Background: A significant side effect of type 2 diabetes mellitus is diabetic nephropathy (DN), which is typified by poor glucose homeostasis and insulin resistance in renal tissues. Thymoquinone (TQ), the active ingredient in Nigella sativa (NS), has been shown to have antioxidant and antidiabetic properties. However, nothing is known about their relative effects on renal glucose metabolism in hyperglycemic situations. The objective of this work was to examine and contrast the regulatory effects of NS and TQ on insulin signaling pathways and glucose transporter expression in NRK-52E renal epithelial cells grown in high-glucose environments. 
 
Methods: TQ (10 &micro;M) or NS extract (0.5 &micro;g/ml) were applied to NRK-52E cells after they were subjected to high glucose (246 mM). RT-qPCR was used to measure the mRNA expression levels of insulin signaling components (Ir, Irs1, Pi3k, Ampk, Gsk3&beta;) and glucose transporters (Glut1, Glut2, Glut3, Glut5, Sglt2). Western blot was used to measure the protein levels of Glut2, Glut3, Sglt2 and Irs1. The Duncan test (p&lt;0.05) and one-way ANOVA were used to determine statistical significance. 
 
Result: Ir, Irs1, Pi3k and Ampk levels were downregulated and Glut1, Glut2, Glut3 and Sglt2 expression was markedly elevated by high glucose exposure. These changes were reversed by TQ and NS therapy, with TQ having a stronger effect. TQ increased the levels of Irs1 and Pi3k while more successfully suppressing the expression of Sglt2 and Glut2. The transcriptional alterations were confirmed by Western blot results. TQ and NS improved insulin signaling pathways and modulated glucose transporter expression to protect renal cells. These results confirm that TQ and NS are safe to use as possible therapeutic agents to treat diabetic nephropathy. 
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Comparative Effects of Nigella sativa and Thymoquinone on Glucose Metabolism in a High Glucose-induced Renal Cell Line

Background: This study investigates the antimicrobial and antioxidant potential of thymoquinone (TQ) rich Nigella sativa L. seed oil (NSO) extracted using supercritical carbon dioxide extraction (SCFE-CO2). 
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Methods: N. sativa seeds were ground, sieved (Mesh No. 24) and subjected to SCFE using CO2&nbsp;at extraction conditions 40oC, 20 MPa and 0.71 x 10-3 m particle size. The extracted oil was characterized for thymoquinone (TQ) content using GC-MS/MS and microstructural differences between raw and defatted seeds post-extraction using Scanning Electron Microscopy (SEM) analysis at 1 KX magnification. Antibacterial efficacy was assessed against five pathogenic strains (Listeria monocytogenes ATCC 13932, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, Vibrio parahaemolyticus ATCC 17802 and Pseudomonas aeruginosa ATCC 9027) using the disc diffusion method, while antioxidant activity was evaluated using the DPPH radical scavenging assay. 
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Result: The extracted oil yielded 18.8% (w/w) with a TQ content of 3.62%. The microstructural matrix of defatted seeds confirmed the effective extraction of oil and its bioactives, showing a lesser oil fraction residue. Zones of inhibition (mm) at 100 &micro;L and 200 &micro;L for Listeria monocytogenes were 13&plusmn;0.09 and 15.3&plusmn;0.05; for Staphylococcus aureus, 10&plusmn;0.20 and 13.3&plusmn;0.06; for Escherichia coli, 12&plusmn;0.15 and 16.6&plusmn;0.12; for Vibrio parahaemolyticus, 10&plusmn;0.32 and 15&plusmn;0.08; for Pseudomonas aeruginosa, 14&plusmn;0.10 and 18.2&plusmn;0.07. NSO exhibited strong antioxidant activity, with 96.76% radical scavenging activity (RSA).

Comparative Effects of Nigella sativa and Thymoquinone on Glucose Metabolism in a High Glucose-induced Renal Cell Line

Assessment of Antimicrobial and Antioxidant Efficacy of SCFE-CO2 Extracted Nigella sativa L. Seed Oil

Assessment of Antimicrobial and Antioxidant Efficacy of SCFE-CO₂ Extracted Nigella sativa L. Seed Oil