Differential toxicity and teratogenic effects of the hot water and cold water extracts of Lignosusrhinocerus (Cooke) Ryvarden sclerotium on zebrafish (Danio rerio) embryos

Anti-angiogenic and anti-tumour activities of Lignosus rhinocerus (Cooke) Ryvarden water extracts on HCT116 human colorectal carcinoma cells implanted in chick embryos

ETHNOPHARMACOLOGICAL RELEVANCE

The sclerotium of Lignosus rhinocerus (Cooke) Ryvarden is used by the local communities in Southeast Asia and China to treat cancer, asthma, fever, and other ailments based on traditional knowledge. The sclerotial water extracts were previously reported to exhibit cytotoxic, apoptotic, and immunomodulatory activities - providing a scientific basis for its use in treating cancer; however, there is still a lack of evidence on its potential anti-angiogenic activity.

AIM OF THE STUDY

This study aimed to investigate the toxicity, anti-angiogenic, and anti-tumour activities of the hot-water and cold-water extracts of L. rhinocerus using HCT116 human colorectal carcinoma cells implanted in the chick chorioallantoic membrane (CAM) model.

MATERIALS AND METHODS

The toxicity of L. rhinocerus extracts towards the chick embryos was determined 24 h post-treatment. The anti-angiogenic activity of the extracts was then investigated at 0.1-10 μg/embryo (6.7-670 μg/mL) at targeted blood vessels. The anti-tumour effect of selected extracts against the HCT116 human colorectal carcinoma cells xenografted onto the chick embryos was also studied.

RESULTS

The cold-water extracts of L. rhinocerus displayed strong in ovo toxicity (LC50: 1.2-37.7 μg/mL) while the hot-water extracts are non-toxic up to 670 μg/mL. Among the extracts, the hot-water extracts demonstrated the highest anti-angiogenic activity with 44.0 ± 17.7% reduction of capillary diameter (relative to the saline-treated control). Moreover, treatment of the HCT116 cells xenografted onto the chick embryos with the hot-water extracts resulted in smaller tumour size and lower number of blood vessels compared to the saline-treated control.

CONCLUSIONS

The hot-water extracts of L. rhinocerus sclerotium demonstrated anti-angiogenic and anti-tumour activities but most of the cold-water extracts at similar concentrations were devoid of that. Our findings provide further scientific validation of the medicinal use of the sclerotium in treating cancer and thus, expanding our knowledge on the possible mechanism of its anti-cancer effect apart from direct cytotoxicity, induction of apoptosis and immunomodulation that have been studied thus far.

Metabolic exploration of the developmental abnormalities and neurotoxicity of Esculentoside B, the main toxic factor in Phytolaccae radix

P: radix is a perennial herb, and its extracts have various biological properties that make it a potential candidate for the treatment of tumors, edema, and lymphatic stasis. However, the main factor contributing to its toxicity are not clear. Here, we used a zebrafish toxicological model to study the main toxicity factor of P. radix and explore the potential mechanisms involved. The results revealed that Esculentoside B was the major toxic factor of P. radix. Exposure of zebrafish larvae to Esculentoside B caused developmental abnormalities, neurotoxicity and altered locomotor behavior. The combination of AChE activity and the expression levels of genes relevant to CNS development demonstrated that Esculentoside B is neurotoxic to zebrafish larvae, impairs their CNS development, and that AChE may be a toxic target of Esculentoside B. Metabolomic analysis has revealed that Esculentoside B exposure can disrupt D-Amino acid metabolism, protein export, autophagy, and mTOR signaling pathways in zebrafish larvae. These findings provide insights into the molecular mechanisms underlying EsB-induced neurotoxicity in zebrafish, which can facilitate further research and development of P. radix for safe consumption.

Analysis toxicity by different methods and anxiolytic effect of the aqueous extract Lippia sidoides Cham

Lippia sidoides Cham. (Verbenaceae) is a species often mentioned in traditional medicine due to the medicinal properties attributed to its leaves, which include antibacterial, antifungal, acaricidal and antioxidant. Several of these actions have been scientifically proven, according to reports in the literature; however, little is known about toxicological aspects of this plant. This work included studies to determine the chemical composition and toxicity tests, using several methods aiming to evaluate the safety for use of the aqueous extract of L. sidoides leaves, in addition, the anxiolytic effect on adult zebrafish was investigated, thus contributing to the pharmacological knowledge and traditional medicine concerning the specie under study. The chemical profile was determined by liquid chromatography coupled to mass spectrometry-HPLC/MS with electrospray ionization. Toxicity was evaluated by zebrafish, Drosophila melanogaster, blood cells, and Artemia salina models. 12 compounds belonging to the flavonoid class were identified. In the toxicity assays, the observed results showed low toxicity of the aqueous extract in all tests performed. In the analysis with zebrafish, the highest doses of the extract were anxiolytic, neuromodulating the GABAa receptor. The obtained results support the safe use of the aqueous extract of L. sidoides leaves for the development of new drugs and for the use by populations in traditional medicine.

Toxic effects of polystyrene nanoplastics and polybrominated diphenyl ethers to zebrafish (Danio rerio)

Nanoplastics (NPs) are good carriers of persistent organic pollutants (POPs) such as polybrominated diphenyl ethers (PBDEs), and can alter their bioavailability and toxic impacts to aquatic organisms. This study highlights the single and combined toxic effects of polystyrene nanoplastics (PS-NPs) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47, one of the dominant congeners of PBDEs) on zebrafish embryos after an exposure duration of up to 120 hpf. Results showed that PS-NPs and BDE-47 co-exposure exacerbated the morphological deformities in terms of pericardial edema, yolk sac edema and curved tail in zebrafish larvae. Compared to BDE-47 single exposure, the combined exposure caused lower survival rates, shorter body lengths, and accelerated spontaneous movements. Further, PS-NPs were quickly aggregated on the surface of the embryonic chorions covered almost the entire membrane at 12 and 48 hpf, and concentration dependent accumulation was also found in the brain, mouth, trunk, gills, heart, liver and gastrointestinal tract at the larval stages. During the recovery period (7 days), PS-NPs were released from all the organs, with the highest elimination from the gastrointestinal tract. Histopathological examination revealed that co-exposure caused greater damage to retinal structures, muscle fibers and cartilage tissues. Responses of hypothalamic-pituitary-thyroid axis (CRH, TSHβ, NIS, TTR, Dio2, TG, TRα and TRβ) and reproduction (Esr2 and Vtg1) related genes were also investigated, and results showed that the co-exposure induced more significant upregulated expressions of TSHβ, TG, Doi 2, and TRβ, compared to BDE-47 single exposure. In conclusion, co-exposure to NPs and BDE-47 exacerbated developmental and thyroid toxicity in zebrafish, generally elucidating the toxicological effects mediated by complex chemical interactions between NPs with POPs in the freshwater environment.