Protective effect of Spirulina against 4-nitroquinoline-1-oxide induced toxicity

Is the carotenoid production from Phaffia rhodozyma yeast genuinely sustainable? a comprehensive analysis of biocompatibility, environmental assessment, and techno-economic constraints

Microorganisms, such as yeasts, filamentous fungi, bacteria, and microalgae, have gained significant attention due to their potential in producing commercially valuable natural carotenoids. In recent years, Phaffia rhodozyma yeasts have emerged as intriguing non-conventional sources of carotenoids, particularly astaxanthin and β-carotene. However, the shift from academic exploration to effective industrial implementation has been challenging to achieve. This study aims to bridge this gap by assessing various scenarios for carotenoid production and recovery. It explores the use of ionic liquids (ILs) and bio-based solvents (ethanol) to ensure safe extraction. The evaluation includes a comprehensive analysis involving Life Cycle Assessment (LCA), biocompatibility assessment, and Techno-Economic Analysis (TEA) of two integrated technologies that utilize choline-based ILs and ethanol (EtOH) for astaxanthin (+β-carotene) recovery from P. rhodozyma cells. This work evaluates the potential sustainability of integrating these alternative solvents within a yeast-based bioeconomy.

Negative terpinen-4-ol modulate potentially malignant and malignant lingual lesions induced by 4-nitroquinoline-1-oxide in rat model

Our aim was to verify the modulative TP-4-ol capacity in 4-nitroquinoline-1-oxide induced oral rat cancer. The stereoisomers of TP-4-ol were used against the human tongue squamous cell line and the negative stereoisomer showed lower IC50. Thirty-one Holtzman rats (120-130 g) were cancer-induced by 4-nitroquinoline-1-oxide (4-NQO/8 weeks/25 ppm) and 32 Holtzman rats (120-130 g) were used to healthy and TP-4-ol toxicity experiments. Six groups were used, healthy, 0.1nL/g of TP-4-ol, 8nL/g of TP-4-ol, 4-NQO, 4-NQO + 0.1nL/g of TP-4-ol, and 4-NQO + 8nL/g of TP-4-ol. We performed the toxicity analysis by biochemical and histopathological analysis. The biochemistry analysis includes alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate transaminase (AST), urea, and creatinine and the histopathology analysis includes the liver, kidney, lung, and spleen. Specifically, for malign modulation, we performed a macroscopic and microscopic analysis. The group exposed to 0.1nL/g of TP-4-ol demonstrated a reduced risk of malignancy in dysplasia considering the criteria of architecture and cytology. Similarly, a drop of percentual rats with SCC diagnosis was observed in 4-NQO + 0.1nL/g (41.6%) when compared to 4-NQO (87.5%). Moreover, the 4-NQO group presented a median of 2.62 SCC/rat and the 4-NQO + 0.1nL/g demonstrated a median of 0.75 SCC/rat. For toxicity analysis, 4-NQO + 0.1nL/g showed focal necrosis in the kidney and 4-NQO showed lung hemorrhagic areas. The concentration of 0.1nL/g was more effective in reducing the tongue induction of potentially malignant and malignant lesions by 4-NQO. A kidney toxicity was observed in healthy animals exposed to 0.1nL/g of TP-4-ol. The negative isoform of terpinen-4-ol negatively modulates the development of potentially malignant and malignant lesions in rats (Rattus nonverdicts albinos, Holtzman) exposed to 4-NQO. (-)-Terpinen-4-ol reduced the mice percentual with squamous cell carcinoma, 87.5 to 41.6%, and decreased the cancer/rat ratio of 2.62 in 4-NQO to 0.75 in 4-NQO + 0.1nL/g. This represents 52.4% by group and 71.3% in the cancer/rat ratio.

Hepatoprotective effect of Spirulina platensis against carbon tetrachloride-induced liver injury in male rats

OBJECTIVES

Spirulina platensis (SP) is an edible Cyanobacterium with ethnomedicinal significance. This study aims at evaluating the beneficial effect of SP against carbon tetrachloride (CCl4)-induced liver toxicity in male rats.

METHODS

Rats received intraperitoneal injections of CCl4 (2 ml/kg body weight [b.w.] per every other day) for 40 days, alone or in combination with oral treatments of SP (400 mg/kg b.w. per day).

KEY FINDINGS

SP attenuated haematological disturbances, serum liver markers, hepatic necrosis and inflammation, and dyslipidemia in CCl4-intoxicated rats. SP also reduced CCl4-induced oxidative stress by increasing the activities of antioxidant enzymes, such as glutathione peroxidase, superoxide dismutase and catalase and glutathione content, and inhibiting lipid peroxidation products and nitric oxide levels in the rat liver. Further investigations revealed that SP counteracted CCl4-induced increased hepatic levels of Ki-67 (a parameter of cell proliferation), interleukin-6, and tumour necrosis factor-alpha and cyclooxygenase-2 messenger RNA expression. Noticeably, the supplementation of SP restored the decrease of proapoptotic p53 protein levels in the liver of rats treated with CCl4.

CONCLUSIONS

SP prevented liver damage in CCl4-treated rats via augmentation of antioxidant defense mechanisms and inhibition of inflammatory cytokines/mediators and antiproliferative effects.

Arthrospira platensis accelerates the formation of an endothelial cell monolayer and protects against endothelial cell detachment after bacterial contamination

Within the last years a comprehensive number of scientific studies demonstrated beneficial effect of Arthropira platensis (AP) as dietary supplement due to a high content of proteins, minerals and vitamins. Positive effects like promoting the immune system, reducing inflammation and an anti-oxidant capacity are reported. In this study, the effect of an aqueous AP extract on primary human venous endothelial cells (HUVEC) was investigated. In addition, the effect of AP on HUVEC treated with a bacterial toxin (lipopolysaccharide, LPA), inducing an activation of HUVEC and cellular detachment, was analyzed. Depending on the concentration of AP extract a significantly accelerated formation of an endothelial cell monolayer was observed. Furthermore, the detachment of HUVEC after LPA addition was dramatically reduced by AP. In conclusion, the data are promising and indicatory for an application of Arthrospira platensis in the clinical field.

Preclinical antitoxic properties of Spirulina (Arthrospira)

CONTEXT

Spirulina (Arthrospira) exerts a wide spectrum of pharmacological activities which are mainly attributed to its antioxidant effect. However, Spirulina has also been reported (both in preclinical and in clinical scenarios) to exhibit other bioactive effects, including an antitoxic potential.

OBJECTIVE

We performed a systematic review of the literature, conducted in TOXNET, PubMed/MEDLINE, and Science Direct-Scopus; all available years were included. Searching criteria included the effects of Spirulina on experimental poisonings from arsenic, cadmium, carbon tetrachloride, deltamethrin, fluoride, hexachlorocyclohexane, iron, lead, lindane, and mercury.

RESULTS

In all cases, it was established that the blue-green alga, and its isolated compounds, effectively counteracted these pollutants toxic effects on the exposed organisms. Some molecular mechanisms are proposed, although they have not been fully elucidated yet.

CONCLUSION

Spirulina could be a useful coadjuvant agent within clinical practice for treatment of these or other pollutants poisonings.

Alleviation of 4-nitroquinoline 1-oxide induced oxidative stress by Oroxylum indicum (L.) leaf extract in albino Wistar rats

Background

4-nitroquinoline 1-oxide (4-NQO) is a mutagen known to be responsible for causing cancer by generating oxidative stress in humans. Oroxylum indicum (L.) possesses various bioactive compounds with antioxidant properties. In this connection, the present study aims to analyze the alleviation of 4-NQO induced oxidative stress in albino Wistar rats using O. indicum (L.) leaf extract.

Methods

O. indicum (L.) belonging to the family Bignoniaceae, has anticancer and anti-inflammatory properties. In this study, we observed severe oxidative stress in 4-NQO induced albino Wistar rats when compared to untreated control. Alleviation of this condition was seen after the oral administration of O. indicum (L.) leaf extract at 50, 100, and 200 mg/kg body weight.

Results

4-NQO (50 ppm) administration in drinking water resulted in the generation of reactive oxygen species (ROS) leading to cellular damage, lipid peroxidation and imbalance in antioxidant status. Administration of O. indicum (L.) leaf extract has alleviated the level of 4-NQO induced oxidative stress by increasing the antioxidant status and decreasing the elevation of liver markers in serum.

Conclusions

Results clearly suggest that O. indicum (L.) leaf extract when administered orally in a dose dependent manner has the ability to overcome the oxidative stress induced by 4-NQO with hepatoprotective and lipid protective properties.

The increase of oncogenic miRNA expression in tongue carcinogenesis of a mouse model

OBJECTIVES

This study investigated the oncogenic miRNA level in the tissue and biofluids in the Nitroquinoline 1-Oxide (4NQO)-induced mouse tongue carcinogenesis model for potential diagnostic or therapeutic application.

MATERIALS AND METHODS

The histological examination, immunohistochemistry, in situ hybridization, quantitative PCR analysis and bioinformatic algorithms were performed to unravel the signaling activation and miRNA expression in female murine samples.

RESULTS

The increase of miR-21 and miR-31 staining, and EGFR activation paralleled the severity of 4NQO-induced epithelial pathogenesis in tongue epithelium. A progressive increase of miR-21, miR-31 and miR-146a in both saliva and plasma samples was also noted. miR-31 was the earliest emerging miRNA in the saliva. The increase of plasma miR-146a, miR-184 and miR-372 was detectable early in the induction, and it was particularly eminent at the most advanced lesion state. The combined analysis of the multiple oncogenic miRNAs in the plasma signified a potent discriminative capacity between normal and pathological states. As the blockage of EGFR or AKT activation drastically reverted the miR-21, miR-31 and miR-146a expression induced by 4NQO in human oral carcinoma cell lines, the results implicated a mechanistic linkage of the oncogenic miRNAs' induction through EGFR/AKT activation.

CONCLUSIONS

In this study, we show the dysregulation of oncogenic miRNAs in murine tongue tumorigenesis, which simulates human counterparts. Increased multiple miRNAs in the biofluids may be valuable non-invasive markers in detecting oral carcinogenesis at an early stage. This animal model may also be useful for developing liquid biopsies and prevention strategies against oral carcinoma by abrogating EGFR or oncogenic miRNAs.

Toxicity of 8-Hydroxyquinoline in Cryprinus carpio Using the Acute Toxicity Test, Hepatase Activity Analysis and the Comet Assay

To evaluate the environmental toxicity of 8-hydroxyquinoline (8-HOQ), an important industrial raw material found in China's major ornamental fish, Cryprinus carpio, using the acute toxicity test, hepatase activity analysis and the comet assay. The results indicated that 8-HOQ had significant acute toxicity in adult C. carpio with a 96 h-LC50 of 1.15 and 0.22 mg L(-1) hepatic quinoline residues as assessed by HPLC. 8-HOQ also induced genotoxicity in the form of strand breaks in the DNA of hepatic cells as shown by the comet assay. With regard to physiological toxicity, 8-HOQ induced a decrease in the activities of hepatic GOT and GPT with increased exposure concentration and time. These data suggest that 8-HOQ may be toxic to the health of aquatic organisms when accidentally released into aquatic ecosystems. The data also suggest that the comet assay may be used in biomonitoring to determine 8-HOQ genotoxicity and hepatic GPT and GOT activities may be potential biomarkers of physiological toxicity.

Antimutagenicity of Methanolic Extracts from Anemopsis californica in Relation to Their Antioxidant Activity

Anemopsis californica has been used empirically to treat infectious diseases. However, there are no antimutagenic evaluation reports on this plant. The present study evaluated the antioxidant activity in relation to the mutagenic and antimutagenic activity properties of leaf (LME) and stem (SME) methanolic extracts of A. californica collected in the central Mexican state of Querétaro. Antioxidant properties and total phenols of extracts were evaluated using DPPH (1,1-diphenyl-2-picrylhydrazyl) and Folin-Ciocalteu methods, respectively. Mutagenicity was evaluated using the Ames test employing Salmonella enterica serovar Typhimurium strains (TA98, TA100, and TA102), with and without an aroclor 1254 (S9 mixture). Antimutagenesis was performed against mutations induced on the Ames test with MNNG, 2AA, or 4NQO. SME presented the highest antioxidant capacity and total phenolic content. None of the extracts exhibited mutagenicity in the Ames test. The extracts produced a significant reduction in 2AA-induced mutations in S. typhimurium TA98. In both extracts, mutagenesis induced by 4NQO or methyl-N′-nitro-N-nitrosoguanidine (MNNG) was reduced only if the exposure of strains was <10 μg/Petri dish. A. californca antioxidant properties and its capacity to reduce point mutations render it suitable to enhance medical cancer treatments. The significant effect against antimutagenic 2AA suggests that their consumption would provide protection against carcinogenic polycyclic aromatic compounds.

Systemic toxic effects during early phases of topical 4-NQO-induced oral carcinogenesis in rats

BACKGROUND

Most studies have demonstrated 4-NQO toxicity to oral epithelium during oral carcinogenesis induction, but systemic toxicity has been poorly addressed. The aim of this study was to describe the systemic effect of 4-NQO topical application during early phases of oral cancer induction.

METHODS

A 4-NQO propylene glycol ointment was topically applied on the rat tongue three times a week for 16 weeks. Local and systemic 4-NQO toxicity was evaluated by body weight gain, hematology, and serum chemistry analyses, histopathology, and proliferating cell nuclear antigen (PCNA) immunohistochemistry.

RESULTS

Significant reduction in body weight gain and in white blood cell count as well as significant increase in serum ALT and AST was observed after 16 weeks of 4-NQO topical application. Focal hepatic lobular necrosis, renal tubular degeneration, and decreased cellularity in the splenic white pulp were also detected.

CONCLUSIONS

4-NQO topical application on the tongue of rats for 16 weeks seems to have caused hepatic, renal, and splenic toxicity. Potential systemic toxicity should be considered to monitor for variables that could interfere in topical oral carcinogenesis experiments.

The protective effect of dietary Arthrospira (Spirulina) maxima against mutagenicity induced by benzo[alpha]pyrene in mice

Benzo[alpha]pyrene (B[α]P) was used to test the possible antimutagenic effects of Arthrospira (Spirulina) maxima (SP) on male and female mice. SP was orally administered at 0, 200, 400, or 800 mg/kg of body weight to animals of both sexes for 2 weeks before starting the B[α]P (intraperitoneal injection) at 125 mg/kg of body weight for 5 consecutive days. For the male dominant lethal test, each male was caged with two untreated females per week for 3 weeks. For the female dominant lethal test, each female was caged for 1 week with one untreated male. All the females were evaluated 13-15 days after mating for incidence of pregnancy, total corpora lutea, total implants and pre- and postimplant losses. SP protected from B[α]P-induced pre- and postimplant losses in the male dominant lethal test, and from B[α]P-induced postimplantation losses in treated females. Moreover, SP treatment significantly reduced the detrimental effect of B[α]P on the quality of mouse semen. Our results illustrate the protective effects of SP in relation to B[α]P-induced genetic damage to germ cells. We conclude that SP, owing mainly to the presence of phycocyanin, could be of potential clinical interest in cancer treatment or prevention of relapse.

Inhibitory Effects of Spirulina platensis on Carcinogen-Activating Cytochrome P450 Isozymes and Potential for Drug Interactions

Spirulina platensis (SP) has been considered as potential food source of 21st century due to its remarkable nutrient profile and therapeutic benefits. However, the cytochrome P450 (CYP)-mediated drug/chemical interaction potential of SP has not yet been pursued. We investigated the effects of SP on the expressions and enzymatic activities of main CYP isozymes. After the rats were orally administered with SP daily for 5 consecutive weeks, there were significant downregulations in hepatic expression levels and inhibition in enzymatic activities of CYP1A2 and CYP2E1 compared to controls. In addition, a significant decrease was observed in CYP2C6-associated enzyme activity with no remarkable changes in messenger RNA (mRNA)/protein levels. The SP application resulted in significant increases in mRNA/protein levels of both CYP2B1 and CYP3A1 without a significant change in enzyme activities. These findings partly explain the chemopreventive properties of SP toward various organ toxicities, mutagenesis, and carcinogenesis; however, its coadministration with some CYP substrates may lead to undesirable drug interactions.

Genotoxic effects of 8-hydroxylquinoline in loach (Misgurnus anguillicaudatus) assessed by the micronucleus test, comet assay and RAPD analysis

This study was a preliminary step in evaluating the genotoxic effects of 8-hydroxylquinoline (8-HOQ) in loach (Misgurnus anguillicaudatus) using the micronucleus, comet and RAPD assays. In the micronucleus test and comet assay, the micronuclei rate (%) and three comet parameters (trailing rate, tail length and tail moment) in treated fish increased with increasing 8-HOQ concentration and treatment time. These results showed that exposure to 8-HOQ significantly induced genetic toxicity in loach blood cells. A subsequent RAPD assay also showed that 8-HOQ induced a genotoxic effect in loach. Among the 23 tested RAPD primers, 11 primers produced unique polymorphic band patterns and generated RAPD profile variations that displayed the band intensity, disappearance of bands and appearance of new bands of amplified DNA in the 8-HOQ-treated genomic DNA samples. In addition, the variation in RAPD profiles was time- and concentration-dependent. These results suggested that 8-HOQ is potentially harmful to fish and may be a toxic contaminant in the aquatic environment.

Roles of Keap1-Nrf2 system in upper aerodigestive tract carcinogenesis

Cancers in the upper aerodigestive tract, including cancers of the tongue and the esophagus, are the third leading cause of cancer-related deaths in the world, and oxidative stress is well recognized as one of the major risk factors for carcinogenesis. The Keap1-Nrf2 system plays a critical role in cellular defense against oxidative stress, but little is known about its association with upper aerodigestive tract carcinogenesis. In this study, we examined whether loss of Nrf2-function exacerbates carcinogenesis by using an experimental carcinogenesis model that is induced by 4-nitroquinoline-1-oxide (4NQO). We found that Nrf2-knockout (Nrf2-KO) mice were more susceptible to 4NQO-induced tongue and esophageal carcinogenesis than wild-type mice, which suggests that Nrf2 is important for cancer prevention. We also examined how the suppression of Keap1 function or the induction of Nrf2 activity affected 4NQO carcinogenesis. Keap1-knockdown (Keap1-KD) mice were resistant to 4NQO-induced tongue and esophageal carcinogenesis. Importantly, no growth advantage was observed in tongue tumors in the Keap1-KD mice. These results show that the Keap1-Nrf2 system regulates an important defense mechanism against upper aerodigestive tract carcinogenesis. In addition to several important functions of Nrf2 that lead to cancer chemoprevention, we hypothesize that a mechanical defense of thickened keratin layers may also be a chemopreventive factor because thickened, stratified, squamous epithelium was found on the tongue of Keap1-KD mice.