Cardioprotective Effect of Rheum turkestanicum Against Doxorubicin-Induced Toxicity in Rats

Mechanisms underlying dose-limiting toxicities of conventional chemotherapeutic agents

Dose-limiting toxicities (DLTs) are severe adverse effects that define the maximum tolerated dose of a cancer drug. In addition to the specific mechanisms of each drug, common contributing factors include inflammation, apoptosis, ion imbalances, and tissue-specific enzyme deficiencies. Among various DLTs are bleomycin-induced pulmonary fibrosis, doxorubicin-induced cardiomyopathy, cisplatin-induced nephrotoxicity, methotrexate-induced hepatotoxicity, vincristine-induced neurotoxicity, paclitaxel-induced peripheral neuropathy, and irinotecan, which elicits severe diarrhea. Currently, specific treatments beyond dose reduction are lacking for most toxicities. Further research on cellular and molecular pathways is imperative to improve their management. This review synthesizes preclinical and clinical data on the pharmacological mechanisms underlying DLTs and explores possible treatment approaches. A comprehensive perspective reveals knowledge gaps and emphasizes the need for future studies to develop more targeted strategies for mitigating these dose-dependent adverse effects. This could allow the safer administration of fully efficacious doses to maximize patient survival.

Cardioprotective effect of Sanguisorba minor against isoprenaline-induced myocardial infarction in rats

Introduction: Oxidative stress is a major instigator of various cardiovascular diseases, including myocardial infarction (MI). Despite available drugs, there is still an increased need to look for alternative therapies or identify new bioactive compounds. Sanguisorba minor (S. minor) is a native herb characterized by its potent antioxidant activity. This study was designed to evaluate the effect of S. minor against isoprenaline-induced MI. Methods: Rats were treated with the hydro-ethanolic extract of the aerial parts of S. minor at doses of 100 or 300 mg/kg orally for 9 days. Isoprenaline was injected subcutaneously at the dose of 85 mg/kg on days 8 and 9. Then, the activities of various cardiac injury markers including cardiac troponin (cTnT), lactate dehydrogenase (LDH), creatinine kinase muscle brain (CK-MB), creatinine phosphokinase (CPK), and antioxidant enzymes in serum were determined. Malondialdehyde (MDA) and thiol content were measured in cardiac tissue, and histopathological analysis was conducted. Results: Our results show that isoprenaline increased the serum levels of cTnT, LDH, CK-MB, and CPK (p < 0.001) and elevated MDA levels (p < 0.001) in cardiac tissue. Isoprenaline also reduced superoxide dismutase (SOD), catalase, and thiol content (p < 0.001). Importantly, the extract abolished isoprenaline-induced MI by elevating SOD and catalase (p < 0.001), reducing levels of MDA, and diminishing levels of cTnT, LDH, CK-MB, and CPK cardiac markers (p < 0.001). Histopathological studies of the cardiac tissue showed isoprenaline-induced injury that was significantly attenuated by the extract. Conclusion: Our results suggest that S. minor could abrogate isoprenaline-induced cardiac toxicity due to its ability to mitigate oxidative stress.

Utilization of Quince (Cydonia oblonga) Peel and Exploration of Its Metabolite Profiling and Cardioprotective Potential Against Doxorubicin-Induced Cardiotoxicity in Wistar Rats

Quince (Cydonia oblonga Mill.) is a pomaceous fruit that is typically processed into jams, jellies, and marmalade. The byproduct, i.e., the quince peel emanated from the processing industry, can be upcycled, ensuring zero waste policy and resulting in a sustainable food system. In our study, the quince peel was explored for in vitro phytochemical analysis and in vivo cardioprotective potential. Two diverse extractions (ultrasonication and reflux) and four different solvents (aqueous, ethanolic, hydroethanolic, and methanolic) were used for the extraction of quince peel and assessed for the phytochemical and antioxidant study. Among all the evaluated extracts, hydroethanolic quince extract extracted through the reflux extraction method showed the maximum phenolic (27.23 ± 0.85 mg GAE/g DW) and flavonoid (16.5 ± 1.02 mg RE/g DW) content. The maximum antioxidant potential (DPPH) with an IC50 value of 204.8 ± 2.24 μg/mL was noted for the hydroethanolic extract. This best active extract was then subjected to HPTLC, UPLC-MS, mineral, and FTIR analysis to study the metabolic profiling and inorganic composition and to confirm the presence of bioactives. Additionally, the in vivo study was done in rats using doxorubicin (DOX)-induced cardiotoxicity. The rats were given extracts orally at 160 and 320 mg/kg bw for 30 days. ECG analysis was done at the termination of the experiment. Besides this, the lipid profile, blood serum parameters (CK-MB, LDH, AST), and tissue parameters (MDA, SOD, GSH, CAT) were analyzed. The DOX-treated group unveiled a substantial variance (p < 0.001) in all the parameters in contrast to the normal control group and extract control groups. However, the pretreated groups substantially alleviated the DOX-induced changes in all the parameters. Additionally, recuperation in histopathological alterations of the cardiac tissue in contrast to the DOX-induced toxicity was also seen in the pretreated groups. Thus, it could be said that the cardioprotective activity of the quince peel extract attributed to the presence of phytoconstituents counteracted the DOX-induced cardiotoxicity and assisted in the restoration of the cardiac injury in rats.

Cardioprotective Effect of Centaurea castriferrei Borbás & Waisb Extract against Doxorubicin-Induced Cardiotoxicity in H9c2 Cells

Doxorubicin (DOX) is one of the most used chemotherapeutic agents in the treatment of various types of cancer. However, a continual problem that is associated with its application in therapeutic regimens is the development of dose-dependent cardiotoxicity. The progression of this process is associated with a range of different mechanisms, but especially with the high level of oxidative stress. The aim of the study was to evaluate the effects of the water and methanol-water extracts from the plant Centaurea castriferrei (CAS) obtained by the ultrasound-assisted extraction method on the DOX-induced cardiotoxicity in the rat embryonic cardiomyocyte cell line H9c2. The H9c2 cells were treated for 48 h with the DOX and water or methanol-water extracts, or a combination (DOX + CAS H₂O/CAS MeOH). The MTT assay, cell cycle analysis, and apoptosis detection revealed that both the tested extracts significantly abolished the cytotoxic effect caused by DOX. Moreover, the detection of oxidative stress by the CellROX reagent, the evaluation of the number of AP sites, and the expressions of the genes related to the oxidative stress defense showed substantial reductions in the oxidative stress levels in the H9c2 cells treated with the combination of DOX and CAS H₂O/CAS MeOH compared with the DOX administered alone. The tested extracts did not affect the cytotoxic effect of DOX on the MCF-7 breast cancer cell line. The obtained results constitute the basis for further research in the context of the application of C. castriferrei extracts as adjuvants in the therapy regiments of cancer patients treated with DOX.