Discovery of novel anticancer flavonoids as potential HDAC2 inhibitors: virtual screening approach based on molecular docking, DFT and molecular dynamics simulations studies.

Virtual screening of a library of 329 flavonoids obtained from the NPACT database was performed to find out potential novel HDAC2 inhibitors. Eleven out of 329 selected flavonoids were screened based on molecular docking studies, as they have higher binding affinities than the standard drugs vorinostat and panobinostat. All screened compounds occupying the catalytic site of HDAC2 showed important molecular interaction with Zn2+ and other important amino acids in the binding pocket. The screened compounds were validated using ADMET filtration and bioactivity prediction from which we obtained six compounds, NPACT00270, NPACT00676, NPACT00700, NPACT001008, NPACT001054, and NPACT001407, which were analyzed using DFT studies. DFT studies were performed for all six screened flavonoids. In DFT studies, three flavonoids, NPACT00700, NPACT001008, and NPACT001407, were found to be better based on HOMO-LUMO and molecular electrostatic potential (MEP) analyses. Furthermore, MD simulations were performed for 100 ns for the three compounds. In the MD analysis, NPACT001407 was found to be more stable in the active site of HDAC2 as zinc formed a coordination bond with ASP181, HIS183, ASP269, and GLY305, along with two hydroxyl groups of the ligand. Our findings reveal that these flavonoids can interact as ligands with the active site of HDAC2. Because of the absence of a hydroxamate group in flavonoids, there are no possibilities for the formation of isocyanate. This suggests that the major drawback of current HDACs inhibitors may be solved. Further experimental validation is needed to understand the selectivity of flavonoids as HDAC2 inhibitors. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03912-5.

Platelet Augmentation Potential of Polyherbal Formulation in Cyclophosphamide-Induced Thrombocytopenia in Wistar Rats.

INTRODUCTION: Thrombocytopenia is a condition characterized by abnormally low levels of thrombocytes, also known as platelets, in the blood. Several medicinal plants possess curative and protective effect against thrombocytopenia associated with diseases or drugs. AIM: In the present study, we have investigated the platelet augmentation activity of polyherbal formulation (VITA PLAT Capsule) in cyclophosphamide-induced thrombocytopenic rat model. MATERIALS AND METHODS: Twenty-four albino Wistar rats were divided into four groups. Thrombocytopenia was induced in the rats by administering cyclophosphamide (25 mg/kg, i.p.) for three days to all the groups except normal controls. The test groups were given orally a polyherbal formulation suspended in normal saline for 14 days. Blood was withdrawn from the retro-orbital plexus of the rats on days 1, 7, and 14 of study to determine platelet counts in all groups. Clotting time and bleeding time were determined on the last day of study. Data were collected and analyzed using GraphPad Prism 8. RESULTS: The results showed that the polyherbal formulation treatment could significantly ameliorate platelet count in thrombocyto-penic rats in the initial as well as in the later phase. The total WBC count was also improved during later phase in test groups. However, there is no significant difference between clotting time and bleeding time in all groups. CONCLUSIONS: Our study suggests a potential role of this formulation in the augmentation of platelet counts in various thrombocyto-penic disorders including a role in ameliorating the haemorrhagic complications of dengue fever.

In Silico Discovery of Novel Phytoconstituents of Amyris pinnata as a Mitotic Spindle Kinase Inhibitor.

BACKGROUND: Despite many successes in the discovery of numerous cancer chemotherapeutic agents from natural sources, some of the moieties were dropped because of its inefficiency or serious toxicity. Mitosis is an ordered series of fundamentally mechanical events in which identical copies of the genome are moved to two discrete locations within the dividing cell. The crucial role of the mitotic spindle in cell division has identified, which is an important target in cancer chemotherapy. In the present study, we are reporting molecular docking studies and in silico pharmacokinetic profiles of selected phytoconstituents obtained from Amyris pinnata. METHODS: Molecular docking studies of selected phytoconstituents were performed using iGEMDOCK. The crystal structure of the protein was exported from the protein data bank (PDB id: 4C4H). In silico pharmacokinetic profile of selected phytoconstituents was performed using the SWISSADME server. RESULTS: Compound AMNP6 showed higher binding affinity as compared to the standard ligand. All the selected phytoconstituents have passed the Lipinski rule of five and shown no violations. CONCLUSION: Good binding affinity and drug likeliness of the AMNP6 suggest that it can be further investigated and explored as mitotic spindle kinase inhibitor in cancer disease.

Anti-anaphylactic and antiasthmatic activity of Euphorbia thymifolia L. on experimental animals.

In Ayurveda, Euphorbia thymifolia L. (Euphorbiaceae) prescribed in the treatment of various ailments like bronchial asthma, cough, diarrhea and bleeding piles. The present study was investigated to evaluate antianaphylactic, mast cell stabilizing and antiasthmatic activity of methanol and aqueous extract of E. thymifolia (ET) on experimental animals. Anaphylaxis was induced by administration of horse serum and triple antigen vaccine intraperitoneal (i.p.) in albino Wistar rats. Extracts of ET were administered to the rats in dose of 250 and 500 mg/kg orally for 14 days. At the end of treatment, asthma score was measured and various blood parameters like differential count (DC), total WBC count and IgE were estimated. Interleukin (IL)-4, IL-5 and TNF-α were measured by ELISA commercial kit from BALF. Histopathological changes of lungs were observed. Antiasthmatic activity of extracts of ET was also studied on histamine-induced bronchospasm in guinea pigs. In vitro mast cell stabilizing activity of extracts was evaluated on compound 48/80 challenged rat intestinal mesenteric mast cells. The treatment with extracts of ET produced significant decrease in asthma score and they also brought to normalcy the increased total WBC, DC counts, serum IgE, TNF-α, IL-4 and IL-5 in BALF. The histopathological study further supported the protective effect of ET extracts. The pretreatment with extracts of ET displayed significant reduction in degranulation of mesenteric mast cell numbers. The treatment with extracts of ET significantly increased in time of PCD. Thus, these findings concluded that E. thymifolia could be effectively used in the treatment of anaphylaxis and asthma.