Evaluation of the acute and 28-day sub-acute intravenous toxicity of α-l-guluronic acid (ALG; G2013) in mice

Monolacunary Wells-Dawson Polyoxometalate as a Novel Contrast Agent for Computed Tomography: A Comprehensive Study on In Vivo Toxicity and Biodistribution

Polyoxotungstate nanoclusters have recently emerged as promising contrast agents for computed tomography (CT). In order to evaluate their clinical potential, in this study, we evaluated the in vitro CT imaging properties, potential toxic effects in vivo, and tissue distribution of monolacunary Wells-Dawson polyoxometalate, α2-K10P2W17O61.20H2O (mono-WD POM). Mono-WD POM showed superior X-ray attenuation compared to other tungsten-containing nanoclusters (its parent WD-POM and Keggin POM) and the standard iodine-based contrast agent (iohexol). The calculated X-ray attenuation linear slope for mono-WD POM was significantly higher compared to parent WD-POM, Keggin POM, and iohexol (5.97 ± 0.14 vs. 4.84 ± 0.05, 4.55 ± 0.16, and 4.30 ± 0.09, respectively). Acute oral (maximum-administered dose (MAD) = 960 mg/kg) and intravenous administration (1/10, 1/5, and 1/3 MAD) of mono-WD POM did not induce unexpected changes in rats' general habits or mortality. Results of blood gas analysis, CO-oximetry status, and the levels of electrolytes, glucose, lactate, creatinine, and BUN demonstrated a dose-dependent tendency 14 days after intravenous administration of mono-WD POM. The most significant differences compared to the control were observed for 1/3 MAD, being approximately seventy times higher than the typically used dose (0.015 mmol W/kg) of tungsten-based contrast agents. The highest tungsten deposition was found in the kidney (1/3 MAD-0.67 ± 0.12; 1/5 MAD-0.59 ± 0.07; 1/10 MAD-0.54 ± 0.05), which corresponded to detected morphological irregularities, electrolyte imbalance, and increased BUN levels.

Polyguluronic acid alleviates doxorubicin-induced cardiotoxicity by suppressing Peli1-NLRP3 inflammasome-mediated pyroptosis

Polyguluronic acid (PG), a polysaccharide from alginate, possesses excellent bioactivities. We prepared high-purity PG with 10.41 kDa molecular weight (Mw) and a 59 average degree of polymerization (DP) by acid hydrolysis, three pH grades, Q-Sepharose column elution, and Sephadex G-25 column desalination. Then, we evaluated the PG protective effects on doxorubicin-induced cardiotoxicity (DIC) in vitro and in vivo. The nontoxic PG enhanced cellular viability, reduced cell pyroptosis morphology, diminished the LDH and IL-1β release, and downregulated expressions of ASC oligomerization, NLRP3, cl-CASP1, and GSDMD, by which PG protected the cardiomyocytes from NLRP3 inflammasome-mediated pyroptosis in doxorubicin-stimulated HL-1 cells and C57BL/6J mice. The probable underlying mechanism may be that PG downregulated doxorubicin -induced Peli1, the deficiency of which could inhibit doxorubicin-induced NLRP3 inflammasome-mediated pyroptosis. These results suggested that polysaccharide PG from alginate could prevent DIC and may be a potential therapeutic agent or bioactive material for preventing DIC.

In vivo toxicity evaluation of a polyoxotungstate nanocluster as a promising contrast agent for computed tomography

In this study, we demonstrate for the first time, that a discrete metal-oxo cluster α-/β-K₆P₂W₁₈O₆₂ (WD-POM) exhibits superior performance as a computed tomography (CT) contrast agent, in comparison to the standard contrast agent iohexol. A toxicity evaluation of WD-POM was performed according to standard toxicological protocols using Wistar albino rats. The maximum tolerable dose (MTD) of 2000 mg/kg was initially determined after oral WD-POM application. The acute intravenous toxicity of single WD-POM doses (1/3, 1/5, and 1/10 MTD), which are at least fifty times higher than the typically used dose (0.015 mmol W kg^-1) of tungsten-based contrast agents, was evaluated for 14 days. The results of arterial blood gas analysis, CO-oximetry status, electrolyte and lactate levels for 1/10 MTD group (80% survival rate) indicated the mixed respiratory and metabolic acidosis. The highest deposition of WD-POM (0.6 ppm tungsten) was found in the kidney, followed by liver (0.15 ppm tungsten), for which the histological analysis revealed morphological irregularities, although the renal function parameters (creatinine and BUN levels) were within the physiological range. This study is the first and important step in evaluating side effects of polyoxometalate nanoclusters, which in recent years have shown a large potential as therapeutics and contrast agents.

The Open, Randomized, Positive Control Clinical Trial of Guluronic Acid (G2013) on SARS-CoV-2 Patients

INTRODUCTION

Recently, the coronavirus disease 2019 (COVID-19) infection, with a vast spectrum of clinical and paraclinical symptoms has been a major health concern worldwide. Therapeutical management of COVID-19 includes antiviral and anti-inflammatory drugs. NSAIDs, as the second-line therapy, are often prescribed to relieve the symptoms of COVID-19. The α-L-guluronic acid (G2013) is a non-steroidal patented (PCT/EP2017/067920) agent with immunomodulatory properties. This study investigated the effect of G2013 on the outcome of COVID-19 in moderate to severe patients.

METHODS

The disease's symptoms were followed up during hospitalization and for 4 weeks postdischarge in G2013 and control groups. Paraclinical indices were tested at the time of admission and discharge. Statistical analysis was performed on clinical and paraclinical parameters and ICU admission and death rate.

RESULTS

The primary and secondary outcomes indicated the efficiency of G2013 on COVID-19 patients' management. There were significant differences in the duration of improvement of fever, coughing, fatigue/malaise. Also, a comparison of paraclinical indices at the time of admission and discharge showed significant change in prothrombin, D-dimer, and platelet. As the main findings of this study, G2013 significantly decreased the percentage of ICU admission (control:17 patients, G2013:1 patient) and death (control: 7 cases, G2013:0).

CONCLUSION

These results conclude that G2013 has sufficient potential to be considered for moderate to severe COVID-19 patients, can significantly reduce the clinical and physical complications of this disease, has a positive effect on modulating the coagulopathy process, and aids in saving lives.

Evaluation of G2013 (α-L-guluronic acid) efficacy on PC-3 cells through inhibiting the expression of inflammatory factors

Given multiple treatment strategies for prostate cancer, its mortality rate is still high; therefore, novel treatment strategies seem necessary. G2013 or α-L-guluronic acid is a new patented drug with immunomodulatory and anti-inflammatory properties. This study aimed to evaluate the property of G2013 on inflammatory molecules involved in tumorigenesis of prostate cancer. MTT assay was used to assess the effect of the drug on the proliferation of PC-3 cells. Expression of interleukin 8 (IL-8), Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), myeloid differentiation factor 88 (MYD-88), cyclooxygenase 2 (COX-2), matrix metalloproteinase-2 (MMP-2), and MMP-9 genes were studied in the PC-3 cells treated with 25 (low dose) or 50 (high dose) µg/mL of G2013 for 24 h using quantitative real-time polymerase chain reaction (qRT-PCR) technique. Protein expression of NF-κB and protein activities of MMP-2 and MMP-9 were assayed using flow cytometry and gelatin zymography, respectively. The expression of COX-2 (p = 0.007 at low dose), MMP-2 (p = 0.023 at low dose, p = 0.002 at high dose), NF-κB (p = 0.004 at low dose) and IL-8 (p < 0.0001 in both doses) genes, NF-κB protein (p < 0.0001 in both doses), and MMP-2 activity (p < 0.0001 in both doses) were significantly reduced in the presence of G2013 as compared to the control group. Cancer cell proliferation was also inhibited under 10-500 µg/mL G2013 treatment. Our results revealed that G2013 has the potential to inhibit PC-3 cell proliferation and reduce the expression of tumour-promoting mediators, COX-2, MMP-2, NF-κB, and IL-8 involved in the progression and metastasis of prostate cancer.