Synthesis of Ursolic Acid-based Hybrids: In Vitro Antibacterial, Cytotoxicity Studies, In Silico Physicochemical and Pharmacokinetic Properties.

BACKGROUND: There is a critical need for the discovery of novel and effective antibacterial or anticancer molecules. OBJECTIVES: Amine-linked ursolic acid-based hybrid compounds were prepared in good yields in the range of 60-68%. METHODS: Their molecular structures were successfully confirmed using different spectroscopic methods including 1H/13C NMR, UHPLC-HRMS and FTIR spectroscopy. The in vitro cytotoxicity of some of these hybrid molecules against three human tumour cells, such as MDA-MB23, MCF7, and HeLa was evaluated using the MTT colorimetric method. RESULT: Their antibacterial efficacy was evaluated against eleven bacterial pathogens using a serial dilution assay. Majority of the bacterial strains were inhibited significantly by compounds 17 and 24, with the lowest MIC values in the range of 15.3-31.25 µg/mL. Compound 16 exhibited higher cytotoxicity against HeLa cells than ursolic acid, with an IC50 value of 43.64 g/mL. CONCLUSION: The in vitro antibacterial activity and cytotoxicity of these hybrid compounds demonstrated that ursolic acid-based hybrid molecules are promising compounds. Further research into ursolic acid-based hybrid compounds is required.

Lithium inhibits NF-κB nuclear translocation and modulate inflammation profiles in Rift valley fever virus-infected Raw 264.7 macrophages.

INTRODUCTION: Rift Valley fever virus (RVFV) is a zoonotic life-threatening viral infection endemic across sub-Saharan African countries and the Arabian Peninsula; however, there is a growing panic of its spread to non-endemic regions. This viral infection triggers a wide spectrum of symptoms that span from fibril illnesses to more severe symptoms such as haemorrhagic fever and encephalitis. These severe symptoms have been associated with dysregulated immune response propagated by the virulence factor, non-structural protein (NSs). Thus, this study investigates the effects of lithium on NF-κB translocation and RFVF-induced inflammation in Raw 264.7 macrophages. METHODS: The supernatant from RVFV-infected Raw 264.7 cells, treated with lithium, was examined using an ELISA assay kit to measure levels of cytokines and chemokines. The H2DCF-DA and DAF-2 DA florigenic assays were used to determine the levels of ROS and RNS by measuring the cellular fluorescence intensity post RVFV-infection and lithium treatment. Western blot and immunocytochemistry assays were used to measure expression levels of the inflammatory proteins and cellular location of the NF-κB, respectively. RESULTS: Lithium was shown to stimulate interferon-gamma (IFN-γ) production as early as 3 h pi. Production of the secondary pro-inflammatory cytokine and chemokine, interleukin-6 (IL-6) and regulated on activation, normal T cell expressed and secreted (RANTES), were elevated as early as 12 h pi. Treatment with lithium stimulated increase of production of tumor necrosis factor-alpha (TNF-α) and Interleukin-10 (IL-10) in RVFV-infected and uninfected macrophages as early as 3 h pi. The RVFV-infected cells treated with lithium displayed lower ROS and RNS production as opposed to lithium-free RVFV-infected control cells. Western blot analyses demonstrated that lithium inhibited iNOS expression while stimulating expression of heme oxygenase (HO) and IκB in RVFV-infected Raw 264.7 macrophages. Results from immunocytochemistry and Western blot assays revealed that lithium inhibits NF-κB nuclear translocation in RVFV-infected cells compared to lithium-free RVFV-infected cells and 5 mg/mL LPS controls. CONCLUSION: This study demonstrates that lithium inhibits NF-kB nuclear translocation and modulate inflammation profiles in RVFV-infected Raw 264.7 macrophage cells.

Induction of Cell Death in Human A549 Cells Using 3-(Quinoxaline-3-yl) Prop-2-ynyl Methanosulphonate and 3-(Quinoxaline-3-yl) Prop-2-yn-1-ol.

Despite major advancements in the development of various chemotherapeutic agents, treatment for lung cancer remains costly, ineffective, toxic to normal non-cancerous cells, and still hampered by a high level of remissions. A novel cohort of quinoxaline derivatives designed to possess a wide spectrum of biological activities was synthesized with promising targeted and selective anticancer drug activity. Hence, this study was aimed at determining in vitro anticancer activity effects of a newly synthesized class of 3-(quinoxaline-3-yl) prop-2-ynyl quinoxaline derivatives on A549 lung cancer cells. An assessment of the quinoxaline derivatives ferric reducing power, free radical scavenging activity, cytotoxic activity, and ability to induce reactive oxygen species (ROS) production was performed using the Ferric Reducing Antioxidant Power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) assays, respectively. The ability of the quinoxaline derivatives to induce apoptosis in A549 cells was assessed using the Acridine Orange/Ethidium Bromide (AO/EB) and Annexin V-FITC/Dead Cell Assay. Of the four quinoxaline derivatives tested, 3-(quinoxaline-3-yl) prop-2-ynyl methanosulphate (LA-39B) and 3-(quinoxaline-3-yl) prop-2-yn-1-ol (LA-55) displayed a dose-dependent reducing power, free-radical scavenging activity, inhibition of cell viability, and stimulation of ROS production which was accompanied by induction of apoptosis in A549 lung cancer cells. None of the quinoxaline derivatives induced cell death or ROS production in non-cancerous Raw 267.4 macrophage cells. Cytotoxicity was observed in A549 lung cancer, HeLa cervical cancer, and MCF-7 breast cancer cells albeit inhibition was more pronounced in A549 cells. The results of the study suggest that 3-(quinoxaline-3-yl) prop-2-ynyl methanosulphate and 3-(quinoxaline-3-yl) prop-2-yn-1-ol induce apoptotic cell death in A549 lung cancer cells.

Semi-purified extracts of Commelina benghalensis (Commelinaceae) induce apoptosis and cell cycle arrest in Jurkat-T cells.

BACKGROUND: Commelina benghalensis (CB) is a small plant whose fleshy stems are used in South Africa to treat skin conditions (e.g., cancerous skin outgrowths). This study was aimed at evaluating the effect of sub-fractions of acetone extracts of CB stems on growth-associated molecular events of apoptosis and cell division cycle of Jurkat-T (JT) cells. METHODS: Acetone extract of CB stems were subfractioned into n-hexane (F1) and dichloromethane (F2) fractions. After treatment of JT cells with these subfractions, cell proliferation, viability and apoptosis were determined using a haemocytometer, the trypan blue dye exclusion assay, and Hoechst 33258 staining, respectively. Cell division cycle distribution profiles were analysed using an Epics Alba Flow Cytometer and the expression of cell division cycle regulatory genes was analysed using RT-PCR, while immunoreactive proteins were detected on western blots. RESULTS: The F1 and F2 fractions inhibited the proliferation and viability of JT cells in a concentration- and time-dependent manner, with IC50 values of 32.5 µg/mℓ and 56 µg/mℓ, respectively. The observed cytotoxicity was established to be a consequence of apoptosis. as verified using Hoechst staining method. Both fractions induced a G1/S interphase arrest of the cell division cycle of JT cells.RT-PCR analyses showed an up-regulatory effect by the F1 fraction in the expression of cyclin B1, cdc2 and bax, with a down-regulatory effect in the expression levels of bcl-2. Fraction F1 also increased the protein expression levels of p53 and its downstream regulators, p21 and Cdc2. However, protein Bax and p21 and p53 transcripts were undetectable under the same experimental conditions. On the other hand, fraction F2 increased the mRNA expression levels of bax, bcl-2, cyclin B1 and cdc2. Concomitantly, fraction F2 showed an up-regulation in the protein expression levels of Cdc2, Bcl-2, Cyclin B1 and p21. Despite the up-regulation in protein expression levels by fraction F2, there was no observable expression levels of the p53 protein and p21 and p53 mRNAs under similar experimental conditions. CONCLUSION: These findings suggest that the F1 and F2 fractions of CB may provide a valuable lead for the development of novel and effective anti-neoplastic drug(s).