The Synthesis and Biological Assessment of Novel Ursolic Acid Derivatives as Potential Chemotherapeutic Agents for Cancer

Glioblastoma (GBM) is considered to be the most biologically aggressive type of brain tumour accounting for approximately 48% of all malignant primary brain tumours. GBM patients diagnosed have poor prognosis with a low five-year survival rate of The aim of this study was to develop novel UA derivatives to enhance its bioavailability. Nine novel UA derivatives: three different diamine linkers, with Boc-protected and deprotected ends, and with folic acid were designed and synthesized to improve compound activity and/or delivery. The structures of the newly synthesised compounds were confirmed using mass spectrometry, FTIR, 1H NMR and 13C NMR. The structural activity relationship (SAR) of UA and novel UA derivatives that were designed to improve its activity and bioavailability (predicted ADMET profile) were explored, and molecular docking studies against proposed targets – FOLR1 and/or VRK1 were utilised, with an in-depth analysis of predicted interactions. The cytotoxic activity was determined using alamarBlueTM cell viability assay in a panel of cancer cell lines and normal cells. It was found that the conjugation of folic acid to UA decreased its cytotoxic activity. Interestingly, our study showed that the Boc-protected compounds have delayed cytotoxicity in comparison to deprotected compounds, which are more evident in U-251 MG and A431 cell lines using 2D cell culture assay. Whereas in 3D cell culture, only deprotected compounds exhibited an activity. The deprotected novel UA derivatives also retained the inherent anti-proliferative and anti-migratory effect of UA in U-251 MG cells. The synergistic studies focusing on the cell membrane damage performed showed that novel UA derivatives (7 – 12) may have a protective effect when exposed to radioactivity. In addition, the initial inhibitor studies suggests that compounds 8 and 10 at longer timepoint, may trigger multiple cell demise pathway. Based on these preliminary results, this study provides a new insight into using novel UA derivatives and a possible MOA for their anti-cancer effect

Ultrasound 96 Probe Device Protocol for cancer cell treatment

Ultrasound is a sound wave with frequencies ranging between 20 kHz and 20 MHz. Ultrasound is able to temporarily and repeatedly open the BBB safely and enhance chemotherapeutic delivery without adverse effects. This novel technique in drug delivery benefits from the powerful ability of ultrasound to produce cavitation activity. Cavitation is the generation and activity of gas-filled bubbles in a medium exposed to ultrasound. As the pressure wave passes through the media, gas bubbles expand at low pressure and contract at high pressure. This leads to oscillation which produces a circulating fluid flow known as microstreaming around the bubble with velocities and shear rates proportional to the amplitude of the oscillation. At high amplitudes the associated shear forces can cut open liposome

Valorisation of Phytochemical from Sitka Spruce (Picea Sitchensis) Needles: Impact of Ultrasound/microwave-assisted Extraction

Sitka spruce (Picea sitchensis) needles contain a variety of bioactive compounds including phenolic compounds and flavonoids, many of which have been used in the cosmetic, pharmaceutical, and food industries. This study aimed to investigate the effects of novel extraction techniques, including ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) and simultaneous ultrasound–microwave-assisted extraction (UMAE) on the recovery of phenolic, flavonoids and associated antioxidant and anti-cancer properties from Sitka spruce (Picea sitchensis) needles. The ferric reducing antioxidant power (FRAP) assay was used to evaluate the antioxidant capacity, and the Alamar Blue assay using the human brain glioblastoma cancer cell line (U-251 MG) was used to evaluate the cytotoxicity activity. Results showed that US-probe accomplished the highest recovery of phenolic and flavonoids at 38 W cm−2 for 10 min (106.3 ± 2.5 mg GAE g−1 DW and 63.2 ± 3.8 mg QE g−1 DW, respectively). Hence, the highest cytotoxicity activity of IC50 (0.0114% w/v) was achieved by US-probe at 19 W cm−2 for 10 min. However, the antioxidant capacity of (2591.3 ± 92.5 mM TE g−1 DW) was achieved under UMAE at ultrasound intensity of 38 W cm−2, microwave power of 302.4 W for 10 min. This study emphasised the potential application of UAE and MAE in the extraction of bioactive as an environmentally friendly method to be used in the valorisation of by-products in food and agro-industries. This supports the use of renewable natural resources in an efficient way to produce high-value compounds therefore it is in line with the new era of bioeconomy and its new biorefinery concepts

Ursolic Acid Inhibits Collective Cell Migration and Promotes JNK-Dependent Lysosomal Associated Cell Death in Gioblastoma Multiforme Cells

Ursolic acid (UA) is a bioactive compound which has demonstrated therapeutic efficacy in a variety of cancer cell lines. UA activates various signalling pathways in Glioblastoma multiforme (GBM) and offers a promising starting point in drug discovery; however, understanding the relationship between cell death and migration has yet to be elucidated. UA induces a dose dependent cytotoxic response demonstrated by flow cytometry and biochemical cytotoxicity assays. Inhibitor and fluorescent probe studies demonstrate that UA induces a caspase independent, JNK dependent, mechanism of cell death. Migration studies established that UA inhibits GBM collective cell migration in a time dependent manner that is independent of the JNK signalling pathway. Cytotoxicity induced by UA results in the formation of acidic vesicle organelles (AVOs), speculating the activation of autophagy. However, inhibitor and spectrophotometric analysis demonstrated that autophagy was not responsible for the formation of the AVOs. Confocal microscopy and isosurface visualisation determined co-localisation of lysosomes with the previously identified AVOs, thus providing evidence that lysosomes are likely to be playing a role in UA induced cell death. Collectively, our data identify that UA rapidly induces a lysosomal associated mechanism of cell death in addition to UA acting as an inhibitor of GBM collective cell migration

Influence of Molecular Weight Fractionation on the Antimicrobial and Anticancer Properties of a Fucoidan Rich-Extract From The Macroalgae Fucus Vesiculosus

The objective of this study was to investigate the antimicrobial and anticancer properties of a fucoidan extract and subsequent fractions isolated from the macroalgae Fucus vesiculosus. The fractions obtained (\u3e300 kDa,kDa,kDa,kDa) could inhibit the growth of B. subtilis, E. coli, L. innocua and P. fluorescens when assayed at concentrations between 12,500 and 25,000 ppm. The bacterial growth was monitored by optical density (OD) measurements (600 nm, 24 h) at 30 °C or 37 °C, depending upon on the strain used. The extracted fractions were also tested for cytotoxicity against brain glioblastoma cancer cells using the Alamar Blue assay for 24 h, 48 h and 6 days. The \u3e300 kDa fraction presented the lowest IC50 values (0.052% - 24 h; 0.032% - 6 days). The potential bioactivity of fucoidan as an antimicrobial and anticancer agent was demonstrated in this study. Hence, the related mechanisms of action should be explored in a near future

Enhanced pyrazolopyrimidinones cytotoxicity against glioblastoma cells activated by ROS-Generating cold atmospheric plasma

Pyrazolopyrimidinones are fused nitrogen-containing heterocyclic systems, which act as a core scaffold in many pharmaceutically relevant compounds. Pyrazolopyrimidinones have been demonstrated to be efficient in treating several diseases, including cystic fibrosis, obesity, viral infection and cancer. In this study using glioblastoma U-251MG cell line, we tested the cytotoxic effects of 15 pyrazolopyrimidinones, synthesised via a two-step process, in combination with cold atmospheric plasma (CAP). CAP is an adjustable source of reactive oxygen and nitrogen species as well as other unique chemical and physical effects which has been successfully tested as an innovative cancer therapy in clinical trials. Significantly variable cytotoxicity was observed with IC50 values ranging from around 11 μM to negligible toxicity among tested compounds. Interestingly, two pyrazolopyrimidinones were identified that act in a prodrug fashion and display around 5–15 times enhanced reactive-species dependent cytotoxicity when combined with cold atmospheric plasma. Activation was evident for direct CAP treatment on U-251MG cells loaded with the pyrazolopyrimidinone and indirect CAP treatment of the pyrazolopyrimidinone in media before adding to cells. Our results demonstrated the potential of CAP combined with pyrazolopyrimidinones as a programmable cytotoxic therapy and provide screened scaffolds that can be used for further development of pyrazolopyrimidinone prodrug derivatives

Enhanced pyrazolopyrimidinones cytotoxicity against glioblastoma cells activated by ROS-Generating cold atmospheric plasma

peer-reviewedPyrazolopyrimidinones are fused nitrogen-containing heterocyclic systems, which act as a core scaffold in many pharmaceutically relevant compounds. Pyrazolopyrimidinones have been demonstrated to be efficient in treating several diseases, including cystic fibrosis, obesity, viral infection and cancer. In this study using glioblastoma U-251MG cell line, we tested the cytotoxic effects of 15 pyrazolopyrimidinones, synthesised via a two-step process, in combination with cold atmospheric plasma (CAP). CAP is an adjustable source of reactive oxygen and nitrogen species as well as other unique chemical and physical effects which has been successfully tested as an innovative cancer therapy in clinical trials. Significantly variable cytotoxicity was observed with IC50 values ranging from around 11 μM to negligible toxicity among tested compounds. Interestingly, two pyrazolopyrimidinones were identified that act in a prodrug fashion and display around 5–15 times enhanced reactive-species dependent cytotoxicity when combined with cold atmospheric plasma. Activation was evident for direct CAP treatment on U-251MG cells loaded with the pyrazolopyrimidinone and indirect CAP treatment of the pyrazolopyrimidinone in media before adding to cells. Our results demonstrated the potential of CAP combined with pyrazolopyrimidinones as a programmable cytotoxic therapy and provide screened scaffolds that can be used for further development of pyrazolopyrimidinone prodrug derivatives

Influence of molecular weight fractionation on the antimicrobial and anticancer properties of a fucoidan rich-extract from the macroalgae Fucus vesiculosus

The objective of this study was to investigate the antimicrobial and anticancer properties of a fucoidan extract and subsequent fractions isolated from the macroalgae Fucus vesiculosus. The fractions obtained (>300 kDa, 300 kDa fraction presented the lowest IC50 values (0.052% - 24 h; 0.032% - 6 days). The potential bioactivity of fucoidan as an antimicrobial and anticancer agent was demonstrated in this study. Hence, the related mechanisms of action should be explored in a near future.European Commission Horizon 2020Science Foundation IrelandSpanish Ministry of Science, Innovation and Universitie

Ursolic Acid Inhibits Collective Cell Migration and Promotes JNK-Dependent Lysosomal Associated Cell Death in Glioblastoma Multiforme Cells

Ursolic acid (UA) is a bioactive compound which has demonstrated therapeutic efficacy in a variety of cancer cell lines. UA activates various signalling pathways in Glioblastoma multiforme (GBM) and offers a promising starting point in drug discovery; however, understanding the relationship between cell death and migration has yet to be elucidated. UA induces a dose dependent cytotoxic response demonstrated by flow cytometry and biochemical cytotoxicity assays. Inhibitor and fluorescent probe studies demonstrate that UA induces a caspase independent, JNK dependent, mechanism of cell death. Migration studies established that UA inhibits GBM collective cell migration in a time dependent manner that is independent of the JNK signalling pathway. Cytotoxicity induced by UA results in the formation of acidic vesicle organelles (AVOs), speculating the activation of autophagy. However, inhibitor and spectrophotometric analysis demonstrated that autophagy was not responsible for the formation of the AVOs. Confocal microscopy and isosurface visualisation determined co-localisation of lysosomes with the previously identified AVOs, thus providing evidence that lysosomes are likely to be playing a role in UA induced cell death. Collectively, our data identify that UA rapidly induces a lysosomal associated mechanism of cell death in addition to UA acting as an inhibitor of GBM collective cell migration