Effects of bioconversion by Battus polydamas on the chemical composition of Aristolochia spp. and evaluation of antimicrobial activity and biocompatibility

Aristolochia plants are emblematic from an ethnopharmacological viewpoint and are know to possess numerous biological properties, including antiseptic. However, the medicinal potential of these species is debatable because of their representative chemical constituents, aristolochic acids (AAs) and aristolactams (ALs), which are associated, for instance, with nephropathy and cancer. These contrasting issues have stimulated the development of approaches intended to detoxification of aristoloquiaceous biomasses, among which is included the bioconversion method using larvae of the specialist phytophagous insect Battus polydamas, previously shown to be viable for chemical diversification and to reduce toxicity. Thus, eleven Aristolochia spp. were bioconverted, and the antimicrobial activities of the plant methanolic extracts and its respective bioconversion products were evaluated. The best results were found for Aristolochia esperanzae, Aristolochia gibertii, and Aristolochia ringens against Bacillus cereus, with MIC ranging from 7.8 to 31.25 μg/mL. These three species were selected for chemical, antioxidant, cytotoxic, hemolytic, and mutagenic analyses. Chemical analysis revealed 65 compounds, 21 of them possible bioconversion products. The extracts showed potential to inhibit the formation and degradation of B. cereus biofilms. Extracts of A. gibertii and its bioconverted biomass showed antioxidant activity comparable to dibutylhydroxytoluene (BHT) standard. Bioconversion decreased the hemolytic activity of A. esperanzae and the cytotoxicities of A. esperanzae and A. gibertii. None of the extracts was found to be mutagenic. The bioactivities of the fecal extracts were maintained, and biocompatibility was improved. Therefore, the results obtained in this study reveal positive expectations about the natural detoxification process of the Aristolochia species.

Chemical composition and effects of ethanolic extract and gel of Cochlospermum regium (Schrank) Pilg. Leaves on inflammation, pain, and wounds

ETHNOPHARMACOLOGICAL RELEVANCE

Cochlospermum regium is well-known as "Algodãozinho do cerrado" in folk Brazilian medicine, and is used to fight infections, inflammation and skin disorders.

AIM OF THE STUDY

To identify the phytochemical constituents and the effects of the ethanolic extract of C. regium leaves (EECR) on inflammation and pain, and the effects of C. regium gel (GEECR) on wound healing.

MATERIALS AND METHODS

Animals were treated with EECR (30-300 mg/kg) or GEECR (1.25 and 2.5%) and studies were conducted using carrageenan-induced pleurisy and paw edema tests, formalin-induced pain model, and excision wound model.

RESULTS

In total, 25 compounds, including quercitrin, methyl gallate, and 1,2,3,4,6-pentagalloylhexose, with highest detectability were identified. The treatments reduced leukocyte migration, nitric oxide production, protein extravasation, edema, mechanical hyperalgesia, pain in both phases (neurogenic and inflammatory), cold hypersensitivity, and improved wound closure and tissue regeneration.

CONCLUSIONS

The present findings established the anti-inflammatory, anti-nociceptive, and wound healing potential of the leaves of C. regium, confirming the potential therapeutic effect of this plant.

General and genetic toxicology studies of Aleurites moluccana (L.) Willd. seeds in vitro and in vivo assays

ETHNOPHARMACOLOGY RELEVANCE

Aleurites moluccana is popularly used for the diseases like ulcers, fever, headache, asthma, conjunctivitis, gonorrhea, inflammation, hepatitis, and rheumatism. The seed, also known as "noz da Índia", has been popularly consumed for weight loss purposes but reports of toxicity have been associated with its ingestion. In the literature, there are not enough studies to elucidate its toxicology, so evaluating the general and genetic toxicological of A. moluccana seeds can provide data to ensure their intake.

AIM OF THE STUDY

The objective of the present study was to elucidate the oral toxicity, mutagenicity, genotoxicity and cytotoxicity of A. moluccana seeds in vitro and in vivo assays.

MATERIALS AND METHODS

The chemical composition of the aqueous extract of A. moluccana seeds (AEAMS) was analyzed in relation to phenolic compounds, tannins, flavonoids and fatty acid. For the in vitro assays, the cytotoxic potential was assessed by the MTS assay whereas the mutagenic potential was assessed by the Ames test. For in vivo assays, was conducted an acute oral toxicity study, with "Up-and-Down Procedure" and repeated dose toxicity with "Repeated Dose 28-Day Oral Toxicity". To assess genetic damage, mutagenic potential was assessed by the micronucleus test whereas the polychromatic erythrocyte/normochromatic erythrocyte ratio was obtained with bone marrow cells to determine the cytotoxic potential and genotoxic potential was assessed by the comet assay using peripheral blood cells.

RESULTS

AEAMS did not show cytotoxic and mutagenic potential in vitro. No clinical signs of toxicity were observed in animals after the acute oral toxicity test, suggesting that the LD₅₀ of aqueous extract of A. moluccana seeds > 2000 mg/kg in a single dose by intragastric route. However, in toxicity at repeated doses for 28 days, the doses initially established (250; 500 and 750 mg/kg/day by intragastric route) caused mortality in the animals and the reestablished doses (25, 50 and 100 mg/kg/day by intragastric route) showed no changes in parameters or clinical signs attributed to toxicity. Furthermore, AEAMS also did not show mutagenic, genotoxic and cytotoxic potential in vivo.

CONCLUSIONS

AEAMS did not show cytotoxic, genotoxic and mutagenic potential in vitro and in vivo. And although the AEAMS has an LD₅₀ > 2000 mg/kg, and does not have physiological, biochemical, hematological, histopathological changes or clinical signs related to toxicity when administered in low concentrations and for a short period, in high concentrations and continued use caused toxicity and mortality in Wistar rats. In order to obtain complementary results, is recommended highly that further mid and long-term toxicological studies are investigated, and in no-rodent specie.

Mutagenic potential of medicinal plants evaluated by the Ames Salmonella/microsome assay: A systematic review

The Ames test has become one of the most commonly used tests to assess the mutagenic potential of medicinal plants since they have several biological activities and thus have been used in traditional medicine and in the pharmaceutical industry as a source of raw materials. Accordingly, this review aims to report previous use of the Ames test to evaluate the mutagenic potential of medicinal plants. A database was constructed by curating literature identified by a search on the electronic databases Medline (via Pubmed), Science Direct, Scopus, and Web of Science from 1975 to April 2020, using the following terms: "genotoxicity tests" OR "mutagenicity tests" OR "Ames test" AND "medicinal plants." From the research, 239 articles were selected, including studies of 478 species distributed across 111 botanical families, with Fabaceae, Asteraceae and Lamiaceae being the most frequent. It was identified that 388 species were non-mutagenic. Of these, 21% (83/388) showed antimutagenic potential, most notable in the Lamiaceae family. The results also indicate that 18% (90/478) of the species were mutagenic, of which 54% were mutagenic in the presence and absence of S9. Strains TA98 and TA100 showed a sensitivity of 93% in detecting plant extracts with mutagenic potential. However, the reliability of many reviewed studies regarding the botanical extracts may be questioned due to technical issues, such as testing being performed only in the presence or absence of S9, use of maximum doses below 5 mg/plate and lack of information on the cytotoxicity of tested doses. These methodological aspects additionally demonstrated that a discussion about the doses used in research on mixtures, such as the ones assessed with botanical extracts and the most sensitive strains employed to detect the mutagenic potential, should be included in a possible update of the guidelines designed by the regulatory agencies.

Cytotoxicity, mutagenicity and acute oral toxicity of aqueous Ocotea minarum leaf extracts

Ocotea minarum (Nees & Mart.) Mez., a native species of Brazil, is used in the treatment of infections and oxidative stress; however, there is no scientific evidence of its toxicological characteristics. We assessed the cytotoxicity, mutagenic activity, and acute oral toxicity of the aqueous extract isolated from O. minarum leaves. The cytotoxicity of this extract was evaluated in tumour and non-tumour cell lines, while the Ames test with a Salmonella Typhimurium was used to determine the mutagenic activity. Wistar rats received a single 2 g/kg dose as part of an LD₅₀ toxicity assessment. Our results showed that the aqueous extract of O. minarum leaves did not present cytotoxic and mutagenic properties and was not toxic, with an LD₅₀ greater than 2 g/kg. Therefore, the O. minarum extracts are pharmacologically safe and can continue to be investigated for the development of new drugs and herbal medicines.

Cochlospermum regium (Schrank) pilger leaf extract inhibit methicillin-resistant Staphylococcus aureus biofilm formation

ETHNOPHARMACOLOGICAL RELEVANCE

Cochlospermum regium, known as "algodãozinho", is an important plant belonging to Brazilian biodiversity used in traditional medicine to treat infections, wounds and skin conditions.

AIM OF THE STUDY

To assess the effects of aqueous and ethanolic extracts from C. regium leaves on methicillin-resistant Staphylococcus aureus planktonic cells and biofilm formation.

MATERIAL AND METHODS

The phytochemical characterization of the extracts was carried out by quantification of flavonoids, phenols and tannins and HPLC-DAD. Minimum inhibitory concentrations, cell viability, and enzyme activity inhibition were determined in planktonic cells exposed to C. regium extracts. The effect of the extracts on biofilms was assessed by quantifying colony-forming units (CFUs) and the extracellular matrix, and by visualizing the biofilm structure using scanning electron microscopy.

RESULTS

Leaf extract contents showed high concentration of phenols and the gallic and ellagic acids were identified. The extracts showed potent antimicrobial activities at concentrations ranging from 62.5-250 μg/mL, and decreased coagulase activity. In addition, the extracts prevented biofilm formation, and the aqueous extract completely inhibited its formation.

CONCLUSIONS

C. regium extracts stand out as promising alternative treatments for the prevention and treatment of methicillin-resistant Staphylococcus aureus infections.

Synthesis, structural characterization, and prospects for new cobalt (II) complexes with thiocarbamoyl-pyrazoline ligands as promising antifungal agents

Candida spp. cause invasive fungal infections. One species, Candida glabrata, may present intrinsic resistance to conventional antifungal agents, thereby increasing mortality rates in hospitalized patients. In this context, metal complexes present an alternative for the development of new antifungal drugs owing to their biological and pharmacological activities demonstrated in studies in the last decades. Accordingly, in this study we have synthesized and characterized two new Co(II) complexes with thiocarbamoyl-pyrazoline ligands to assess their antimicrobial, mutagenic, and cytotoxic potential. For antimicrobial activity, the broth microdilution method was performed against ATCC strains of Candida spp. and fluconazole dose-dependent isolates of C. glabrata obtained from urine samples. The Ames test was used to assess mutagenic potential. The reduction method of the MTS reagent (3 [4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium) was performed with HeLa, SiHa, and Vero cells to determine cytotoxicity. Both complexes exhibited fungistatic and fungicidal activity for the yeasts used in the study, demonstrating greater potential for C. glabrata ATCC 2001 and the C. glabrata CG66 isolate with a Minimum Inhibitory Concentration MIC from 3.90 to 7.81 μg mL^-1 and fungicidal action from 7.81 to 15.62 μg mL^-1. The complexes inhibited and degraded biofilms by up to 90% and did not present mutagenic and cytotoxic potential at the concentrations evaluated for MIC. Thus, the complexes examined herein suggest promising alternatives for the development of new antifungal drugs.

Sulphonates' mixtures and emulsions obtained from technical cashew nut shell liquid and cardanol for control of Aedes aegypti (Diptera: Culicidae)

Aedes aegypti is the main mosquito vector of dengue, zika, chikungunya, and yellow fever diseases. The low effectiveness of vector control options is mainly related to the increased insect's resistance and to the toxicity of products used for non-target organisms. The development of new environmentally friendly and safer products is imperative. Technical cashew nut shell liquid (tCNSL), mostly composed by cardanol (C), is an abundant by-product of the cashew (Anacardium occidentale L.) production chain, available at low cost, and with proven larvicidal activity. However, chemical modifications in both tCNSL and cardanol were required to increase their water solubilities. Our objectives were to synthesise and characterise sustainable, low-cost and easy-to-use multiple function products based on tCNSL, cardanol, and the sulphonates obtained from both; and to evaluate all these products efficacy as surfactants, larvicidal, and antimicrobial agents. None of the sulphonates presented antimicrobial and larvicidal activities. tCNSL and cardanol were successfully emulsified with sodium technical cashew nut shell liquid sulphonate (NatCNSLS, complex mixture of surfactants). The emulsions obtained presented larvicidal activity due to the presence of tCNSL and cardanol in their composition. Our results showed that the tCNSL+NatCNSLS mixture emulsion was an effective larvicide and surfactant multiple function product, with high availability and easy-to-use, which can facilitate its large-scale use in different environments. Graphical abstract.

Influence of Land Use and Cover on Toxicogenetic Potential of Surface Water from Central-West Brazilian Rivers

The objective of this study was to evaluate toxicogenetic potential of surface water samples from rivers of center-west Brazil and analyze the influence of land use and cover and physicochemical parameters in genetic damage. Samples were collected during winter (June) and summer (November) at sampling sites from Dourados and Brilhante Rivers (Mato Grosso do Sul/Brazil). The toxicogenetic variables, including chromosomal alterations, micronuclei, and mitotic index, were analyzed in meristematic cells of Allium cepa; and micronuclei, nuclear abnormalities, and DNA strand breaks (arbitrary units, AU_T) were analyzed in erythrocytes of Astyanax lacustris. The rivers presented physicochemical values outside the Brazilian laws, which can be a characteristic of human pollution (domestic sewage and local agriculture). The results of A. cepa test suggest that the water samples from Dourados and Brilhante rivers exerted significant (p < 0.05) cytotoxic and genotoxic effects, in both periods of collection, especially alterations in mitotic index. In blood cells of A. lacustris, genotoxic effect of the water samples from the rivers also was observed as significant nuclear abnormalities, DNA breaks (UA_T), in both sampling periods, compared with the negative control. Spearman correlation analyses revealed that data of land use and cover and physicochemical parameters were statistically correlated with DNA damages in bioassays. This study demonstrates toxicogenetic potential of water samples from Dourados and Brilhante rivers; furthermore, the type of land use and land cover and physicochemical parameters were revealed to have influence on toxicogenetic damage.

In Vitro Control of Uropathogenic Microorganisms with the Ethanolic Extract from the Leaves of Cochlospermum regium (Schrank) Pilger

The roots of Cochlospermum regium, popularly known as "algodãozinho-do-cerrado," are used for the treatment of genitourinary infections. However, the removal of their subterranean structures results in the death of the plant, and the use of the leaves becomes a viable alternative. Therefore, the antimicrobial activity of Cochlospermum regium leaf's ethanolic extract and its action on the biofilm formation of microorganisms associated with urinary infection were evaluated. The total phenolic compounds, flavoids, and tannins were quantified using the reagents Folin-Ciocalteu, aluminum chloride, and vanillin, respectively. The antimicrobial activity was evaluated by the broth microdilution method and the effect of the extract in the biofilm treatment was measured by the drop plate method. Cytotoxicity was evaluated by the method based on the reduction of MTS and the mutagenicity by the Ames test. The ethanolic extract of C. regium leaves presented 87.4 mg/EQ of flavonoids, 167.2 mg/EAG of total phenolic compounds, and 21.7 mg/ECA of condensed tannins. It presented reduction of the biofilm formation for E. coli and C. tropicalis and antimicrobial action of 1 mg/mL and 0.5 mg/mL, respectively. The extract showed no cytotoxicity and mutagenicity at the concentrations tested. This study demonstrated that C. regium leaves are a viable option for the treatment of genitourinary infections and for the species preservation.

Identification of class 1 and 2 integrons from clinical and environmental Salmonella isolates

Introduction: The indiscriminate use of antimicrobials has selected for the emergence of resistant strains. Many mechanisms contribute to the spread of antimicrobial-resistant genes, and integrons play a key role in this process. The aim of this study was to describe the serotypes and resistance profiles, and to characterize the presence of integrons in Salmonella strains isolated from Dourados, Mato Grosso do Sul, Brazil. Methodology: Thirty-six isolates from different sources were used. To evaluate the resistance profiles, the determination of minimum inhibitory concentrations together with polymerase chain reaction were used to screen for the presence of class 1 and class 2 integrons. Results: The Infantis serotype of Salmonella was the most frequently isolated serotype. Minimum inhibitory concentrations showed that out of the 36 isolates, 11 (30.5%) were resistant to all the antimicrobials tested. These resistant isolates were separated into three groups: 4 clinical isolates (36.4%), 3 food isolates (36.4%), and 4 water isolates (27.2%). Class 1 integrons occurred in 31 (86.1%) isolates and were found in all 11 resistant isolates (35.5 %) and in 20 (64.5%) of the non-resistant isolates. Class 2 integrons were found in 3 (8.3%) isolates, which were all non-resistant. Conclusion: The presence of an integron did not necessarily confer resistance. Future studies will seek to identify the mechanism behind integron-mediated antimicrobial resistance.