Modulation of Metabolic Pathways and Protection against Cadmium-Induced Disruptions with Taxifolin-Enriched Extract

Abstract

Cadmium, a ubiquitous environmental pollutant, has been implicated in the disruption of various metabolic pathways, contributing to the development of insulin resistance, glucose intolerance, and associated metabolic disorders. This study aimed to investigate the cadmium chloride (CdCl₂) exposure on metabolic pathways and to assess the potential therapeutic efficacy of the taxifolin-enriched extract in mitigating these disruptions by modulating biochemical pathways. Taxifolin-enriched extract (TEE) was prepared from Pinus roxburghii bark using a green extraction method. About 60 Wistar albino rats were divided into six groups: the control group (n = 10), the CdCl₂ group (30 mg/kg) (n = 10), and four groups (each comprises n = 10) treated with 30 mg/kg CdCl₂ in combination with metformin (100 mg/kg), ascorbic acid, taxifolin (30 mg/kg), and TEE (30 mg/kg), respectively. After the treatment period of 1 month, a comprehensive assessment of metabolic biomarkers and gene expressions that regulate the metabolism of carbohydrates and lipids was conducted to evaluate the impact of CdCl₂ exposure and the potential protective effects of TEE. The results revealed that CdCl₂ exposure significantly increased (P < 0.001) serum levels of α-glucosidase, α-amylase, insulin, G6PC, hexokinases, TGs, LDL, HMG-CoA reductase, and pro-inflammatory cytokines such as IL-6 and TNF-α. Conversely, CdCl₂ exposure led to a reduction in HDL, antioxidant enzyme levels, phosphofructokinases, and glucose-6-phosphatase dehydrogenase. However, the administration of TEE alongside CdCl₂ substantially mitigated (P < 0.001) these fluctuations in metabolic and inflammatory biomarker levels induced by CdCl₂ exposure. Both TEE and taxifolin treatment effectively lowered the elevated levels of α-amylase, α-glucosidase, G6PC, insulin, TGs, HMG-CoA reductase, leptin, ALT, AST, blood urea nitrogen, creatinine, and pro-inflammatory cytokines while simultaneously enhancing levels of HDL cholesterol and antioxidant enzymes. Moreover, CdCl₂ exposure suppressed mRNA expression of critical metabolic biomarkers such as glucose transporter 2 (GLUT2), insulin-like growth factor 1 (IGF-1), lactate dehydrogenase, and HMG-CoA lyases while upregulating the mRNA expression of angiotensin receptor 2 and vasopressin, key metabolic biomarkers involved in glucose metabolism and insulin regulation. TEE demonstrated the potential to restore normal metabolic functions and reduce the adverse impacts caused by CdCl₂ exposure by mitigating disturbances in several metabolic pathways and restoring gene expression of critical metabolic biomarkers related to glucose metabolism and insulin regulation. Nevertheless, further investigation is warranted to comprehensively understand the underlying mechanisms and optimize the appropriate dosage and duration of TEE treatment for achieving the most effective therapeutic outcomes.