Sinapic acid restores blood parameters, serum antioxidants, and liver and kidney functions in obesity

Nephroprotective Effect of Hibiscus Sabdariffa Leaf Flavonoid Extracts via KIM-1 and TGF-1β Signaling Pathways in Streptozotocin-Induced Rats

Diabetes-induced kidney damage represents a substantial health hazard, emphasizing the imperative to explore potential therapeutic interventions. This study investigates the nephroprotective activity of flavonoid-rich extracts from Hibiscus sabdariffa leaves in streptozotocin-induced diabetic rats. The flavonoid-rich extracts of H. sabdariffa leaves was obtained using a standard procedure. The animals were induced with streptozotocin and thereafter treated with both low (LDHSFL) and high doses (HDHSFL) of flavonoid-rich extracts from H. sabdariffa leaves and metformin (MET), and other groups are diabetic control (DC) and normal control (NC). The study assesses diverse renal parameters, encompassing kidney redox stress biomarkers, serum electrolyte levels, kidney inflammatory biomarkers, serum concentrations of creatinine, urea, and uric acid, kidney phosphatase activities, renal histopathology, and relative gene expressions of kidney injury molecule-1 (KIM-1) and transforming growth factor beta-1 (TGF-1β), comparing these measurements with normal and diabetic control groups (NC and DC). The findings indicate that the use of extracts from H. sabdariffa leaves markedly (p < 0.05) enhanced renal well-being by mitigating nephropathy, as demonstrated through the adjustment of various biochemical and gene expression biomarkers, indicating a pronounced antioxidative and anti-inflammatory effect, improved kidney morphology, and mitigation of renal dysfunction. These findings suggest that H. sabdariffa leaf flavonoid extracts exhibit nephroprotective properties, presenting a potential natural therapeutic approach for the treatment of diabetic nephropathy.

Development and Evaluation of a Self-Nanoemulsifying Drug Delivery System for Sinapic Acid with Improved Antiviral Efficacy against SARS-CoV-2

This study aimed to develop a self-nanoemulsifying drug delivery system (SNE) for sinapic acid (SA) to improve its solubility and antiviral activity. Optimal components for the SA-SNE formulation were selected, including Labrafil as the oil, Cremophor EL as the surfactant, and Transcutol as the co-surfactant. The formulation was optimized using surface response design, and the optimized SA-SNE formulation exhibited a small globule size of 83.6 nm, high solubility up to 127.1 ± 3.3, and a 100% transmittance. In vitro release studies demonstrated rapid and high SA release from the formulation. Pharmacokinetic analysis showed improved bioavailability by 2.43 times, and the optimized SA-SNE formulation exhibited potent antiviral activity against SARS-CoV-2. The developed SA-SNE formulation can enhance SA's therapeutic efficacy by improving its solubility, bioavailability, and antiviral activity. Further in silico, modeling, and Gaussian accelerated molecular dynamics (GaMD)-based studies revealed that SA could interact with and inhibit the viral main protease (Mpro). This research contributes to developing effective drug delivery systems for poorly soluble drugs like SA, opening new possibilities for their application via nebulization in SARS-CoV-2 therapy.

Sinapic Acid Attenuate Liver Injury by Modulating Antioxidant Activity and Inflammatory Cytokines in Thioacetamide-Induced Liver Cirrhosis in Rats

Sinapic acid (SA) is a natural pharmacological active compound found in berries, nuts, and cereals. The current study aimed to investigate the protective effects of SA against thioacetamide (TAA) fibrosis in rats by histopathological and immunohistochemical assays. The albino rats (30) were randomly divided into five groups (G). G1 was injected with distilled water 3 times/week and fed orally daily with 10% Tween 20 for two months. G2-5 were injected with 200 mg/kg TAA three times weekly for two months and fed with 10% Tween 20, 50 mg/kg silymarin, 20, and 40 mg/kg of SA daily for 2 months, respectively. The results showed that rats treated with SA had fewer hepatocyte injuries with lower liver index (serum bilirubin, total protein, albumin, and liver enzymes (ALP, ALT, and AST) and were similar to that of control and silymarin-treated rats. Acute toxicity for 2 and 4 g/kg SA showed to be safe without any toxic signs in treated rats. Macroscopic examination showed that hepatotoxic liver had an irregular, rough surface with micro and macro nodules and histopathology expressed by Hematoxylin and Eosin, and Masson Trichrome revealed severe inflammation and infiltration of focal necrosis, fibrosis, lymphocytes, and proliferation bile duct. In contrast, rats fed with SA had significantly lower TAA toxicity in gross and histology and liver tissues as presented by less liver tissue disruption, lesser fibrosis, and minimum in filtered hepatocytes. Immunohistochemistry of rats receiving SA showed significant up-regulation of HSP 70% and down-regulation of alpha-smooth muscle actin (α-SMA) protein expression compared to positive control rats. The homogenized liver tissues showed a notable rise in the antioxidant enzymes (SOD and CAT) actions with significantly lower malondialdehyde (MDA) levels compared to that of the positive control group. Furthermore, the SA-treated rats had significantly lower TNF-a, IL-6, and higher IL-10 levels than the positive control rats. Thus, the findings suggest SA as a hepatoprotective compound due to its inhibitory effects on fibrosis, hepatotoxicity, liver cell proliferation, up-regulation of HSP 70, and downregulation of α-SMA expression, inhibiting lipid peroxidation (MDA), while retaining the liver index and antioxidant enzymes to normal.

Targeting mTOR Signaling by Dietary Polyphenols in Obesity Prevention

Dietary polyphenols can be utilized to treat obesity and chronic disorders linked to it. Dietary polyphenols can inhibit pre-adipocyte proliferation, adipocyte differentiation, and triglyceride accumulation; meanwhile, polyphenols can also stimulate lipolysis and fatty acid β-oxidation, but the molecular mechanisms of anti-obesity are still unclear. The mechanistic target of rapamycin (mTOR) is a protein kinase that regulates cell growth, survival, metabolism, and immunity. mTOR signaling is also thought to play a key role in the development of metabolic diseases such as obesity. Recent studies showed that dietary polyphenols could target mTOR to reduce obesity. In this review, we systematically summarized the research progress of polyphenols in preventing obesity through the mTOR signaling pathway. Mechanistically, polyphenols can target multiple signaling pathways and gut microbiota to regulate the mTOR signaling pathway to exert anti-obesity effects. The main mechanisms include: modulating lipid metabolism, adipogenesis, inflammation, etc. Dietary polyphenols exerting an anti-obesity effect by targeting mTOR signaling will broaden our understanding of the anti-obesity mechanisms of polyphenols and provide valuable insights for researchers in this novel field.