Fucoxanthin and Rosmarinic Acid Combination Has Anti-Inflammatory Effects through Regulation of NLRP3 Inflammasome in UVB-Exposed HaCaT Keratinocytes

Excessive exposure to ultraviolet (UV) radiation is the main risk factor to develop skin pathologies or cancer because it encourages oxidative condition and skin inflammation. In this sense, strategies for its prevention are currently being evaluated. Natural products such as carotenoids or polyphenols, which are abundant in the marine environment, have been used in the prevention of oxidative stress due to their demonstrated antioxidant activities. Nevertheless, the anti-inflammatory activity and its implication in photo-prevention have not been extensively studied. Thus, we aimed to evaluate the combination of fucoxanthin (FX) and rosmarinic acid (RA) on cell viability, apoptosis induction, inflammasome regulation, and anti-oxidative response activation in UVB-irradiated HaCaT keratinocytes. We demonstrated for the first time that the combination of FX and RA (5 µM RA plus 5 µM FX, designated as M2) improved antioxidant and anti-inflammatory profiles in comparison to compounds assayed individually, by reducing UVB-induced apoptosis and the consequent ROS production. Furthermore, the M2 combination modulated the inflammatory response through down-regulation of inflammasome components such as NLRP3, ASC, and Caspase-1, and the interleukin (IL)-1β production. In addition, Nrf2 and HO-1 antioxidant genes expression increased in UVB-exposed HaCaT cells pre-treated with M2. These results suggest that this combination of natural products exerts photo-protective effects by down-regulating NRLP3-inflammasome and increasing Nrf2 signalling pathway.Junta de Andalucía, Consejería de Innovación, Ciencia y Empresa-POLFANAT-P12-AGR-430Portugal, Fundação para a Ciência e a Tecnologia (FCT)-CESAM-UID/AMB/50017/2019Portugal, Fundação para a Ciência e a Tecnologia (FCT)-CEECIND/04050/2017Universidad de Sevilla "V Plan Propio US-PPI2015-1.5"

Biological activity studies on marine natural products as therapeutic strategies in in vitro models of inflammation and colon cancer

Motivation: The inflammatory response is a highly regulated process, and its dysregulation can lead to the establishment of chronic inflammation and, in some cases, it is the cause of several diseases, including cancer. Marine invertebrates are exceptional sources of new natural products, such as terpenoids, which are secondary metabolites that can exhibit anti-inflammatory and anticancerogenic activities. Colon cancer is a disease with a high genetic factor in which inflammation, and therefore its mediators, play an important role.This study focuses on the analysis of the biological activity of various natural terpenoids isolated from marine corals.Methods:HT-29 cells (human adenocarcinoma colon cell line) were grown in McCoy´s 5A and THP-1 cells (human monocytic leukemia cell line) in RPMI1640, both supplemented with 10% FBS and Strep/Pen (37ºC in 5% CO2 atmosphere). Cytotoxic activity was evaluated with the sulforhodamine (SRB) assay. The anti-inflammatory activity was tested on THP-1 through quantification of TNF-alpha, IL-6, IL-8, IL-1B and IL-10 by ELISA and COX-2 and iNOS levels by western-blot. Adherent macrophages were treated with terpenoids (10, 20 and 50 µM) for 1h, followed by stimulation of 1μg/mL LPS for 24h in both assays. Antioxidant activity was measured by ABTS assay.Results: Terpenes showed a moderate cytotoxic activity in both HT-29 and THP-1 macrophages after 48 and 72h. Pre-treatment with these compounds significantly reduced LPS-stimulated cytokines production in THP-1 cells as well as attenuated LPS-induced COX-2 and iNOS protein expression after 24 h. In addition, ABTS assay showed a low antioxidant activity.Conclusions: The five terpenes present a moderate antioxidant and cytotoxic activity as well as a potent anti-inflammatory effect in vitro. This kind of marine natural products may represent an interesting alternative for the treatment of inflammation-related diseases or cancer

Anti-inflammatory and anticancer effects of microalgal carotenoids

Acute inflammation is a key component of the immune system's response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as a- and |3 -carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, a- and 3-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.Universidad de Sevilla 2021/0000019

Fucoxanthin-Containing Cream Prevents Epidermal Hyperplasia and UVB-Induced Skin Erythema in Mice

Microalgae represent a source of bio-active compounds such as carotenoids with potent anti-inflammatory and antioxidant properties. We aimed to investigate the effects of fucoxanthin (FX) in both in vitro and in vivo skin models. Firstly, its anti-inflammatory activity was evaluated in LPS-stimulated THP-1 macrophages and TNF-α-stimulated HaCaT keratinocytes, and its antioxidant activity in UVB-irradiated HaCaT cells. Next, in vitro and ex vivo permeation studies were developed to determine the most suitable formulation for in vivo FX topical application. Then, we evaluated the effects of a FX-containing cream on TPA-induced epidermal hyperplasia in mice, as well as on UVB-induced acute erythema in hairless mice. Our results confirmed the in vitro reduction of TNF-α, IL-6, ROS and LDH production. Since the permeation results showed that cream was the most favourable vehicle, FX-cream was elaborated. This formulation effectively ameliorated TPA-induced hyperplasia, by reducing skin edema, epidermal thickness, MPO activity and COX-2 expression. Moreover, FX-cream reduced UVB-induced erythema through down-regulation of COX-2 and iNOS as well as up-regulation of HO-1 protein via Nrf-2 pathway. In conclusion, FX, administered in a topical formulation, could be a novel natural adjuvant for preventing exacerbations associated with skin inflammatory pathologies as well as protecting skin against UV radiation

Cytotoxic Activity of Microalgal-derived Oxylipins against Human Cancer Cell lines and their Impact on ATP Levels

Oxylipins are metabolites derived from lipid peroxidation. The plant oxylipin methyl jasmonate (MJ) shows cytotoxic activity against cancer cell lines of various origins, with ATP-depletion being one of the mechanisms responsible for this effect. The cytotoxic activity of oxylipins (OXLs) isolated from the microalgae Chlamydomonas debaryana (13-HOTE) and Nannochloropsis gaditana (15-HEPE) was higher against UACC-62 (melanoma) than towards HT-29 (colon adenocarcinoma) cells. OXLs lowered the ATP levels of HT-29 and UACC-62 cells, but the effect was higher on the second cell line, which had higher basal ATP. This result proves a link between the cytotoxicity and the capability of these compounds to deplete ATP. In addition, the combination of 13-HOTE with the anticancer drug 5-fluorouracil (5-FU) induced a synergistic toxicity against HT-29 cells. These results highlight the therapeutic potential of oxylipins derived from microalgae.España MINECO and FEDER (research project IPT-2011-1370- 060000