A molecular and computational study of galbanic acid as a regulator of Sirtuin1 pathway in inhibiting lipid accumulation in HepG2 cells

INTRODUCTION

Sirtuin1 (SIRT1) plays a crucial role in the pathophysiology of non-alcoholic fatty liver disease. We investigated the mechanistic role of galbanic acid (Gal) as a regulator of SIRT1 in silico and in vitro.

METHODS

HepG2 cells were treated with Gal in the presence or absence of EX-527, a SIRT1-specific inhibitor, for 24 h. Sirtuin1 gene and protein expression were measured by RT-PCR and Western blotting, respectively. It has been docked to the allosteric reign of SIRT1 (PDB ID: 4ZZJ) to study the effect of Gal on SIRT1, and then the protein and complex molecular dynamic (MD) simulations had been studied in 100 ns.

RESULTS

The semi-quantitative results of Oil red (p < .03) and TG level (p < .009) showed a significant reduction in lipid accumulation by treatment with Gal. Also, a significant increase was observed in the gene and protein expression of SIRT1 (p < .05). MD studies have shown that the average root mean square deviation (RMSD) was about 0.51 Å for protein structure and 0.66 Å for the complex. The average of radius of gyration (Rg) is 2.33 and 2.32 Å for protein and complex, respectively, and the pattern of root mean square fluctuation (RMSF) was almost similar.

CONCLUSION

Computational studies show that Gal can be a great candidate to use as a SIRT1 ligand because it does not interfere with the structure of the protein, and other experimental studies showed that Gal treatment with SIRT1 inhibitor increases fat accumulation in HepG2 cells.

Galbanic acid suppresses melanoma cell migration and invasion by reducing MMP activity and downregulating N-cadherin and fibronectin

High mortality rate of melanoma is due to the metastasis of malignant cells. Galbanic acid (GBA) is a natural sesquiterpene coumarin with valuable pharmaceutical activities. Our study aimed to investigate whether GBA can affect the migration, invasion, and adhesion of melanoma cells. The survival rate of B16F10 cells was measured using the alamarBlue assay. Scratch, adhesion, and invasion assays were performed to determine the effect of GBA on metastatic behavior of cells. Moreover, gelatin zymography was done to assess the activity of MMP-2 and MMP-9, and qRT-PCR was used to investigate the effect of GBA on the expression of candidate genes. Based on the results of alamarBlue assay, 40 µM GBA was chosen as the optimum concentration for all tests. Our findings indicated that GBA significantly decreased the invasion and migration of B16F10 cells while enhancing their adhesion ability. In addition, gelatin zymography demonstrated that GBA reduced the enzymatic activity of MMP-2 and MMP-9. Moreover, qRT-PCR revealed that GBA reduced the expression of N-cadherin and fibronectin. Current findings demonstrated, for the first time, that GBA inhibited the migration and invasion of melanoma cells via reducing the activity of MMP-2 and MMP-9 and downregulating N-cadherin and fibronectin expression. Accordingly, GBA could be suggested as a potential therapeutic agent for the treatment of melanoma.

Acute oral toxicity assessment of galbanic acid in albino rat according to OECD 425 TG

In spite of the broad biological and also anticarcinogenic effects which have been reported for galbanic acid in various studies, its toxic effects are not still well characterized. The study was accomplished to evaluate the acute oral toxicity of galbanic acid pursuant to Organisation for Economic Co-operation and Development (OECD) TG No. 425. Female rats were received asafoetida extract and galbanic acid in distilled water by oral gavage. According to the existing information, limit test was done for aqueous extract of asafoetida and main test was done for galbanic acid. The animals were monitored for 2 weeks. Then under general anesthesia, the blood samples were obtained from the heart for biochemical and hematological assessment and the vital organs of rats were isolated for pathological evaluation. The results showed that although the Median lethal dose (LD50) of asafoetida extract was above the 2000 mg/kg body weight, the galbanic acid estimated LD50 was 310.2 mg/kg. There was no considerable change in body weight of vehicle and extract treated animals but in galbanic acid treated animals, the body weights were not normally increased. A significant rise was observed in high-density lipoprotein (HDL), (aspartate aminotransferase) AST and (alanine aminotransferase) ALT levels as well as in white blood cells (WBC), platelet and lymphocytes counts in galbanic acid group compared to vehicle and extract groups. Based on the obtained results, we suggest that although the asafoetida aqueous extract could be categorized as group 5 (LD50 > 2000 mg/kg), but galbanic acid estimated LD50 is about 310.2 mg/kg and toxicity signs also appeared in lung, liver enzymes and complete blood count (CBC) of galbanic acid treated animals.

Galbanic Acid Improves Accumulation and Toxicity of Arsenic Trioxide in MT-2 Cells

BACKGROUND

Galbanic acid (GBA) is a sesquiterpene coumarin with valuable pharmacological effects. Adult T-cell lymphoma (ATL) is an aggressive lymphoid malignancy with a low survival rate. Although arsenic trioxide (ATO) is a standard therapeutic agent for ATL treatment, the efficacy of chemotherapy is limited due to the chemoresistance of cells.

OBJECTIVE

The present study was carried out to investigate whether GBA in combination with ATO would improve cytotoxicity against ATL cells.

METHODS

GBA was isolated from the roots of Ferula szowitsiana by column chromatography on silica gel. MT-2 cells were treated with 20 μM GBA + 4 μM ATO, and viability was evaluated by alamarBlue assay. The cell cycle was analyzed by PI staining, while the activity of P-glycoprotein (P-gp) was evaluated by mitoxantrone efflux assay. To understand the molecular mechanisms of GBA effects, the expression of NF-κB (RelA), P53, CDK4, c-MYC, c-FLIPL, and c-FLIPS was evaluated using real-time PCR.

RESULTS

Combinatorial use of GBA + ATO significantly reduced the viability of MT-2 cells and induced cell cycle arrest in the sub-G1 phase. GBA improved mitoxantrone accumulation in cells, indicating that this agent has inhibitory effects on the functionality of the P-gp efflux pump. Moreover, real-time PCR analysis revealed that GBA + ATO negatively regulated the expression of P53, CDK4, c-FLIPL, and c-FLIPS.

CONCLUSION

Due to the interesting effects of GBA on the accumulation and toxicity of ATO, combinatorial use of these agents could be considered a new therapeutic approach for ATL treatment.

Targeted delivery of galbanic acid to colon cancer cells by PLGA nanoparticles incorporated into human mesenchymal stem cells

Objective

The aim of this study was to investigate the efficacy of mesenchyme stem cells (MSCs) derived from human adipose tissue (hMSCs) as carriers for delivery of galbanic acid (GBA), a potential anticancer agent, loaded into poly (lactic-co-glycolic acid) (PLGA) nanoparticles (nano-engineered hMSCs) against tumor cells.

Materials and Methods

GBA-loaded PLGA nanoparticles (PLGA/GBA) were prepared by single emulsion method and their physicochemical properties were evaluated. Then, PLGA/GBA nanoparticles were incorporated into hMSCs (hMSC/PLGA-GBA) and their migration ability and cytotoxicity against colon cancer cells were investigated.

Results

The loading efficiency of PLGA/GBA nanoparticles with average size of 214±30.5 nm into hMSCs, was about 85 and 92% at GBA concentration of 20 and 40 μM, respectively. Nano-engineered hMSCs showed significant higher migration to cancer cells (C26) compared to normal cells (NIH/3T3). Furthermore, nano-engineered hMSCs could effectively induce cell death in C26 cells in comparison with non-engineered hMSCs.

Conclusion

hMSCs could be implemented for efficient loading of PLGA/GBA nanoparticles to produce a targeted cellular carrier against cancer cells. Thus, according to minimal toxicity on normal cells, it deserves to be considered as a valuable platform for drug delivery in cancer therapy.

The effect of RGD-targeted and non-targeted liposomal Galbanic acid on the therapeutic efficacy of pegylated liposomal doxorubicin: From liposomal preparation to in-vivo studies

The anti-cancer therapeutic application of Galbanic acid (Gba) as a strong antiangiogenic sesquiterpene coumarin has been limited due to its low water solubility. This issue necessitates developing new liposomal formulations for the efficient delivery of Gba in vivo. In this study, various liposomal formulations were prepared by a thin-film hydration method, and Gba was incorporated into the liposomal bilayers, which consequently increased its release profile compared to formulations in our previous study prepared by remote loading methods. The most stable formulation with desired properties was selected and decorated with RGD peptide (cyclo [Arg-Gly-Asp-D-Tyr-Cys]) to target tumor vasculature actively. The fluorescently-labeled model liposomes showed that the targeting could improve the receptor-mediated endocytosis of the liposomes higher than those prepared in our previous study in vitro in human umbilical vein endothelial cells (HUVECs), which was confirmed by chicken chorioallantoic membrane angiogenesis (CAM) model in vivo. Although not significant, it also could increase the accumulation of liposomes in colon tumors. In BALB/c mice bearing colon cancer, not only non-targeted Gba liposomes but also even RGD-targeted ones combinatorial therapy with pegylated liposomal doxorubicin could improve the anti-tumor efficacy as compared to their monotherapy. These outcomes have strong consequences for cancer therapy.

Galbanic acid potentiates TRAIL induced apoptosis in resistant non-small cell lung cancer cells via inhibition of MDR1 and activation of caspases and DR5

Galbanic acid (GBA) is known a sesquiterpene coumarin to have apoptotic, anti-hypoxic, anti-proliferative, anti-hepatitis, anti-angiogenic, anti-bacteria and anti-thrombotic effects. Also, antitumor effect of GBA was reported in prostate, ovary, breast and lung cancers. Nevertheless, the underlying molecular mechanism of GBA was not fully understood to overcome chemoresistance in resistant lung cancer so far. Thus, synergistic antitumor mechanism of GBA and TNF-related apoptosis-inducing ligand (TRAIL) was elucidated in H460 and resistant H460/R non-small cell lung cancer cells (NSCLCs). Combination of GBA and TRAIL significantly exerted cytotoxicity in a dose dependent manner compared to GBA or TRAIL alone in H460/R cells. Also, GBA and TRAIL significantly increased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells and sub-G1 population in a dose dependent manner in H460/R cells. Consistently, GBA and TRAIL induced cleavages of poly (ADP-ribose) polymerase (PARP), caspase-9 and caspase-8 along with upregulation of death receptor 5 (DR5) and also attenuated the expression of B-cell lymphoma-extra-large (Bcl-x_L), B-cell lymphoma 2 (Bcl-2), X-linked inhibitor of apoptosis protein (XIAP) in H460/R cells. Furthermore, combination of GBA and TRAIL remarkably inhibited the expression of decoy receptor 1 (DcR1) and multidrug resistance 1(MDR1) in H460/R cells. Consistently, GBA and TRAIL effectively maintained Rhodamine 123 accumulation in H460/R cells compared to GBA or TRAIL alone by blocking multidrug efflux pump from the cells. Overall, our findings suggest that galbanic acid enhances TRAIL induced apoptosis via inhibition of MDR1 and activation of caspases and DR5 in H460/R cells as a potent TRAIL sensitizer.

Proposed binding mechanism of galbanic acid extracted from Ferula assa-foetida to DNA

Recently, galbanic acid (GA), a sesquiterpenoid coumarin, has been introduced as an apoptotic and geno/cytotoxicity agent. In the present study, GA has been extracted from Ferula assa-foetida, a native medicinal plant in Iran, and characterized by ¹H NMR, mass spectroscopy. Additionally, spectroscopic studies have been performed in order to investigate its DNA-interaction mode. The electrochemical behavior of GA has been studied by cyclic voltammetry (CV) in various scan rates. In neutral media (pH=7.3) one irreversible cathodic peak was obtained at -1.46 V, while in higher scan rates an irreversible one was determined at -1.67 V. According to the voltametric data GA can be easily reduced by 2e^-/2H⁺ mechanism at hanging mercury drop electrode (HMDE). The interaction of GA with ct-DNA was evaluated by CV, differential pulse voltammetry (DPV), enhancement fluorescence, UV-Vis, FT-IR spectroscopy and molecular docking. The molecular docking study shows that the GA interacts to DNA on partial intercalation mode via DNA groove binding and forms a complex by van der Waals and electroastatic interactions. In addition, the thermodynamic parameters of GA-DNA complex were investigated with ΔH°, ΔS° and ΔG° values of 15.81KJmol^-1, 133.95Jmol^-1 and -23.10KJmol^-1, respectively. All data revealed that the GA is binding to DNA by van der Waals and electrostatic interactions through the partial intercalations from the DNA's grooves.

Apoptotic Effect of Galbanic Acid via Activation of Caspases and Inhibition of Mcl-1 in H460 Non-Small Lung Carcinoma Cells

Galbanic acid (GBA), a major compound of Ferula assafoetida, was known to have cytotoxic, anti-angiogenic and apoptotic effects in prostate cancer and murine Lewis lung cancer cells; the underling apoptotic mechanism of GBA still remains unclear so far. Thus, in the present study, the apoptotic mechanism of GBA was investigated mainly in H460 non-small cell lung carcinoma (NSCLC) cells because H460 cells were most susceptible to GBA than A549, PC-9 and HCC827 NSCLC cells. Galbanic acid showed cytotoxicity in wild EGFR type H460 and A549 cells better than other mutant type PC-9 and HCC827 NSCLC cells. Also, GBA significantly increased the number of Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells and sub G1 population in H460 cells. Western blotting revealed that GBA cleaved poly (ADP-ribose) polymerase (PARP), activated Bax and caspase 9, attenuated the expression of Bcl-2, Bcl-x(L), and Myeloid cell leukemia 1 (Mcl-1) in H460 cells. However, interestingly, overexpression of Mcl-1 blocked the ability of GBA to exert cytotoxicity, activate caspase9 and Bax, cleave PARP, and increase sub G1 accumulation in H460 cells. Overall, these findings suggest that GBA induces apoptosis in H460 cells via caspase activation and Mcl-1 inhibition in H460 cells as a potent anticancer agent for NSCLC treatment.

Effect of galbanic Acid, a sesquiterpene coumarin from ferula szowitsiana, as an inhibitor of efflux mechanism in resistant clinical isolates of Staphylococcus aureus

Galbanic acid, a sesquiterpene coumarin from Ferula szowitsiana roots, was investigated for its potentiating effect on the antimicrobial activity of antibiotics as well as ethidium bromide, in 6 multidrug resistance (MDR) clinical isolates of Staphylococcus aureus. Galbanic acid had inhibitory effect on none of the isolated bacteria tested (up to 800 μg /ml). The MIC range of ciprofloxacin, tetracycline and ethidium bromide, against all tested S. aureus were 10-80, 10-80 and 4-16 μg/ml, respectively. These were reduced to ≤2.5-5, 2.5-5 and 0.5-2 μg/ml in the presence of galbanic acid (300 μg /ml) or verapamil (100 μg /ml). The rate of ethidium bromide (2 μg /ml) accumulation in clinical isolates was enhanced with galbanic acid (300 μg /ml). There is also a decrease in loss of ethidium bromide from bacteria in the presence of galbanic acid. Similar results were obtained when verapamil (100 μg /ml) was used as an efflux pump inhibitor. Galbanic acid, like verapamil, a typical inhibitor of efflux pump, reduced the MIC of ethidium bromide and tested antibiotics. Since efflux is the only known reported mechanism for ethidium bromide resistance, the reduction in ethidium bromide MIC and enhanced accumulation as well as decreased efflux of ethidium bromide in the presence of galbanic acid, can be attributed to this efflux inhibitory properties.

badrakema, as modulators of multi-drug resistance in clinical isolates of Escherichia coli and Staphylococcus aureus

Galbanic acid, a sesquiterpene coumarin from Ferula szowitsiana, and conferol, another sesquiterpene coumarin from F. badrakema, were evaluated for their effects on the reversal of multi-drug resistance in clinical isolates of Staphylococcus aureus and Escherichia coli, respectively. Neither galbanic acid (up to 1000 μg/ml) nor conferol (up to 400 μg/ml) by itself shows any antibacterial activities against tested strains. The minimum inhibitory concentrations (MICs) of ciprofloxacin and tetracycline were determined using macrodilution technique in the presence and absence of sub-inhibitory concentrations of galbanic acid (31.25-1000 μg/ml) or conferol (50-400 μg/ml), however they caused no change in MICs of the antibiotics. Galbanic acid did not show any inhibitory effect on efflux phenomenon of E. coli. This can be related to the outer membrane of gram-negative bacteria which is impermeable to lipophilic compounds or another mechanism rather than efflux responsible for resistance in tested E. coli strains. An inhibitory effect of conferol on the efflux was compared with verapamil as a positive control. Because efflux is the only known mechanism of resistance to ethidium bromide (model efflux substrate) and verapamil reduced MIC of ethidium bromide, efflux mechanism can be considered as one of the resistance mechanisms in tested S. aureus strains. Conferol, however, did not enhance the antibiotic efficacy mediated by inhibiting efflux pumps in bacteria.