Altered Elemental Distribution in Male Rat Brain Tissue as a Predictor of Glioblastoma Multiforme Growth—Studies Using SR-XRF Microscopy

Glioblastoma multiforme (GBM) is a particularly malignant primary brain tumor. Despite enormous advances in the surgical treatment of cancer, radio- and chemotherapy, the average survival of patients suffering from this cancer does not usually exceed several months. For obvious ethical reasons, the search and testing of the new drugs and therapies of GBM cannot be carried out on humans, and for this purpose, animal models of the disease are most often used. However, to assess the efficacy and safety of the therapy basing on these models, a deep knowledge of the pathological changes associated with tumor development in the animal brain is necessary. Therefore, as part of our study, the synchrotron radiation-based X-ray fluorescence microscopy was applied for multi-elemental micro-imaging of the rat brain in which glioblastoma develops. Elemental changes occurring in animals after the implantation of two human glioma cell lines as well as the cells taken directly from a patient suffering from GBM were compared. Both the extent and intensity of elemental changes strongly correlated with the regions of glioma growth. The obtained results showed that the observation of elemental anomalies accompanying tumor development within an animal’s brain might facilitate our understanding of the pathogenesis and progress of GBM and also determine potential biomarkers of its extension. The tumors appearing in a rat’s brain were characterized by an increased accumulation of Fe and Se, whilst the tissue directly surrounding the tumor presented a higher accumulation of Cu. Furthermore, the results of the study allow us to consider Se as a potential elemental marker of GBM progression.

Parkia biglobosa aqueous extract ameliorates risk markers of cardiometabolic diseases in spironolactone treated and high-salt fed Sprague-Dawley male rat

Background: The numbers of people with salt-sensitive hypertension and cardiometabolic diseases (CMD) are increasing due to high-salt diet (HSD) consumption globally. Parkia biglobosa (PB), an African locust bean tree, has been reported to have several cardiovascular protective properties but its ameliorative effects on CMD are scarcely reported. Therefore, this study aimed at investigating the effects of PB stem bark aqueous extract on some risk markers of CMD in weanling male rats subjected to HSD and Spironolactone (Sp) treatment.Twenty-five weanling male rats (95-105 g) were divided into 5 groups: Group 1 (Control); Group 2 (untreated HSD) fed on normal chow and HSD (8% NaCl); Group 3 (HSD+Sp); Group 4 (HSD+PB); Group 5 (HSD+Sp+PB) fed on HSD (8% NaCl) and received either 80 mg/kg of Sp or 400 mg/kg of PB and both as treatment, respectively. After 6 weeks of treatment, blood samples and heart were collected from each animal for biochemical analysis.Results: Administration of both PB and Sp or only PB, significantly decreased the plasma or cardiac adenosine deaminase, xanthine oxidase, C-reactive protein, lipids (except high density lipoprotein), uric acid, sodium, and potassium concentrations. Contrarily, the plasma as well as cardiac nitric oxide and endothelial nitric oxide synthase increased significantly by the same treatment.Conclusion: Parkia biglobosa or its administration with Spironolactone ameliorates associated-risk markers of cardiometabolic disease which are triggered by high salt diet.

CircRNA-WNK2 acts as a ceRNA for miR-328a-3p to promote AANAT expression in the male rat pineal gland

Noncoding RNAs (ncRNAs), including miRNAs and circRNAs, which are expressed with a daily rhythm in the rat pineal gland, are associated with the regulation of melatonin secretion and other biological functions. However, the mechanisms of these molecules in the rat pineal gland are not yet fully understood. In this study, we found circR-WNK2 was highly expressed at night, which may be involved in the regulation of melatonin secretion through the ceRNA mechanism. By dual luciferase reporter, RNA pulldown, and FISH assays, we found that miR-328a-3p can target circR-WNK2 and the Aa-nat mRNA 3’UTR. Transfection experiments indicated that circR-WNK2 could competitively bind to miR-328a-3p, reduce miR-328a-3p expression, and promote Aa-nat gene expression and melatonin secretion. And by constructing an SCGx rat model, we found that ncRNAs expressed in the pineal gland was regulated by signals from the SCN. This finding supports the hypothesis that these noncoding RNAs may interact to shape the circadian rhythm through transcriptional processing in melatonin synthesis.

Effect of Aqueous Extract of Rauvolfia vomitoria (Apocynaceae) Leaves with on Sexual Activity of Male Rats

Objective: The aim of this study is to determine the pharmacological effects of Rauvolfia vomitoria leaves on the sexual activity of animal model (male rat) Methods: Acute toxicity was performed according to OECD Guideline 423, by a dose limit of 2000 mg /kg body weight. The observations (during 14 days) focused on the number of deaths, convulsions, sleep and coma. Study of sexual activity has been realized by using 20 male rats, distributed in 4 lots of 5 animals. Group 1 treated with distilled water, group 2 treated with 5 mg/kg B.W. of sildenafil citrate and the other two batches received respectively the doses 500 and 1000 mg/kg of the aqueous extract of Rauvolfia vomitoria. Females in estrus state (in heat) were introduced for a period of 30 minutes. During this period, parameters of sexual behavior were recorded. At the end of the 8-day treatment, organs such as penis testicles, seminal vesicles, prostate, epididymis and elevator muscle were removed. These organs were studied in order to determine pharmacological effects of aqueous extract of Rauvolfia vomitoria. Results: The aqueous extract of Rauvolfia vomitoria showed no evidence of single dose toxicity (2000 mg/kg) when studying acute toxicity. Ride latency time, coitus latency time and ejaculation latency time was significantly decreased (P<0.001) with regard to negative control (distilled water). Ride frequency, coitus fraquency and ejaculation frequency was significantly increased (P<0.001) with regard to negative control (distilled water). No significant difference (P˃0.05) has been recorded on organ androgeno-dependant. Conclusion: Aqueous extract of R. vomitoria has sexual stimulating activity or an aphrodisiac potential which could justify its traditional use. The aphrodisiac potential is higher at the dose of 1000 mg/kg b.w .

Effect of CKD-MBD therapies on the gastrointestinal expression of phosphate transporters

Background: Chronic kidney disease-mineral and bone disorder (CKD-MBD) is prevalent and encompasses biochemical abnormalities, bone alterations, and vascular calcifications. CKD-MBD treatments include phosphate binders and calcimimetics that effectively lower phosphorus and PTH, respectively, but the impact of these treatments on phosphate transporters in the gastrointestinal tract is still unknown. NaPi2B is considered the primary intestinal phosphate transporter. However, NaPi2B inhibition shows limited effectiveness, thus the importance of PIT1 and PIT2 requires further investigation. Methods: We tested the effects phosphate binders (ferric citrate (FC) and calcium gluconate (Ca)) and the calcimimetic KP2326 (KP) in (Cy/+ male rat; CKD) and untreated normal littermates (NL). Treatments lasted 10 weeks until euthanasia at 28 weeks (moderate-to-advanced CKD), where we collected mucosa samples from duodenum, jejunum, and ileum. Blood was collected for biochemistry measurements. Total RNA was isolated, and qPCR performed to assess phosphate transporters expression (NaPi2B, PIT1, PIT2) normalized to b-actin. Results were analyzed via 2-way ANOVA. Results: As expected, CKD had abnormal plasma concentrations of phosphorus, PTH, and FGF23. FC and KP effectively lowered phosphorus. KP and Ca lowered PTH, but Ca increased FGF23. NaPi2B was expressed in the duodenum and jejunum but not in the ileum, and its expression was upregulated with FC compared to NL. PIT1 was expressed in all segments, but the expression was the highest in the ileum, while PIT2 was constitutively expressed in all segments. Ca led to higher PIT1 and PIT2 expression in the duodenum and jejunum compared to NL, CKD, or KP. KP led to higher expression of PIT1 in the ileum compared to CKD, FC, and Ca. Conclusions: CKD-MBD therapies differentially impacted biochemistries and phosphate transporters expression. The effect of Ca on gastrointestinal expression of PIT1 and PIT2 may explain the higher plasma phosphorus and should be further explored.

Sex-specific Stress and Behavioural Responses to Human Experimenters in Rats

The sex of the experimenter may cause stress in animal models and be a major confounding factor in preclinical research. We studied the effects of the sex of the experimenter on female and male rat anxiety behaviours using thigmotaxis in the open field test, anxiety-induced changes in brain and back temperature using infra-red thermography, and alterations in plasma concentrations of stress hormones, corticosterone and oxytocin. Female rats displayed consistently exacerbated anxiety-related behaviours along with increased infrared cutaneous temperature during repeated exposure to male experimenters. Experimental stress further intensified thermal responses to a male experimenter, especially in female rats. These behavioural responses to a male experimenter in females were associated with higher circulating corticosterone and lower oxytocin levels. Similar responses were induced by a T-shirt worn by a human male. These findings suggest that emotional and physiological responses of female rats to a male experimenter are influenced by visual and olfactory cues. These results emphasize the need to standardize and report experimenter sex throughout a study to avoid ambiguity in interpretation of the results.