Emergence of Dengue as one of the deadliest viral diseases prompts the need for development of effective therapeutic agents. Dengue virus (DV) exists in four different serotypes and infection caused by one serotype predisposes its host to another DV serotype heterotypic re-infection. We undertook virtual ligand screening (VLS) to filter compounds against DV that may inhibit inclusively all of its serotypes. Conserved non-structural DV protein targets such as NS1, NS3/NS2B and NS5, which play crucial role in viral replication, infection cycle and host interaction, were selected for screening of vital antiviral drug leads. A dataset of plant based natural antiviral derivatives was developed. Molecular docking was performed to estimate the spatial affinity of target compounds for the active sites of DV’s NS1, NS3/NS2B and NS5 proteins. The drug likeliness of the screened compounds was followed by ADMET analysis whereas the binding behaviors were further elucidated through molecular dynamics (MD) simulation experiments. VLS screened three potential compounds including Canthin-6-one 9-O-beta-glucopyranoside, Kushenol W and Kushenol K which exhibited optimal binding with all the three conserved DV proteins. This study brings forth novel scaffolds against DV serotypes to serve as lead molecules for further optimization and drug development against all DV serotypes with equal effect against multiple disease causing DV proteins. We therefore anticipate that the insights given in the current study could be regarded valuable towards exploration and development of a broad-spectrum natural anti-dengue therapy.

Tea is one of the top beverages used around the world every day, which contains a high amount of polyphenols and antioxidants. The main aim of this research is to quantify some marketed black tea (Rabea, Lipton, Alkbous, Green gold and Haritham) for phenolic contents and antioxidant potential evaluation by ultrasound solvent extraction and was compared with conventional extraction. Ultrasonic extraction was optimized by considering frequencies (26 kHz, 40 kHz), temperature (30, 40 and 50 °C), and power (30, 40 and 50%) at a fixed time of 30 min. In both the ultrasonic frequencies, 40 °C temperature and 40% power combination exhibited highest cumulative yield (mg/100 g DW), total phenolic content (mg gallic acid/g DW), flavonoids (mg/g DW) and DPPH radical scavenging activity (%) in all branded tea. Within each brand of tea, at any temperature-power combination at particular frequency results were not significantly different. But, at a similar condition of temperature power results were found significantly different between two frequencies. Furthermore, ultrasonic extraction process was analyzed thermodynamically by selecting some basic parameters. Thermodynamics results showed the extraction process was feasible, spontaneous and irreversible. Also, 26 kHz ultrasonic probe is more appropriate for the extraction purpose and thermodynamically more acceptable as compared to 40 kHz ultrasonic bath. Moreover, Haritham was selected as the best tea brand due to its high polyphenol contents and antioxidant potential.

In this paper, we focused on the green synthesis of titanium dioxide (TiO₂) nanoparticles via an ecofriendly process using Citrus limon extract. Several analytical techniques were used to characterize the prepared samples: X-ray diffraction (XRD), infrared spectroscopy, Raman spectroscopy, Scanning Electron Microscopy (SEM) and X-ray photoelectrons spectroscopy (XPS). XRD diffractograms revealed an anatase crystal structure of TiO₂. SEM analysis showed the presence of particles with nanometric sizes, and the Fourier transform infrared (FTIR) spectra confirmed the presence of the synthesized nanoparticles. The antibacterial activity of the green prepared TiO₂ nanoparticles was assessed. Additionally, the antibacterial efficiency of the green prepared TiO₂ nanoparticles was compared with TiO₂ nanoparticles prepared via a chemical process. The results prove the efficacy of this ecofriendly process. This method can be used for the rapid and environmentally friendly biosynthesis of stable titanium oxide nanoparticles. This work is a contribution to the valorization of bio-sources for the synthesis of titanium dioxide crystals using Citrus limon fruit extract and tetrabutile titanate as a precursor. GRAPHICAL ABSTRACT

This research work is focused on pharmacokinetic and biochemical experiments to assess baicalin-loaded lipid–polymer hybrid nanoparticles (LPHNPs) with colon-targeting specificity. The nanoprecipitation method was used to develop the LPHNPs, and the characterized formulation revealed the 184.3 nm particle size, PDI of 0.177, spherical shape, and zeta potential of −19.8 mV. The baicalin LPHNPs are said to be poorly absorbed in the stomach and small intestine, and in vitro drug release tests have shown that the drug is released mostly in the caecal fluid. Additionally, the LPHNPs showed stability and nonsignificant drug loss at 25 °C for 3 months. The least viable population of baicalin-loaded LPHNPs was detected at a lower IC₅₀ value after 48 h, and no cytotoxicity was observed by blank suspension and blank LPHNPs up to the concentration of 100 µg/mL. Apart from this, the pharmacokinetics study showed that baicalin from LPHNPs is much less absorbed and least available in the blood plasma and maximum available in the colon. Concurrently, organ distribution studies demonstrated that baicalin-loaded LPHNPs were distributed more widely in the colon compared to baicalin suspension. Moreover, baicalin-loaded LPHNPs were found to be superior to a baicalin suspension in reducing elevated liver enzyme levels. In a nutshell, baicalin-loaded LPHNPs show superior efficacy and can be maximally localized into the colon rectal cancer along with systemic availability of the drug.

Background: 1,3,4-Oxadiazole heterocycles possess a broad spectrum of biological activities. They were reported as potent cytotoxic agents and tubulin inhibitors; hence it is of great interest to explore new oxadiazoles as cytotoxic agents targeting tubulin polymerization. Objective: Two new series of oxadiazoles (5a-h and 12a-h) were synthesized, structurally related to the heterocyclic linked aryl core of IMC-038525, NSC 776715, and NSC 776716, with further modification by incorporating methylene linker. Method: The 2,5-disubstituted-1,3,4-oxadiazoles (5a-h and 12a-h) were synthesized by refluxing an equimolar mixture of the intermediates [(4) and (8a-d)] and aromatic aldehydes in water-ethanol system using sodium bisulphite catalyst. The cytotoxicity evaluation was carried out according to the National Cancer Institute (NCI US) Protocol, while the tubulin polymerization assay kits from Cytoskeleton ™(bk011p) was used to perform an in vitro tubulin polymerization assay. Results: 2-(5-{[(4-Chlorophenyl)amino]methyl}-1,3,4-oxadiazol-2-yl)phenol (5f) and 2-[(2,4-dichlorophenoxy) methyl]-5-(3,4-dimethoxyphenyl)-1,3,4-oxadiazole (12c) showed maximum cytotoxicity with the mean percent growth inhibitions (GIs) of 71.56 and 72.68 respectively at 10 µM drug concentrations. Both the compounds (5f and 12c) showed superior cytotoxicity than clinically prevalent anticancer drugs, Imatinib and Gefitinib in one dose assay. The compound 12c showed promising results in five dose assay, with GI50 values varies between 1.61 and >100 µM. Furthermore, the compounds, 5f and 12c also inhibited the polymerization of tubulin with, an IC50 of 2.8 and 2.2 µM, respectively. Conclusion: The oxadiazoles reported herein are tubulin inhibitors and cytotoxic agents. These findings will be helpful in future drug design of more potent tubulin inhibitor cytotoxic agents.