Polygonum multiflorum Thunb. Induces hepatotoxicity in SD rats and hepatocyte spheroids by Disrupting the metabolism of bilirubin and bile acid

2,3,5,4'- tetrahydroxystilbene-2-O-β-D- glucopyranoside (TSG)-Driven immune response in the hepatotoxicity of Polygonum multiflorum

ETHNOPHARMACOLOGICAL RELEVANCE

2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucopyranoside (TSG) as the primary constituent of Polygonum multiflorum Thumb. (PM) possesses anti-oxidative, antihypercholesterolemic, anti-tumor and many more biological activities. The root of PM has been used as a tonic medicine for thousands of years. However, cases of PM-induced liver injury are occasionally reported, and considered to be related to the host immune status.

AIM OF THE STUDY

The primary toxic elements and specific mechanisms PM causing liver damage are still not thoroughly clear. Our study aimed to investigate the influences of TSG on the immune response in idiosyncratic hepatotoxicity of PM.

MATERIALS AND METHODS

The male C57BL/6 mice were treated with different doses of TSG and the alterations in liver histology, serum liver enzyme levels, proportions of T cells and cytokines secretion were evaluated by hematoxylin and eosin (HE), RNA sequencing, quantitative real time polymerase chain reaction (qRT-PCR), Flow cytometry (FCM), and enzyme-linked immunosorbent assay (ELISA), respectively. Then, primary spleen cells from drug-naive mice were isolated and cultured with TSG in vitro. T cell subsets proliferation and cytokines secretion after treated with TSG were assessed by CCK8, FCM and ELISA. In addition, mice were pre-treated with anti-CD25 for depleting regulatory T cells (Tregs), and then administered with TSG. Liver functions and immunological alterations were analyzed to evaluate liver injury.

RESULTS

Data showed that TSG induced liver damage, and immune cells infiltration in the liver tissues. FCM results showed that TSG could activate CD4+T and CD8+T in the liver. Results further confirmed that TSG notably up-regulated the levels of inflammatory cytokines including TNF-α, IFN-γ, IL-18, perforin and granzyme B in the liver tissues. Furthermore, based on transcriptomics profiles, some immune system-related pathways including leukocyte activation involved in inflammatory response, leukocyte cell-cell adhesion, regulation of interleukin-1 beta production, mononuclear cell migration, antigen processing and presentation were altered in TSG treated mice. CD8+T/CD4+T cells were also stimulated by TSG in vitro. Interestingly, increased proportion of Tregs was observed after TSG treatment in vitro and in vivo. Foxp3 and TGF-β1 mRNA expressions were up-regulated in the liver tissues. Depletion of Tregs moderately enhanced TSG induced the secretion of inflammatory cytokines in serum.

CONCLUSIONS

Our findings showed that TSG could trigger CD4+T and CD8+T cells proliferation, promote cytokines secretion, which revealed that adaptive immune response associated with the mild liver injury cause by TSG administration. Regulatory T cells (Tregs) mainly sustain immunological tolerance, and in this study, the progression of TSG induced liver injury was limited by Tregs. The results of our investigations allow us to preliminarily understand the mechanisms of PM related idiosyncratic hepatotoxicity.

Progress of research on the role of active ingredients of Citri Reticulatae Pericarpium in liver injury

BACKGROUND

Liver is a vital organ responsible for metabolizing and detoxifying both endogenous and exogenous substances in the body. However, it is susceptible to damage from chemical and natural toxins. The high incidence and mortality rates of liver disease and its associated complications impose a significant economic burden and survival pressure on patients and their families. Various liver diseases exist, including cholestasis, viral and non-viral hepatitis, fatty liver disease, drug-induced liver injury, alcoholic liver injury, and severe end-stage liver diseases such as cirrhosis, hepatocellular carcinoma (HCC), and cholangiocellular carcinoma (CCA). Recent research has shown that flavonoids found in Citri Reticulatae Pericarpium (CRP) have the potential to normalize blood glucose, cholesterol levels, and liver lipid levels. Additionally, these flavonoids exhibit anti-inflammatory properties, prevent oxidation and lipid peroxidation, and reduce liver toxicity, thereby preventing liver injury. Given these promising findings, it is essential to explore the potential of active components in CRP for developing new drugs to treat liver diseases.

OBJECTIVE

Recent studies have revealed that flavonoids, including hesperidin (HD), hesperetin (HT), naringenin (NIN), nobiletin (NOB), naringin (NRG), tangerine (TN), and erodcyol (ED), are the primary bioactive components in CRP. These flavonoids exhibit various therapeutic effects on liver injury, including anti-oxidative stress, anti-cytotoxicity, anti-inflammatory, anti-fibrosis, and anti-tumor mechanisms. In this review, we have summarized the research progress on the hepatoprotective effects of HD, HT, NIN, NOB, NRG, TN, ED and limonene (LIM), highlighting their underlying molecular mechanisms. Despite their promising effects, the current clinical application of these active ingredients in CRP has some limitations. Therefore, further studies are needed to explore the full potential of these flavonoids and develop new therapeutic strategies for liver diseases.

METHODS

For this review, we conducted a systematic search of three databases (ScienceNet, PubMed, and Science Direct) up to July 2022, using the search terms "CRP active ingredient," "liver injury," and "flavonoids." The search data followed the PRISMA standard.

RESULTS

Our findings indicate that flavonoids found in CRP can effectively reduce drug-induced liver injury, alcoholic liver injury, and non-alcoholic liver injury. These therapeutic effects are mainly attributed to the ability of flavonoids to improve liver resistance to oxidative stress and inflammation while normalizing cholesterol and liver lipid levels by exhibiting anti-free radical and anti-lipid peroxidation properties.

CONCLUSION

Our review provides new insights into the potential of active components in CRP for preventing and treating liver injury by regulating various molecular targets within different cell signaling pathways. This information can aid in the development of novel therapeutic strategies for liver disease.