Igor Vivian Almeida

Textile dyes are persistent pollutants that pose significant risks to the environment and living organisms. Before being released into aquatic ecosystems, these dyes require effective treatment. Among these dyes, the azo dye Disperse Blue 291 exhibits relevant toxicological and mutagenic activity. However, a scarcity of studies has been identified that evaluate the effects of the DB291 dye before and after decolorization. Endophytic fungi have shown promising potential in bioremediation, particularly through biosorption and biodegradation. This study aimed to evaluate the ability of endophytic fungi to decolorize the textile dye Disperse Blue 291 (DB291). Seven fungal strains were screened in a minimal medium containing 10 µg/mL of DB291 for seven days. Aspergillus flavus CL07 and Alternaria alternata PL75 showed decolorization rates above 90% and were selected for further analysis. Both fungi achieved complete decolorization, A. flavus CL07 within 48 h and A. alternata PL75 within 168 h. Spectroscopic and enzymatic analyses suggested that biosorption was the main mechanism for A. flavus CL07, while A. alternata PL75 also employed extracellular laccase activity in dye degradation. Infrared spectroscopy analysis indicated chemical interactions between dye molecules and fungal biomass. Ecotoxicity assays using Artemia salina revealed that the original dye was highly toxic, causing developmental arrest and complete lethality. In contrast, the decolorization product from A. alternata PL75 exhibited no significant toxicity, supporting normal development in all tested stages. These results suggest that endophytic fungi, particularly A. alternata PL75, offer an effective and environmentally safe approach to the bioremediation of textile dye-contaminated environments. Graphical abstract

SUMMARY Feathers are among the main by-products of the poultry meat industry and are a serious environmental and health liability, with millions of tons being burned or buried annually. However, given their protein nature, they can be used as an energy matrix based on methane-rich biogas, the so-called biomethane. In theory, energy conversion is very cost-effective and would be employable to generate heat or electricity for the producer or the industry. This review presents biotechnological aspects to increase the production of methane-rich biogas (MRB). Topics such as feather quality, keratin hydrolysis (by keratinolytic microorganisms, by alkali and by reducing agents), keratin extraction by rapid vapour explosion, methane production, inoculants for anaerobic digestion and ammonia stripping are addressed.

The study aim was to evaluate the cytotoxic activity, using the MTT test [3-(4,5-Dimethilthiazol-2-yl)-2,5-diphenil tetrazolium bromide], from the crude extract of Picrasma crenata (Pau Tenente) and its isolated compounds, quassin and parain, in culture of rat liver tumor cells (HTC). The test was carried out exposing the cells for 24, 48 and 72 hours to concentrations of 5, 10, 50, 100, 200, 300, 400, 500 and 1000 μg of crude extract of Pau Tenente/mL of culture medium and 1, 5, 10, 15, 20, 40, 60, 80 and 100 μg of quassin or parain compounds/mL of culture medium. The absorbances averages results obtained showed that the crude extract did not present cytotoxicity for the HTC cells in all the concentrations and evaluated times. For quassin, the concentrations of 80 and 100 μg/mL were cytotoxic, after 72 hours of treatment. For parain, the concentrations of 1, 5, 20, 40, 60, 80 and 100 µg/mL, in 72 hours, were cytotoxic, revealing a new activity for this compound. Thus, the results demonstrate a first indication of the cytotoxic activity of compounds quassin and parain, adding an important social and economic value to them, and may have application in future research and in pharmaceutical industry.

Capsaicin (CAP) is the main compound responsible for the spicy flavor of Capsicum plants. However, its application can be inhibited due to its pungency and toxicity. This study aimed to evaluate and compare the cytotoxic effect of CAP and its analogs N-benzylbutanamide (AN1), N-(3-methoxybenzyl) butanamide (AN2), N-(4-hydroxy-3-methoxybenzyl) butanamide (AN3), N-(4-hydroxy-3-methoxybenzyl) hexanamide (AN4) and N-(4-hydroxy-3-methoxybenzyl) tetradecanamide (AN5) on the hepatoma cells of Rattus norvegicus using the MTT test. The results showed cytotoxicity of CAP at concentrations of 100, 150, 175, and 200 μM (24 hours), AN1 at 150 and 175 μM (48 hours), AN2 at 50 μM (24 hours) and 10, 25, 50, and 75 μM (48 hours), AN4 at 175 μM (24 hours), and AN5 at 50 μM (48 hours). Removing the hydroxyl radical from the vanillyl group of capsaicin, together with reducing the acyl chain to 3 carbons, which is the case of AN2, resulted in the best biological activity. Increasing the carbon chain in the acyl group of the capsaicin molecule, which is the case of AN5, also showed evident cytotoxic effects. The present study proves that the chemical modifications of capsaicin changed its biological activity.

Iodine-131 (I-131) radioisotope it causes the formation of free radicals, which lead to the formation of cell lesions and the reduction of cell viability. Thus, the use of radioprotectors, especially those from natural sources, which reduce the effects of radiation to healthy tissues, while maintaining the sensitivity of tumor cells, stands out. The objective of the present study was to evaluate the cytoprotective/radioprotective effects of whole grape juices manufactured from the conventional or organic production systems, whether or not exposed to ultraviolet (UV-C) light irradiation. The results showed that I-131 presented a cytotoxic effect on human hepatocellular cells (HepG2/C3A) at concentrations above 1.85 MBq/mL, after 24 and 48 hours of treatment, though all concentrations (0.0037 to 7.40 MBq/mL) were cytotoxic to non-tumor human lung fibroblast (MCR-5) cells, after 48 hours. However, grape juices (10 and 20 µL/mL) did not interfere with the cytotoxic effect of the therapeutic dose of I-131 on tumor cells within 48 hours of treatment, while protecting the non-tumor cells, probably due to its high antioxidant activity. In accordance with their nutraceutical potential, antioxidant and radioprotective activity, these data stimulate in vivo studies on the use of natural products as radioprotectants, such as grape juice, in order to confirm the positive beneficial potential in living organisms.

The search for compounds with anticancer effects is of paramount importance today due to the high incidence of the disease. The Euphorbiaceae family is known for having compounds with therapeutic properties, one of its genera being Croton. It has several species, which contain compounds already known for their biological activities, presenting anti-inflammatory, antimicrobial and anticancer properties. Thus, the cytotoxicity/antiproliferative activity of semi-purified fractions and compounds isolated from Croton echioides in liver tumor cells of Rattus norvegicus (HTC) was evaluated by the MTT test. The semi-purified fractions showed cytotoxicity at concentrations above 200 µg/mL, at 24, 48 and 72 hours, reaching cell viability of 24.78% [400 µg/mL] at 24 hours, 12.79% [500 µg/mL] at 48 hours and 10.57% [300 µg/mL] at 72 hours. For the isolated compounds, lupeol had a cytotoxic effect in all concentrations (1, 5, 10, 15, 20, 40, 60, 80 and 100 µg/mL) and tested times (24, 48 and 72 hours), reaching minimum viability of 4.37% [100 µg/mL], within 72 hours. The clerodan diterpenes CEH-1 and CEH-4 also showed antiproliferative activity, with minimum viability of 36.19% [100 µg/mL] over 72 hours and 21.33% [100 µg/mL] over 48 hours, respectively. However, the clerodan diterpenes CEH-2 and CEH-3 did not shows a cytotoxic effect for HTC cells. Thus, there is a cytotoxic/antiproliferative potential of C. echioides against tumor cells, with targeted to mitochondrial enzymes, associated with cell proliferation, indicating that this species deserves prominence in the search for new molecules for the treatment of cancer.

Nanotechnology has stood out significantly in several areas of science, especially in the pharmaceutical field. Drug nanocarriers are considered a safe and effective alternative because they possess essential properties from the pharmacotherapeutic perspective. In this regard, nanoemulsions stand out as a vehicle for already established drugs. These are systems made up of tiny globules on a nanometric scale, which can transport the active ingredient and are still suitable for the distribution on the skin, allowing more excellent absorption. In this sense, the present review describes methodologies for the synthesis of nanoemulsions using vegetable extracts and oils, conventional allopathic medicines, and metallic nanoparticles for the composition of the formula. A Nanotecnologia tem se destacado significativamente em diversas áreas da ciência, em especial, na área farmacêutica. Os nanocarreadores de fármacos apresentam uma alternativa segura e eficaz, apresentando propriedades importantes do ponto de vista farmacoterápico. Sob esse aspecto, destacam-se as nanoemulsões como veículo de fármacos já consagrados. Trata-se de sistemas constituídos por glóbulos bastante reduzidos, em escala manométrica, que podem veicular princípio ativo sendo ainda adequados à distribuição de substâncias ativas na pele, permitindo maior absorção. Dentro deste contexto, o presente estudo de revisão descreve metodologias de síntese de nanoemulsões utilizando para composição da fórmula, extratos e óleos vegetais, medicamentos alopáticos convencionais e nanopartículas metálicas.

Os coagulantes naturais são compostos naturais, como sementes, mucilagem e outros compostos baseados ou não baseados em plantas, que possuem a capacidade de remoção de contaminantes da água, esgotos e efluentes. Seu uso possui forte apelo ambiental, econômico e social, especialmente por se tratarem de compostos facilmente encontrados na natureza, como a moringa, quiabo e cáctus, e, por isso, baratos, aumentando a qualidade de vida da sociedade e mitigando o dano ou impacto ambiental. Esta revisão teve por objetivo apresentar os diferentes tipos de coagulantes naturais, seus respectivos usos e características. Esta pesquisa foi elaborada por meio de consultas na literatura especializada, com cerca de 160 artigos pesquisados e 38 efetivamente utilizados; concentrou-se em discutir os benefícios dos coagulantes naturais frente aos coagulantes químicos, bem como as implicações dos diferentes tipos de coagulantes naturais no tratamento de água, efluentes líquidos e esgotos. Em suma, verificou-se que as questões que envolvem a pesquisa dos coagulantes naturais é um caminho ambientalmente correto, barato e um objetivo a ser alcançado, visto a grande demanda de tratamento de água e efluentes que ocorre ao redor do mundo.