Analysis of marine diversity and anthropogenic pressures on Seixas coral reef ecosystem (northeastern Brazil).

Coral reefs, vital and ecologically significant ecosystems, are among the most jeopardized marine environments in the Atlantic Ocean, particularly along the northeastern coast of Brazil. The persistent lack of effective management and conservation has led to fragmented information on reef use and pressures, hindering the understanding of these ecosystems' health. Major difficulties and challenges include inadequate data, diverse anthropogenic pressures, and the complex interaction between marine species. This study sought to bridge this knowledge gap by conducting a comprehensive analysis of marine diversity and anthropogenic pressures, specifically focusing on Seixas coral reef near João Pessoa city, an area notably impacted by tourism. Utilizing 25 monitoring transects, subdivided into 1 m2 quadrants, the marine diversity was meticulously evaluated through innovative procedures including (a) sedimentological and geochemical field surveys, (b) application of Shannon-Weaver diversity and Simpson dominance indices, (c) cluster analysis, (d) species identification of macroalgae, coral, and fish, and (e) an examination of anthropogenic interactions and pressures on the coral reef. The assessment encompassed three distinct zones: Back Reef, Reef Top, and Fore Reef, and identified a total of 25 species across 15 genera and 10 fish families. The findings revealed the prevalence of brown macroalgae, fish, and coral, with heightened abundance of red macroalgae in the Fore Reef, which also exhibited the greatest diversity (2.816) and dominance (0.894). Original achievements include the identification of specific spatial variations, recognition of the anthropogenic factors leading to ecological changes, and the formulation of evidence-based recommendations. The study concludes that escalating urbanization and burgeoning daily tourist visits to the reef have exacerbated negative impacts on Seixas coral reef's marine ecosystem. These insights underscore the urgent need for strategic planning and resource management to safeguard the reef's biodiversity and ecological integrity.

Dataset of macrobenthic species in urban coastal reef environments in Brazilian northeast.

This dataset presents the macrobenthic species occurrence frequency in four coastal intertidal reefs environment of Paraiba state Brazil. The species were classified in bioindicators groups based in morpho-anatomical, physiological and ecological characteristics. In the dry and wet season in each reef, the sampling units were randomly positioned and photographed inside a circular area with a 10 m radius. Thirty points were plotted over photos to quantify the percentage of species occurrence frequency. Taxons hard to identify by photo were grouped in a unique category. Currently, macrobenthic species are used as bioindicators of the local state of conservation by managing agencies. The population ecology monitoring of macrobenthic species with bioindicator potential is useful to recognize seasonal environmental patterns or local anthropic impactful. The research article on these data [1] will be published in the journal Ocean and Coastal Management for some interpretive insights. Title: Evaluation of the conservation status and monitoring proposal for the coastal reefs of Paraíba, Brazil: bioindication as an environmental management tool.

Modulation of drug resistance in Staphylococcus aureus by 132-hydroxy-(132-R/S)-pheophytin isolated from Sargassum polyceratium.

Efflux pumps are integral parts of the bacterial plasma membrane that are responsible for many cases of antibiotic resistance. Modulators of drug resistance are regarded as the most suitable new antibacterial therapies. We evaluated the extracts of Sargassum polyceratium and the isolated compound pheophytin (Sp-1) for antibiotic modifying activity in strains of Staphylococcus aureus with efflux pump. The minimum inhibitory concentrations (MICs) for norfloxacin, tetracycline and erythromycin were determined by the microdilution broth method, in the absence and presence of the extract at a sub-inhibitory concentration (MIC/4). The extracts and isolated compounds showed no significant antimicrobial activity, but they changed the antibiotic activity, decreasing bacterial resistance by 2 to 4x. Using a checkerboard method, it was also possible to observe the synergistic effect (ΣFIC ≤ 0.5) between Sp-1 and the antibiotics erythromycin and norfloxacin. The results indicate that the seaweed Sargassum polyceratium and pheophytin are potential sources of an antibiotic adjuvant that modulates bacterial resistance, acting as a putative efflux pump inhibitor.

Dolastane diterpenes from Canistrocarpus cervicornis and their effects in modulation of drug resistance in Staphylococcus aureus.

One new diterpene (4R,7R,14S)-4α,7α-diacetoxy-10-one-14α-hydroxydolasta-1(15),8-diene (1), and five known compounds (4R,7R,14S)-4α,7α-diacetoxy-14α-hydroxydolasta-1(15),8-diene (2), (4R,14S)-4α,14α-dihydroxydolasta-1(15),8-diene (3), (4S,9R,14S)-4α-acetoxy-9ß,14α-dihydroxydolasta-1(15),7-diene (4), 4-acetoxy-14-hydroxydolasta-1(15),7,9-triene (5) and isolinearol (6), were isolated from Canistrocarpus cervicornis. In this study, dolastane diterpenes were isolated from the alga C. cervicornis and evaluated as modifiers of antibiotic activity in Staphylococcus aureus: SA-1199B, which overexpresses the norA gene RN-4220, which encodes for the protein efflux of macrolides (MRSA), and IS-58 which has the gene encoding the protein TetK. The minimum inhibitory concentrations (MICs) for norfloxacin, tetracycline and erythromycin were determined by the microdilution broth nutrient in the absence and presence of diterpenes at a sub-inhibitory concentration (MIC/4). The extracts of C. cervicornis and isolated diterpenes showed no antibacterial activity, but showed modulatory activity, decreasing the MIC of antibiotics by 4-256 fold. The results indicate that seaweed extracts and diterpenes are potential sources of antibiotic adjuvant, acting as potential inhibitors of efflux pump.

The Bisindole Alkaloid Caulerpin, from Seaweeds of the Genus Caulerpa, Attenuated Colon Damage in Murine Colitis Model.

Caulerpin (CLP), an alkaloid from algae of the genus Caulerpa, has shown anti-inflammatory activity. Therefore, this study aimed to analyze the effect of CLP in the murine model of peritonitis and ulcerative colitis. Firstly, the mice were submitted to peritonitis to evaluate which dose of CLP (40, 4, or 0.4 mg/kg) could decrease the inflammatory infiltration in the peritoneum. The most effective doses were 40 and 4 mg/kg. Then, C57BL/6 mice were submitted to colitis development with 3% dextran sulfate sodium (DSS) and treated with CLP at doses of 40 and 4 mg/kg. The disease development was analyzed through the disease activity index (DAI); furthermore, colonic tissue samples were submitted to histological analysis, NFκB determination, and in vitro culture for cytokines assay. Therefore, CLP at 4 mg/kg presented the best results, triggering improvement of DAI and attenuating the colon shortening and damage. This dose was able to reduce the TNF-α, IFN-γ, IL-6, IL-17, and NFκB p65 levels, and increased the levels of IL-10 in the colon tissue. Thus, CLP mice treatment at a dose of 4 mg/kg showed promising results in ameliorating the damage observed in the ulcerative colitis.

Brown Algae Padina sanctae-crucis Børgesen: A Potential Nutraceutical.

Padina sanctae-crucis Børgesen is distributed worldwide in tropical and subtropical seas; belongs to the Dictyotaceae family, and has proven to be an exceptional source of biologically active compounds. Four compounds were isolated and identified, namely: dolastane diterpene new for the genus Padina; phaeophytin and hidroxy-phaeophytin new for the family Dictyotaceae, and; mannitol first described in this species. Saturated fatty acids as compared to the percentages of unsaturated fatty acids were shown to be present in greater abundance. Palmitic and linolenic acid were the main saturated and unsaturated acids, respectively. Cytotoxic and antioxidant activities were evaluated using human erythrocytes. In vivo evaluations of acute toxicity and genotoxicity were performed in mice. Methanolic extract of P.sanctae-crucis presented antioxidant activity and did not induce cytotoxicity, genotoxicity or acute toxicity. Since Padina sanctae-crucis is already used as food, has essential fatty acids for the nutrition of mammals, does not present toxicity and has antioxidant activity, it can be considered as a potential nutraceutical.

Involvement of ß adrenergic receptors in spasmolytic effect of caulerpine on guinea pig ileum.

Previously, we demonstrated that caulerpine has spasmolytic effect on guinea pig ileum. The aim of this study was to investigate pathways of its spasmolytic action. We test caulerpine against phasic contractions induced by carbachol in the circular layer of guinea pig ileum and this alkaloid did not inhibit these contractions, indicating that caulerpine did not interfering with the mobilisation of Ca2+ from intracellular stores. Additionally, the spasmolytic effect of caulerpine did not involve K+ channels. Furthermore, we observed that α2-adrenergic receptors were not involved in the spasmolytic effect of caulerpine, since the relaxation curve induced by caulerpine was not shifted in the presence of yohimbine (α2-adrenergic antagonist). However, in the presence of propranolol (ß-adrenergic antagonist), the relaxation curve induced by caulerpine was right-shifted, resulting in a fivefold increase in EC50. Thus, a possible mechanism for the spasmolytic action of caulerpine is the activation of ß-adrenergic receptors.

Anti-inflammatory effects of methanolic extract of green algae Caulerpa mexicana in a murine model of ulcerative colitis

Abstract Inflammatory bowel diseases, which include Crohn's disease and ulcerative colitis, are characterized by chronic and relapsed gut inflammation. Caulerpa mexicana is a type of green marine algae that can be found in tropical areas, such as the Brazilian Coastland. These macrophytes exhibit in vitro and in vivo anti-inflammatory properties such as the ability to reduce both cell migration to different sites and edema formation induced by chemical irritants. The aim of this study was to examine the effect of the C. mexicana methanolic extract on the treatment of colitis induced by dextran sodium sulfate. Acute experimental colitis was induced in BALB/c mice by treatment with 3% dextran sodium sulfate orally for 14 days. During this 14-day period, C. mexicana methanolic extract (2 mg/kg/day) was given intravenously on alternate days. Treatment with the methanolic extract significantly attenuated body weight loss and severe clinical symptoms. This was associated with a remarkable amelioration of colonic architecture disruption and a significant reduction in pro-inflammatory cytokine production. These results suggest that the anti-inflammatory action of C. mexicana methanolic extract on colorectal sites may be a useful therapeutic approach for inflammatory bowel diseases.

Incidental histological diagnosis of acute rheumatic myocarditis: case report and review of the literature.

Rheumatic fever (RF) remains endemic in many countries and frequently causes heart failure due to severe chronic rheumatic valvular heart disease, which requires surgical treatment. Here, we report on a patient who underwent an elective surgical correction for mitral and aortic valvular heart disease and had a post-operative diagnosis of acute rheumatic carditis. The incidental finding of Aschoff bodies in myocardial biopsies is frequently reported in the nineteenth-century literature, with prevalences as high as 35%, but no clinical or prognostic data on the patients is included. The high frequency of this finding after cardiac surgery in classical reports suggests that these patients were not using secondary prophylaxis for RF. We discuss the clinical diagnosis of acute rheumatic myocarditis in asymptomatic patients and the laboratorial and imaging methods for the diagnosis of acute rheumatic carditis. We also discuss the prognostic implications of this finding and review the related literature.

Assessment of mechanisms involved in antinociception produced by the alkaloid caulerpine.

In previous works we showed that oral administration of caulerpine, a bisindole alkaloid isolated from algae of the genus Caulerpa, produced antinociception when assessed in chemical and thermal models of nociception. In this study, we evaluated the possible mechanism of action of this alkaloid in mice, using the writhing test. The antinociceptive effect of caulerpine was not affected by intraperitoneal (i.p.) pretreatment of mice with naloxone, flumazenil, l-arginine or atropine, thus discounting the involvement of the opioid, GABAergic, l-arginine-nitric oxide and (muscarinic) cholinergic pathways, respectively. In contrast, i.p. pretreatment with yohimbine, an α2-adrenoceptor antagonist, or tropisetron, a 5-HT3 antagonist, significantly blocked caulerpine-induced antinociception. These results suggest that caulerpine exerts its antinociceptive effect in the writhing test via pathways involving α2-adrenoceptors and 5-HT3 receptors. In summary, this alkaloid could be of interest in the development of new dual-action analgesic drugs.

Spasmolytic effect of caulerpine involves blockade of Ca²âº influx on guinea pig ileum.

In this work, we investigated the spasmolytic effect of caulerpine, a bisindole alkaloid isolated from marine algae of the Caulerpa genus, on guinea pig ileum. Our findings indicated that caulerpine inhibited phasic contractions induced by carbachol (IC50 = 7.0 ± 1.9 × 10⁻5 M), histamine (IC50 = 1.3 ± 0.3 × 10⁻4 M) and serotonin (IC50 = 8.0 ± 1.4 × 10⁻5 M) in a non-selective manner. Furthermore, caulerpine concentration-dependently inhibited serotonin-induced cumulative contractions (pD'2 = 4.48 ± 0.08), shifting the curves to the right with Emax reduction and slope of 2.44 ± 0.21, suggesting a noncompetitive antagonism pseudo-irreversible. The alkaloid also relaxed the ileum pre-contracted by KCl (EC50 = 9.0 ± 0.9 × 10⁻5 M) and carbachol (EC50 = 4.6 ± 0.7 × 10⁻5 M) in a concentration-dependent manner. This effect was probably due to inhibition of Ca²âº influx through voltage-gated calcium channels (CaV), since caulerpine slightly inhibited the CaCl2-induced contractions in depolarizing medium without Ca²âº, shifting the curves to the right and with Emax reduction. According to these results, the spasmolytic effect of caulerpine on guinea pig ileum seems to involve inhibition of Ca²âº influx through CaV. However, other mechanisms are not discarded.

Antinociceptive and anti-inflammatory activities of crude methanolic extract of red alga Bryothamnion triquetrum.

The marine environment is an extraordinary reservoir of bioactive natural products, many of which exhibit chemical and structural features not found in terrestrial natural products. In this regard, the aim of this study was to investigate the possible antinociceptive and anti-inflammatory activities of a crude methanolic extract of the red alga Bryothamnion triquetrum (BT-MeOH) in murine models. Groups of Swiss mice of both sexes (25-30 g) were used throughout the experiments. The potential antinociceptive of BT-MeOH was evaluated by means of the following tests: acetic acid-induced writhing, hot-plate test and glutamate- and formalin-induced nociception. The anti-inflammatory activity of BT-MeOH was investigated using the zymosan A-induced peritonitis test. The tests were conducted using 100 mg/kg (p.o.) BT-MeOH, 33.3 mg/kg (p.o.) dipyrone, 35.7 mg/kg (p.o.) indomethacin and 5.7 mg/kg (s.c.) morphine. The extract and all standard drugs were administered 40 min before the nociceptive/inflammatory stimulus. In the acetic acid-induced writhing test, BT-MeOH and dipyrone inhibited the nociceptive response by 55.9% (22.2 ± 2.0 writhings; p < 0.01) and 80.9% (9.6 ± 2.1 writhings; p < 0.01). In the hot-plate test, BT-MeOH did not increase the latency time of the animals in the time evaluated. In addition, BT-MeOH inhibited glutamate-induced nociception by 50.1%. While BT-MeOH did not inhibit the neurogenic phase in formalin-induced nociception, the inflammatory phase was inhibited by 53.1% (66.8 ± 14.2 s; p < 0.01). Indomethacin inhibited the inflammatory phase by 60.2% (56.8 ± 8.7 s; p < 0.01). In the zymosan-induced peritonitis test, BT-MeOH inhibited 55.6% (6.6 ± 0.2 × 10(6) leukocytes/mL; p < 0.01) of leukocyte migration, while indomethacin inhibited 78.1% (3.2 ± 0.1 × 10(6) leukocytes/mL; p < 0.01). Based on the results obtained in this study, we conclude that BT-MeOH has peripheral antinociceptive and anti-inflammatory activities. However, more studies need to be conducted to confirm these properties.

Effects of temperature, salinity and irradiance on carposporeling development of Hidropuntia caudata (Gracilariales, Rhodophyta)

The success of seaweed cultivation depends on the scientific control of the tolerance limits and the optimal physiological conditions that affect the spore germination and the early development of algal species. In order to establish cultivation techniques for spores of Hidropuntia caudata (J. Agardh) Gurgel & Fredericq, the effects of irradiance, salinity, and temperature on the carpospore germination and carposporeling development were evaluated under laboratory conditions. Five photon flux densities (PFD, from 18 to 200 µmol photons m-2s-1), six salinity values (from 7 to 55 psu), and four temperatures (from 20 ºC to 35 ºC) were investigated. The level of irradiance caused significant differences in the growth, in the following order: 200±5 > 100±5 ~= 62.5±2.5 > 30±1.5 > 18±1 µmol of photons m-2s-1, but they did not inhibit the carposporeling development. Maximum growth occurred under 35 psu, while at 15 psu the formation of carposporeling erect axis was limited. The optimal temperature for growth was 25 ºC, while at 35 ºC the spores died. These results show the importance of previous knowledge on the tolerance limits and optimal conditions for sporeling development of H. caudata for the implementation of an aquaculture program.

Vasorelaxation, induced by Dictyota pulchella (Dictyotaceae), a brown alga, is mediated via inhibition of calcium influx in rats.

This study aimed to investigate the cardiovascular effects elicited by Dictyota pulchella, a brown alga, using in vivo and in vitro approaches. In normotensive conscious rats, CH(2)Cl(2)/MeOH Extract (CME, 5, 10, 20 and 40 mg/kg) from Dictyota pulchella produced dose-dependent hypotension (-4 ± 1; -8 ± 2; -53 ± 8 and -63 ± 3 mmHg) and bradycardia (-8 ± 6; -17 ± 11; -257 ± 36 and -285 ± 27 b.p.m.). In addition, CME and Hexane/EtOAc Phase (HEP) (0.01-300 µg/mL) from Dictyota pulchella induced a concentration-dependent relaxation in phenylephrine (Phe, 1 µM)-pre-contracted mesenteric artery rings. The vasorelaxant effect was not modified by the removal of the vascular endothelium or pre-incubation with KCl (20 mM), tetraethylammonium (TEA, 3 mM) or tromboxane A(2) agonist U-46619 (100 nM). Furthermore, CME and HEP reversed CaCl(2)-induced vascular contractions. These results suggest that both CME and HEP act on the voltage-operated calcium channel in order to produce vasorelaxation. In addition, CME induced vasodilatation after the vessels have been pre-contracted with L-type Ca(2+) channel agonist (Bay K 8644, 200 nM). Taken together, our data show that CME induces hypotension and bradycardia in vivo and that both CME and HEP induce endothelium-independent vasodilatation in vitro that seems to involve the inhibition of the Ca(2+) influx through blockade of voltage-operated calcium channels.