DOSE-DEPENDENT PROTECTIVE FEATURES OF LOBOPHORA VARIEGATA METHANOLIC EXTRACT (LVME) IN N-NITROSODIETHYLAMINE INDUCED EXPERIMENTAL HEPATOCARCINOGENESIS IN RATS

Objective: This study explores the anti-cancer property of Lobophora variegata, also an effective dose to treat hepatocarcinoma in Male Albino Wistar rats in N-nitrosodiethylamine induced hepatocarcinoma paradigm and its possible mechanism of action. Methods: In this study, rats were segregated into five groups; group-1 (control), group-2 treated with 0.01% NDEA through drinking water for 15 w, group-3 NDEA+treated with Lobophora variegata methanolic extract (LVME) (100 mg/kg b.w.), group-4 NDEA+treated with (LVME) (200 mg/kg b.w.) and group-5 NDEA+treated with (LVME) (400 mg/kg b.w.). Results: After the experimental period, functional and morphological changes in the liver were observed both macro and microscopically, the activities of liver marker enzymes, alkaline phosphatase (ALP), aspartate and alanine transaminases (AST and ALT) were analyzed. Administration of LVME as 200 mg/kg b.w. (to NDEA treated rats) significantly (i) reduced the preneoplastic lesions alleviated lipid peroxidation through scavenging free radicals, (ii) enhanced antioxidant status and reverted liver/disease marker enzymes plausibly by modulating xenobiotics metabolizing enzymes (XMEs) and by exhibiting antiproliferative and cytoprotective effects. Conclusion: LVME doses higher than 200 mg/kg b.w. are not effective in quenching the free radicals and restoring the liver functions as saturation level could have been reached; also, doses lower than 200 mg/kg b.w. could not be effective as they are below the optimum dose required to exhibit the pharmacological effects.

Diversity and distribution of the brown macroalgae (Phaeophyceae Kjellman, 1891) in cham islands, Quang Nam province, Vietnam

The study investigated the Phaeophyceae during the year 2019 at sixteen sampling sites representative for Cham islands. Specimens were collected by scuba diving, snorkelling and walking at the upper tidal zone in both dry and rainy seasons. Twenty-five species of the Phaeophyceae identified for Cham islands from four orders, four families and eleven genera. The Sargassaceae family is the most abundant species composition, followed by Dictyotaceae, Scytosiphonaceae and Asteronemataceae family. In the six islands surveyed, Hon Lao has the highest diversity with 19 species recorded; Hon Dai, Hon Tai, Hon Kho and Hon Mo island recorded from 10 to 14 species, and the lowest diversity is at the Hon La island with 8 species. Ten species Canistrocarpus cervicornis, Dictyota spinulosa, Lobophora obscura, Lobophora variegata, Pandina minor, Sargassum bicorne, Sargassum herklotsii, Sargassum parvifolium, Turbinaria conoides, Asteronema breviarticulatum reported as new records for the marine flora of Cham islands.

Distribución de macroalgas e invertebrados bentónicos en la laguna arrecifal del Arrecife de Banco Chinchorro, Quintana Roo, México

Con el propósito de obtener una descripción ecológica de los elementos que integran la comunidad coralina de Banco Chinchorro, arrecife del Caribe Mexicano, los datos de invertebrados y macroalgas obtenidos en 2016 y 2017 mediante transectos fotográficos en 36 sitios de la laguna arrecifal fueron analizados. Los indicadores ecológicos utilizados fueron: dominancia, diversidad ecológica, análisis de similitud y ordenación espacial. Las especies con mayor dominancia en la laguna arrecifal fueron: los corales escleractinios Orbicella annularis y Agaricia agaricites el gorgonáceo Pseudopterogorgia acerosa y la macroalga Lobophora variegata con más del 35 % de la dominancia total de la laguna arrecifal. Se observó un gradiente de diversidad del sur al norte. Dado ese gradiente, la disposición de las muestras y los resultados del análisis de similitud total, la laguna se dividió en Sur Centro y Norte, que fue analizada con los mismos descriptores ecológicos de la laguna total, con la intención de conocer la estructura interna de cada zona. Este análisis mostró fuertes separaciones y uniones entre diferentes áreas en cada zona, especialmente con las variables relacionadas con la influencia de los vientos y a las presiones ambientales. Se espera que los resultados obtenidos sirvan como base para estudios detallados que definan áreas prioritarias de conservación en este arrecife.

Three competitors in three dimensions: photogrammetry reveals rapid overgrowth of coral during multispecies competition with sponges and algae

Competition for limited space is an important driver of benthic community structure on coral reefs. Studies of coral-algae and coral-sponge interactions often show competitive dominance of algae and sponges over corals, but little is known about the outcomes when these groups compete in a multispecies context. Multispecies competition is increasingly common on Caribbean coral reefs as environmental degradation drives loss of reef-building corals and proliferation of alternative organisms such as algae and sponges. New methods are needed to understand multispecies competition, whose outcomes can differ widely from pairwise competition and range from coexistence to exclusion. In this study, we used 3D photogrammetry and image analyses to compare pairwise and multispecies competition on reefs in the US Virgin Islands. Sponges (Desmapsamma anchorata, Aplysina cauliformis) and macroalgae (Lobophora variegata) were attached to coral (Porites astreoides) and arranged to simulate multispecies (coral-sponge-algae) and pairwise (coral-sponge, coral-algae) competition. Photogrammetric 3D models were produced to measure surface area change of coral and sponges, and photographs were analyzed to measure sponge-coral, algae-coral, and algae-sponge overgrowth. Coral lost more surface area and was overgrown more rapidly by the sponge D. anchorata in multispecies treatments, when the sponge was also in contact with algae. Algae contact may confer a competitive advantage to the sponge D. anchorata, but not to A. cauliformis, underscoring the species-specificity of these interactions. This first application of photogrammetry to study competition showed meaningful losses of living coral that, combined with significant overgrowths by competitors detected from image analyses, exposed a novel outcome of multispecies competition.

Gallic Acid-Laminarin Conjugate Is a Better Antioxidant than Sulfated or Carboxylated Laminarin

A 12.4 kDa laminarin (LM) composed of β(1→3)-glucan with β(1→6)-branches was extracted from brown seaweed Lobophora variegata and modified via carboxylation using dielectric barrier discharge (LMC), conjugation with gallic acid (LMG), and sulfation (LMS). Analyses of the chemical composition of LMC, LMG, and LMS yielded 11.7% carboxyl groups, 1.5% gallic acid, and 1.4% sulfate content, respectively. Antioxidant activities of native and modified laminarins were assessed using six different in vitro methods. Sulfation stopped the antioxidant activities of LM. On the other hand, carboxylation improved cooper chelation (1.2 times). LMG was found to be a more efficient antioxidant agent than LM in terms of copper chelation (1.3 times), reducing power (1.3 times), and total antioxidant capacity (80 times). Gallic acid conjugation was further confirmed using Fourier transform infrared spectroscopy (FT-IR) and one- and two-dimensional NMR spectroscopy analyses. LMG also did not induce cell death or affect the cell cycle of Madin–Darby canine kidney (MDCK) cells. On the contrary, LMG protected MDCK cells from H2O2-induced oxidative damage. Taken together, these results show that LMG has the potent antioxidant capacity, and, therefore, potential applications in pharmacological and functional food products.

Rediscovery of the sponge crab Cryptodromia fallax (Latreille in Milbert, 1812) (Decapoda: Brachyura: Dromiidae) at Mauritius, with the description of a new genus and the confirmation of an unusual seaweed-carrying camouflage mode

Cryptodromia fallax (Latreille in Milbert, 1812) has been serendipitously found again on the island of Mauritius, almost 200 yrs after its discovery. The new material provides new information about the structure of the female sternum, providing stronger evidence that a new genus, Alcockdromiagen. nov., is required. Observations show that this crab cuts out and carries pieces of seaweed in the manner of a paraglider, rather than pieces of sponge normally carried by dromiid crabs. The crab uses Ulva lactuca Linnaeus, a green alga, and Lobophora variegata (J.V. Lamouroux), a brown alga. This discovery shows that the last two prehensile dromiid pereopods, which are used to carry soft camouflage, are multi-purpose, having only minor structural differences allowing them to carry seaweeds.