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Phenolics, abundant in plants, constitute a significant portion of phytoconstituents consumed in the human diet. The phytochemical screening of the aerial parts of Centaurium spicatum led to the isolation of five phenolics. The anti-tyrosinase activities of the isolated compounds were assessed through a combination of in vitro experiments and multiple in silico approaches. Docking and molecular dynamics (MD) simulation techniques were utilized to figure out the binding interactions of the isolated phytochemicals with tyrosinase. The findings from molecular docking analysis revealed that the isolated phenolics were able to bind effectively to tyrosinase and potentially inhibit substrate binding, consequently diminishing the catalytic activity of tyrosinase. Among isolated compounds, cichoric acid displayed the lowest binding energy and the highest extent of polar interactions with the target enzyme. Analysis of MD simulation trajectories indicated that equilibrium was reached within 30 ns for all complexes of tyrosinase with the isolated phenolics. Among the five ligands studied, cichoric acid exhibited the lowest interaction energies, rendering its complex with tyrosinase the most stable. Considering these collective findings, cichoric acid emerges as a promising candidate for the design and development of a potential tyrosinase inhibitor. Furthermore, the in vitro anti-tyrosinase activity assay unveiled significant variations among the isolated compounds. Notably, cichoric acid exhibited the most potent inhibitory effect, as evidenced by the lowest IC 50 value (7.92 ± 1.32 µg/ml), followed by isorhamnetin and gentiopicrin. In contrast, sinapic acid demonstrated the least inhibitory activity against tyrosinase, with the highest IC 50 value. Moreover, cichoric acid exhibited a mixed inhibition mode against the hydrolysis of l-DOPA catalyzed by tyrosinase, with K i value of 1.64. Remarkably, these experimental findings align well with the outcomes of docking and MD simulations, underscoring the consistency and reliability of our computational predictions with the actual inhibitory potential observed in vitro., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Diabetic nephropathy (DN) is a serious complication of diabetes and can lead to renal failure. Telmisartan (TEL) is an approved angiotensin II type 1 receptor blocker for the treatment of hypertension and possesses nephroprotective efficacy. The study investigated the beneficial effect of TEL on renal oxidative stress, inflammatory response, and apoptosis in type 1 diabetic rats, pointing to the possible role of Nrf2/HO-1 signaling. Diabetes was induced by streptozotocin (STZ), and TEL (5 and 10 mg/kg) was supplement for 8 weeks. TEL ameliorated hyperglycemia, prevented body weight loss and kidney hypertrophy, decreased serum creatinine and urea, and prevented histopathological alterations in diabetic rats. Malondialdehyde (MDA), nitric oxide (NO), NF-κB p65 and TNF-α were increased, whereas GSH, SOD and Bcl-2 were decreased in the kidney of diabetic rats. Treatment with TEL ameliorated oxidative stress, suppressed NF-κB p65 and TNF-α, and boosted cellular antioxidant defenses and Bcl-2. TEL upregulated Nrf2 and HO-1 in the kidney of both normal and diabetic rats. In addition, TEL downregulated VEGF and MMP-9 in the kidney of diabetic rats. In silico molecular docking simulations revealed the potent binding affinity of TEL to NF-κB, MMP-9, Keap1 and HO-1. In conclusion, TEL attenuates DN by ameliorating hyperglycemia, oxidative stress, inflammation, apoptosis and angiogenesis and upregulation of Nrf2/HO-1 signaling., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Nephrotoxicity is a major complication that limits the therapeutic application of cisplatin (CIS). Oxidative stress and inflammation are implicated in CIS-induced acute kidney injury (AKI) and apoptotic cell death. Punicalagin (PUN), a polyphenol in pomegranate, possesses promising anti-inflammatory and antioxidant activities, and its beneficial effect against CIS-induced AKI has not been fully elucidated. This investigation evaluated the protective effect of PUN against CIS-induced renal oxidative stress, inflammation and cell death. Rats received PUN (25 and 50 mg/kg) for 10 days and a single injection of CIS at day 7. The results showed increased serum urea and creatinine and several histopathological alterations in the kidney of CIS-intoxicated rats. Renal malondialdehyde (MDA) and nitric oxide (NO) were increased, and reduced glutathione, superoxide dismutase and catalase were declined in rats treated with CIS. PUN effectively ameliorated kidney function and attenuated tissue injury induced by CIS, decreased MDA and NO, and enhanced antioxidant defenses. Additionally, PUN downregulated NF-κB p65, iNOS, TNF-α, IL-6 and IL-1β in the kidney of rats that received CIS. Bax and caspase-3 were increased, and Bcl-2 was decreased in the kidney of CIS-intoxicated rats, an effect that was reversed by PUN. PUN upregulated Nrf2 expression in the kidney of CIS-intoxicated rats. In conclusion, PUN prevents CIS-induced AKI in rats by attenuating oxidative stress, inflammatory response and apoptosis, and upregulating Nrf2 and antioxidants., (Copyright © 2021 Elsevier Inc. All rights reserved.)