Enhanced remedial effects for vitamin D3 and calcium co-supplementation against pre-existing lead nephrotoxicity in mice: The roles of renal calcium homeostatic molecules

Improved Glycaemic Control and Nephroprotective Effects of Empagliflozin and Paricalcitol Co-Therapy in Mice with Type 2 Diabetes Mellitus

Herein, we measured the antidiabetic and nephroprotective effects of the sodium-glucose cotransporter-2 inhibitor (empagliflozin; SGLT2i) and synthetic active vitamin D (paricalcitol; Pcal) mono- and co-therapy against diabetic nephropathy (DN). Fifty mice were assigned into negative (NC) and positive (PC) control, SGLT2i, Pcal, and SGLT2i+Pcal groups. Following establishment of DN, SGLT2i (5.1 mg/kg/day) and/or Pcal (0.5 µg/kg/day) were used in the designated groups (5 times/week/day). DN was affirmed in the PC group by hyperglycaemia, dyslipidaemia, polyuria, proteinuria, elevated urine protein/creatinine ratio, and abnormal renal biochemical parameters. Renal SREBP-1 lipogenic molecule, adipokines (leptin/resistin), pro-oxidant (MDA/H2O2), pro-inflammatory (IL1β/IL6/TNF-α), tissue damage (iNOS/TGF-β1/NGAL/KIM-1), and apoptosis (TUNEL/Caspase-3) markers also increased in the PC group. In contrast, renal lipolytic (PPARα/PPARγ), adiponectin, antioxidant (GSH/GPx1/SOD1/CAT), and anti-inflammatory (IL10) molecules decreased in the PC group. Both monotherapies increased insulin levels and mitigated hyperglycaemia, dyslipidaemia, renal and urine biochemical profiles alongside renal lipid regulatory molecules, inflammation, and oxidative stress. While SGLT2i monotherapy showed superior effects to Pcal, their combination demonstrated enhanced remedial actions related to metabolic control alongside renal oxidative stress, inflammation, and apoptosis. In conclusion, SGLT2i was better than Pcal monotherapy against DN, and their combination revealed better nephroprotection, plausibly by enhanced glycaemic control with boosted renal antioxidative and anti-inflammatory mechanisms.

Protective effect of Agaricus bisporus mushroom against maternal and fetal damage induced by lead administration during pregnancy in rats

INTRODUCTION

Lead (Pb) is a toxic pollutant, which can affect different tissues of the human body. The use of natural elements, as medicinal mushroom can reduce the toxic effects of Pb.

OBJECTIVE

We evaluated, through preclinical tests, the oral co exposures to mushroom Agaricus bisporus (Ab) by gavage and Pb in drinking water, and the capability of Ab be a protective agent for both pregnant rats and their fetuses.

METHODS

Female Wistar rats were divided into four groups (n = 5/group): Group I-Control; Group II-Ab 100 mg/kg; Group III-Pb 100 mg/L; Group IV-Ab +Pb -100 mg/kg +100 mg/L. Exposure was performed until the 19th day of gestation. On the 20th day, pregnant rats were euthanized, and the outcomes evaluated were weight gain; hematological profile; biochemical markers; oxidative stress markers; reproductive capacity; and embryo fetal development.

RESULTS

The characterization of mushrooms reveals them to be a valuable source of nutrients. However, Pb ingestion resulted in reduced weight gain and negative impacts on hematological and biochemical parameters. Fortunately, co administration of mushrooms helped to mitigate these negative effects and promote recovery. The mushroom also showed antioxidant activity, improving parameters of oxidative stress. In addition, Ab partially recovered the damage in fetal morphology and bone parameters.

CONCLUSION

Our findings indicated that the co administration of Ab improved the toxicity caused by Pb, and the mushroom could be used as a natural alternative as a protective/chelator agent.

Vitamin D and calcium co-therapy mitigates pre-established cadmium nephropathy by regulating renal calcium homeostatic molecules and improving anti-oxidative and anti-inflammatory activities in rat

BACKGROUND

Cadmium (Cd) is a major environmental pollutant and chronic toxicity could induce nephropathy by increasing renal oxidative stress and inflammation. Although vitamin D (VD) and calcium (Ca) prophylactic treatments attenuated Cd-induced cell injury, none of the prior studies measure their renoprotective effects against pre-established Cd-nephropathy.

AIMS

To measure the alleviating effects of VD and/or Ca single and dual therapies against pre-established nephrotoxicity induced by chronic Cd toxicity prior to treatment initiation.

METHODS

Forty male adult rats were allocated into: negative controls (NC), positive controls (PC), Ca, VD and VC groups. The study lasted for eight weeks and all animals, except the NC, received CdCl₂ in drinking water (44 mg/L) throughout the study. Ca (100 mg/kg) and/or VD (350 IU/kg) were given (five times/week) during the last four weeks to the designated groups. Subsequently, the expression of transforming growth factor-β (TGF-β1), inducible nitric oxide synthase (iNOS), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), VD synthesising (Cyp27b1) and catabolizing (Cyp24a1) enzymes with VD receptor (VDR) and binding protein (VDBP) was measured in renal tissues. Similarly, renal expression of Ca voltage-dependent channels (Ca_V1.1/Ca_V3.1), store-operated channels (RyR1/ITPR1), and binding proteins (CAM/CAMKIIA/S100A1/S100B) were measured. Serum markers of renal function alongside several markers of oxidative stress (MDA/H₂O₂/GSH/GPx/CAT) and inflammation (IL-6/TNF-α/IL-10) together with renal cell apoptosis and expression of caspase-3 were also measured.

RESULTS

The PC group exhibited hypovitaminosis D, hypocalcaemia, hypercalciuria, proteinuria, reduced creatinine clearance, and increased renal apoptosis/necrosis with higher caspase-3 expression. Markers of renal tissue damage (TGF-β1/iNOS/NGAL/KIM-1), oxidative stress (MDA/H₂O₂), and inflammation (TNF-α/IL-1β/IL-6) increased, whilst the antioxidants (GSH/GPx/CAT) and IL-10 decreased, in the PC group. The PC renal tissues also showed abnormal expression of Cyp27b1, Cyp24a1, VDR, and VDBP, alongside Ca-membranous (Ca_V1.1/Ca_V3.1) and store-operated channels (RyR1/ITPR1) and cytosolic Ca-binding proteins (CAM/CAMKIIA/S100A1/S100B). Although VD was superior to Ca monotherapy, their combination revealed the best mitigation effects by attenuating serum and renal tissue Cd concentrations, inflammation and oxidative stress, alongside modulating the expression of VD/Ca-molecules.

CONCLUSIONS

This study is the first to show improved alleviations against Cd-nephropathy by co-supplementing VD and Ca, possibly by better regulation of Ca-dependent anti-oxidative and anti-inflammatory actions.

Intracellular Helix-Loop-Helix Domain Modulates Inactivation Kinetics of Mammalian TRPV5 and TRPV6 Channels

TRPV5 and TRPV6 are calcium-selective ion channels expressed at the apical membrane of epithelial cells. Important for systemic calcium (Ca²⁺) homeostasis, these channels are considered gatekeepers of this cation transcellular transport. Intracellular Ca²⁺ exerts a negative control over the activity of these channels by promoting inactivation. TRPV5 and TRPV6 inactivation has been divided into fast and slow phases based on their kinetics. While slow inactivation is common to both channels, fast inactivation is characteristic of TRPV6. It has been proposed that the fast phase depends on Ca²⁺ binding and that the slow phase depends on the binding of the Ca²⁺/Calmodulin complex to the internal gate of the channels. Here, by means of structural analyses, site-directed mutagenesis, electrophysiology, and molecular dynamic simulations, we identified a specific set of amino acids and interactions that determine the inactivation kinetics of mammalian TRPV5 and TRPV6 channels. We propose that the association between the intracellular helix-loop-helix (HLH) domain and the TRP domain helix (TDh) favors the faster inactivation kinetics observed in mammalian TRPV6 channels.

Deferasirox and vitamin D3 co-therapy mitigates iron-induced renal injury by enhanced modulation of cellular anti-inflammatory, anti-oxidative stress, and iron regulatory pathways in rat

BACKGROUND

Chronic iron overload could induce nephropathy via oxidative stress and inflammation, and chelating therapy has limited efficacy in removing excess intracellular iron. Although vitamin D (VD) has shown potent antioxidant and anti-inflammatory effects, as well contribute to iron homeostasis, none of the previous studies measured its potential remedial effects against chronic iron toxicity.

AIMS

To measure the alleviating effects of deferasirox (DFX) and/or vitamin D (VD) single and combined therapies against nephrotoxicity induced by chronic iron overload.

METHODS

Forty male rats were divided into negative (NC) and positive (PC) controls, DFX, VD, and DFX/VD groups. The designated groups received iron for six weeks followed by DFX and/or VD for another six weeks. Then, the expression pattern of renal genes and proteins including hepcidin, ferroportin (FPN), megalin, transferrin receptor 1 (TfR1), ferritin heavy and light chains, VD receptor (VDR), VD synthesizing (Cyp27b1) and catabolizing (Cyp24a1) enzymes were measured alongside serum markers of renal function and iron biochemical parameters. Additionally, several markers of oxidative stress (MDA/H₂O₂/GSH/SOD1/CAT/GPx4) and inflammation (IL-1β/IL-6/TNF-α/IL-10) together with renal cell apoptosis and expression of caspase-3 (Casp-3) were measured.

RESULTS

The PC rats showed pathological iron and renal biochemical markers, hypovitaminosis D, increased renal tissue iron contents with increased Cyp24a1/Megalin/ferritin-chains/hepcidin, and decreased Cyp27b1/VDR/TfR1/FPN expression than the NC group. The PC renal tissues also showed abnormal histology, increased inflammatory (IL-1β/IL-6/TNF-α), oxidative stress (MDA/H₂O₂), and apoptosis markers with decreased IL-10/GSH/SOD1/CAT/GPx4. Although DFX monotherapy reduced serum iron levels, it was comparable to the PC group in renal iron concentrations, VD and iron-homeostatic molecules, alongside markers of oxidative stress, inflammation, and apoptosis. On the other hand, VD monotherapy markedly modulated renal iron and VD-related molecules, reduced renal tissue iron concentrations, and preserved renal tissue relative to the PC and DFX groups. However, serum iron levels were equal in the VD and PC groups. In contrast, the best significant improvements in serum and renal iron levels, expression of renal iron-homeostatic molecules, oxidative stress, inflammation, and apoptosis were seen in the co-therapy group.

CONCLUSIONS

iron-induced nephrotoxicity was associated with dysregulations in renal VD-system together with renal oxidative stress, inflammation, and apoptosis. While DFX reduced systemic iron, VD monotherapy showed better attenuation of renal iron concentrations and tissue damage. Nonetheless, the co-therapy approach exhibited the maximal remedial effects, possibly by enhanced modulation of renal iron-homeostatic molecules alongside reducing systemic iron levels.

AVAILABILITY OF DATA AND MATERIALS

All data generated or analysed during this study are included in this published article [and its Supplementary information files].

Involvement of calcium homeostasis and unfolded protein response in autophagy co-induced by molybdenum and cadmium in duck (Anas platyrhyncha) brain

Excess molybdenum (Mo) and cadmium (Cd) are harmful to animals, but neurotoxicity caused by Mo and Cd co-exposure in ducks is yet unknown. To assess joint impacts of Mo and Cd on autophagy via calcium homeostasis and unfolded protein response (UPR) in duck brain, 40 healthy 7-day-old ducks (Anas platyrhyncha) were assigned to 4 groups at random and fed diets supplemented with different doses of Mo or/and Cd for 16 weeks, respectively. Brain tissues were excised for experiment. Results exhibited that Mo or/and Cd disturbed calcium homeostasis by decreased ATPase activities and increased calcium (Ca) content, and upregulated calcium homeostasis-related factors Ca²⁺/CAM-dependent kinase IIɑ (CaMKIIɑ), calcineurin (CaN), inositol-1,4,5-trisphosphate receptor (IP₃R), and calreticulin (CRT) expression levels. Meanwhile, the upregulation of UPR-related factor expression levels indicated that Mo or/and Cd activated UPR. Moreover, Mo or/and Cd triggered autophagy through promoting the number of autophagosomes and LC3II immunofluorescence intensity and altering autophagy key factor expression levels. Correlation analysis showed that there were obvious connections among Ca²⁺ homeostasis, endoplasmic reticulum (ER) stress, and autophagy induced by Mo or/and Cd. Thence, it can be speculated that autophagy initiated by Mo or/and Cd may be associated with interfering Ca²⁺ homeostasis and triggering UPR.

In Vivo and In Vitro Enhanced Tumoricidal Effects of Metformin, Active Vitamin D3, and 5-Fluorouracil Triple Therapy against Colon Cancer by Modulating the PI3K/Akt/PTEN/mTOR Network

Simple Summary

Failure of chemotherapy is common during the treatment of colon cancer, and there is a compelling need to develop alternative therapeutic approaches against this common malignancy. Metformin, which is an oral hypoglycaemic agent used for treating diabetes mellitus, and vitamin D have shown promising anticancer activities, and both agents boosted the actions of chemotherapy against colon cancer. This study, therefore, measured the potential beneficial effects of adding metformin and/or active vitamin D to the main cytotoxic drug used for treating colon cancer. The results demonstrate that metformin had superior anticancer effects relative to active vitamin D and ameliorated the effects of chemotherapy in animals and in cells. To the best of our knowledge, this study is also the first to report that triple treatment with the drugs of interest showed the best inhibition of cancer progression, which could provide a better therapeutic strategy against colon cancer.

Abstract

Chemoresistance to 5-fluorouracil (5-FU) is common during colorectal cancer (CRC) treatment. This study measured the chemotherapeutic effects of 5-FU, active vitamin D₃ (VD₃), and/or metformin single/dual/triple regimens as complementary/alternative therapies. Ninety male mice were divided into: negative and positive (PC) controls, and 5-FU, VD₃, Met, 5-FU/VD₃, 5-FU/Met, VD₃/Met, and 5-FU/VD₃/Met groups. Treatments lasted four weeks following CRC induction by azoxymethane. Similar regimens were also applied in the SW480 and SW620 CRC cell lines. The PC mice had abundant tumours, markedly elevated proliferation markers (survivin/CCND1) and PI3K/Akt/mTOR, and reduced p21/PTEN/cytochrome C/caspase-3 and apoptosis. All therapies reduced tumour numbers, with 5-FU/VD₃/Met being the most efficacious regimen. All protocols decreased cell proliferation markers, inhibited PI3K/Akt/mTOR molecules, and increased proapoptotic molecules with an apoptosis index, and 5-FU/VD₃/Met revealed the strongest effects. In vitro, all therapies equally induced G1 phase arrest in SW480 cells, whereas metformin-alone showed maximal SW620 cell numbers in the G0/G1 phase. 5-FU/Met co-therapy also showed the highest apoptotic SW480 cell numbers (13%), whilst 5-FU/VD₃/Met disclosed the lowest viable SW620 cell percentages (81%). Moreover, 5-FU/VD₃/Met revealed maximal inhibitions of cell cycle inducers (CCND1/CCND3), cell survival (BCL2), and the PI3K/Akt/mTOR molecules alongside the highest expression of cell cycle inhibitors (p21/p27), proapoptotic markers (BAX/cytochrome C/caspase-3), and PTEN in both cell lines. In conclusion, metformin monotherapy was superior to VD₃, whereas the 5-FU/Met protocol showed better anticancer effects relative to the other dual therapies. However, the 5-FU/VD₃/Met approach displayed the best in vivo and in vitro tumoricidal effects related to cell cycle arrest and apoptosis, justifiably by enhanced modulations of the PI3K/PTEN/Akt/mTOR pathway.

Enhanced in vitro tumoricidal effects of 5-Fluorouracil, thymoquinone, and active vitamin D3 triple therapy against colon cancer cells by attenuating the PI3K/AKT/mTOR pathway

AIMS

This study measured the effects of 5-Fluorouracil (5-FU), calcitriol (VD₃), and/or thymoquinone (TQ) single/dual/triple therapies on cell cycle progression, apoptosis, inhibition of the PI3K/AKT/mTOR pathway, and oxidative stress against colorectal cancer (CRC).

MAIN METHODS

The HT29, SW480 and SW620 cell lines were treated with 5-FU (50 μM), VD₃ (25 μM), and TQ (75 μM), alone or combined for 12 h, prior to cell cycle/apoptosis analyses.

KEY FINDINGS

TQ monotherapy had greater anticancer effects to active VD₃ or 5-FU, revealing higher expression of p21/p27/PTEN/BAX/Cyto-C/Casp-3 and increased levels of total glutathione, with inhibitions in CCND1/CCND3/BCL-2 and PI3K/AKT/mTOR molecules, alongside higher rates of apoptosis in HT29, SW480 and SW620 cells (P < 0.005 for all markers). Additionally, all combination protocols revealed enhanced modulations of the PI3K/PTEN/Akt/mTOR pathway, higher expression of p21/p27/PTEN/BAX/Cyto-C/Casp-3, and better anti-oxidant effects, than the monotherapies. Although TQ/5-FU and TQ/VD₃ co-therapies were better relative to the VD₃/5-FU regimen, the best tumoricidal effects were observed with triple therapy in the HT29 and SW480 cell lines, possibly by boosted attenuations of the PI3K/AKT/mTOR oncogenic pathway. In contrast, TQ single treatment was more effective than the triple therapy regimen in metastatic SW620 cells, suggesting that this protocol would be more useful therapeutically in late-stage CRC.

SIGNIFICANCE

In conclusion, this study is the first to demonstrated enhanced anti-tumorigenic effects for VD₃, TQ, and 5-FU triple therapy against CRC cells and could represent the best strategy for treating early stages of malignancy, whereas TQ monotherapy could be a better approach for treating metastatic forms of the disease.

Physiological Alterations of Subchronic Lead Exposure Induced Degeneration of Epithelial Cells in Proximal Tubules and the Remedial Effect of Curcumin-III in Meriones shawi: a Possible Link with Vasopressin Release

At the industrial working conditions, lead exposure could induce several alterations for the human body. Subchronic lead exposure is linked with several injuries including cerebral and renal dysfunctions. The present work discusses the effects of subchronic lead toxicity (3 g/l) in drinking water during the period of treatment (6 weeks) on vasopressin system and epithelial cells in proximal tubules. Also, we aimed to evaluate the protective effect of curcumin-III administered orally by gavage (30 mg/kg BW), against subchronic Pb exposure in Meriones shawi. The biochemical and histopathological examinations demonstrate renal damages induced by lead toxicity. In addition, the behavioral and immunohistochemical studies revealed that Pb neurotoxicity exhibited an anxious behavior with a significant elevation of the vasopressin (AVP) staining within the paraventricular nuclei. The study showed also curcumin-III restored the renal alterations with an anxiolytic effect. Moreover, it restored the AVP level in the studying nuclei. Our work supports a possible link between AVP release and epithelial degeneration in the proximal tubules, and shows a new pharmacological effect of curcumin-III as an anxiolytic agent against lead toxicity.

In vivo assessment of molybdenum and cadmium co-induce nephrotoxicity via causing calcium homeostasis disorder and autophagy in ducks (Anas platyrhyncha)

Excess molybdenum (Mo) and cadmium (Cd) are widespread environmental and industrial metal pollutants. To evaluate the combined effects of Mo and Cd on calcium homeostasis and autophagy in duck kidneys. 160 healthy 7-day-old ducks (Anas platyrhyncha) were randomized into 4 groups and given to a basic diet, adding various doses of Mo or/and Cd for 16 weeks. On the 4th, 8th, 12th and 16th weeks, kidney tissues were collected. The study exhibited that Mo or/and Cd caused histological abnormality, reduced the activities of Ca2+ ATPase, Mg2+ ATPase, Na+-K+ ATPase and Ca2+-Mg2+ ATPase, K and Mg contents, and increased Na and Ca contents, upregulated CaMKKβ, CaMKIIɑ, CaN, IP3R, GRP78, GRP94, CRT mRNA levels and CaMKIIɑ, CaN, IP3R protein levels. Moreover, exposure to Mo or/and Cd notably promoted the amount of autophagosomes and LC3II immunofluorescence, upregulated AMPKα1, ATG5, Beclin-1, LC3A, LC3B mRNA levels and Beclin-1, LC3II/LC3I protein levels, downregulated mTOR, Dynein, P62 mRNA levels and P62 protein level. The changes of above indicators in combined group were more obvious. Overall, the results suggest that Mo and Cd co-exposure may can synergistically induce nephrotoxicity via causing calcium homeostasis disorder and autophagy in ducks.

Enhanced anti-cancer effects of oestrogen and progesterone co-therapy against colorectal cancer in males

Although ovarian sex steroids could have protective roles against colorectal cancer (CRC) in women, little is currently known about their potential anti-tumorigenic effects in men. Hence, this study measured the therapeutic effects of 17β-oestradiol (E2) and/or progesterone (P4) against azoxymethane-induced CRC in male mice that were divided into (n = 10 mice/group): negative (NC) and positive (PC) controls, E2 (580 µg/Kg/day; five times/week) and P4 (2.9 mg/Kg/day; five times/week) monotherapies, and concurrent (EP) and sequential (E/P) co-therapy groups. Both hormones were injected intraperitoneally to the designated groups for four consecutive weeks. Similar treatment protocols with E2 (10 nM) and/or P4 (20 nM) were also used in the SW480 and SW620 human male CRC cell lines. The PC group showed abundant colonic tumours alongside increased colonic tissue testosterone levels and androgen (AR) and oestrogen (ERα) receptors, whereas E2 and P4 levels with ERβ and progesterone receptor (PGR) decreased significantly compared with the NC group. E2 and P4 monotherapies equally increased ERβ/PGR with p21/Cytochrome-C/Caspase-3, reduced testosterone levels, inhibited ERα/AR and CCND1/survivin and promoted apoptosis relative to the PC group. Both co-therapy protocols also revealed better anti-cancer effects with enhanced modulation of colonic sex steroid hormones and their receptors, with E/P the most prominent protocol. In vitro, E/P regimen showed the highest increases in the numbers of SW480 (2.1-fold) and SW620 (3.5-fold) cells in Sub-G1 phase of cell cycle. The E/P co-therapy also disclosed the lowest percentages of viable SW480 cells (2.8-fold), whilst both co-therapy protocols equally showed the greatest SW620 apoptotic cell numbers (5.2-fold) relative to untreated cells. Moreover, both co-therapy regimens revealed maximal inhibitions of cell cycle inducers, cell survival markers, and AR/ERα alongside the highest expression of cell cycle suppressors, pro-apoptotic molecules, and ERβ/PGR in both cell lines. In conclusion, CRC was associated with abnormal levels of colonic sex steroid hormones alongside aberrant protein expression of their receptors. While the anti-cancer effects of E2 and P4 monotherapies were equal, their combination protocols showed boosted tumoricidal actions against CRC in males, possibly by promoting ERβ and PGR-mediated androgen deprivation together with inhibition of ERα-regulated oncogenic pathways.

Protective Effect of Vitamin D3 Against Pb-Induced Neurotoxicity by Regulating the Nrf2 and NF-κB Pathways

Lead (Pb) is a known toxic heavy metal which accumulates in different tissues and causes oxidative stress (OS) and inflammation. The brain tissue is considered as one of the most vulnerable organs to the Pb-induced toxicity. The aim of this study was to investigate the therapeutic effects of vitamin D3 (VD) supplementation against the damages caused by chronic Pb toxicity in the cerebral cortex. Forty Wistar rats were divided into four equal groups and were treated as follows: control group received no treatment, VD group received 1000 IU/kg of VD by intramuscular injection every other day, Pb group received 1000 mg/L of Pb in drinking water, and Pb + VD group received VD and Pb simultaneously. The experiment lasted for 4 weeks and the analyses were conducted 24 h after the last administrations. The obtained results demonstrated that Pb significantly increased cortical lipid peroxidation and reactive oxygen species (ROS) levels. At the same time, there was a significant reduction in glutathione (GSH) content, catalase (CAT), and superoxide dismutase (SOD) activities, as well as a significant increase in the tissue level of inflammatory cytokines. Furthermore, Pb increased the messenger RNA (mRNA) expression level of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB). Anyhow, VD administration during the period of Pb exposure suppressed the OS and inflammation by increasing the antioxidant molecules and decreasing the inflammatory cytokines and consequently repaired Pb-induced cortical tissue damages. Remarkably, these responses were concomitant with the alterations in Nrf2 and NF-κB gene expressions. In conclusion, the present study discloses the potential protective effects for VD against Pb-induced neurotoxicity via anti-inflammatory and antioxidative mechanisms.

Chemopreventive effects of vitamin D3 and its analogue, paricalcitol, in combination with 5-fluorouracil against colorectal cancer: The role of calcium signalling molecules

BACKGROUND

Although vitamin D (VD) is chemoprotective and enhances 5-fluorouracil (5-FU) cytotoxicity against colorectal cancer (CRC), little is known about its potential calcium (Ca²⁺)-mediated anti-tumorigenic actions. Therefore, this study compared between VD and its non-calcaemic analogue, Paricalcitol (Pcal), ± 5-FU in relation to chemoprevention and Ca²⁺-mediated apoptosis in vivo and in vitro.

METHODS

Seventy male mice were distributed to: negative controls, positive controls (PC), VD, Pcal, 5-FU, VD + 5-FU and Pcal+5-FU groups. All groups, except negative, received two consecutive azoxymethane (AOM)-injections (10 mg/Kg/week) for CRC induction. VD₃ (1000 IU/kg; three times/week) and Pcal (1.25 μg/kg; three times/week) injections started week-16 post-AOM and for 10 weeks. Three successive 5-FU cycles began at week-21 (50 mg/Kg/week). Similar protocols with VD₃, Pcal and/or 5-FU were applied in the HT29 colon cancer cells.

RESULTS

The PC group had abundant malignant tumours, markedly elevated proliferation markers (survivin/CCND1) and declines in cyclin-dependent kinase-inhibitor-1A, pro-apoptotic molecules (p53/BAX/cytochrome_C/caspase-3), tissue Ca²⁺ concentrations and Ca²⁺-dependent proteins (CaSR/CAM/CAMKIIA). All monotherapies equally reduced tumour numbers and proliferation markers whilst promoting the anti-tumorigenic molecules. VD and/or 5-FU, but not Pcal monotherapy, enhanced Ca²⁺ levels and Ca²⁺-related molecules (CaSR/CAM/CAMKIIA/BAX/cytochrome_C) in vivo and in vitro. However, VD + 5-FU co-therapy showed the lowest tumour numbers, the highest cell numbers in sub-G1 phase of cell cycle, alongside the most effective modulations of oncogenes, tumour suppressors and Ca²⁺-related molecules at the gene and protein levels in vivo and in vitro.

CONCLUSIONS

VD₃ was superior than Paricalcitol in potentiating 5-FU cytotoxicity, possibly by upregulating several Ca²⁺-related molecules involved in tumour suppression.

Modulating effect of vitamin D3 on the mutagenicity and carcinogenicity of doxorubicin in Drosophila melanogaster and in silico studies

Vitamin D3 (VD3) deficiency increases DNA damage, while supplementation may exert a pro-oxidant activity, prevent viral infections and formation of tumors. The aim of this study was to investigate the mutagenicity and carcinogenicity of VD3 alone or in combination with doxorubicin (DXR) using the Somatic Mutation and Recombination Test and the Epithelial Tumor Test, both in Drosophila melanogaster. For better understanding of the molecular interactions of VD3 and receptors, in silico analysis were performed with molecular docking associated with molecular dynamics. Findings revealed that VD3 alone did not increase the frequency of mutant spots, but reduced the frequency of mutant spots when co-administered with DXR. In addition, VD3 did not alter the recombinogenic effect of DXR in both ST and HB crosses. VD3 alone did not increase the total frequency of tumor, but significantly reduced the total frequency of tumor when co-administered with DXR. Molecular modeling and molecular dynamics between calcitriol and Ecdysone Receptor (EcR) showed a stable interaction, indicating the possibility of signal transduction between VD3 and EcR. In conclusion, under these experimental conditions, VD3 has modulatory effects on the mutagenicity and carcinogenicity induced by DXR in somatic cells of D. melanogaster and exhibited satisfactory interactions with the EcR.

Luteolin protects against lead acetate-induced nephrotoxicity through antioxidant, anti-inflammatory, anti-apoptotic, and Nrf2/HO-1 signaling pathways

Lead (Pb) is one of the most common heavy metal pollutants affecting living organisms. It induces nephrotoxicity with significant alterations in renal structure and function. Luteolin (LUT) a flavonoid present in various plant products is well known for exhibiting numerous pharmacological properties. We evaluated the protective efficacy of LUT against Pb-induced renal injury in male Wistar rats. Four experimental groups: control, LUT (50 mg/kg, orally), PbAc (20 mg/kg, i.p.), LUT + PbAc (at the aforementioned doses) were maintained for 7 days. PbAc administration significantly increased renal Pb accumulation, urea, and creatinine levels in serum, and induced renal histological alterations. Additionally, compared to the control rats, PbAc-treated rats exhibited significantly low levels of antioxidant enzyme activity and expression (SOD, CAT, GPx and GR), as well as high MDA levels. Moreover, PbAc exposure downregulated Nfe212 and Homx1 mRNA expression and significantly increased inflammatory marker (TNF-α, IL-1β and NO) levels in renal tissue. PbAc significantly upregulated the synthesis of apoptotic related proteins and downregulated antiapoptotic protein expression. Notably, LUT pretreatment of PbAc-treated rats provided significant nephroprotection and reversed the alterations in the abovementioned parameters. In conclusion, LUT provided significant protection against PbAc intoxication via antioxidant, anti-inflammatory, and anti-apoptotic activities by activating the Nrf2/ARE signaling pathway.

Lead-induced oxidative damage in rats/mice: A meta-analysis

BACKGROUND

Lead (Pb) is ubiquitous in the environment and is an environmental genotoxic metal. Pb accumulation in the body could cause the oxidative stress.

OBJECTIVE

This meta-analysis aimed to perform a systematic evaluation of the extent of oxidative damage in rats/mice induced by lead.

METHODS

All relevant articles in English or Chinese were retrieved from Embase, PubMed, Web of Science, Medline, China National Knowledge Infrastructure, and Chinese Biological Medicine databases from their inception date until July 22, 2018.

RESULTS

A total of 108 eligible articles were included in this study. The indicators of oxidative stress included malondialdehyde (MDA), glutathione disulfide (GSSG), reactive oxygen species (ROS), hydrogen peroxide (H₂O₂), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced glutathione (GSH), superoxide dismutase (SOD), and glutathione-s-transferase (GST). The meta-analysis showed that lead significantly increased oxidants levels, such as MDA, GSSG, ROS, and H₂O₂ (P < 0.05), and significantly reduced the level of antioxidants, such as CAT, GPx, GR, GSH, SOD, and GST (P < 0.05). The intraperitoneal mode was more effective than water drinking mode in reducing the levels of CAT, GPx, GSH, and SOD (P < 0.05). Other factors that influenced the overall oxidative stress, including species of animals, type of tissues, and intervention dosage and time, were comprehensively evaluated.

CONCLUSION

The results of meta-analysis indicated that mice were more sensitive to lead than rats, and intraperitoneal mode was an effective intervention mean. High doses and long periods of lead treatment can cause serious oxidative damage. Moreover, testicular was more vulnerable to lead than other tissues. These results provided scientific evidence for preventing and treating lead toxicity.

Vitamin D3 and calcium cosupplementation alleviates cadmium hepatotoxicity in the rat: Enhanced antioxidative and anti-inflammatory actions by remodeling cellular calcium pathways

Although vitamin D (VD) and calcium (Ca) attenuate cadmium (Cd) metabolism, their combined antioxidant and anti-inflammatory actions against Cd toxicity have not been previously explored. Hence, this study measured the protective effects of VD ± Ca supplements against Cd hepatotoxicity. Forty adult male rats were distributed to: negative controls (NCs), positive controls (PCs), VD, Ca, and VD₃ and Ca (VDC) groups. All groups, except NC, received CdCl₂ in drinking water (44 mg/L) for 4 weeks individually or concurrently with intramuscular VD₃ (600 IU/kg; three times per week) and/or oral Ca (100 mg/kg; five times per week). The PC group showed abnormal hepatic biochemical parameters and increase in cellular cytochrome C, caspase-9, and caspase-3 alongside the apoptotic/necrotic cell numbers by terminal deoxynucleotidyl transferase dUTP nick end labeling technique. The PC hepatic tissue also had substantially elevated pro-oxidants (malondialdehyde [MDA]/H₂ O₂ /protein carbonyls) and inflammatory cytokines (interleukin 1β [IL-1β]/IL-6/IL17A/tumor necrosis factor-α), whereas the anti-inflammatory (IL-10/IL-22) and antioxidants (glutathione [GSH]/GPx/catalase enzyme [CAT]) markers declined. Hypovitaminosis D, low hepatic tissue Ca, aberrant hepatic expression of VD-metabolizing enzymes (Cyp2R1/Cyp27a1/cyp24a1), receptor and binding protein alongside Ca-membrane (Ca_V 1.1/Ca_V 3.1), and store-operated (RyR1/ITPR1) channels, and Ca-binding proteins (CAM/CAMKIIA/S100A1/S100B) were observed in the PC group. Both monotherapies decreased serum, but not tissue Cd levels, restored the targeted hepatic VD/Ca molecules' expression. However, these effects were more prominent in the VD group than the Ca group. The VDC group, contrariwise, disclosed the greatest alleviations on serum and tissue Cd, inflammatory and oxidative markers, the VD/Ca molecules and tissue integrity. In conclusion, this report is the first to reveal boosted protection for cosupplementing VD and Ca against Cd hepatotoxicity that could be due to enhanced antioxidative, anti-inflammatory, and modulation of the Ca pathways.

Protective effect of Vitamin D3 against lead induced hepatotoxicity, oxidative stress, immunosuppressive and calcium homeostasis disorders in rat

Lead (Pb) is an extremely poisonous, non-essential trace element and toxicity develops in humans following frequent exposure to the heavy metal in polluted environmental and occupational settings. Pb induces hepatic damage through the depletion of the antioxidant system, enhancing cellular oxidative stress and stimulation of proinflammatory cytokines. Although the antioxidant and anti-inflammatory actions of vitamin D₃ (VD₃) are well-established, a minority of studies measured the protective actions of VD₃ against Pb toxicity. Therefore, this work studied the effects of vitamin VD₃ therapy on the fundamental molecular basis underlying hepatic injury induced by chronic Pb toxicity. Twenty-four adult male rats were distributed equally into the negative controls (NC), positive controls (PC) and VD3 groups. While both the PC and VD3 groups received Pb-acetate in drinking water (1000 mg/L) for four weeks, the latter group also received intramuscular VD3 injections (1000 IU/kg; 3 days/week) simultaneously with Pb. The liver enzymes together with the serum and hepatic tissue Pb concentrations increased markedly in the PC group compared with the NC group. Pb toxicity also drastically induced hepatocyte apoptosis/necrosis, increased the hepatic tissue concentrations of malondialdehyde and the pro-inflammatory cytokines (TGF-β, IL-4 & TNF-α) as well as reduced the anti-oxidative enzymes (GSH, GPx & CAT) and the anti-inflammatory cytokine, IL-10, compared with the NC group. Pb also significantly decreased the serum concentrations of VD3 and Ca²⁺. Additionally, the hepatic expressions of VD receptor, Cyp24a1 enzyme, L-type Ca²⁺-channel, calbindin-D_28k & -D_29k, calmodulin and calmodulin-dependent protein kinase II were significantly upregulated, whereas the VD binding protein, CYP2R1 enzyme and T-type Ca²⁺-channel were markedly inhibited at the gene and protein levels following Pb intoxication. VD3 alleviated the hepatic damage, inhibited the oxidative stress and pro-inflammatory molecules as well as upregulated the anti-oxidant and anti-inflammatory markers and restored the expression of the VD/Ca²+ regulatory molecules compared with the PC group. VD3 supplementation discloses promising protective effects against Pb-induced hepatic damage, through its anti-inflammatory and antioxidant actions as well as by modulating the hepatocyte calcium homeostatic molecules.

Vitamin D protects against oxidative stress, inflammation and hepatorenal damage induced by acute paracetamol toxicity in rat

Acute paracetamol (APAP) toxicity is a leading cause of liver, and less commonly renal, injuries through oxidative stress and inflammation. Albeit vitamin D (VD) is a well-known anti-oxidant and anti-inflammatory hormone, there is no report on its potential protective/therapeutic actions against APAP acute toxicity. This study, therefore, measured the interplay between APAP toxicity and the hepatorenal expressions of the VD-metabolising enzymes (Cyp2R1, Cyp27b1 & cyp24a1), receptor (VDR) and binding protein (VDBP) alongside the effects of VD treatment on APAP-induced hepatorenal injuries. Thirty-two male rats were distributed equally into negative (NC) and positive (PC) controls besides VD prophylactic (P-VD) and therapeutic (T-VD) groups. All groups, except the NC, received a single oral dose of APAP (1200 mg/kg). The P-VD also received by intraperitoneal injection two cycles of VD₃ (1000 IU/Kg/day; 5 days/week) prior to, and a third round after, APAP administration. Similarly, the T-VD group received VD₃ (3000 IU/Kg/day) for five successive days post-APAP intoxication. Euthanasia was on the sixth day post-APAP toxicity. The PC group had marked alterations in the hepatorenal biochemical parameters, upregulation in cellular cleaved caspase-3 as well as pronounced increase in the numbers of apoptotic/necrotic cells by TUNEL technique. The PC group plasma levels of 25-hydroxyvitamin D (25-OH VD) also declined markedly and coincided with significant inhibitions in the expression of Cyp2R1 and Cyp27b1 enzymes and VDR, whereas the VDBP and Cyp24a1 increased substantially, in the hepatorenal tissues at the gene and protein levels compared with the NC group. Coherently, the lipid peroxidation marker (MDA) and pro-inflammatory cytokines (IL1β, IL6, IL17A, IFN-γ & TNF-α) augmented significantly, while the anti-oxidative markers (GSH, GPx & CAT) and anti-inflammatory cytokines (IL10 & IL22) diminished substantially, in the PC hepatorenal tissues. Both VD regimens alleviated the APAP-induced hepatorenal damages and restored the 25-OH VD levels together with the hepatorenal expression of Cyp2R1, Cyp27b1, Cyp24a1, VDR and VDBP. Additionally, MDA and all the targeted pro-inflammatory cytokines declined, whereas all the anti-oxidative and anti-inflammatory markers increased, in both VD groups hepatorenal tissues and the results were significantly different than the PC group. Although the P-VD anti-inflammatory and anti-oxidative stress actions were more pronounced than the T-VD group, the results remained markedly abnormal than the NC group. In conclusion, this report is the first to reveal that the circulatory VD levels alongside the hepatorenal VD-metabolising enzymes and VDR are pathologically altered following acute APAP toxicity. Moreover, the prophylactic protocol showed better anti-oxidative and anti-inflammatory effects than the therapeutic regimen against APAP-induced hepatorenal injuries.

The remedial effect of Thymus vulgaris extract against lead toxicity-induced oxidative stress, hepatorenal damage, immunosuppression, and hematological disorders in rats

The Thymus vulgaris (T. vulgaris) has been used in foods for the flavor, aroma, and preservation and in folk medicines. The objective of the present work was to determine the antioxidant and protective effects of T. vulgaris extract against lead (Pb)-intoxicated rats. A thirty-two male Sprague-Dawley were randomly assigned into 4 equal groups and treated for six weeks as follows: group I (GP-I), served as negative control; GP-II, -III, and -IV received either Pb acetate in drinking water (500 mg/L), T. vulgaris extract (500 mg/kg/day) by oral gavage or Pb acetate with T. vulgaris extract, respectively. Blood samples were collected at the end of the study week 6 to measure the hepatic and renal biochemical markers, complete blood count alongside the serum levels of interleukin (IL)-1β, IL-6, IL-10, tumor necrosis (TNF)-α, and interferon (IFN)-γ. Additionally, liver and kidney tissue specimens were collected for histopathology as well as to measure the antioxidant-reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) alongside the lipid peroxidation marker, malonaldehyde (MDA). The results indicated that Pb toxicity increased the serum levels of IL-1β, IL-6, and TNF-α, whereas IL-10 and IFN-γ were reduced. The results showed disturbed liver and renal functions; increased serum levels of ALT, AST, ALP, total bilirubin, creatinine, and urea; and decreased total protein, albumin, and calcium. The GSH, Gpx, and CAT levels were significantly decreased in the Pb-administrated group, while MDA was increased. However, regarding the hepatorenal markers, those animals treated with T. vulgaris alone did not induce any significant changes. Moreover, the combined treatment with T. vulgaris extract together with Pb showed significant improvement in Pb-induced toxicity in all the tested parameters compared to the negative control group. We investigated the potential protective effects of the medicinal plant T. vulgaris in vivo, since there are no publications that address the potential protective effect of this leaf extract against Pb-induced hepatorenal toxicity. Our studies concluded that the T. vulgaris extract reduces Pb overload in hepatorenal tissues, and that this has a potential immunomodulatory role, antioxidant activity, and a protective effect against Pb toxicity.