Permitted daily exposure from preclinical studies of Ginkgo biloba L. dry extract

Abstract Resolution 658/2022 of the Brazilian Regulatory Agency requires the determination of the permitted daily exposure (PDE) of pharmaceutical agents. Ginkgo biloba L. is used therapeutically to treat memory deficits and other brain diseases. However, published results indicate that more studies are needed to confirm the safety of Ginkgo biloba. This study aimed to evaluate the dry extract of Ginkgo biloba L. leaves PDE as an ingredient in an oral pharmaceutical product in preclinical studies using mice. Acute oral toxicity and repeated dose experiments were performed based on OECD guidelines, as well as genotoxicity tests. The results indicate that Ginkgo biloba L. has low acute toxicity, no liver toxicity, and does not alter blood glucose levels. No changes in weight gain were observed, but food intake decreased in males during the first week of treatment at the highest dose. Hematological parameters were not altered in males, whereas females presented lower leukocyte and lymphocyte counts and higher neutrophil counts at the highest dose. The lipid profile was not altered in males, whereas total cholesterol was increased in females. The estimated PDE was 0.1 mg/day and, when related to the maximum residual concentration, indicates that the cleaning process used is safe and does not require reassessment.

Vortioxetine liposomes as a novel alternative to improve drug stability under stress conditions: toxicity studies and evaluation of antidepressant-like effect.

BACKGROUND: Vortioxetine hydrobromide (VXT), a new therapeutic option in the treatment of major depressive disorder, is a poorly soluble drug, and instability under stress conditions has been reported. The aim of the present study was to prepare VXT liposomes (VXT-Ls) with an antidepressant-like effect, to improve drug stability and reduce toxicity of the free drug. METHODS: Liposomes were prepared using the thin lipid film hydration method and properly characterized. Forced degradation studies were conducted in photolytic and oxidative conditions. The cytotoxicity was evaluated in VERO cells through MTT assay and in vivo toxicity was assessed in mice. The antidepressant-like effect in mice was confirmed using the open-field test paradigm and tail suspension test. RESULTS: The optimized VXT-Ls have multilamellar vesicles with an average size of 176.74 nm ± 2.43. The liposomal formulation increased the stability of VXT. VERO cell viability was maintained at around 40% when the VXT-Ls were tested at higher concentrations and no signs of acute toxicity were observed in mice. The antidepressant-like effect was effective, for VXT-Ls, at doses ranging from 2.5 mg/kg to 10 mg/kg, measured by the tail suspension test in mice. The non-liposomal formulation was effective at a dose of 10 mg/kg. The open field test was performed and any unspecific changes in locomotor activity were revealed. CONCLUSIONS: Liposomes seem to be a promising alternative for an oral VXT formulation at lower doses (2.5 mg/kg).

Nanoemulsions containing a synthetic chalcone as an alternative for treating cutaneous leshmaniasis: optimization using a full factorial design.

Nanoemulsions are drug delivery systems that may increase the penetration of lipophilic compounds through the skin, enhancing their topical effect. Chalcones are compounds of low water solubility that have been described as promising molecules for the treatment of cutaneous leishmaniasis (CL). In this context, the aim of this work was to optimize the development of a nanoemulsion containing a synthetic chalcone for CL treatment using a 2(2) full factorial design. The formulations were prepared by spontaneous emulsification and the experimental design studied the influence of two independent variables (type of surfactant - soybean lecithin or sorbitan monooleate and type of co-surfactants - polysorbate 20 or polysorbate 80) on the physicochemical characteristics of the nanoemulsions, as well as on the skin permeation/retention of the synthetic chalcone in porcine skin. In order to evaluate the stability of the systems, the antileishmanial assay was performed against Leishmania amazonensis 24 hours and 60 days after the preparation of the nanoemulsions. The formulation composed of soybean lecithin and polysorbate 20 presented suitable physicochemical characteristics (droplet size 171.9 nm; polydispersity index 0.14; zeta potential -39.43 mV; pH 5.16; and viscosity 2.00 cP), drug content (91.09%) and the highest retention in dermis (3.03 µg·g(-1)) - the main response of interest - confirmed by confocal microscopy. This formulation also presented better stability of leishmanicidal activity in vitro against L. amazonensis amastigote forms (half maximal inhibitory concentration value 0.32±0.05 µM), which confirmed the potential of the nanoemulsion soybean lecithin and polysorbate 20 for CL treatment.

Factorial design applied to the optimization of lipid composition of topical antiherpetic nanoemulsions containing isoflavone genistein.

The aim of this study was to optimize topical nanoemulsions containing genistein, by means of a 23 full factorial design based on physicochemical properties and skin retention. The experimental arrangement was constructed using oil type (isopropyl myristate or castor oil), phospholipid type (distearoylphosphatidylcholine [DSPC] or dioleylphosphaditylcholine [DOPC]), and ionic cosurfactant type (oleic acid or oleylamine) as independent variables. The analysis of variance showed effect of third order for particle size, polydispersity index, and skin retention of genistein. Nanoemulsions composed of isopropyl myristate/DOPC/oleylamine showed the smallest diameter and highest genistein amount in porcine ear skin whereas the formulation composed of isopropyl myristate/DSPC/oleylamine exhibited the lowest polydispersity index. Thus, these two formulations were selected for further studies. The formulations presented positive ζ potential values (>25 mV) and genistein content close to 100% (at 1 mg/mL). The incorporation of genistein in nanoemulsions significantly increased the retention of this isoflavone in epidermis and dermis, especially when the formulation composed by isopropyl myristate/DOPC/oleylamine was used. These results were supported by confocal images. Such formulations exhibited antiherpetic activity in vitro against herpes simplex virus 1 (strain KOS) and herpes simplex virus 22 (strain 333). Taken together, the results show that the genistein-loaded nanoemulsions developed in this study are promising options in herpes treatment.

Association between Na⁺,K⁺-ATPase activity and the vulnerability/resilience to mood disorders induced by early life experience.

There is increasing evidence that early life events can influence neurodevelopment and later susceptibility to disease. Chronic variable stress (CVS) has been used as a model of depression. The objective of this study was to evaluate the interaction between early experience and vulnerability to chronic variable stress in adulthood, analyzing emotional, metabolic and neurochemical aspects related to depression. Pups were (1) handled (10 min/day) or (2) left undisturbed from day 1 to 10 after birth. When the animals reached adulthood, the groups were subdivided and the rats were submitted or not to CVS, which consisted of daily exposure to different stressors for 40 days, followed by a period of behavioral tasks, biochemical (plasma corticosterone and insulin sensitivity) and neurochemical (Na⁺,K⁺-ATPase activity in hippocampus, amygdala and parietal cortex) measurements. Neonatally-handled rats demonstrated shorter immobility times in the forced swimming test, independently of the stress condition. There was no difference concerning basal corticosterone or insulin sensitivity between the groups. Na⁺,K⁺-ATPase activity was decreased in hippocampus and increased in the amygdala of neonatally-handled rats. CVS decreased the enzyme activity in the three structures, mainly in the non-handled group. These findings suggest that early handling increases the ability to cope with chronic variable stress in adulthood, with animals showing less susceptibility to neurochemical features associated with depression, confirming the relevance of the precocious environment to vulnerability to psychiatric conditions in adulthood.

Fabry disease in hemodialysis patients in southern Brazil: prevalence study and clinical report.

BACKGROUND: Fabry disease (FD) is a lysosomal storage disorder caused by a deficiency of alpha-Galactosidase A (alpha-Gal A). Fabry nephropathy typically progresses throughout the fifth decade to end-stage renal disease (ESRD), requiring hemodialysis and/or kidney transplantation. OBJECTIVE: To estimate the prevalence of FD among ESRD males on hemodialysis treatment in Rio Grande do Sul, the southernmost state of Brazil. METHODS: Screening for alpha-Gal A activity was performed by a dried blood spot (normal reference value: >1.5 nmoles/hour/mL). Positive screening results were confirmed by plasma alpha-Gal A activity assay (reference value: >3.3 nmoles/hour/mL). RESULTS: Five hundred fifty-eight male patients on hemodialysis were evaluated. Of these, only two had low alpha-Gal A activity and were diagnosed with Fabry disease (0.36%). One of these, age 42, had left ventricular hypertrophy and renal manifestations of Fabry disease without the classic symptoms. The other, age 46, had the classical manifestations of angiokeratomas, acroparesthesias, hypohidrosis, and ocular opacities. CONCLUSIONS: Although the prevalence of Fabry disease was very low in our study (0.36%), routine screening of male hemodialysis patients would enable earlier identification of many other affected relatives in their families who might benefit from specific clinical treatment.

Frequency and clinical profile of patients with polycystic kidney disease in southern Brazil.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common genetic nephropathies, affecting one in every 800-1000 individuals in the worldwide general population and 5-10% of hemodialysis patients. Little data concerning the prevalence of ADPKD in Brazil are available. Thus, the aim of the present study was to investigate both the frequency and clinical profile of ADPKD among hemodialysis patients in south of Brazil. METHODS: This cross-sectional study consisted of patients from 24 hemodialysis centers. Patients were screened for ADPKD by clinical, laboratorial, and image examination in medical records. RESULTS: Of 1326 patients on hemodialysis in the south of Brazil that composed this study, 99 (7.5%) had polycystic kidney as primary cause for chronic renal failure. Comparisons between ADPKD and non-ADPKD patients revealed no differences regarding mean age, gender, and ethnicity. CONCLUSIONS: Our data revealed that ADPKD is prevalent among patients on hemodialysis in the south of Brazil. In addition, the clinical profile of ADPKD is similar to reported data from North America and Europe, putatively due to the similar ethnic composition mainly based on European descents.

Prevalence of 4977bp deletion in mitochondrial DNA from patients with chronic kidney disease receiving conservative treatment or hemodialysis in southern Brazil.

BACKGROUND: Damage to mitochondrial DNA (mtDNA) has been described in patients with chronic kidney disease (CKD). The presence of mtDNA 4977bp deletion in many different tissues can serve as a marker of this damage. However, no attempt has been made to detect the presence of mtDNA 4977bp in blood cells of patients with CKD. METHODS: Polymerase chain reaction techniques (PCR) were used to detect mtDNA 4977bp deletion in blood samples of 94 CKD patients. RESULTS: The prevalence of 4977bp deletion in mtDNA was 73.1% (38/52) in patients with CKD undergoing hemodialysis, 57.1% (27/42) in patients with CKD receiving conservative treatment, and 27.8% (15/54) in control samples (p < 0.001). Higher prevalence of this mutation was not associated with patient age (p = 0.54) or time on hemodialysis (p = 0.70). CONCLUSION: The higher prevalence of mtDNA 4977bp deletion in patients in this study indicates that the CKD can induce damage to mtDNA in blood cells and could be exacerbated by hemodialysis.

Danos moleculares em pacientes urêmicos submetidos à hemodiálise / Molecular damage in uremic patients on hemodialysis

Os efeitos tóxicos decorrentes do estado urêmico e do tratamento através de hemodiálise vêmsendo sugeridos como responsáveis por danos no DNA em pacientes com insuficiência renal crônica.Dessa forma, muitos trabalhos têm desenvolvido marcadores capazes de identificar esses danosatravés da análise cromossômica, teste de micronúcleos, teste do cometa, teste eletroquímico e,mais recentemente, análise do DNA mitocondrial. Considerando que esses danos podem aumentara incidência de câncer, mais estudos devem continuar sendo desenvolvidos nesse sentido.

The toxic effects caused by the uremic state and hemodialysis have been suggested asbeing responsible for DNA damage in patients with chronic renal failure. Thus, many researchershave developed markers capable of identifying these damages using chromosome analysis,micronucleus test, comet assay, electrochemical test and, more recently, mitochondrial DNA analysis.Further studies must be undertaken, since these damages can increase the incidence of cancer.

Genes envolvidos no controle do desenvolvimento inicial do rim / Genes involved in the control of early kidney development

As doenças renais humanas são uns dos maiores problemas de saúde, e vários genes quecontrolam a nefrogênese estão associados com essas doenças. Os principais genes envolvidosno desenvolvimento inicial do rim são PAX2, EYA1, SIX1 E 2, SALL1, FOXC1, WT1, HOX11, e amaioria dos fatores transcricionais desses genes é importante na regulação do gene GDNF. Essesgenes interagem uns com os outros, formando uma espécie de rede genética. O estudo dessasinterações genéticas é essencial para o entendimento das bases moleculares das malformaçõesdo desenvolvimento renal, que é necessário para a prevenção e tratamento dessas desordens.

Renal human diseases are among the leading health problems and many genes that controlnephrogenesis are associated with these diseases. The main genes involved in early kidneydevelopment are PAX2, EYA1, SIX1 and 2, SALL1, FOXC1, WT1, HOX11, and the majority oftheir transcriptional factors are relevant to the regulation of GDNF. Those genes interact with oneanother to create a genetic network. The study of such genetic interactions is crucial forunderstanding the molecular basis of kidney development malformations, which is necessary forthe prevention and treatment of these disorders.

Principais malformações congênitas macroscópicas do trato urinário superior / Major macroscopic congenital malformations of the upper urinary tract

Praticamente um terço de todas as malformações congênitas é encontrado no sistemaurogenital. A grande maioria das anormalidades do trato urinário tem pouco efeito no feto dentro doútero. Mesmo malformações letais para os neonatos não comprometem os fetos, uma vez que aplacenta e a mãe administram a função hidrostática renal. As principais malformações do tratourogenital são: agenesia renal, persistência de lobação fetal, fusão renal ou rim em ferradura,duplicação de ureter, obstrução ureteral ou ectopia dos ureteres, rim supranumerário e rim ectópico.Em termos de clínica médica, as ferramentas mais usadas na investigação das malformações dotrato urinário são os exames de imagem. A identificação desses distúrbios é importante para amanutenção dos pacientes. Esta revisão busca descrever as principais malformações renais,contribuindo para o desenvolvimento da nefrogenética.

Almost 1/3 of all congenital malformations are found in the urogenital tract. Most urinary tractabnormalities have little impact on fetus development. Even newborn lethal malformations do notrepresent a difficulty for the fetus, since the placenta and the mother manage the renal hydrostaticfunction. Major urogenital tract anomalies are renal agenesia, persistent fetal lobation, horseshoekidney, ureteral duplication, ureteral obstruction or ectopic ureter, supernumerary kidney and ectopickidney. Imaging examinations are the most common tools used in the clinical investigation of urinarytract malformations. The identification of these disorders is important for patient maintenance. Thisreview reports the major renal anomalies, thus contributing to the development of nephrogenetics.