and tumor) was carried out to obtain pathological alterations due to ZOTC treatment. The effect of ZOTC on the mechanistic target of rapamycin (mTOR) gene and accumulation of corresponding gene product was also investigated. mTOR plays a central role in cell metabolism and proliferation in normal and cancer cells. Transcriptional and immunohistochemical analysis showed the downregulation of mTOR expression in the mammary tissues of ZOTC-treated rats. In conclusion, the results obtained suggest that ZOTC can suppress tumor progression in DMBA-induced breast cancer rats via inhibition of the mTOR pathway.

Pigments Production, Growth Kinetics, and Bioenergetic Patterns in Dunaliella tertiolecta (Chlorophyta) in Response to Different Culture Media

This work dealt with the study of growth parameters, pigments production, and bioenergetic aspects of the microalga Dunaliella tertiolecta in different culture media. For this purpose, cultures were carried out in Erlenmeyer flasks containing F/2 medium, Bold’s Basal medium, or an alternative medium made up of the same constituents of the Bold’s Basal medium dissolved in natural seawater instead of distilled water. D. tertiolecta reached the highest dry cell concentration (Xmax = 1223 mgDM·L−1), specific growth rate (µmax = 0.535 d−1), cell productivity (PX = 102 mgDM·L−1·d−1), and photosynthetic efficiency (PE = 14.54%) in the alternative medium, while the highest contents of carotenoids (52.0 mg·g−1) and chlorophyll (108.0 mg·g−1) in the biomass were obtained in Bold’s Basal medium. As for the bioenergetic parameters, the biomass yield on Gibbs energy dissipation was higher and comparable in both seawater-based media. However, the F/2 medium led to the highest values of moles of photons absorbed to produce 1 C-mol of biomass (nPh), total Gibbs energy absorbed by the photosynthesis (ΔGa) and released heat (Q), as well as the lowest cell concentration, thus proving to be the least suitable medium for D. tertiolecta growth. On the other hand, the highest values of molar development of O2 and consumption of H+ and H2O were obtained in the alternative medium, which also ensured the best kinetic parameters, thereby allowing for the best energy exploitation for cell growth. These results demonstrate that composition of culture medium for microalgae cultivation has different effects on pigments production, growth kinetics, and bioenergetics parameters, which should be taken into consideration for any use of biomass, including as raw material for biofuels production.

Metagenomic Analysis of the Faecal Microbiome of Rats with 1, 2-Dimethylhydrazine Induced Colon Cancer and Prophylactic Whole-Cell Carotenoid Intervention

Rapidly evolving sequencing technologies have enabled efficient sequencing of complex genomes and metagenomes. Here, we have presented our metagenomic analysis of rat faeces isolated DNA, sequenced using long-read sequencing technology. The microbiome changes in the rat faeces after sixteen weeks of prolonged administration of subcutaneous 1,2 dimethylhydrazine to induce colon carcinogenesis and oral carotenoid-rich whole-cell lyophilised Dunaliella salina supplement. The faecal pellets were aseptically collected, and DNA was isolated and sequenced subsequently. The post-sequencing analysis revealed that the rat gut microbiome is highly complex and diverse. There was a significant difference between the microbiome of rats that received Dunaliella salina supplement in comparison with rats treated with 1,2 dimethylhydrazine and control rats. We observed the dominance of Bacteroidetes over Firmicutes in both cases of administration. The dominance was notably contributed by individuals like B. vulgatus, B. dorei, B. fragilis, P. ruminicola, and P. copri. The presence of protozoans like Trypanosoma, Trichomonas, and Leishmania was also identified among other commensal eukaryotes. Moreover, there was an abundant presence of bacteriophages targeting probiotic organisms like Lactobacillus among the identified DNA viruses.

Daucosterol from Crateva adansonii DC (Capparaceae) reduces 7,12-dimethylbenz(a)anthracene-induced mammary tumors in Wistar rats

This study aimed to evaluate the in vivo anticancer effects of daucosterol which was earlier reported to possess in vitro anticancer effects. Breast tumor was induced in 30 rats using the environmental carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) while 6 control rats received olive oil (NOR). Animals with palpable tumors were randomized into five groups (n = 6) each as follows: negative control group treated with the vehicle (DMBA); positive control group treated with 5 mg/kg BW doxorubicin (DOXO + DMBA); three groups treated with daucosterol at doses of 2.5, 5, and 10 mg/kg BW (DAU + DMBA). Treatment lasted 28 days afterward, tumor (mass, volume, cancer antigen [CA] 15-3 level and histoarchitecture), hematological and toxicological parameters were examined. The tumor volume gradually increased in the DMBA group during the 28 days, with a tumor volume gain of ∼390 cm³ . Daucosterol at all doses reduced tumor volume (∼133.7 cm³ at 10 mg/kg) as well as protein, malondialdehyde (MDA), and CA 15-3 levels compared to DMBA rats. Tumor sections in daucosterol-treated rats showed a lower proliferation of mammary ducts with mild (5 and 10 mg/kg) to moderate (2.5 mg/kg) inflammatory responses. Moreover, it exhibited an antioxidant effect, evidenced by a significant and dose-dependent decreased in MDA levels, as well as an increase in catalase activity compared to the DMBA group. Daucosterol showed for the first time in vivo antitumor effects that corroborate its previous in vitro effects.

Deciphering the Biological Activities of Dunaliella sp. Aqueous Extract from Stressed Conditions on Breast Cancer: from in Vitro to in Vivo Investigations

In order to harness local resources to improve well-being and human health, we aim in this study to investigate if the microalgae Dunaliella sp. isolated from the Tunisian coastal zone possesses any anticancer activity. Dunaliella sp. was cultured under normal (DSC) or stressed (DSS) conditions and extracted using different procedures. The biological activity assessment was performed on the Triple Negative Breast Cancer (TNBC) using 4T1 murine cells as a model. Results indicate that: (i) aqueous extract was the most cytotoxic compared to ethanolic and hydroalcoholic extracts; (ii) DSS activity was superior to that of DSC. DSS extracts induced apoptosis rather than necrosis, as evidenced by DNA fragmentation, PARP-1 cleavage and caspase-3 activation. Evaluation in an orthotopic TNBC model validated the anticancer activity in vivo. Intratumoral injection of DSS extract resulted in reduced tumor growth and an enhanced immune system activation. On the transcriptional side, the expression level of the immunosuppressive enzyme Arg-1 was decreased, as well as those of NOS-2 and COX-2 genes. These results suggest a potential anticancer activity of Tunisian Dunaliella sp. deserving further attention.

The dietary c9,t11-conjugated linoleic acid enriched from butter reduces breast cancer progression in vivo

The c9,t11-conjugated linoleic acid (CLA), which is the minor polyunsaturated fatty acid (PUFA) naturally present in butter, has gained attention due to its important preventive effect against breast cancer in vitro. In this paper, the enrichment of c9,t11-CLA from butter was optimized and the preventive effect of dietary c9,t11-CLA against breast cancer in vivo was investigated. Results showed that the concentration of c9,t11-CLA increased more than 10 times via a one-step urea complexation. Furthermore, the dietary c9,t11-CLA showed obvious preventive effect against breast cancer in decreasing the tumor weight and volume, and reducing the tumor incidence up to 50%. In addition, the expression of progesterone receptor and Ki-67 decreased significantly with the treatment of c9,t11-CLA. In conclusion, the dietary c9,t11-CLA enriched from butter showed a preventive effect against breast cancer in vivo via the inhibition of the hormonal receptor and cell proliferation. PRACTICAL APPLICATIONS: This paper provided new insight into the preparation of specific c9,t11-CLA isomer. It can be enriched from butter in large-scale with low-cost by urea complexation. Meanwhile, the enriched dietary c9,t11-CLA can be further processed into cancer prevention functional foods.

Lutein: A potential antibiofilm and antiquorum sensing molecule from green microalga Chlorella pyrenoidosa

The increasing resistance of Pseudomonas aeruginosa towards antimicrobial agents has been a major cause for the escalation of untreatable diabetic foot ulcer cases around the globe. This demands research towards alternative natural products that inhibit biofilm formation by P. aeruginosa. The study focuses on enhancing as well as understanding the anti-biofilm property of lutein from Chlorella pyrenoidosa against MTCC strain of P. aeruginosa PAO1. C. pyrenoidosa was subjected to nutrient starvation (N^-, S^- and P^-) and their growth, biomass, chlorophyll pigments and total carotenoids were estimated. Lutein extracted from nutrient starved C. pyrenoidosa were quantified using High Performance Liquid Chromatography (HPLC) and also used for quantification of biofilm formation, cell surface hydrophobicity (CSH), extracellular polymeric substances (EPS) and pyocyanin degradation. The results showed 20 μg/mL concentration of lutein showed maximum inhibition and degradation of biofilm formation, pyocyanin production, Cell Surface Hydrophobicity Extracellular Polymeric Substances, when compared to other concentrations. Azithromycin was used as a standard drug to compare the efficiency of lutein as a potential antibiofilm compound. Docking studies confirmed the interaction of lutein with the four proteins - LasI, LasR, RhlI and RhlR, involved in the quorum sensing mechanism during biofilm formation. Among them, RhlI protein was found to strongly interact and LasI exhibiting the least interaction with lutein. Gene expression analyses of las and rhl genes in P. aeruginosa PAO1 revealed a significant down regulation of both the genes in the cultures treated with different concentrations of lutein. Therefore, it can be understood that lutein is an effective antibiofilm agent and can be used in combination with generic drugs that are used for treating diseases such as diabetic foot ulcers, which are ineffective due to high biofilm forming capability of P. aeruginosa and other bacterial species.

Flocculation-flotation harvesting mechanism of Dunaliella salina: From nanoscale interpretation to industrial optimization

Dunaliella salina is a green microalgae species industrially exploited for its capacity to produce important amounts of carotenoid pigments. However in low nitrogen conditions in which they produce these pigments, their concentration is low, which results in harvesting difficulties and high costs. In this work, we propose a new solution to efficiently harvest D. salina at the pre-industrial scale, using flocculation/flotation harvesting induced by NaOH addition in the medium. We first show, using numerical simulations and nanoscale atomic force spectroscopy experiments, that sweeping mechanism in formed magnesium hydroxide precipitate is only responsible for D. salina flocculation in hypersaline culture medium upon NaOH addition. Based on this understanding of the flocculation mechanism, we then evaluate the influence of several parameters related to NaOH mixing and magnesium hydroxide precipitation and show that NaOH concentration, mixing, and salinity of the medium can be optimized to achieve high flocculation/flotation harvesting efficiencies in laboratory-scale experiments. We finally successfully scale-up the data obtained at lab-scale to a continuous pre-industrial flotation pilot, and achieve up to 80% of cell recovery. This interdisciplinary study thus provides original results, from the nano to the pre-industrial scale, which allow the successful development of an efficient large-scale D. salina harvesting process. We thus anticipate our results to be the starting point for further optimization and industrial use of this flocculation/flotation harvesting technique.

New Drugs from the Sea: Pro-Apoptotic Activity of Sponges and Algae Derived Compounds

Natural compounds derived from marine organisms exhibit a wide variety of biological activities. Over the last decades, a great interest has been focused on the anti-tumour role of sponges and algae that constitute the major source of these bioactive metabolites. A substantial number of chemically different structures from different species have demonstrated inhibition of tumour growth and progression by inducing apoptosis in several types of human cancer. The molecular mechanisms by which marine natural products activate apoptosis mainly include (1) a dysregulation of the mitochondrial pathway; (2) the activation of caspases; and/or (3) increase of death signals through transmembrane death receptors. This great variety of mechanisms of action may help to overcome the multitude of resistances exhibited by different tumour specimens. Therefore, products from marine organisms and their synthetic derivates might represent promising sources for new anticancer drugs, both as single agents or as co-adjuvants with other chemotherapeutics. This review will focus on some selected bioactive molecules from sponges and algae with pro-apoptotic potential in tumour cells.