Chemoprotective effects of Ulva lactuca (green seaweed) aqueous‐ethanolic extract against subchronic exposure to benzo(a)pyrene by CYP1A1 inhibition in mice

Toxicity of the organic UV filter oxybenzone to the brown macroalga Hormosira banksii and the green macroalga Ulva lactuca

Oxybenzone (BP-3), a common sunscreen ingredient, has been detected in marine ecosystems and shown to be toxic to various marine species, raising environmental concerns. However, its effects on macroalgae remain largely unknown. This study investigated the toxicity of BP-3 on two macroalgae species: Hormosira banksii and Ulva lactuca. A chronic germination-inhibition experiment with H. banksii and an acute study with mature U. lactuca were conducted using BP-3 concentrations ranging from 0.03 to 27 mg/L. Results revealed significant inhibition of H. banksii spore germination at 3, 9, and 27 mg/L BP-3 at 72 h, with a 10 % effect concentration of 0.363 mg/L (95 % confidence interval: 0.27-0.45 mg/L). For U. lactuca, relative growth rate decreased by 20-70 % compared to controls in treatments of 0.1, 3, 9, and 27 mg/L BP-3 after 72 h. Exposure to ≥0.3 mg/L BP-3 resulted in lower chlorophyll a and b concentrations and higher lipid peroxidation, with significant differences observed between the control and ≥9 mg/L BP-3 treatments. Exposure to 1 mg/L BP-3 induced significant alterations in several key metabolic pathways associated with stress response mechanisms, energy metabolism, and cellular signalling in U. lactuca. These findings suggest that BP-3 does not pose an acute risk to mature U. lactuca or a chronic risk to H. banksii at concentrations typically observed in the marine environment, as in both cases effect concentrations exceeded BP-3 concentrations typically observed in marine environmental water samples. However, further research is needed to assess potential risks associated with chronic exposure to environmentally relevant concentrations. These toxicity data contribute valuable information for future risk assessments of BP-3 and aid in setting water quality guidelines for this widely used organic UV filter.

Mechanisms and targeted reversion/prevention of hepatic fibrosis caused by the non-hereditary toxicity of benzo(a)pyrene

The effect of long term exposure to low concentrations of environmental pollutants on hepatic disorders is a major public health concern worldwide. Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants. In recent years, an increasing number of studies have focused on the deleterious effects of low concentrations of PAHs in the initiation or exacerbation of the progression of chronic liver disease. However, the underlying molecular mechanisms and effective intervention methods remain unclear. Here, we found that in hepatocytes, a low concentration of benzo(a)pyrene (B[a]P, an indicator of PAHs) chronic exposure continuously activated 14-3-3η via an epigenetic accumulation of DNA demethylation. As a "switch like" factor, 14-3-3η activated its downstream PI3K/Akt signal, which in turn promoted vascular endothelial growth factor (VEGF) production and secretion. As the characteristic fibrogenic paracrine factor regulated by B[a]P/14-3-3η, VEGF significantly induced the neovascularization and activation of hepatic stellate cells, leading to the development of hepatic fibrosis. Importantly, targeted 14-3-3η by using its specific inhibitor invented by our lab could prevent B[a]P-induced hepatic fibrosis, and could even reverse existent hepatic fibrosis caused by B[a]P. The present study not only revealed novel mechanisms, but also proposed an innovative approach for the targeted reversion/prevention of the harmful effects of exposure to PAHs on chronic liver disease.

Seaweed Exhibits Therapeutic Properties against Chronic Diseases: An Overview

Seaweeds or marine macroalgae are known for producing potentially bioactive substances that exhibit a wide range of nutritional, therapeutic, and nutraceutical properties. These compounds can be applied to treat chronic diseases, such as cancer, cardiovascular disease, osteoporosis, neurodegenerative diseases, and diabetes mellitus. Several studies have shown that consumption of seaweeds in Asian countries, such as Japan and Korea, has been correlated with a lower incidence of chronic diseases. In this study, we conducted a review of published papers on seaweed consumption and chronic diseases. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method for this study. We identified and screened research articles published between 2000 and 2021. We used PubMed and ScienceDirect databases and identified 107 articles. This systematic review discusses the potential use of bioactive compounds of seaweed to treat chronic diseases and identifies gaps where further research in this field is needed. In this review, the therapeutic and nutraceutical properties of seaweed for the treatment of chronic diseases such as neurodegenerative diseases, obesity, diabetes, cancer, liver disease, cardiovascular disease, osteoporosis, and arthritis were discussed. We concluded that further study on the identification of bioactive compounds of seaweed, and further study at a clinical level, are needed.

Detoxification of Oral Exposure to Benzo(a)pyrene by Lactobacillus plantarum CICC 23121 in Mice

This study's previous work showed that the carcinogen and mutagen benzo(a)pyrene (BaP) can be adsorbed by Lactobacillus cells in vitro. However, in vivo BaP detoxification by lactic acid bacteria has not yet been investigated. The present study evaluates the effects of orally administered Lactobacillus plantarum CICC 23121 in BaP-treated mice. Oral administration of 50 mg kg^-1 BaP perturbed the intestinal microflora, caused Proteobacteria to predominate, and severely damaged DNA. However, oral administration of 5 × 10¹⁰ CFU mL^-1 CICC 23121 in BaP-treated mice enhances fecal BaP excretion from 181.70 ± 1.04 µg/(g∙h) to 271.47 ± 11.71 µg/(g∙h) after 6 h. Fecal BaP excretion reaches up to 280.66 ± 22.97 µg/(g∙h) after the first 4 days of orally administered CICC 23121 and decreased to 94.31 ± 2.64 µg/(g∙h) by day 11. Intestinal microbiota are restored and Firmicutes predominates. CICC 23121 alleviates BaP-induced DNA damage and reduces tail length from 56.37 ± 5.31  to 39.69 ± 4.27 µm. Therefore, oral CICC23121 consumption is a promising strategy for reducing BaP toxicity in mice. To the best of our knowledge, this report is the first report to demonstrate in vivo that Lactobacillus cells can detoxify BaP.

Melatonin inhibits Benzo(a)pyrene-Induced apoptosis through activation of the Mir-34a/Sirt1/autophagy pathway in mouse liver

Benzo(a)pyrene (BaP), an important environmental pollutant, is produced as the result of incomplete combustion of organic materials in many industries and food cooking process. It has been purposed that BaP induces hepatotoxicity through oxidative stress and apoptosis. Several studies have shown that melatonin can protect against chemical-induced apoptosis through autophagy pathway. In this study, we assessed the modulating effect of melatonin, a well-known antioxidant, on BaP-induced hepatotoxicity through induction of autophagy. Thirty male mice were treated daily for 28 consecutive days. BaP (75 mg/kg; oral gavage) and melatonin (10 and 20 mg/kg, i.p.) were administered to mice. The liver histopathology and the levels of apoptosis and autophagy proteins as well as the expression of miR-34a were determined. The BaP exposure induced severe liver histological injury and markedly enhanced AST, ALT and MDA level. Also, apoptosis proteins and hepatic miR-34a expression increased. However, the level of Sirt1 and autophagy markers such as LC3 II/I ratio and Beclin-1 reduced. The co-administration of melatonin reversed all changes caused by BaP. In summary, melatonin appears to be effective in BaP-induced hepatotoxicity maybe through the miR-34a/Sirt1/autophagy molecular pathway.

Cytochrome P450s regulates aloperine-induced pathological changes in mouse liver and kidney

Aloperine is a major active component in Sophora alopecuroides L that plays diverse pharmacological properties. Recent studies have indicated the potential effect of aloperine against hypertension and cancers. However, possible toxicity of aloperine has not been carefully studied in vivo. The aim of this study was to assess the effect of intraperitoneal aloperine injection on mouse liver and kidney tissues and to investigate the role of CYP450 genes in aloperine-induced toxicity. 72 BALB/c mice were randomly divided into four groups: vehicle control group (normal saline), low-dose group (4 mg/kg), medium-dose group (8 mg/kg), and high-dose group (16 mg/kg). 18 mice in each group were intraperitoneally injected with aloperine daily for 4 weeks, and were then kept for another 1 or 4 weeks without aloperine treatment. Serum was colleted for analysis of serum biochemical indexes including ALT, AST, BUN and CRE. The liver and kidney were collected for analysis of histopathologic changes and CYP450 expression and activity. Vacuolization of cytoplasm in liver cells, swelling in kidney tubular cells, increased levels of ALT, AST, BUN, and CRE, and alteration in the expression and activity of CYP450 were observed in the high-dose group after 4 weeks of treatment. However, all aloperine-induced damages were recovered to a certain degree after maintained without aloperine for 1 week, and fully recovered after maintained without aloperine for 4 weeks. These findings suggested that aloperine regulated the expression of CYP450, which was possibly involved in aloperine-induced reversible toxicity in mouse liver and kidney tissues.