Toxicity of Three Optical Brighteners: Potential Pharmacological Targets and Effects on Caenorhabditis elegans.

Optical brighteners (OBs) have become an integral part of our daily lives and culture, with a growing number of applications in various fields. Most industrially produced OBs are derived from stilbene, which has been found in environmental matrices. The main objectives for this work are as follows: first, to identify protein targets for DAST, FB-28, and FB-71, and second, to assess their effects in some behaviors physiologic of Caenorhabditis elegans. To achieve the first objective, each OB was tested against a total of 844 human proteins through molecular docking using AutoDock Vina, and affinities were employed as the main criteria to identify potential target proteins for the OB. Molecular dynamics simulations took and validated the best 25 docking results from two protein databases. The highest affinity was obtained for the Hsp70-1/DAST, CD40 ligand/FB-71, and CD40 ligand/FB-28 complexes. The possible toxic effects that OBs could cause were evaluated using the nematode C. elegans. The lethality, body length, locomotion, and reproduction were investigated in larval stage L1 or L4 of the wild-type strain N2. In addition, transgenic green fluorescent protein (GFP) strains were employed to estimate changes in relative gene expression. The effects on the inhibition of growth, locomotion, and reproduction of C. elegans nematodes exposed to DAST, FB-71, and FB-28 OBs were more noticeable with respect to lethality. Moreover, an interesting aspect in OB was increased the expression of gpx-4 and sod-4 genes associated with oxidative stress indicating a toxic response related to the generation of reactive oxygen species (ROS). In all cases, a clear concentration-response relationship was observed. It is of special attention that the use of OBs is increasing, and their different sources, such as detergents, textiles, plastics, and paper products, must also be investigated to characterize the primary emissions of OBs to the environment and to develop an adequate regulatory framework.

Simira cordifolia protects against metal induced-toxicity in Caenorhabditis elegans.

Simira cordifolia (Hook.f.) Steyerm (Rubiaceae) is a vascular plant used in Northern Colombia as a source of pigments and wood. However, there is a lack of information regarding its pharmacology and toxicity. This research aimed to study the hydroalcoholic extract of Simira cordifolia as a protector against metal-induced toxicity in Caenorhabditis elegans. Preliminary phytochemical screening of the hydroalcoholic extract of S. cordifolia (HAE-Sc) was conducted using HPLC-ESI-QTOF. Wild-type N2 C. elegans larvae were exposed to different concentrations of HAE-Sc evaluating lethality (50-5000 µg/mL), growth, lifespan, resistance to heat stress, and its protective effect against Mercury (Hg)-, Lead (Pb)- and Cadmium (Cd)-induced lethality (50-1000 µg/mL). The main metabolites present in the extract were iridoids, ß-carboline-alkaloids and polyphenols. Bioassays demonstrated that HAE-Sc exhibited low toxicity, with significant lethality (4.2% and 9.4%) occurring at 2500-5000 µg/mL. Growth inhibition reached up to 23.3%, while reproduction declined 13% and 17% at concentrations 500 and 1000 µg/mL, respectively. HAE-Sc enhanced the survival rate of the nematode under thermal stress by up to 79.8%, and extended the mean lifespan of worms by over 33% compared to control. The average lifespan was prolonged by 15.3% and 18.5% at 50 and 100 µg/mL HAE-Sc, respectively. The extract (1000 µg/mL) was able to reduce the death of C. elegans in the presence of heavy metals up to 65.9, 96.8% and 87% for Pb, Hg, and Cd, respectively. In summary, S. cordifolia shows potential protective effects in C. elegans against toxicity caused by heavy metals and heat.

Mercury assessment in invasive Lionfish Pterois (Oken, 1817) from marine protected areas in the Colombian Caribbean.

Lionfish (Pterois spp.) are invasive species reported since 2009 in the Corales del Rosario y San Bernardo National Natural Park in the Caribbean. Their capture and consumption are strategies to control their dispersion and limit ecological damage. The natural park is influenced by the vicinity of Cartagena's residential, industrial, and touristic activities, as well as sediments loaded with mercury from the Dique Channel. For the first time, total mercury levels in muscle from 58 lionfish were determined, with values ranging from 0.01 to 0.38 µg/g (mean = 0.11 ± 0.01 µg/g). Fish length ranged from 17.4 to 44.0 cm (mean = 28.0 ± 0.63 cm). Mercury levels did not increase proportionally to fish length for pooled data, but the relationship was significant for specimens from Rosario Island. Mercury levels comply with legislation for fish consumption, but the risk to human health may appear if it occurs daily. Therefore, precautionary approach and a permanent monitoring strategy are strongly advised.

Vaccines platforms and COVID-19: what you need to know.

BACKGROUND: The novel SARS-CoV-2, responsible for the COVID-19 pandemic, is the third zoonotic coronavirus since the beginning of the 21 first century, and it has taken more than 6 million human lives because of the lack of immunity causing global economic losses. Consequently, developing a vaccine against the virus represents the fastest way to finish the threat and regain some "normality." OBJECTIVE: Here, we provide information about the main features of the most important vaccine platforms, some of them already approved, to clear common doubts fostered by widespread misinformation and to reassure the public of the safety of the vaccination process and the different alternatives presented. METHODS: Articles published in open access databases until January 2022 were identified using the search terms "SARS-CoV-2," "COVID-19," "Coronavirus," "COVID-19 Vaccines," "Pandemic," COVID-19, and LMICs or their combinations. DISCUSSION: Traditional first-generation vaccine platforms, such as whole virus vaccines (live attenuated and inactivated virus vaccines), as well as second-generation vaccines, like protein-based vaccines (subunit and viral vector vaccines), and third-generation vaccines, such as nanoparticle and genetic vaccines (mRNA vaccines), are described. CONCLUSIONS: SARS-CoV-2 sequence information obtained in a record time provided the basis for the fast development of a COVID-19 vaccine. The adaptability characteristic of the new generation of vaccines is changing our capability to react to emerging threats to future pandemics. Nevertheless, the slow and unfair distribution of vaccines to low- and middle-income countries and the spread of misinformation are a menace to global health since the unvaccinated will increase the chances for resurgences and the surge of new variants that can escape the current vaccines.

Hydroalcoholic extract of Haematoxylum brasiletto protects Caenorhabditis elegans from cadmium-induced toxicity.

BACKGROUND: H. brasiletto is used in popular culture due to its therapeutic properties, including antioxidant, anti-inflammatory and antiproliferative properties, although little is known about its role as a protector against metal toxicity. This study aimed to investigate the chemical composition and efficacy of the hydroalcoholic extract from H. brasiletto (HAE-Hbrasiletto) collected in northern Colombia to defend against cadmium (Cd)-induced toxicity. METHODS: Phytochemical characterization was performed using HPLC-ESI-QTOF. Caenorhabditis elegans was employed to assess the shielding effect of HAE-Hbrasiletto against Cd toxicity in vivo, and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was utilized to measure radical scavenging activity. RESULTS: The main secondary metabolites identified by HPLC-ESI-QTOF in the extracts were hematoxylins (brazilein and hematein) and protosappanins (protosappanin A, B and C, 10-O-methylprotosappanin B, and protosappanin A dimethyl acetal). The HAE-Hbrasiletto elicited low lethality in N2 worms and significantly reduced the Cd-induced death of the nematodes. It also improved Cd-induced motility inhibition, as well as body length and reproduction reduction provoked by the heavy metal. The extract displayed a good capacity to halt Cd-induced DAF-16 translocation. As this last process was associated with lethality (r = 0.962, p < 0.01), the antioxidant properties of the extract may contribute to ameliorating tissue damage induced by oxidative stress from Cd exposure. CONCLUSION: HAE-Hbrasiletto has remarkable properties to protect against Cd-induced toxicity.

The aqueous extract of Fridericia chica grown in northern Colombia ameliorates toxicity induced by Tergitol on Caenorhabditis elegans.

The aqueous extract of fallen leaves from Fridericia chica (Bonpl.) L.G. Lohmann is utilized as a remedy in communities at northern Colombia. Traditional uses include wound healing, gastrointestinal inflammation, leukemia and psoriasis, among others. The aims of this research were to evaluate the potential of the aqueous extract of fallen leaves of F. chica (AEFchica) to inhibit ethoxylated nonylphenol (Tergitol)-induced toxicity in Caenorhabditis elegans; and to identify its main components. The pharmacological properties of AEFchica was evaluated using a Tergitol-induced toxicity model in Caenorhabditis elegans. Lethality, locomotion, reproduction, and DAF-16 nuclear translocation were quantified. The chemical composition of AEFchica was carried out using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry. AEFchica induced very little lethality on C. elegans (5.6%) even at high concentrations (10,000 µg/mL). The extract had no effect on locomotion impairing induced by ethoxylated nonylphenol. However, AEFchica (1000 µg/mL) abrogated Tergitol-induced mortality, recovering up to 53.3% of the nematodes from lethality induced by 10 mM Tergitol. Similarly, it also blocked Tergitol-dependent reproduction inhibition (82.1% recovery), as well as DAF-16 nuclear translocation (>95%), suggesting a prominent role on oxidative stress control. The chemical analysis indicated the presence of a great variety of molecules with known antioxidant, metabolic and immune modulator properties, such as hydroxylated methoxy flavones, N-methyl-1-deoxynojirimycin, and rehmaionoside A. In short, the aqueous extract of F. chica protects C. elegans from the deleterious effects of Tergitol on lethality, reproduction and oxidative stress involving DAF-16-mediated pathway. This extract is a promising source of bioactive phytochemicals for multi-target pharmacological purposes.

Effects of cadmium exposure on sperm and larvae of the neotropical fish Prochilodus magdalenae.

Cadmium (Cd) is a heavy metal with known deleterious effects on animal reproduction, decreasing the rate of fertilization of organisms such as fish. Prochilodus magdalenae is a very important fish species in Colombia, widely used by riparian communities from many rivers. Unfortunately, its population has been declining, whereas Cd seems to be more frequently detected in environmental matrices at Colombian ecosystems. The aim of this work was to determine the toxic effects of cadmium chloride on fertilization, sperm quality and mortality at 0, 1, 6 and 7 days post-hatching (dph) in this vulnerable species. The results indicated that Cd altered the fertilization and sperm quality by decreasing total motility and rapid and medium motilities of swimming spermatozoa. Results showed Cd produced 16.4 and 46.5% sperm motility inhibition, at 2.5 and 25 ppm, respectively. The heavy metal also impaired sperm curvilinear and straight-line velocities in a concentration-response dose. Cadmium-induced a dose-dependent effect on the mortality of the exposed larvae that depends on its development stage, with greater effects after 6 and 7 dph, observed at concentrations as low as 0.025 ppm. The results showed that the exposure to environmentally relevant Cd concentrations causes physiological changes in the initial stages of development of P. magdalenae, likely increasing the risk of reducing the fertility rate of this valuable fish species.

Mercury levels in birds and small rodents from Las Orquideas National Natural Park, Colombia.

Mercury (Hg) is a heavy metal known as one of the most toxic elements on the planet. The importance of Hg on living organisms resides on its biomagnification ability. Artisanal gold extraction activities release substantial amounts of this metal, polluting the ecosystems. To assess the impact of gold mining in Las Orquideas National Natural Park (Colombia), total Hg (T-Hg) levels were evaluated from 37 bird and 8 small rodent species collected at two sites within the boundaries of the Natural Park (Abriaqui and Frontino municipalities) that have experienced some gold-extraction history. The mean concentration of T-Hg in bird feathers from both sites was 0.84 ± 0.05 µg/g fw. Differences between species were found according to diet. Total Hg levels were greater on insectivorous (1.00 ± 0.08 µg/g fw), followed by nectarivorous (0.73 ± 0.07 µg/g fw) and frugivorus (0.57 ± 0.09 µg/g fw) species. These Hg levels were greater than those found in feathers from a control sample belonging to the species Penelope perspicax (0.53 ± 0.03 µg/g fw), a frugivorous species living at the Otun Quimbaya Fauna and Flora Sanctuary, a forest without known gold mining. Mercury concentrations in the livers of small rodents were greater in specimens from Frontino (0.15 ± 0.01 µg/g fw) than those from Abriaqui (0.11 ± 0.01 µg/g fw), but levels were not different between species. These results indicate that Hg in birds depends mainly on their diet, but geographical location may affect Hg concentration in rodents. Moreover, Hg sources in natural parks of Colombia may not rely solely on gold mining, atmospheric deposition, among others factors, could be influencing its accumulation in biota.