Pharmaceutical Emulsions: A Viable Approach for Ocular Drug Delivery

Ocular disorders can lead to serious sight impairment and irreversible blindness. Generally simple topical and systemic treatments are recommended for treating these vision-threatening illnesses. The distinctive architecture of the eye complicates ocular drug delivery. The ophthalmic emulsion formulations have been found to increase bioavailability in the eye by prolonging residence time and improving permeability through the cornea. Therefore, this study highlights ophthalmic emulsions meant for both the anterior and posterior parts of the eye while examining a wide range of ocular disorders that affect individuals globally. This review presents, in brief, recent emulsion-based patented innovations, clinical trials, and marketed emulsion formulations for ocular drug delivery, which are strengthening development of the new ophthalmic drug products for managing different ocular diseases and disorders.

iNOS regulates hematopoietic stem and progenitor cells via mitochondrial signaling and is critical for bone marrow regeneration

Hematopoietic stem cells (HSCs) replenish blood cells under steady state and on demand, that exhibit therapeutic potential for Bone marrow failures and leukemia. Redox signaling plays key role in immune cells and hematopoiesis. However, the role of reactive nitrogen species in hematopoiesis remains unclear and requires further investigation. We investigated the significance of inducible nitric oxide synthase/ nitric oxide (iNOS/NO) signaling in hematopoietic stem and progenitor cells (HSPCs) and hematopoiesis under steady-state and stress conditions. HSCs contain low levels of NO and iNOS under normal conditions, but these increase upon bone marrow stress. iNOS-deficient mice showed subtle changes in peripheral blood cells but significant alterations in HSPCs, including increased HSCs and multipotent progenitors. Surprisingly, iNOS-deficient mice displayed heightened susceptibility and delayed recovery of blood progeny following 5-Fluorouracil (5-FU) induced hematopoietic stress. Loss of quiescence and increased mitochondrial stress, indicated by elevated MitoSOX and MMPhi HSCs, were observed in iNOS-deficient mice. Furthermore, pharmacological approaches to mitigate mitochondrial stress rescued 5-FU-induced HSC death. Conversely, iNOS-NO signaling was required for demand-driven mitochondrial activity and proliferation during hematopoietic recovery, as iNOS-deficient mice and NO signaling inhibitors exhibit reduced mitochondrial activity. In conclusion, our study challenges the conventional view of iNOS-derived NO as a cytotoxic molecule and highlights its intriguing role in HSPCs. Together, our findings provide insights into the crucial role of the iNOS-NO-mitochondrial axis in regulating HSPCs and hematopoiesis.

Solanum nigrum Toxicity and Its Neuroprotective Effect Against Retinal Ganglion Cell Death Through Modulation of Extracellular Matrix in a Glaucoma Rat Model

Purpose: Glaucoma is a complex degenerative optic neuropathy characterized by loss of retinal ganglion cells (RGCs) leading to irreversible vision loss and blindness. Solanum nigrum has been used for decades in traditional medicine system. However, no extensive studies were reported on its antiglaucoma properties. Therefore, this study was designed to investigate the neuroprotective effects of S. nigrum extract on RGC against glaucoma rat model. Methods: High performance liquid chromatography and liquid chromatography tandem mass spectrometry was used to analyze the phytochemical profile of aqueous extract of S. nigrum (AESN). In vitro, {3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide} (MTT) and H2DCFDA assays were used to determine cell viability and reactive oxygen species (ROS) production in Statens Seruminstitut Rabbit Cornea cells. In vivo, AESN was orally administered to carbomer-induced rats for 4 weeks. Intraocular pressure, antioxidant levels, and electrolytes were determined. Histopathological and immunohistochemical analysis was carried out to evaluate the neurodegeneration of RGC. Results: MTT assay showed AESN exhibited greater cell viability and minimal ROS production at 10 μg/mL. Slit lamp and funduscopy confirmed glaucomatous changes in carbomer-induced rats. Administration of AESN showed minimal peripheral corneal vascularization and restored histopathological alterations such as minimal loss of corneal epithelium and moderate narrowing of the iridocorneal angle. Immunohistochemistry analysis showed increased expression of positive BRN3A cells and decreased matrix metalloproteinase (MMP)-9 activation in retina and cornea, whereas western blot analysis revealed downregulation of extracellular matrix proteins (COL-1 and MMP-9) in AESN-treated rats compared with the diseased group rats. Conclusions: AESN protects RGC loss through remodeling of MMPs and, therefore, can be used for the development of novel neurotherapeutics for the treatment of glaucoma.

Role of angiotensin pathway and its target therapy to rescue from experimental cerebral malaria

Cerebral malaria (CM) induced by Plasmodium falciparum is a devastating neurological complication that may lead the patient to coma and death. This study aimed to protect Plasmodium-infected C57BL6 mice from CM by targeting the angiotensin II type 1 (AT1) receptor, which is considered the common connecting link between hypertension and CM. In CM, AT-1 mediates blood-brain barrier (BBB) damage through the overexpression of β-catenin. The AT-1-inhibiting drugs, such as irbesartan and losartan, were evaluated for the prevention of CM. The effectiveness of these drugs was determined by the down regulation of β-catenin, TCF, LEF, ICAM-1, and VCAM-1 in the drug-treated groups. The expression levels of VE-cadherin and vinculin, essential for the maintenance of BBB integrity, were found to be restored in the drug-treated groups. The pro-inflammatory cytokine levels were decreased, and the anti-inflammatory cytokine levels increased with the treatment. As a major highlight, the mean survival time of treated mice was found to be increased even in the absence of treatment with an anti-malarial agent. The combination of irbesartan or losartan with the anti-malarial agent α/β-arteether has contributed to an 80% cure rate, which is higher than the 60% cure rate observed with α/β-arteether alone treatment.

Cooperative STAT3-NFkB signaling modulates mitochondrial dysfunction and metabolic profiling in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) continues to pose a significant health challenge and is often diagnosed at advanced stages. Metabolic reprogramming is a hallmark of many cancer types, including HCC and it involves alterations in various metabolic or nutrient-sensing pathways within liver cells to facilitate the rapid growth and progression of tumours. However, the role of STAT3-NFκB in metabolic reprogramming is still not clear.

APPROACH AND RESULTS

Diethylnitrosamine (DEN) administered animals showed decreased body weight and elevated level of serum enzymes. Also, Transmission electron microscopy (TEM) analysis revealed ultrastructural alterations. Increased phosphorylated signal transducer and activator of transcription-3 (p-STAT3), phosphorylated nuclear factor kappa B (p-NFκβ), dynamin related protein 1 (Drp-1) and alpha-fetoprotein (AFP) expression enhance the carcinogenicity as revealed in immunohistochemistry (IHC). The enzyme-linked immunosorbent assay (ELISA) concentration of IL-6 was found to be elevated in time dependent manner both in blood serum and liver tissue. Moreover, immunoblot analysis showed increased level of p-STAT3, p-NFκβ and IL-6 stimulated the upregulation of mitophagy proteins such as Drp-1, Phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK-1). Meanwhile, downregulation of Poly [ADP-ribose] polymerase 1 (PARP-1) and cleaved caspase 3 suppresses apoptosis and enhanced expression of AFP supports tumorigenesis. The mRNA level of STAT3 and Drp-1 was also found to be significantly increased. Furthermore, we performed high-field 800 MHz Nuclear Magnetic Resonance (NMR) based tissue and serum metabolomics analysis to identify metabolic signatures associated with the progression of liver cancer. The metabolomics findings revealed aberrant metabolic alterations in liver tissue and serum of 75th and 105th days of intervention groups in comparison to control, 15th and 45th days of intervention groups. Tissue metabolomics analysis revealed the accumulation of succinate in the liver tissue samples, whereas, serum metabolomics analysis revealed significantly decreased circulatory levels of ketone bodies (such as 3-hydroxybutyrate, acetate, acetone, etc.) and membrane metabolites suggesting activated ketolysis in advanced stages of liver cancer.

CONCLUSION

STAT3-NFκβ signaling axis has a significant role in mitochondrial dysfunction and metabolic alterations in the development of HCC.

Unraveling the interplay between vital organelle stress and oxidative stress in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease characterized by excessive accumulation of extracellular matrix, leading to irreversible fibrosis. Emerging evidence suggests that endoplasmic reticulum (ER) stress, mitochondrial stress, and oxidative stress pathways play crucial roles in the pathogenesis of IPF. ER stress occurs when the protein folding capacity of the ER is overwhelmed, triggering the unfolded protein response (UPR) and contributing to protein misfolding and cellular stress in IPF. Concurrently, mitochondrial dysfunction involving dysregulation of key regulators, including PTEN-induced putative kinase 1 (PINK1), Parkin, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and sirtuin 3 (SIRT3), disrupts mitochondrial homeostasis and impairs cellular energy metabolism. This leads to increased reactive oxygen species (ROS) production, release of pro-fibrotic mediators, and activation of fibrotic pathways, exacerbating IPF progression. The UPR-induced ER stress further disrupts mitochondrial metabolism, resulting in altered mitochondrial mechanisms that increase the generation of ROS, resulting in further ER stress, creating a feedback loop that contributes to the progression of IPF. Oxidative stress also plays a pivotal role in IPF, as ROS-mediated activation of TGF-β, NF-κB, and MAPK pathways promotes inflammation and fibrotic responses. This review mainly focuses on the links between ER stress, mitochondrial dysfunctions, and oxidative stress with different signaling pathways involved in IPF. Understanding these mechanisms and targeting key molecules within these pathways may offer promising avenues for intervention.

Imperatorin ameliorates kidney injury in diabetic mice by regulating the TGF-β/Smad2/3 signaling axis, epithelial-to-mesenchymal transition, and renal inflammation

Diabetic nephropathy (DN) is a serious concern in patients with diabetes mellitus. Prolonged hyperglycemia induces oxidative damage, chronic inflammation, and build-up of extracellular matrix (ECM) components in the renal cells, leading to kidney structural and functional changes. Imperatorin (IMP) is a naturally occurring furanocoumarin derivative with proven antioxidative and anti-inflammatory properties. We investigated whether IMP could improve DN and employed high glucose (HG)-induced HK-2 cells and high-fat diet-fed streptozotocin (HFD/STZ)-generated DN experimental model in C57BL/6 mice. In vitro, IMP effectively reduced the HG-activated reactive oxygen species generation, disturbance in the mitochondrial membrane potential (MMP) and epithelial-to-mesenchymal transition (EMT)-related markers, and the transforming growth factor (TGF)-β and collagen 1 expression in HK-2 cells. In vivo, we found an elevation of serum creatinine, kidney histology alterations, and collagen build-up in the kidneys of the DN control group. Also, we found an altered expression of EMT-related markers, upregulation of the TGF-β/Smad2/3 axis, and elevated pro-inflammatory molecules, TNF-α, IL-1β, IL-18 and phospho-NF-kB (p65) in the DN control group. IMP treatment did not significantly reduce the blood glucose level compared to the DN control group. However, IMP treatment effectively improved renal damage by ameliorating kidney histological changes and serum renal injury markers. IMP treatment restored renal antioxidants and exhibited anti-inflammatory effects in the kidneys. Moreover, the abnormal manifestation of EMT-related attributes and elevated levels of TGF-β, phospho-Smad2/3, and collagen 1 were also normalized in the IMP treatment group. Our findings highlight that IMP may be a potential candidate for treating DN.

Mitochondrial-mediated nuclear remodeling and macrophage polarizations: A key switch from liver fibrosis to HCC progression

Liver fibrosis is a significant health burden worldwide and has emerged as the leading cause of Hepatocellular carcinoma (HCC) incidence. Mitochondria are the dynamic organelles that regulate the differentiation, survival, and polarization of macrophages. Nuclear-DNA-associated proteins, micro-RNAs, as well as macrophage polarization are essential for maintaining intracellular and extra-cellular homeostasis in the liver parenchyma. Dysregulated mitochondrial coding genes (ETS complexes I, II, III, IV, and V), non-coding RNAs (mitomiRs), and nuclear alteration lead to the production of reactive oxygen species (ROS) and inflammation which are implicated in the transition of liver fibrosis into HCC. Recent findings indicated the protecting effect of E74-like factor 3/peroxisome proliferator-activated receptor-γ (Elf-3/PPAR-γ). HDAR-y inhibits the deacetylation of PPAR-y and maintains the PPAR-y pathway. Elf-3 plays a tumor suppressive role through epithelial-mesenchymal transition-related gene and zinc finger E-box binding homeobox 2 (ZEB-2) domain. Additionally, the development of HCC includes the PI3K/Akt/mTOR and transforming Growth Factor β (TGF-β) pathway that promotes the Epithelial-mesenchymal transition (EMT) through Smad/Snail/Slug signaling cascade. In contrast, the TLR2/NOX2/autophagy axis promotes M2 polarization in HCC. Thus, a thorough understanding of the mitochondrial and nuclear reciprocal relationship related to macrophage polarization could provide new research opportunities concerning diseases with a significant impact on liver parenchyma towards developing liver fibrosis or liver cancer. Moreover, this knowledge can be used to develop new therapeutic strategies to treat liver diseases.

Surface-Modified Lyotropic Crystalline Nanoconstructs Bearing Doxorubicin and Buparvaquone Target Sigma Receptors through pH-Sensitive Charge Conversion to Improve Breast Cancer Therapy

In the current study, we aimed to develop lyotropic crystalline nanoconstructs (LCNs) based on poly(l-glutamic acid) (PLG) with a two-tier strategy. The first objective was to confer pH-responsive charge conversion properties to facilitate the delivery of both doxorubicin (DOX) and buparvaquone (BPQ) in combination (B + D@LCNs) to harness their synergistic effects. The second goal was to achieve targeted delivery to sigma receptors within the tumor tissues. To achieve this, we designed a pH-responsive charge conversion system using a polymer consisting of poly(ethylenimine), poly(l-lysine), and poly(l-glutamic acid) (PLG), which was then covalently coupled with methoxybenzamide (MBA) for potential sigma receptor targeting. The resulting B + D@LCNs were further modified by surface functionalization with PLG-MBA to confer both sigma receptor targeting and pH-responsive charge conversion properties. Our observations indicated that at physiological pH 7.4, P/B + D-MBA@LCNs exhibited a negative charge, while under acidic conditions (pH 5.5, characteristic of the tumor microenvironment), they acquired a positive charge. The particle size of P/B + D-MBA@LCNs was determined to be 168.23 ± 2.66 nm at pH 7.4 and 201.23 ± 1.46 nm at pH 5.5. The crystalline structure of the LCNs was confirmed through small-angle X-ray scattering (SAXS) diffraction patterns. Receptor-mediated endocytosis, facilitated by P/B + D-MBA@LCNs, was confirmed using confocal laser scanning microscopy and flow cytometry. The P/B + D-MBA@LCNs formulation demonstrated a higher rate of G2/M phase arrest (55.20%) compared to free B + D (37.50%) and induced mitochondrial depolarization (59.39%) to a greater extent than P/B + D@LCNs (45.66%). Pharmacokinetic analysis revealed significantly improved area under the curve (AUC) values for both DOX and BPQ when administered as P/B + D-MBA@LCNs, along with enhanced tumor localization. Tumor regression studies exhibited a substantial reduction in tumor size, with P/B + D-MBA@LCNs leading to 3.2- and 1.27-fold reductions compared to B + D and nontargeted P/B + D@LCNs groups, respectively. In summary, this two-tier strategy demonstrates substantial promise for the delivery of a drug combination through the prototype formulation. It offers a potential chemotherapeutic option by minimizing toxic effects on healthy cells while maximizing therapeutic efficacy.

Longitudinal assessment of bleomycin-induced pulmonary fibrosis by evaluating TGF-β1/Smad2, Nrf2 signaling and metabolomic analysis in mice

INTRODUCTION

Pulmonary fibrosis (PF) is characterized by an increase in collagen synthesis and deposition of extracellular matrix. Several factors, including transforming growth factor-β1 (TGF-β1), mothers against decapentaplegic homolog family proteins (Smad), and alpha-smooth muscle actin (α-SMA) trigger extracellular matrix (ECM) accumulation, fibroblast to myofibroblasts conversion, and epithelial-to-mesenchymal-transition (EMT) leading to PF. However, the role of cellular defense mechanisms such as the role of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling during the onset and progression of PF is not understood completely.

AIM

The present study aims to analyze the involvement of TGF-β1/Smad signaling, and Nrf2 in the EMT and metabolic alterations that promote fibrosis in a time-dependent manner using bleomycin (BLM)-induced PF model in C57BL/6 mice.

KEY FINDINGS

Histopathological studies revealed loss of lung architecture and increased collagen deposition in BLM-exposed mice. BLM upregulated TGF-β1/Smad signaling and α-SMA at all time-points. The gradual increase in the accumulation of α-SMA and collagen implied the progression of PF. BLM exposure raises Nrf2 throughout each specified time-point, which suggests that Nrf2 activation might be responsible for TGF-β1-induced EMT and the development of PF. Further, metabolomic studies linked the development of PF to alterations in metabolic pathways. The pentose phosphate pathway (PPP) was consistently enriched across all the time-points. Additionally, alterations in 22 commonly enriched pathways, associated with fatty acid (FA) and amino acid metabolism were observed in 30- and 60-days.

SIGNIFICANCE

This study elucidates the association of TGF-β1/Smad and Nrf2 signaling in the EMT and metabolic alterations associated with the etiology and progression of PF.

CYP2E1 triggered GRP78/ATF6/CHOP signaling axis inhibit apoptosis and promotes progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide. Cytochrome P450 2E1 (CYP2E1) is an enzyme, primarily involved in the metabolism of xenobiotics and procarcinogens. The present study was designed to investigate the potential role of CYP2E1 triggered endoplasmic reticulum stress in the progression of HCC through inhibition of apoptosis. In vitro CYP2E1 promotes HepG2 cell migration, reduced chromatin condensation, enhanced intracellular ROS accumulation and induce cell cycle progression. Conversely this effect was averted by CYP2E1 siRNA, selective inhibitor Diallyl sulphide (DAS) and antioxidants (vitamin C and E). In vivo Diethylnitrosamine (DEN) induced HCC rats showed decreased body weight and increased relative liver weight. Moreover, macro trabecular-massive HCC (MTM-HCC) histological subtyping showed pathological features like well-differentiated tumors, micro-trabecular and pseudo glandular patterns, megakaryocytes and cholestasis. Masson's trichrome staining revealed an intensive accumulation of collagen fibers in the extracellular matrix (ECM). Increased CYP2E1, VEGF and PCNA enhance the carcinogenicity as revealed in immunohistochemistry results. Immunoblot analysis showed reduced expression of copper-zinc superoxide dismutase (CuZnSOD) and manganese superoxide dismutase (MnSOD) in cytosolic as well as mitochondrial fraction of rat liver tissue respectively. Also, increased level of CYP2E1 stimulated the upregulation of unfolded proteins response (UPR) and ER stress-related proteins such as Glucose regulatory protein 78 (GRP78), activating transcription factor 6 (ATF6) and CCAAT enhancer-binding protein (C/EBP) homologous protein (CHOP). Meanwhile, CYP2E1 stimulated ER-stress reduces BCL2 and downregulates the cleaved caspase 3 thus suppresses apoptosis. in. Furthermore, immunofluorescence revealed increased expression level of α-SMA in the HCC rat liver tissue. The level of CYP2E1 mRNA was significantly increased. Altogether, these findings indicate that CYP2E1 has a dynamic role in the pathogenesis of HCC and might be a budding agent in liver carcinogenesis therapy.

Role of lncRNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the deadliest cancer in human malignancies. It is the most common and severe type of primary liver cancer. However, the molecular mechanisms underlying HCC pathogenesis remain poorly understood. Long non-coding RNAs (lncRNAs), a new kind of RNA and epigenetic factors, play a crucial role in tumorigenesis and the progression of HCC. LncRNAs are capable of promoting the autophagy, proliferation, and migration of tumor cells by targeting and modulating the expression of downstream genes in signaling pathways related to cancer; these transcripts modify the activity and expression of various tumor suppressors and oncogenes. LncRNAs could act as biomarkers for treatment approaches such as immunotherapy, chemotherapy, and surgery to effectively treat HCC patients. Improved knowledge regarding the aetiology of HCC may result from an advanced understanding of lncRNAs. Enhanced oxidative stress in the mitochondrial and Endoplasmic reticulum leads to the activation of unfolded protein response pathway that plays a crucial role in the pathophysiology of hepatocellular carcinoma. The mutual regulation between LncRNAs and Endoplasmic reticulum (ER) stress in cancer and simultaneous activation of the unfolded protein response (UPR) pathway determines the fate of tumor cells in HCC. Mitochondria-associated lncRNAs work as essential components of several gene regulatory networks; abnormal regulation of mitochondria-associated lncRNAs may lead to oncogenesis, which provides further insight into the understanding of tumorigenesis and therapeutic strategies.

Biochanin A Ameliorates Nephropathy in High-Fat Diet/Streptozotocin-Induced Diabetic Rats: Effects on NF-kB/NLRP3 Axis, Pyroptosis, and Fibrosis

Nephropathy is the most prevalent microvascular disorder in diabetes mellitus. Oxidative stress and inflammatory cascade provoked by the persistent hyperglycemic milieu play integral roles in the aggravation of renal injury and fibrosis. We explored the impact of biochanin A (BCA), an isoflavonoid, on the inflammatory response, nod-like receptor protein 3 (NLRP3) inflammasome activation, oxidative stress, and fibrosis in diabetic kidneys. A high-fat-diet/streptozotocin (HFD/STZ)-induced experimental model of diabetic nephropathy (DN) was established in Sprague Dawley rats, and in vitro studies were performed in high-glucose-induced renal tubular epithelial (NRK-52E) cells. Persistent hyperglycemia in diabetic rats was manifested by perturbation of renal function, marked histological alterations, and oxidative and inflammatory renal damage. Therapeutic intervention of BCA mitigated histological changes, improved renal function and antioxidant capacity, and suppressed phosphorylation of nuclear factor-kappa B (NF-κB) and nuclear factor-kappa B inhibitor alpha (IκBα) proteins. Our in vitro data reveal excessive superoxide generation, apoptosis, and altered mitochondrial membrane potential in NRK-52E cells that were cultured in a high-glucose (HG) environment were subsided by BCA intervention. Meanwhile, the upregulated expressions of NLRP3 and its associated proteins, the pyroptosis-indicative protein gasdermin-D (GSDMD) in the kidneys, and HG-stimulated NRK-52E cells were significantly ameliorated by BCA treatment. Additionally, BCA blunted transforming growth factor (TGF)-β/Smad signaling and production of collagen I, collagen III, fibronectin, and alfa-smooth muscle actin (α-SMA) in diabetic kidneys. Our results indicate the plausible role of BCA in attenuating DN, presumably through modulation of the apoptotic cascade in renal tubular epithelial cells and the NF-κB/NLRP3 axis.

CLUH functions as negative regulator of inflammation in human macrophages and determines ulcerative colitis pathogenesis

Altered mitochondrial function without a well-defined cause has been documented in the patients with ulcerative colitis (UC). In our efforts to understand UC pathogenesis, we observed reduced expression of clustered mitochondrial homologue, CLUH, only in the active UC tissues compared to the unaffected areas from the same patient and healthy controls. Stimulation with bacterial toll like receptor (TLR) ligands similarly reduced CLUH expression in the human primary macrophages. Further, CLUH negatively regulated secretion of pro-inflammatory cytokines IL6, TNF-α and rendered a pro-inflammatory niche in the TLR stimulated macrophage. CLUH was further found to bind to mitochondrial fission protein DRP-1 and also regulated DRP-1 transcription in the human macrophages. In the TLR ligand stimulated macrophages, absence of CLUH led to enhanced DRP-1 availability for mitochondrial fission and smaller dysfunctional mitochondrial pool was observed. Mechanistically, this fissioned mitochondrial pool in turn enhanced mitochondrial ROS production, reduced mitophagy and lysosomal function in the CLUH knockout macrophages. Remarkably, our studies in the mice model of colitis with CLUH knockdown displayed exacerbated disease pathology. Taken together, this is the first report signifying the role of CLUH in UC pathogenesis, by means of regulating inflammation via maintaining mitochondrial-lysosomal functions in the human macrophages and intestinal mucosa.

Anti-inflammatory activity of carvacrol protects the heart from lipopolysaccharide-induced cardiac dysfunction by inhibiting pyroptosis via NLRP3/Caspase1/Gasdermin D signaling axis

AIMS

Lipopolysaccharide (LPS) is a well-known agent to induce septic conditions. Sepsis-induced cardiomyopathy has an overwhelming death rate. Carvacrol (CVL), a monoterpene phenol, has anti-inflammatory and antioxidant properties. The research aimed to investigate the effect of CVL on LPS-induced dysfunction in the heart. In this study, we evaluated the effect of CVL in LPS-stimulated H9c2 cardiomyoblast cells and Balb/c mice.

MAIN METHODS

LPS was used to induce septic conditions in H9c2 cardiomyoblast cells in vitro and in Balb/C mice. A survival study was conducted to assess the survival rate of mice after LPS and/or CVL treatment.

KEY FINDINGS

In vitro studies indicated that CVL inhibits reactive oxygen species (ROS) generation and abates pyroptosis mediated by NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in H9c2 cells. In mice, CVL intervention improved the survival rate in septic conditions. The CVL administration markedly improved the echocardiographic parameters and alleviated the LPS-induced reduction in the ejection fraction (%) and fraction shortening (%). The CVL intervention restored the myocardial antioxidants and histopathological alterations and decreased the pro-inflammatory cytokine contents in the heart. Further findings disclosed that CVL reduced the protein levels of NLRP3, apoptosis-associated speck-like protein (ASC), caspase 1, interleukin (IL)-18, IL-1β, and the pyroptosis-indicative protein, gasdermin-D (GSDMD) in the heart. The autophagy-indicative proteins, beclin 1, and p62, in the heart were also restored in the CVL-treated group.

SIGNIFICANCE

Altogether, our findings demonstrated that CVL has a beneficial effect and can be a potential molecule against sepsis-induced myocardial dysfunction.

Synergistic delivery of Imatinib through multifunctional nano-crystalline capsules, in response to redox environment for improved breast cancer therapy

Chondroitin anchored crystalline nano-capsules bearing Imatinib (IMT), and simvastatin (SMV) was developed using Poly (L-lactic acid) (PLLA) by two-step method, i.e., firstly, by synthesizing chondroitin (CSA) anchored simvastatin (SMV) using cystamine as a spacer (SMV-SS-CSA) for disulfide triggered glutathione (GSH) sensitive release and secondly, by developing phenyl boronic ester grafted Pluronic F68 (PEPF) for H₂O₂ responsive release. By combining these conjugates, we have prepared crystalline nano-capsules (CNs) for preferential targeting of CD44 receptors. The developed CNs were spherical when characterized through SEM, TEM, and AFM for surface morphology, while changes in particle size and crystalline structure were confirmed through Quasi-Elastic light scattering (QELS) and Wide Angle X-ray Scattering (WAXS). The enhanced cellular uptake was noted in chondroitin-modified nano-capsules IMT/SMV-SS-CSA@CNs compared to unmodified nano-capsules IMT+SMV@CNs. IMT/SMV-SS-CSA@CNs displayed significantly higher G2/M phase arrest (76.9%) than unmodified nano-capsules. The prototype formulation (IMT/SMV-SS-CSA@CNs) showed an overall improved pharmacokinetic profile in terms of both half-life and AUC_0-α. When tested in the 4T1 subcutaneously injected tumor-bearing Balb/c mice model, the tumor growth inhibition rate of IMT/SMV-SS-CSA@CNs was significantly higher (91%) than the IMT+SMV combination. Overall, the findings suggest that the proposed dual responsive chondroitin-modified drug delivery could have a step forward in achieving spatial and temporal targeting at the tumor site.

Alternanthera brasiliana L. extract alleviates carbon tetrachloride-induced liver injury and fibrotic changes in mice: Role of matrix metalloproteinases and TGF-β/Smad axis

ETHNOPHARMACOLOGICAL RELEVANCE

Alternanthera brasiliana L. is a flowering plant belonging to the family Amaranthaceae and is popularly known as "penicillin". It is used in folk medicine to treat infections, coughs, wound healing, and inflammatory diseases.

AIM OF THE STUDY

We investigated the effect of Alternanthera brasiliana L. leaves hydroalcoholic extract (AB) against oxidative stress, inflammation, and fibrotic changes in an experimental model of carbon tetrachloride (CCl₄)-induced liver injury and fibrosis in mice.

MATERIALS AND METHODS

Thirty-six male Balb/C mice were randomized into five groups: normal control, AB control, CCl₄ control, CCl₄ + AB-200 mg/kg, and CCl₄ + AB-400 mg/kg. In mice, liver injury was induced by intraperitoneal injection of CCl₄ (20% in corn oil, 5 ml/kg body weight) thrice a week for six consecutive weeks. AB extract at two doses (200 mg/kg and 400 mg/kg body weight) was administered orally for six consecutive weeks. Liver injury-related serum markers (ALT, AST, ALP), antioxidants (GSH, GST, SOD, and vitamin C), pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-18, ultrasonographic and histological alterations, proteins of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinase-1 (TIMP-1), nuclear factor-κB (p65) (NF-κB), nod-like receptor protein 3 (NLRP3), and TGF-β/Smad signaling were accessed. LC-Q-TOF-MS/MS analysis of AB was performed.

RESULTS

AB treatment significantly decreased the CCl₄-induced rise in serum ALT, AST, and ALP activities and improved the histological alterations. Compared with the CCl₄-treated group, treatment with AB significantly restored the hepatic antioxidants and reduced the pro-inflammatory cytokines in the liver. The antioxidant activity of AB may be attributed to its terpenoid constituents, which was confirmed by LC-Q-TOF-MS/MS analysis. The CCl₄-induced rise in expression of MMP-2 and MMP-9 and decrease in TIMP-1 were markedly restored in the AB-treated groups. Further findings revealed a significant reduction in the protein levels of phospho-NF-κB (p65), NLRP3, TGF-β, pSmad2/3, collagen I, and α-smooth muscle actin (α-SMA) in the AB treatment groups.

CONCLUSIONS

The hepatoprotective effect of AB may be attributed to the high content of terpenoid compounds and alleviates liver injury and associated fibrotic changes through modulating MMPs, NF-κB (p65), and the TGF-β/Smad axis.

Nuciferine alleviates intestinal inflammation by inhibiting MAPK/NF-κB and NLRP3/Caspase 1 pathways in vivo and in vitro

Nuciferine (NCF) is an aporphine alkaloid and a principal bioactive constituent in the lotus plant. Herewith, we investigated the potential anti-inflammatory effect and underlying mechanisms of NCF employing dextran sulfate sodium (DSS)-induced ulcerative colitis in mice, a predominant intestinal inflammatory disease, and mouse RAW 264.7 cells in vitro. Lipopolysaccharide (LPS) was used to generate an inflammatory response in the RAW 264.7 cells. The disease activity index (DAI), colon morphology, colonoscopy, and colon histopathology were performed to assess experimental colitis. The biochemical assays, enzyme-linked immunosorbent assay (ELISA), and immunoblot analysis were performed to understand the underlying mechanisms. In RAW 264.7 cells, NCF pretreatment significantly decreased the expression of inducible nitric oxide synthase (iNOS), the expression and release of pro-inflammatory cytokines including interleukin (IL)-1β, IL-18, and tumor necrosis factor-α (TNF-α) and interfered with the activation of mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), and NOD-like family pyrin domain containing 3 (NLRP3) signaling pathways. The oral treatment of NCF substantially alleviated the DSS-induced DAI, increased colon length, and restored colon morphology and histology. Compared to the DSS-induced mice, the proteins involved in the activation of MAPK/NF-κB/NLRP3 pathways and the cytokines were markedly decreased in the NCF-treated mice. Moreover, the tight junction architecture of the colon was well-maintained in NCF treatment groups by regulating the expression of claudin-1 and zonula occludens-1 (ZO-1) proteins. All these findings suggest that NCF can be a promising molecule to modulate ulcerative colitis.

Carvacrol preserves antioxidant status and attenuates kidney fibrosis via modulation of TGF-β1/Smad signaling and inflammation

Chronic kidney disease (CKD) with diverse aetiologies is emerging as a challenging kidney disorder associated with inflammation and interstitial fibrosis. Carvacrol (CVL) is a bioactive monoterpenoid found abundantly in oregano, thyme, and bergamot, having diverse pharmacological benefits. However, the effect of CVL against fibrotic changes in the kidneys is poorly defined. In the current study, a robust mouse model of renal fibrosis induced through unilateral ureteral obstruction (UUO) is used to investigate the anti-fibrotic activity of CVL. The mice were treated with two different oral doses of CVL (25 mg kg^-1 and 50 mg kg^-1 body weight) for 14 consecutive days. The UUO induction resulted in impaired renal function, severe histological damage, and collagen deposition in the obstructed kidney. Our findings revealed profound activation of transforming growth factor-β1 (TGF-β1) and NF-κB (p65) signaling along with the downregulation of antioxidant proteins, nuclear factor-erythroid factor 2-related factor 2 (Nrf2), NAD(P)H: quinone oxidoreductase 1 (NQO1), and superoxide dismutase (SOD) in the obstructed kidney. CVL administration markedly recovered antioxidant proteins and kidney histological changes. In addition, CVL blunted the NF-κB (p65) phosphorylation and reduced the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and cyclooxygenase 2 (COX-2) compared to the UUO control group. CVL also alleviated the increased fibrotic protein levels of TGF-β1, pSmad2/3, collagen I, collagen III, fibronectin, and myofibroblast activation and epithelial-mesenchymal transition (EMT) markers, including alpha-smooth muscle actin (α-SMA), E-cadherin, and vimentin in the kidneys. Findings from in vitro study also confirmed that CVL inhibits the EMT process in TGF-β1 stimulated renal tubular epithelial cells (NRK 52E cells). Collectively, our findings indicate that CVL administration attenuates kidney fibrosis by targeting oxidative stress and inflammation.

Redoxisome and diabetic retinopathy: Pathophysiology and therapeutic interventions

Diabetic retinopathy (DR) is a chronic microvascular complication of diabetes mellitus (DM). It is a worldwide growing epidemic disease considered to be the leading cause of vision-loss and blindness in people with DM. Redox reactions occurring at the extra- and intracellular levels are essential for the maintenance of cellular homeostasis. Dysregulation of redox homeostasis are implicated in the onset and development of DR. Thioredoxin1 (TRX1) and Thioredoxin2 (TRX2) are cytoplasmic and mitochondrially localized antioxidant proteins ubiquitously expressed in various cells and control cellular reactive oxygen species (ROS) by reducing the disulfides into thiol groups. Thioredoxin-interacting protein (TXNIP) binds to TRX system and inhibits the active reduced form of TRX through disulfide exchange reaction. Recent studies indicate the association of TRX/TXNIP with redox signal transduction pathways including activation of Nod-like receptor pyrin domain containing protein-3 (NLRP3) inflammasome, apoptosis, autophagy/mitophagy, epigenetic modifications in a redox-dependent manner. Thus, it is important to gain a more in-depth understanding about the cellular and molecular mechanisms that links redoxisome and ER/Mitochondrial dysfunction to drive the progression of DR. The purpose of this review is to provide a mechanistic understanding of the complex molecular mechanisms and pathophysiological roles associated with redoxisome, the TRX/TXNIP redox signaling complex under oxidative stress in the development of DR. Also, the molecular targets of FDA approved drugs and clinical trials in addition to effective antioxidant strategies for the treatment of diabetic retinopathy are reviewed.

Up-regulation of Nrf2/HO-1 and inhibition of TGF-β1/Smad2/3 signaling axis by daphnetin alleviates transverse aortic constriction-induced cardiac remodeling in mice

Oxidative damage and accumulation of extracellular matrix (ECM) components play a crucial role in the adverse outcome of cardiac hypertrophy. Evidence suggests that nuclear factor erythroid-derived factor 2 related factor 2 (Nrf2) can modulate oxidative damage and adverse myocardial remodeling. Daphnetin (Daph) is a coumarin obtained from the plant genus Daphne species that exerts anti-oxidative and anti-inflammatory properties. Herein, we investigated the roles of Daph in transverse aortic constriction (TAC)-induced cardiac hypertrophy and fibrosis in mice. TAC-induced alterations in cardiac hypertrophy markers, histopathological changes, and cardiac function were markedly ameliorated by oral administration of Daph in mice. We found that Daph significantly reduced the reactive oxygen species (ROS) generation, increased the nuclear translocation of Nrf2, and consequently, reinstated the protein levels of NAD(P)H quinone dehydrogenase1 (NQO1), heme oxygenase-1 (HO-1), and other antioxidants in the heart. Besides, Daph significantly inhibited the TAC-induced accumulation of ECM components, including α-smooth muscle actin (α-SMA), collagen I, collagen III, and fibronectin, and interfered with the TGF-β1/Smad2/3 signaling axis. Further studies revealed that TAC-induced terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive nuclei and the protein levels of Bax/Bcl2 ratio and cleaved caspase 3 were substantially decreased by Daph treatment. We further characterized the effect of Daph on angiotensin II (Ang-II)-stimulated H9c2 cardiomyoblast cells and observed that Daph markedly decreased the Ang-II induced increase in cell size, production of ROS, and proteins associated with apoptosis and fibrosis. Mechanistically, Daph alone treatment enhanced the protein levels of Nrf2, NQO1, and HO-1 in H9c2 cells. The inhibition of this axis by Si-Nrf2 transfection abolished the protective effect of Daph in H9c2 cells. Taken together, Daph effectively counteracted the TAC-induced cardiac hypertrophy and fibrosis by improving the Nrf2/HO-1 axis and inhibiting the TGF-β1/Smad2/3 signaling axis.

Biochanin A alleviates unilateral ureteral obstruction-induced renal interstitial fibrosis and inflammation by inhibiting the TGF-β1/Smad2/3 and NF-kB/NLRP3 signaling axis in mice

AIMS

Tubulointerstitial fibrosis, a frequent complication of chronic kidney disease (CKD) is a major public health issue. Biochanin A (BCA), an isoflavone, has numerous pharmacological activities. However, its effect on renal fibrosis and underlying molecular mechanism has not yet been clarified. This study explored the effect of BCA on renal tubulointerstitial fibrosis and inflammation in mice.

MAIN METHODS

The mouse model of unilateral ureteral obstruction (UUO) in vivo and transforming growth factor (TGF)-β1 activated renal fibroblast (NRK 49F) cells in vitro model were used to assess the antifibrotic effect of BCA. Biochemical analysis, histopathology, western blotting, and immunofluorescent staining methods were performed to elucidate the mechanism of BCA.

KEY FINDINGS

In vitro, BCA suppressed the expression of fibrogenic proteins in TGF-β1-activated renal fibroblasts. The treatment with BCA displayed less tubular injury, prevented the aberrant accumulation of extracellular matrix (ECM) components, and inhibited the TGF-β1/Smad2/3 signaling axis in the kidneys. Furthermore, BCA impeded the phosphorylation of NF-kB(p65) and blunted the expression of inflammatory genes in the obstructed kidneys. The UUO induced expressions of nod-like receptor protein 3 (NLRP3), active caspase 1, interleukin(IL)-18, and IL-1β proteins were decreased in the BCA treated groups. We also found the increased expression of redox-sensitive nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) proteins in BCA treated groups compared to the UUO control.

SIGNIFICANCE

These findings indicate that BCA has a therapeutic benefit against renal fibrosis, and the ameliorative effect is mediated via inhibiting the TGF-β1/Smad2/3 and NF-kB/NLRP3 signaling axis.

Assessment of antidiabetic effect of 4-HIL in type 2 diabetic and healthy Sprague Dawley rats

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by chronic hyperglycemia and insulin resistance. 4-hydroxyisoleucine (4-HIL) is a non-proteinogenic amino acid isolated from the fenugreek seeds and has enormous pharmacological activities. The present study was undertaken to investigate the antihyperglycemic effect of 4-HIL in streptozotocin (STZ)-induced diabetic rats. Moreover, its toxicity was evaluated in vitro and in vivo employing human embryonic kidney cells (HEK-293) and healthy rats, respectively. In experiment 1, STZ-induced diabetic male rats were subjected to an oral treatment of 4-HIL (100 mg/kg), while experiment 2 deals with the effects of 4-HIL on healthy male and female rats following oral administration. The treatment (experiment 1) declined the elevated blood glucose level, feed intake, and increased body weight(s). Additionally, blood glucose impairment was improved as observed by OGTT and IPGT tests. Pancreatic histopathology revealed mild changes in the 4-HIL group. Moreover, experiment 2 showed increased body weight, normal blood glucose levels (male—106.06 ± 7.49 mg/dl and female—100.06 ± 14.69 mg/dL), hematological parameters, and histopathological profiles in the treatment group. 4-HIL did not affect the viability of HEK-293 cells, and no signs of toxicity were observed in healthy rats. Therefore, the study concludes that 4-HIL has potential antihyperglycemic activity without any toxic effects.

Aloin alleviates pathological cardiac hypertrophy via modulation of the oxidative and fibrotic response

AIMS

Pathological cardiac hypertrophy is a characteristic feature in many cardiovascular diseases (CVDs). Aloin is an anthraquinone glycoside from Aloe species, and the effect of aloin on cardiac hypertrophy and associated fibrotic changes have not been elucidated. This study investigated the effect of aloin against the isoproterenol (ISO)-induced cardiac hypertrophy in rats.

MAIN METHODS

Cardiac hypertrophy experimental model was induced in rats by subcutaneous injection of ISO for 14 days. Meanwhile, the animals were administered orally with aloin at doses of 25 and 50 mg/kg/day. On the 15th day, cardiac echocardiography was performed, the heart was collected and subjected for histopathological, gene expression, and immunoblot studies. Additionally, the effect of aloin on ISO-induced hypertrophic changes in H9c2 cells was investigated.

KEY FINDINGS

Aloin markedly alleviated ISO-induced heart injury, reduced cardiac hypertrophy, improved cardiac function, and histological alterations in the heart. Mechanistically, aloin attenuated ISO-induced fibrosis via inhibition of the levels of collagen I, α-smooth muscle actin (α-SMA), fibronectin, transforming growth factor-β (TGF-β) and pSmad2/3 proteins in the heart. Aloin alleviated ISO-induced myocardial oxidative damage and up-regulated the levels of antioxidant transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) proteins. Moreover, aloin treatment attenuated ISO-induced hypertrophic changes and the generation of reactive oxygen species (ROS) in H9c2 cells in vitro.

SIGNIFICANCE

Our findings demonstrated that aloin alleviated ISO-induced cardiac hypertrophy and fibrosis via inhibiting TGF-β/pSmad2/3 signaling and restoring myocardial antioxidants, and therefore has promising therapeutic potential against cardiac hypertrophy and fibrosis.

Regulatory safety pharmacology and toxicity assessments of a standardized stem extract of Cassia occidentalis Linn. in rodents

Cassia occidentalis Linn (CO) is an annual/perennial plant having traditional uses in the treatments of ringworm, gastrointestinal ailments and piles, bone fracture, and wound healing. Previously, we confirmed the medicinal use of the stem extract (ethanolic) of CO (henceforth CSE) in fracture healing at 250 mg/kg dose in rats and described an osteogenic mode of action of four phytochemicals present in CSE. Here we studied CSE's preclinical safety and toxicity. CSE prepared as per regulations of Current Good Manufacturing Practice for human pharmaceuticals/phytopharmaceuticals and all studies were performed in rodents in a GLP-accredited facility. In acute dose toxicity as per New Drug and Clinical Trial Rules, 2019 (prior name schedule Y), in rats and mice and ten-day dose range-finding study in rats, CSE showed no mortality and no gross abnormality at 2500 mg/kg dose. Safety Pharmacology showed no adverse effect on central nervous system, cardiovascular system, and respiratory system at 2500 mg/kg dose. CSE was not mutagenic in the Ames test and did not cause clastogenicity assessed by in vivo bone marrow genotoxicity assay. By a sub chronic (90 days) repeated dose (as per OECD, 408 guideline) study in rats, the no-observed-adverse-effect-level was found to be 2500 mg/kg assessed by clinico-biochemistry and all organs histopathology. We conclude that CSE is safe up to 10X the dose required for its osteogenic effect.

Insights from a Pan India Sero-Epidemiological survey (Phenome-India Cohort) for SARS-CoV2

To understand the spread of SARS-CoV2, in August and September 2020, the Council of Scientific and Industrial Research (India) conducted a serosurvey across its constituent laboratories and centers across India. Of 10,427 volunteers, 1058 (10.14%) tested positive for SARS-CoV2 anti-nucleocapsid (anti-NC) antibodies, 95% of which had surrogate neutralization activity. Three-fourth of these recalled no symptoms. Repeat serology tests at 3 (n = 607) and 6 (n = 175) months showed stable anti-NC antibodies but declining neutralization activity. Local seropositivity was higher in densely populated cities and was inversely correlated with a 30-day change in regional test positivity rates (TPRs). Regional seropositivity above 10% was associated with declining TPR. Personal factors associated with higher odds of seropositivity were high-exposure work (odds ratio, 95% confidence interval, p value: 2.23, 1.92-2.59, <0.0001), use of public transport (1.79, 1.43-2.24, <0.0001), not smoking (1.52, 1.16-1.99, 0.0257), non-vegetarian diet (1.67, 1.41-1.99, <0.0001), and B blood group (1.36, 1.15-1.61, 0.001).

In Vitro: Cytotoxicity, Apoptosis and Ameliorative Potential of Lawsonia inermis Extract in Human Lung, Colon and Liver Cancer Cell Line

Cancer has emerged as a major public health issue in developed as well as in developing countries. Plant-derived molecules are widely being used in the treatment of cancer due to their minimum side effects. Lawsonia inermis (Henna) is one of the medicinal plants containing many therapeutic properties. In the present study, bioactive components of L. inermis extract were analyzed by LCMS/MS method and validated. Lawsone (3.5%) is primarily responsible for cytotoxic and anti-cancerous activities. These properties were studied on human lung carcinoma (A549), colorectal cancer (DLD1) and Hepatocellular carcinoma (HepG2) cancer cell lines. The activities were assessed by MTT assay, evaluation of apoptosis by measuring the production of Reactive Oxygen Species (ROS) and mitochondrial membrane potential of the cancer cell lines. Moreover, apoptosis in the respective cancer cell lines was also determined by chromatin condensation and DNA fragmentation using Hoechst 33528 and propidium iodide (PI) staining. The preliminary in vitro result of MTT showed that the henna extract induces cytotoxic properties against A549, DLD1, HepG2 with IC₅₀values 490, 480 and 610 μg/ml respectively (more than 40% growth inhibition). In addition, the extract induced a concentration-dependent rise in ROS production which was 84, 102, and 110% in HepG2, DLD1 AND A549 respectively at 300 μg/ml, whereas at 400 μg/ml concentration it was 86, 102, and 106% in respective cell lines while decreasing mitochondrial membrane potential was more than 20% in the investigated cell lines. The extract also provoked changes associated with apoptosis and the data indicate that the ROS production leads to a diminution in mitochondrial membrane potential and this correlated with the extract cytotoxicity.

Safety assessment of the pharmacological excipient, diethylene glycol monoethyl ether (DEGEE), using in vitro and in vivo systems

BACKGROUND

Diethylene glycol monoethyl ether (DEGEE) is widely used as a solubilizer in cosmetics as well as in oral, topical, transdermal and injectable pharmaceutical formulations. Due to the unavailability of detailed toxicological studies on DEGEE, the Scientific Committee on Consumer Products (SCCP) found its toxicological reports to be unsatisfactory, comprising only summaries. Also, a few reports have raised concern on the use of DEGEE as it might cause damage to the kidneys.

OBJECTIVE

Safety assessment of DEGEE using in vitro and in vivo models.

METHODS

In vitro effects of DEGEE (0.5-25 mg/ml) were assessed in the HEK293 human embryonic kidney cells. In vivo effects were evaluated after single acute exposure of DEGEE via intraperitoneal route in Swiss albino mice and further, a 28 days subchronic exposure study was conducted where DEGEE was administered orally, once daily.

RESULTS

DEGEE was cytotoxic to HEK293 cells, and an IC₅₀ of 15 mg/ml was established. An increase in the intracellular levels of ROS and alteration in the mitochondrial membrane potential led to nuclear fragmentation and induction of apoptosis in these cells. Survival rate of animals administered intraperitoneally with a single acute dose of 1000 mg/kg DEGEE was 100% with no significant changes in the behavioural and histological parameters. However, the dose of 3000 mg/kg and above led to total mortality within 14 days of acute exposure. Subchronic oral exposure of 500-2000 mg/kg DEGEE showed no significant changes in the hematological, biochemical and histopathological parameters.

CONCLUSIONS

The in vitro findings indicate that the nephrotoxic potential of DEGEE cannot be ruled out. The results of the in vivo studies reveal that the degree of toxic effects shown by DEGEE varies, depending on the dose, duration of exposure and routes of administration. Therefore, the present findings are of relevance and thorough studies should be conducted before using this substance in clinical formulations. Graphical abstract Evaluation of the toxic potential of Diethylene glycol monoethyl ether.