Artemia Salina Nauplii Research Articles

In vitro cytotoxic activity of medicinal plants from Nigeria ethnomedicine on Rhabdomyosarcoma cancer cell line and HPLC analysis of active extracts

BackgroundCancer is a leading cause of death world-wide, with approximately 17.5 million new cases and 8.7 million cancer related deaths in 2015. The problems of poor selectivity and severe side effects of the available anticancer drugs, have demanded the need for the development of safer and more effective chemotherapeutic agents. The present study was aimed at determining the cytotoxicities of 31 medicinal plants extracts, used in Nigerian ethnomedicine for the treatment of cancer.MethodsThe plant extracts were screened for cytotoxicity, using the brine shrimp lethality assay (BSLA) and MTT cytotoxicity assay. Rhabdomyosarcoma (RD) cell line, normal Vero cell line and the normal prostate (PNT2) cell line were used for the MTT assay, while Artemia salina nauplii was used for the BSLA. The phytochemical composition of the active plant extracts was determined by high performance liquid chromatography (HPLC) analysis.ResultsThe extract of Eluesine indica (L.) Gaertn (Poaceae), with a LC50 value of 76.3 μg/mL, had the highest cytotoxicity on the brine shrimp larvae compared to cyclophosphamide (LC50 = 101.3 μg/mL). Two plants extracts, Macaranga barteri Mull. Arg. (Euphorbiaceae) and Calliandra portoricensis (Jacq.) Benth (Leguminosae) exhibited significant cytotoxic activity against the RD cell line and had comparable lethal activity on the brine shrimps. Further cytotoxic investigation showed that the dichloromethane fraction of Macaranga barteri (DMB) and the ethyl acetate fraction of Calliandra portoricensis (ECP), exhibited approximately 6-fold and 4-fold activity, respectively, compared to cyclophosphamide on RD cell line. Determination of selective index (SI) using Vero and PNT2 cell line indicated that DMB and ECP displayed a high degree of selectivity against the cancer cell under investigation. HPLC analysis showed that 3,5dicaffeoylquinic acid, acteoside, kampferol-7-O-glucoside and bastadin 11 were the major components of DMB while the major components of ECP were neurolenin B, nigrosporolide and trans-geranic acid.ConclusionThe results demonstrate the cytotoxicity of Macaranga barteri and Calliandra portoricensis extracts, which are used in Nigerian folklore for cancer treatment.

Synthesis of platinum nanoparticles using seaweed Padina gymnospora and their catalytic activity as PVP/PtNPs nanocomposite towards biological applications

In the recent years, synthesis of nanomaterials using seaweeds and their diverse applications is escalating research in modern era. Among the noble metals, platinum nanoparticles (PtNPs) are of great importance owing to their catalytic property and less toxicity. The significance of this work is a simple one-step synthesis of PtNPs using aqueous extract of Indian brown seaweed Padina gymnospora and their catalytic activity with a polymer Polyvinylpyrrolidone (PVP) as PVP/PtNPs nanocomposite towards antimicrobial, haemolytic, cytotoxic (Artemia salina) and antioxidant properties. Fourier Transform Infrared (FT-IR) spectrum results showed diversified functional groups (biomoeities such as carbohydrates and proteins) present in the seaweed extract is responsible for the reduction of platinum ions (Pt+) to PtNPs. The seaweed mediated PtNPs was characterized by UV–vis spectrophotometer, X-ray diffraction (XRD) pattern, Field Emission Scanning Electron Microscopy (FESEM) equipped with Energy Dispersive X-ray (EDX) spectroscopy and High Resolution Transmission Electron Microscopy (HRTEM) analysis. The synthesized PtNPs was found to be truncated octahedral in shape with the range of 5–50nm. Crystalline nature of the nanoparticles was evidenced by Selected Area Electron Diffraction (SAED) pattern with bright circular spots corresponding to (111), (200), (220) and (311) Bragg’s reflection planes. The size of the PtNPs was further evidenced by Dynamic Light Scattering (DLS) analysis and it is originate to be stable at −22.5mV through Zeta Potential (ZP) analysis. The present study shows that the catalytic behavior of PtNPs as polymer/metal nanocomposite (PVP/PtNPs) preparation for an antibacterial activity against seven disease causing pathogenic bacterial strains with the maximum activity against Escherichia coli (15.6mm) followed by Lactococcus lactis (14.8mm) and Klebsiella pneumoniae (14.4mm). But no haemolytic activity was seen at their effective bactericidal concentration, whereas increase in the haeomyltic activity was seen only in higher concentrations (600, 900 and 1200μgmL−1). On the other hand, PVP/PtNPs nanocomposite has shown cytotoxic activity at 100±4μgmL−1 (LC50) against Artemia salina nauplii. Furthermore, PVP/PtNPs nanocomposite showed an enhanced scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide, nitric oxide and hydroxyl radicals.

Physiological responses and lipid storage of the coral Lophelia pertusa at varying food density

ABSTRACTDespite the importance of the cold-water coral Lophelia pertusa to deep-sea reef ecosystem functioning, current knowledge of key physiological responses to available food resources is scarce. Scenarios with varying food density may help to understand how corals deal with seasonal variations in the dark ocean and might be used to study consequences of anthropogenic activities potentially affecting food availability. Thus, the physiological responses of L. pertusa to varying food (Artemia salina nauplii) concentration, ranging from 20% to 300% of carbon equivalent turned over by basal coral respiration, were investigated. A starvation group was also included. Measurements of respiration, growth, mucus production, and energy reserves (storage fatty acids) were performed at several time intervals over 26 weeks. In general, data showed a stronger effect of experimental time on measured responses, but no significant influence of food density treatment. In starved corals, respiration rate declined to 52% of initial respiration, while skeleton growth rate was maintained at the same rate as Artemia-fed corals throughout the investigation. Mucus production measured as the sum of dissolved organic carbon (DOC) and particulate organic carbon (POC) was also similar across food treatments, but POC production exceeded that of DOC at the highest food density. No marked effect was observed on storage fatty acids. These results confirm that L. pertusa is highly resilient to environmental conditions with suboptimal food densities over a time scale of months. Regulation of several physiological processes, including respiration and mucus production, possibly in combination with an opportunistic feeding strategy, contributed to this tolerance to maintain viable corals. Thus, it appears that L. pertusa is well adapted to life in the deep sea.

Antimicrobial Potential of Rosmarinus officinalis Commercial Essential Oil in the Treatment of Vaginal Infections in Pregnant Women

Treating inflammatory conditions .such as vaginosis, vaginitis, and vulvovaginitis in pregnancy is- a special problem due to limitations. of available drugs. However, possible treatment options can be found also in naturally originated products, such as essential oils (EOs) of different plants. The aim of this study was to evaluate in -vitro antimicrobial and toxic activities of the commercial EO of Rosmiarinus officinalis L. (Lamiaceae) against five Gram-positive and Gram-negative bacterial strains and two Candida strains obtained from pregnant women with Vaginal infection. Gas chromatography-mass spectrometry of the tested EO revealed oxygenated monoterpenes to be the major ingredients, while microdilution assay showed the highest activity on Staphylococcus aureus II strain at 6.2 mg/mL. After 24 hours, toxicity was determined at 19.4 mg/mL on Artemia salina nauplii. The obtained results show this EO to be a promising alternative therapy for vaginal infections, although further toxicity and safety research is required.

Antioxidant, cytotoxic and antimicrobial activities of green synthesized silver nanoparticles from crude extract of Bergenia ciliata

BackgroundThe methods like bio-green are advantageous over chemical and physical methods due to ecofriendly and cost-effective synthesis of nanoparticles. Current study was designed for green synthesis of silver nanoparticles (AgNPs) and their biological evaluation. MethodsMethanolic extract of Bergenia ciliata (BC) rhizomes prepared by maceration was used for the synthesis of AgNPs and confirmed by UV–visible and Fourier Transform Infra-Red (FTIR) spectroscopy. Further field emission scanning electron microscope (SEM) was used for the shape and size determination. In vitro Antioxidant, antimicrobial and cytotoxic potential was determined by using standard protocols. ResultsThe nanoparticles were spherical in shape having average particle size of 35 nm. FTIR analysis revealed the possible involvement of phyto-constituents in silver nanoparticles of crude extract. Green synthesized nanoparticles (BCAgNPs) showed the enhanced antioxidant properties compared to the crude extract. These nanoparticles showed the cytotoxic effects against brine shrimp (Artemia salina) nauplii with a value of 33.92 μg/ml LD50. BCAgNPs were found effective against the pathogenic fungal and bacterial strains in comparison to the Bergenia ciliata extract. ConclusionGreen synthesized BCAgNPs showed enhanced biological activities. Present results also support the advantages of using bio-green method for the production of nanoparticles having the potential of antimicrobial and cytotoxic activities.

Feeding behaviors of three tropical scleractinian corals in captivity

This study examined the capture rates and prey digestion of three corals species in two genera (Acropora and Pocillopora) found dominantly in Thailand and the Federated States of Micronesia using Artemia salina nauplii as a food source. In addition, feeding during day and night times of corals was investigated. Results showed that all three coral species, namely, Acropora millepora, Acropora nobilis, and Pocillopora damicornis captured and consumed A. salina nauplii under both light and dark conditions. The capture rates of the three species ranged between 0.44 and 2.39 individuals/polyp/12 h. The results also showed complete digestions of A. salina nauplii by A. millepora and A. nobilis after 2 h, whereas P. damicornis took 2.5 h to complete the prey digestion. Even though feeding corals with Artemia is not a novel implication since this is widely used, the results of optimum daily feeding frequency of corals by Artemia may be applied for optimum corals growth and survival in captivity or aquarium.

Cytolytic and systemic toxic effects induced by the aqueous extract of the fire coral Millepora alcicornis collected in the Mexican Caribbean and detection of two types of cytolisins.

BackgroundMillepora alcicornis is a branching hydrocoral common throughout the Caribbean Sea. Like other members of this genus, this species is capable of inducing skin eruptions and blisters with severe pain after contact. In the present study, we investigated the toxicity of the M. alcicornis aqueous extract on several animal models. Considering that some cnidarian hemolysins have been associated to local tissue damage, since they also induce lysis of other cell types, we also made a partial characterization of the hemolytic activity of M. alcicornis aqueous extract. This information is important for understanding the defense mechanisms of the “fire corals”.MethodsThe effects of pH, temperature, and some divalent cations on the hemolytic activity of the extract were assayed, followed by a zymogram analysis to detect the cytolysins and determine their approximate molecular weight. The toxicity of the aqueous extract was assayed in mice, by intravenous administration, and histopathological changes on several tissues were analyzed by light microscopy. The toxicity of the extract was also tested in Artemia salina nauplii, and the damages caused on the crustaceans were analyzed by transmission and scanning electron microscopy.ResultsThe hemolytic activity of the hydrocoral extract was enhanced in the presence of Ca2+ (≥2 mM), Mg2+ (≥6 mM), and Ba2+ (≥0.1 mM); however, it was reduced in the presence of Cu2+ (≥0.1 mM), Zn2+ (≥6 mM), and EDTA (≥0.34 mM). Differences in the pH did not affect the hemolytic activity, but it was temperature-sensitive, since preincubation at ≥ 50 °C sharply reduced hemolysis. The zymogram showed the presence of two types of hemolysins: ~ 28–30 kDa proteins with phospholipase A2 activity and ~ 200 kDa proteins that do not elicit enzymatic activity. The aqueous extract of this cnidarian was lethal to mice (LD50 = 17 μg protein/g), and induced kidney, liver, and lung damages. Under denaturing conditions, the aqueous extract completely lost its toxic and hemolytic activities.ConclusionsThe results showed that the M. alcicornis aqueous extract contains two types of thermolabile hemolysins: proteins of approximately 28–30 kDa with PLA2 activity, while the others are larger proteins of approximately 200 kDa, which do not possess PLA2 activity. Those thermolabile cytolysins, which are stable to pH changes and whose activity is calcium dependent, are capable of inducing damage in lung, kidney and liver tissues, resulting in a slow death of mice. M. alcicornis cytolysins also provoke tissue dissociation in Artemia salina nauplii that might be attributed to pore forming mechanisms.

Determination of TiO2 and AgTiO2 Nanoparticles in Artemia salina: Toxicity, Morphological Changes, Uptake and Depuration.

In this study, aquatic stability and toxic effects of TiO2 and AgTiO2 nanoparticles (NPs) were investigated on Artemia salina nauplii. AgTiO2 was found to be more toxic to nauplii compared to TiO2. The mortality rate in nauplii increased significantly with increasing concentrations and duration of exposure. TiO2 eliminations ranged between 27.8% and 96.5% at 50 and 1 mg/L TiO2 exposed to nauplii, respectively. Accumulation and elimination of Ag in AgTiO2 exposed nauplii were similar except at 1 mg/L AgTiO2. When NPs were mixed with water, the hydrodynamic dimensions of NPs significantly increased because of aggregation in saltwater but NP size decreased over time. NPs-exposed nauplii showed changes in eye formation, enlargement of the intestine, malformations in the outer shell and antennae loss were also observed. Since accumulation and toxicity of AgTiO2 NPs was higher than TiO2 alone, inevitably release of AgTiO2 into aqueous environments can cause ecological risks.

Ovulation and initial rearing of Steindachneridion parahybae (Siluriformes: Pimelodidae) larvae from different accumulated thermal units

Steindachneridion parahybae is an endemic catfish to the Paraiba do Sul river basin classified as critically endangered. Little is known about the reproductive management of this species in captivity, adopting for this practice empirical measures. The objectives were to: (1) determine suitable Accumulated Thermal Units (ATUs) at the moment of ovulation in January 2011 and 2012; (2) follow initial larvae rearing in 180, 240 and 300 degree-hours. Nine selected females were divided into three experimental groups of three specimens each (replications), distributed at pre-established times: 140, 160, 180, 200, 220, 240, 260, 280 and 300 degree-hours. The females were induced with two doses of 0.5 and 5.0 mg kg−1 of dry carp pituitary, respectively, at an interval of 12 h. The extruded oocytes were kept at average water temperature of 22.35 ± 0.53 °C (2011) and 21.88 ± 0.15 °C (2012). Fertilization and hatching rates were: 84.22 and 71.33 % at 174.2 ATUs in 2011, and 55.58 % and 36.13 % at 251.0 ATUs in 2012. In January 2012, 900 larvae were distributed in three replications (triplicate) consisting of 100 larvae each and were fed: 120 (second day), 300 (third–fourth day), 600 (fifth–eighth day), and 1,200 Artemia salina nauplii per larva (ninth–15th day), six times a day. The larvae exhibited mean weight of 523.67 ± 54.42, 496.67 ± 61.98 and 475.00 ± 22.83 mg, length of 17.75 ± 0.57, 17.58 ± 0.51 and 17.45 ± 0.25 cm and survival of 63.95 ± 24.50, 71.71 ± 6.61 and 79.65 ± 0.82 %, when hatched in 180, 240 and 300 ATUs, respectively. The larvae body parameters did not show significant differences at these degree-hours.

Ocean acidification reduces feeding rates in the scleractinian coral Stylophora pistillata

A general decline in coral calcification has been observed in response to ocean acidification. It has recently been shown that heterotrophic feeding (the acquisition of organic nutrients) enables one massive coral species to maintain its calcification rates while exposed to ocean acidification but the consequences of higher seawater partial pressure of CO2 ( p CO 2 ) on coral feeding capacities themselves have never been investigated. Exposing long-term acclimated starved and fed colonies of the major reef builder Stylophora pistillata to either ambient pHT (8.06 ± 0.05; 417 Pa p CO 2 ) or low pHT (7.51 ± 0.06; 1697 Pa p CO 2 ) showed that higher feeding rates can counterbalance the negative effects of seawater acidification on coral calcification. Indeed, relative to unfed corals under ambient pHT conditions, calcification rates in unfed corals decreased by 53.6% but remained constant in fed corals under high p CO 2 conditions. Results also clearly show that acidification affects the feeding capacity and feeding effort of the branching coral S. pistillata. Organic nutrient acquisition was severely reduced under high p CO 2 , with a simultaneous decrease in the dissolved free amino acid uptake rates, the alkaline phosphatase activities, and the feeding rates on Artemia salina nauplii. Considering that all these processes are needed to fulfill the nutrient needs of the symbiotic association, on a long-term basis, lower feeding rates will likely aggravate the already fragile physiological state of many corals under warmer, more acidic conditions.

Características morfológicas, morfométricas, merísticas y manejo de la primera alimentación de larvas de escalar altum (Pterophyllum altum) (Pellegrin, 1903)

El escalar altum ha sido una especie representativa de la ictiofauna suramericana por su amplia aceptación en el mercado de la acuariofilia, lo que lo convierte en una especie con gran potencial productivo. En el presente estudio se realizó una descripción morfológica, detalle de algunos parámetros merísticos de los primeros estadios de vida de larvas de P. altum y aspectos de su primera alimentación. Se utilizaron diez parejas de reproductores mantenidas en acuarios de 50 L, con aireación y temperatura constante. Luego del proceso de reproducción se tomaron 15 larvas/h hasta las 75 horas poseclosión, (HPE) estas fueron fijadas en formol bufferado al 4% para posterior descripción de las características merísticas y morfométricas. Así mismo, se suministraron diferentes dietas luego de la reabsorción del saco vitelino, así: (T1) larvas alimentadas con nauplios de Artemia salina, (T2) cistos de Artemia salina decapsulados, y (T3) zooplancton silvestre para determinar algunos parámetros productivos. Morfológicamente, las larvas de P. altum tienen un cuerpo cilíndrico, redondeado, cola alargada y saco vitelino ovoide evidente hasta su desarrollo en postlarva. En cuanto a sus características morfométricas, presentaron una longitud total promedio de 4.64±0.5 mm, una longitud estándar de 3.8±0.2 mm, el diámetro del ojo de 0.49±0.2 mm, así como una longitud de de cabeza 0.71±0.8 mm y la altura del cuerpo de 0.76±0.6 mm a las 75 HPE. Con el suministro de las diferentes dietas no se observaron diferencias estadísticas significativas (P>0.05), en los pesos finales. Sin embargo, se observaron diferencias (P<0.05) en la tasa de crecimiento especifico y en la sobrevivencia. Como conclusión, las larvas de P. altum presentan un crecimiento acelerado hasta el segundo día de vida, debido a la disminución de la relación entre las características morfométricas. Por otro lado, el mejor desempeño productivo se observó en los individuos alimentados con nauplios de artemia, constituyéndose en una importante alternativa como fuente de alimento durante la larvicultura de esta especie

The influence of flow velocity and suspended particulate concentration on net prey capture rates by the scleractinian coral Balanophyllia europaea (Scleractinia: Dendrophylliidae)

Balanophyllia europaea is an endemic Mediterranean sublittoral zooxanthellate solitary coral. Given the broad distribution of the species throughout many areas of the Mediterranean surprisingly little is known of preferred habitat niches or susceptibility of the species to environmental change. In this study we investigated in the laboratory the net prey capture rates of the coral achievable under a range of flow velocities (2.5, 5, 7.5 and 15 cm s−1) and under exposure to different suspended particulate concentrations (0, 7.3 and 170 mg l−1). In recirculation flumes we simulated both commonly occurring and the occasionally high flow velocities and various suspended particulate concentrations reported from the Gulf of Lions (north-west Mediterranean). We then delivered ca 500 A. salina nauplii l−1 as food (Artemia salina nauplii) to the flumes and monitored net prey capture over time. We found net prey capture rates by the species to be highest under flow velocities of 5 cm s−1, with 230 µg C coral individual−1 h−1 achieved. The presence or absence of even environmentally high particulate concentrations (up to 170 mg l−1 resuspended seabed material) did not significantly affect the net prey capture rates achieved by the coral polyps. We found that net prey capture in Balanophyllia europaea is not inhibited during periods of heavy particle exposure, as has been observed in other temperate scleractinian corals. Also, flow velocities of ca ~5 s−1 appear to be optimal for maximum net prey capture by the species.

Carbon translocation from symbiont to host depends on irradiance and food availability in the tropical coral Stylophora pistillata

Reef-building corals live in symbiosis with dinoflagellates that translocate a large proportion of their photosynthetically fixed carbon compounds to their coral host for its own metabolism. The carbon budget and translocation rate, however, vary depending on environmental conditions, coral host species, and symbiont clade. To quantify variability in carbon translocation in response to environmental conditions, this study assessed the effect of two different irradiance levels (120 and 250 μmol photons m−2 s−1) and feeding regimes (fed with Artemia salina nauplii and unfed) on the carbon budget of the tropical coral Stylophora pistillata. For this purpose, H13CO3 −-enriched seawater was used to trace the conversion of photosynthetic carbon into symbiont and coral biomass and excrete particulate organic carbon. Results showed that carbon translocation (ca. 78 %) and utilization were similar under both irradiance levels for unfed colonies. In contrast, carbon utilization by fed colonies was dependent on the growth irradiance. Under low irradiance, heterotrophy was accompanied by lower carbon translocation (71 %), higher host and symbiont biomass, and higher calcification rates. Under high irradiance, heterotrophy was accompanied by higher rates of photosynthesis, respiration, and carbon translocation (90 %) as well as higher host biomass. Hence, levels of resource sharing within coral–dinoflagellate symbioses depend critically on environmental conditions.

Heterotrophy in recruits of the scleractinian coral Pocillopora damicornis

Heterotrophy is essential for meeting the metabolic requirements of scleractinian corals but the feeding mechanisms of coral juveniles are poorly understood. In this study, we observed that two-day-old Pocillopora damicornis recruits were able to immobilize and capture Artemia salina nauplii that come into direct contact with their tentacles. The recruits were able to consume up to six nauplii h−1 and the shortest time required to fully ingest one nauplius was 1 min 25 s. This is the first study to describe the feeding mechanisms employed by coral recruits, and provided both observational and quantitative evidence to show that coral juveniles are able to commence heterotrophy at an early stage.

Screening of Derris indica Bennet. for cytotoxicity against Artemia salina and phytotoxicity on mustard seeds

Chloroform extracts of the fruit shell, leaves, root bark, root wood, seeds, stem bark and stem wood of Derris indica Bennet. were tested against the brine shrimp, Artemia salina nauplii. All the test extracts of D. indica were found to be effective. The LC50 values of the extracts were 15312.37, 92.074 and 29.661 ppm for the fruit shell; 60922.83, 61.522 and 23.777 ppm for the leaf; 15312.37, 51.477 and 19.169 ppm for the root bark; 2598.584, 30.480 and 8.260 ppm for the root wood; 545.025,26.730 and 7.719 ppm for the seed; 60922.83, 114.549 and 29.572 ppm for the stem bark and 7734.618, 58.501 and 23.694 ppm for the stem wood at 30 minute, 24 hours and 48 hours post exposures respectively at doses 200, 100, 50, 25, 12.5, 6.25, 3.125 and 1.563 ppm against A. salina . The toxicity of the extracts could be arranged in the order: seed > root wood > root bark> stem wood > leaf > fruit shell > stem bark extract. However, the extracts did not significantly inhibit the germination of mustard oil seeds, and thus its application to crops or to the crop field may not cause any harm to crop plants.DOI: http://dx.doi.org/10.3329/ujzru.v31i0.15402Univ. j. zool. Rajshahi Univ. Vol. 31, 2012 pp. 59-64

Maintenance, feeding and growth of Carybdea marsupialis (Cnidaria: Cubozoa) in the laboratory

The box jellyfish Carybdea marsupialis has proliferated in some areas of the north-western Mediterranean Sea since July 2008. As for many species, controlled experimentation in the laboratory is needed to improve our knowledge about C. marsupialis, with the ultimate goal of extrapolating the knowledge gained to the marine environment. The aims of this study were to identify the optimal conditions (i.e. aquarium design, environmental parameters and prey type) for the growth and maintenance of this cubomedusa in the laboratory and, additionally, to quantify the feeding rates of the juveniles of this species. We were able to maintain healthy medusae for 140days. During this time they reached the subadult condition (fact corroborated by observing the gonadal tissue), growing from 2 to 15mm in diagonal bell width from June to November 2010, respectively. We observed a progressive shift in their preferred dietary composition as the individuals grew. The medusae fed on Artemia salina nauplii along the entire development. Other, larger, prey types (e.g. Mysis sp., Acartia granii copepods and adult Artemia salina) were progressively ingested at the same time as they increased their umbrella size. We also describe the clearance rates, ingestion rates, prey selectivity and digestion times of juvenile C. marsupialis on natural zooplankton and on the copepod Acartia grani. Growth and mortality rates were also calculated.

Controlling Effects of Irradiance and Heterotrophy on Carbon Translocation in the Temperate Coral Cladocora caespitosa

Temperate symbiotic corals, such as the Mediterranean species Cladocora caespitosa, live in seasonally changing environments, where irradiance can be ten times higher in summer than winter. These corals shift from autotrophy in summer to heterotrophy in winter in response to light limitation of the symbiont’s photosynthesis. In this study, we determined the autotrophic carbon budget under different conditions of irradiance (20 and 120 µmol photons m−2 s−1) and feeding (fed three times a week with Artemia salina nauplii, and unfed). Corals were incubated in H13CO3 −-enriched seawater, and the fate of 13C was followed in the symbionts and the host tissue. The total amount of carbon fixed by photosynthesis and translocated was significantly higher at high than low irradiance (ca. 13 versus 2.5–4.5 µg cm−2 h−1), because the rates of photosynthesis and carbon fixation were also higher. However, the percent of carbon translocation was similar under the two irradiances, and reached more than 70% of the total fixed carbon. Host feeding induced a decrease in the percentage of carbon translocated under low irradiance (from 70 to 53%), and also a decrease in the rates of carbon translocation per symbiont cell under both irradiances. The fate of autotrophic and heterotrophic carbon differed according to irradiance. At low irradiance, autotrophic carbon was mostly respired by the host and the symbionts, and heterotrophic feeding led to an increase in host biomass. Under high irradiance, autotrophic carbon was both respired and released as particulate and dissolved organic carbon, and heterotrophic feeding led to an increase in host biomass and symbiont concentration. Overall, the maintenance of high symbiont concentration and high percentage of carbon translocation under low irradiance allow this coral species to optimize its autotrophic carbon acquisition, when irradiance conditions are not favourable to photosynthesis.

Early ontogenesis of the angelfish, Pterophyllum scalare Schultze, 1823 (Cichlidae)

This study describes the egg membrane structures of angelfish (Pterophyllum scalare), morpho-physiological changes during angelfish embryogenesis from activation to hatching under optimal conditions (28°C; pH 6.8), the developing larvae and fry, the effect of alkaline pH on the early developmental stages of the species, the relationship between food item size and fry survival. Egg membranes (thin, transparent, 1.67-2.18 µm thick) are covered by a sticky substance. The amber-coloured angelfish eggs were oval in shape, with average diameters of 1.436 and 1.171 mm, i.e., a mean volume of 1.033 ± 0.095 mm³. The survival rate of embryos and larvae kept in water with an elevated, slightly alkaline pH was very low: as few as 2% of the embryos survived, while in the batch kept in optimal water conditions very few eggs died. The first larvae hatched after 1288 h of embryonic development. The newly hatched larvae measured on average 2.60 ± 0.093 mm and had large (0.64 ± 0.077 mm³) yolk sacs. They attached themselves to the substrate with a secretion of thin, viscous threads, which was released from glands situated on the top of the head. The glands vanished on day 5. The 1-day-old larvae showed the first pigment cells on the body and the eyes of the 2-day-olds were already fully pigmented. Between day 4 and 5 of larval life, the larvae began feeding on live food. The 23-day-old fry looked like a miniature versions of the adults. Mortality of the angelfish larvae during their first days after hatching was higher in those fed brine shrimp (Artemia salina) nauplii than those fed protozoans and rotifers.

Light induced degradation of phorbol esters

Jatropha curcas (Jatropha) is a tropical shrub that is gaining popularity as a biofuel feedstock plant. Phorbol esters (PEs) are tetracyclic tiglian diterpenoids that are present in Jatropha seeds and other parts of plant. Epidermal cell irritating and cancer promoting PEs not only reduce commercial values of Jatropha seed cake but also cause some safety and environment concerns on PE leaching to soil. A simple bioassay of PE toxicity was conducted by incubating 48h old brine shrimp (Artemia salina) nauplii with Jatropha oil for 24h. 1–4% of Jatropha oil (corresponding to PE concentration of 25–100mgL−1) had mortality rate of 5–95%, with LC50 estimated to be 2.7% of oil or 67mgL−1 of PE. Jatropha oil was incubated with clay or black soil (autoclaved or non-autoclaved) in the darkness or under sunlight for different periods of time before oil was re-extracted and tested for PE content by HPLC and for remaining toxicity with the brine shrimp bioassay. Under sunlight, PE decreased to non-detectable level within six days. Toxicity reduced to less than 5% mortality rate that is comparable to rapeseed oil control within the same period. In contrast, PE level and toxicity remained little changed when Jatropha oil was incubated in the darkness. Such PE degradation/detoxification was also found independent of the presence of soil or soil microorganisms. We conclude that sunlight directly degrades and detoxifies PEs and this finding should alleviate the concern on long term environmental impact of PE leaching.

Novel Mononuclear Ruthenium(II) Compounds in Cancer Therapy

The present study was conducted to evaluate in vivo anticancer activity of two novel mononuclear ruthenium(II) compounds, namely Ru(1,10-phenanthroline)2(2-nitro phenyl thiosemicarbazone)Cl2 (Compound R1) and Ru (1,10-phenanthroline)2(2-hydroxy phenyl thiosemicarbazone)Cl2 (Compound R2) against Ehrlich ascites carcinoma (EAC) mice and in vitro cytotoxic activity against IEC-6 (small intestine) cell lines and Artemia salina nauplii using MTT [(3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide)] and BLT [brine shrimp lethality] assays respectively. The test ruthenium compounds at the doses 2 and 4 mg/kg body weight showed promising biological activity, especially in decreasing tumor volume, viable ascites cell counts and body weights. These compounds prolonged the life span (% ILS), mean survival time (MST) of mice bearing-EAC tumor. The results for in vitro cytotoxicity against IEC-6 cells showed the ruthenium compound R2 to have significant cytotoxic activity with a IC50 value of 20.0 μg/mL than R1 (IC50=78.8 μg/mL) in the MTT assay and the LC50 values of R1 and R2 compounds were found to be 38.3 and 43.8 μg/mL respectively in the BLT assay. The biochemical and histopathological results revealed that there was no significant hepatotoxicity and nephrotoxicity associated with the ruthenium administration to mice.