Mario Nieves-Soto

Antioxidant, antimutagenic and antiproliferative activities in selected seaweed species from Sinaloa, Mexico

Abstract Context Seaweeds from the Mexican Pacific Ocean have not been evaluated as a source of chemoprotectants. Objective The objective of this study is to evaluate chemopreventive activities of the seaweeds Phaephyceae – Padina durvillaei (Dictyotaceae) – Rodhophyceae – Spyridia filamentosa (Spyridiaceae), Gracilaria vermiculophylla (Gracilariaceae) – and Chlorophyceae – Ulva expansa (Ulvaceae), Codium isabelae (Codiaceae), Rhizoclonium riparium (Cladophoraceae) and Caulerpa sertularioides (Caulerpaceae). Materials and methods Methanol, acetone and hexane seaweed extracts were assessed at 30 and 3 mg/mL on antioxidant capacity (DPPH and ABTS assays), 0.003–3.0 mg/plate on antimutagenic activity against AFB1 using Salmonella typhimurium TA98 and TA100 tester strains in Ames test, and 12.5 to 100 μg/mL on antiproliferative activity on Murine B-cell lymphoma. Phenols, flavonoids and pigments content were also assessed as antioxidant compounds. Results Extraction yield was higher in methanol than in acetone and hexane extracts (6.4, 2.7 and 1.4% dw). Antioxidant capacity was higher in brown and green than in red seaweed species, particularly in P. durvillaei extracted in acetone (EC50  value= 16.9 and 1.56 mg/mL for DPPH and ABTS). Flavonoids and chlorophylls were identified as mainly antioxidant components; particularly in hexane extracts, which were correlated with the antioxidant capacity. Highest mutagenesis inhibition (> 40%) occurred in R. riparium at the lowest concentration assayed (0.003 mg/plate), while highest antiproliferative inhibition (37 and 72% for 12.5 and 25 μg/mL) occurred in C. sertularioides. Discussion and conclusion Flavonoids and chlorophylls explained the chemopreventive activities assessed in S. filamentosa, R. riparium and C. sertularioides. These seaweeds have a high potential as a source of novel chemoprotectants.

Current Status of Mangrove Wetlands in Sinaloa: A Biological Corridor Along the Eastern Margin of the Gulf of California, México

The state of Sinaloa, located in northwestern Mexico, possesses significant mangrove coverage (ranked fourth in this country), which can be considered a biological corridor because of its ecological relevance for many resident and migratory species. Several ecosystem services are provided by mangrove wetlands; however, diverse drivers of change, mainly anthropogenic stressors, e.g. urban development, pollution, agricultural and aquaculture activities, have modified this large ecosystem during the last decades. It has been reported that Sinaloa has lost more than 5000 ha since 1985, yet the impacts on mangrove structure and functioning are still poorly understood. Furthermore, the frequency and intensity of climate phenomena like “El Nino” events might impact the phenology of mangroves in this region and deserve further studies. Bioaccumulation of contaminants, land cover change, aquaculture, hydrological changes, low and increasing temperature conditions and the impact of hurricanes on mangroves are discussed in this chapter in addition to recommendations for future studies, e.g. the impact of plagues and phytopathogens on mangroves in Sinaloa.

Gender Differences and Short-Term Exposure to Mechanical, Thermic, and Mechanical—Thermic Stress Conditions on Hemocyte Functional Characteristics and Hsp70 Gene Expression in Oyster Crassostrea corteziensis (Hertlein, 1951)

ABSTRACT On sea farms, oysters are constantly submitted to mechanical manipulation through size sorting and cleaning of epibionts, and also are maintained out of seawater and exposed to air and sunlight radiation during cleaning and transport to marketplaces. Therefore, the aim of this work was to evaluate gender differences and short-term changes in the immune response, glucose plasma levels, and Hsp70 gene expression in oyster Crassostrea corteziensis exposed for 0 (control), 15, 30, 45, and 60 min to mechanical (agitated), thermic (sunlight), and a combination of both stressors. Variations in total hemocyte count (THC) and granulocyte count (GC), as well in functional characteristics [i.e., mortality of hemocytes, phagocytosis, and anion superoxide production (SOA)] of hemocytes, suggest that oysters seems well adapted to mechanical disturbance, because SOA values increased, phagocytic activity was not affected, and hemocyte counts and mortality were rapidly recovered. Contrary with prolonged exposure of oysters to thermic conditions, which exerted a constantly increase of THC, whereas both hemocyte mortality and phagocytic activity decreased, but oxidative capacity (i.e., SOA) decreased in male and increased in female oysters. Immune competence and Hsp70 gene expression were significantly diminished in oysters exposed for 30 min to a combination of both stressors (i.e., mechanical and thermic), indicating the most vulnerable stress conditions. Hsp70 gene expression showed that females were more susceptible than male oyster to short-term (i.e., 15–30 min) exposure to mechanical and thermic stresses, but prolonged (i.e., 60 min) exposure of combined stressors exerted a particular effect on male oysters. The immune responses assessed and glucose levels in plasma demonstrated that thermic and mechanical—thermic stress conditions were more stressful than mechanical disruption, and that females were more susceptible than male oysters to stress conditions assayed. These environmental and anthropogenic stressors should be considered for the cultivation of this oyster species, as well for further research related with immune response of C. corteziensis.