Isolation, preparation and investigation of leaf extracts of Aloe barbadensis for its remedial effects on tumor necrosis factor alpha (TNF-α) and interleukin (IL-6) by in vivo and in silico approaches in experimental rats.

Aloe barbadensis is a stemless plant with a length of 60-100 cm with juicy leaves which is used for its remedial and healing properties in different suburbs of various countries. The present study was conducted to investigate the effect of A. barbadensis leaf extract (aqueous and ethanolic) in yeast induced pyrexia and acetic acid induced writhing in rat model to evaluate the antipyretic biomarkers and its phytochemical screening with computational analysis. For analgesic activity model 60 Albino rats (160-200 kg) were divided into four groups. Of the 4 groups, control consisted of 6 rats (Group I) treated with normal saline, standard comprised of 6 rats treated with drug diclofenac (Group I). Experimental groups consisted of 48 rats, treated with A. barbadensis ethanolic and aqueous leaf extracts at doses of 50 mg/kg, 100 mg/kg, 200 mg/kg, and 400 mg/kg (Group III. IV). For antipyretic activity group division was same as in analgesic activity. All groups were treated the same as in the analgesic activity except for the second group which was treated with paracetamol. In both antipyretic and analgesic activity at the dose of 400 mg/kg, group III showed significant inhibition. TNF-α and IL-6 showed significant antipyretic activity at a dose of 400 mg/kg. For molecular docking aloe emodin and cholestanol were used as ligand molecules to target proteins Tnf-α and IL-6. Acute oral toxicity study was performed. There was no mortality even at the dose of 2000 mg/kg. Quantitative and qualitative phytochemical screening was performed for the detection of various phytochemicals. Hence, A. barbadensis leaf extracts can be used in the form of medicine for the treatment of pain and fever.

Antiatherogenic Effects of Quercetin in the THP-1 Macrophage Model In Vitro, With Insights Into Its Signaling Mechanisms Using In Silico Analysis.

Background: Atherosclerosis (AS), a major risk factor for stroke and brain tissue destruction, is an inflammatory disease of the blood vessels, and the underlying pathology is inflammation mediated by various chemokines and cytokines. Quercetin, a natural flavonol, is reported to have both anti-inflammatory and antioxidant properties. As such, in the present study, we evaluated the antiatherogenic effects of quercetin in a human THP-1 cell line in vitro and also the signaling mechanisms using in silico analysis. Materials and Methods: THP-1 macrophages exposed to different concentrations of quercetin (5-100 µM for 24 h) were tested for cytotoxicity. Real-time gene expression assay for intercellular adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein-1 (MCP-1) was carried out following treatment with quercetin at 15 and 30 µM for 24 h either in the absence or presence of interferon (IFN-γ) for 3 h to induce inflammation. Monocyte migration and cholesterol efflux were also assessed. Results: Quercetin did not exert any cytotoxic effects on THP-1 cells at the various concentrations tested. The gene expression assay showed a significant decrease in ICAM-1 (by 3.05 and 2.70) and MCP-1 (by 22.71 and 27.03), respectively. Quercetin at 15 µM decreased THP-1 monocyte migration by 33% compared to the MCP-1-treated cells. It also increased cholesterol efflux significantly by1.64-fold and 1.60-fold either alone or in combination with IFN-γ, respectively. Ingenuity Pathway Analysis of the molecular interactions of quercetin identified canonical pathways directly related to lipid uptake and cholesterol efflux. Furthermore, CD36, SR-A, and LXR-α also demonstrated significant increases by 72.16-, 149.10-, and 29.68-fold, respectively. Conclusion: Our results from both in vitro and in silico studies identified that quercetin inhibited the THP-1 monocyte migration, MCP-1, and ICAM-1 and increased cholesterol efflux probably mediated via the LXR/RXR signaling pathway. Therefore, quercetin will help prevent cell infiltration in atherosclerotic plaques and reduce the risk of stroke or brain destruction.