Hepatoprotection in a rat model of acute liver damage through inhibition of CY2E1 activity by total alkaloids extracted from Rubus alceifolius Poir

Hepatoprotective Potential of Malaysian Medicinal Plants: A Review on Phytochemicals, Oxidative Stress, and Antioxidant Mechanisms

Hepatotoxicity is a major global public health concern. Despite advances in modern medicine, the demerits of chemically prepared drugs outweigh their merits. In addition, the treatment of liver diseases based on modern medical principles has been found to produce several undesired side effects. Therefore, the exploration of medicinal plants has gained worldwide attention for treating various diseases, including liver diseases, owing to their potential efficacy and cost effectiveness. Several plants, including Andrographis paniculata, Bauhinia purpurea, Commelina nudiflora, Dillenia suffruticosa, Elaeis guineensis, Lygodium microphyllum, and Nephrolepis biserrata, have been reported with hepatoprotection. Moreover, these plants have been shown to play a vital role in ameliorating cellular damage because they contain several phytochemicals, including alkaloids, saponins, flavonoids, tannins, terpenoids, steroids, polyphenols, and diterpenoid lactones. The following antioxidant, anti-inflammatory, immunomodulatory, and hepatoprotective compounds have been found in these plants: andrographolide, rosmarinic acid, phenol, eugenol, 9,12-octadecadienoic, n-hexadecanoic acid, dihydroxy dimethoxy flavone, sitosterol, demethoxycurcumin, quercetin, linoleic acid, stigmasterol, kojic acid, indole-2-one, α-terpinol, linalool, kaempferol, catechin, ellagic acid, and oleanolic acid. This paper aimed to provide an in-depth review of in vivo studies on Malaysian medicinal plants possessing hepatoprotective properties, phytochemical ingredients, and antioxidant mechanisms, with an emphasis on the species proven particularly useful for treating hepatic disorders.

Hepatoprotective Effect of Corm of Ensete ventricosum (Welw.) Cheesman Extract against Isoniazid and Rifampicin Induced Hepatotoxicity in Swiss Albino Mice

Drug-induced liver injury (DILI) is one of the cumbersome health-related problems which render approximately 50% of liver failure and patients to receiving liver transplantation every year. Antituberculosis drugs such as isoniazid and rifampicin are potentially rendering hepatotoxicity. Ensete ventricosum (Welw.) Cheesman is an herbaceous perennial plant that contributes to the indigenous ethnomedicinal values for the society. This study aimed to investigate the hepatoprotective effect of corm of Ensete ventricosum (Welw.) Cheesman extracts against isoniazid and rifampicin induced hepatotoxicity in Swiss albino mice. The study was conducted on 30 Swiss albino mice randomly allocated into five groups. Group I, group II, group III, group IV, and group V were the groups in which mice were given distilled water, only isoniazid and rifampicin, isoniazid and rifampicin along with 200 mg/kg corm of Ensete ventricosum (Welw.) Cheesman extract, isoniazid and rifampicin along with 400 mg/kg corm of Ensete ventricosum (Welw.) Cheesman extract, and isoniazid and rifampicin along with silymarin per oral per day, respectively. On the 30th day of the experiment, mice were sacrificed after anesthetized, and blood was drawn for the liver function test, and the liver was also taken from each experimental mouse for histopathological evaluation. Data were entered into EpiData version 3.1 subsequently exported to SPSS version 25 for analysis by using one-way ANOVA. Plasma alanine aminotransferase (ALT) levels, aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin (TBIL) of group II mice were significantly (p < 0.05) elevated as compared to group I. The group of mice treated with a corm of Ensete ventricosum (Welw.) Cheesman at a dose of 400 mg/kg (group IV) and silymarin100 mg/kg (group V) showed a significant (p < 0.05) decrease in ALT, AST, ALP, and TBIL as compared to the group II. The liver section of group II showed a change in liver architecture; however, these deformities were not noticed in group IV mice. The result showed corm of Ensete ventricosum (Welw.) Cheesman extract has a very promising hepatoprotective potential against isoniazid and rifampicin induced liver injury.

Hepatoprotective effect of the solvent extracts of Viola canescens Wall. ex. Roxb. against CCl4 induced toxicity through antioxidant and membrane stabilizing activity

Background

Viola canescens Wall. ex. Roxb. exhibits analgesic, antimalarial and antispasmodic activities. It is used folklorically for the treatment of liver diseases, hypertension, malaria and cancer. The current study investigates phytochemical constituents, antioxidant and hepatoprotective activity of solvent extracts of whole plant of Viola canescens.

Methods

Phytochemicals, acute toxicity study and antioxidant activity of Viola canescens methanolic extract (VCME), ethyl acetate fraction (EAF), and partially purified EAF (90% EAF and combination of 80% EAF + 20% methanol fraction (EAF + Me) was carried out. Hepatoprotective activity of VCME, EAF (200 and 400 mg/kg body weight) and partially purified EAF (50 mg/kg body weight) was investigated in carbon tetrachloride (CCl₄) intoxicated BALB/c mice for 7 days. Membrane stabilization effect was determined by hypotonic solution induced hemolysis while DNA ladder assay was carried out by polyacrylamide gel electrophoresis.

Results

Phytochemical screening of VCME showed the presence of alkaloids, phenols, flavonoids, saponins, carbohydrates, tannins and triterpenes. VCME, EAF (at 200 and 400 mg/kg body weight) and partially purified EAF (90% EAF and EAF + Me) at 50 mg/kg body weight significantly reduced the level of ALT, ALP, total bilirubin and restored the level of serum protein in comparison to CCl₄ treated group. A significant reduction in malondialdehyde (MDA) and elevation in catalase (CAT) and superoxide dismutase (SOD) level was observed in extract treated animals as compared to CCl₄ (p < 0.05). The IC₅₀ values in membrane stabilization potential for VCME, EAF and sodium salicylate were 3.7 ± 0.11, 3.4 ± 0.15 and 3.2 ± 0.09 mg/ml, respectively. Similarly, CCl₄ induced degradation of DNA was counteracted by VCME and EAF. The liver biopsy of mice treated with the solvent extracts showed remarkable restoration of normal histological archeitecture.

Conclusions

Viola canescens showed significant hepatoprotective potential due to its antioxidant and membrane stabilization effect.

Artemisia capillaris formula inhibits hepatic steatosis via an miR‑122‑induced decrease in fatty acid synthase expression in vivo and in vitro

Non‑alcoholic fatty liver disease (NAFLD) is a widespread health concern, and there is currently insufficient understanding regarding its pathogenesis and treatment. The present study aimed to explore the effects of Artemisia capillaris formula (ACF) on high‑fat diet‑induced hepatic steatosis and fatty acid‑induced intracellular lipid accumulation, by micro (mi)RNA regulation. A total of 72 Sprague‑Dawley rats were divided into six groups (n=12/group). One group was designated as the control group and fed a normal diet, and the remaining five groups were allowed ad libitum access to a high‑fat diet for eight weeks, in order to establish an NAFLD rat model. The rats were subsequently administered polyene phosphatidylcholine (PP; 0.076 g/kg body weight/day), low dose of ACF (0.462 g/kg body weight/day), middle dose of ACF (0.924 g/kg body weight/day) or high dose of ACF (1.848 g/kg body weight/day) intragastrically for four weeks. HepG2 human hepatocellular carcinoma cells were treated with oleic acid and palm acid, followed by treatment with various concentrations of ACF. Serum alanine transaminase (ALT), aspartate aminotransferase (AST), triglycerides (TG), total cholesterol (TC), high‑density lipoprotein cholesterol (HDL‑C), low‑density lipoprotein cholesterol (LDL‑C), and steatotic HepG2 human liver carcinoma cell TC and TG levels were measured. ACF and PP treatments attenuated high‑fat diet‑induced hepatic steatosis and fatty acid‑induced intracellular lipid accumulation. A modified high‑fat diet significantly increased ALT, AST, TG, TC, LDL‑C levels and decreased HDL‑C levels. Treatment with ACF and PP abrogated the increase in liver enzymes and TG, TC and LDL‑C levels, but did not influence HDL‑C levels in a high‑fat diet induced rat model of steotosis. Steatotic HepG2 cells exhibited significantly increased levels of both TG and TC. Treatment with ACF significantly decreased TC and TG levels in vivo, and ACF and PP treatment decreased the expression levels of fatty acid synthase (FASN) and increased miR‑122 in vivo and in vitro. In conclusion, these results suggested that ACF may inhibit hepatic steatosis via miR‑122‑induced downregulation of FASN in vivo and in vitro.

Aconitum carmichaelii protects against acetaminophen-induced hepatotoxicity via B-cell lymphoma-2 protein-mediated inhibition of mitochondrial dysfunction

We previously reported the clinical profile of processed Aconitum carmichaelii (AC, Aconibal(®)), which included inhibition of cytochrome P450 (CYP) 2E1 activity in healthy male adults. CYP2E1 is recognized as the enzyme that initiates the cascade of events leading to acetaminophen (APAP)-induced toxicity. However, no studies have characterized its role in APAP-induced hepatic injury. Here, we investigated the protective effects of AC on APAP-induced hepatotoxicity via mitochondrial dysfunction. AC (5-500 μg/mL) significantly inhibited APAP-induced reduction of glutathione. In addition, AC decreased mitochondrial membrane potential (Δψm) and B-cell lymphoma 2 (Bcl-2)-associated X protein levels (% change 46.63) in mitochondria. Moreover, it increased Bcl-2 (% change 55.39) and cytochrome C levels (% change 38.33) in mitochondria, measured using immunofluorescence or a commercial kit. Furthermore, cell membrane integrity was preserved and nuclear fragmentation inhibited by AC. These results demonstrate that AC protects hepatocytes against APAP-induced toxicity by inhibiting mitochondrial dysfunction.

Treatment of Nonalcoholic Fatty Liver Disease with Total Alkaloids in Rubus aleaefolius Poir through Regulation of Fat Metabolism

Total alkaloids in Rubus aleaefolius Poir (TARAP) is a folk medicinal herb that has been used clinically in China to treat nonalcoholic fatty liver disease (NAFLD) for many years. However, the mechanism of its anti-NAFLD effect is largely unknown. In this study, we developed a NAFLD rat model by supplying a modified high-fat diet (mHFD) ad libitum for 8 weeks and evaluated the therapeutic effect of TARAP in NAFLD rats as well as the underlying molecular mechanism. We found that TARAP could reduce the serum triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL-C) levels and increase the serum high-density lipoprotein (HDL-C) level in NAFLD rats. In addition, TARAP treatment reduced expression of fatty acid synthetase (FAS), and acetyl-CoA carboxylase (ACC) and upregulated the expression of carnitine palmitoyltransferase (CPT). Our results suggest that regulation of lipid metabolism may be a mechanism by which TARAP treats NAFLD.

Whey-hydrolyzed peptide-enriched immunomodulating diet prevents progression of liver cirrhosis in rats

OBJECTIVE

Liver fibrosis and subsequent cirrhosis is a major cause of death worldwide, but few effective antifibrotic therapies are reported. Whey-hydrolyzed peptide (WHP), a major peptide component of bovine milk, exerts anti-inflammatory effects in experimental models. A WHP-enriched diet is widely used for immunomodulating diets (IMD) in clinical fields. However, the effects of WHP on liver fibrosis remain unknown. The aim of this study was to investigate the antifibrotic effects of WHP in a rat cirrhosis model.

METHODS

Progressive liver fibrosis was induced by repeated intraperitoneal administration of dimethylnitrosamine (DMN) for 3 wk. Rats were fed either a WHP-enriched IMD (WHP group) or a control enteral diet (control group). The degree of liver fibrosis was compared between groups. Hepatocyte-protective effects were examined using hepatocytes isolated from rats fed a WHP diet. Reactive oxygen species and glutathione in liver tissue were investigated in the DMN cirrhosis model.

RESULTS

Macroscopic and microscopic progression of liver fibrosis was remarkably suppressed in the WHP group. Elevated serum levels of liver enzymes and hyaluronic acid, and liver tissue hydroxyproline content were significantly attenuated in the WHP group. Necrotic hepatocyte rates with DMN challenge, isolated from rats fed a WHP-enriched IMD, were significantly lower. In the DMN cirrhosis model, reactive oxygen species were significantly lower, and glutathione was significantly higher in the WHP group's whole liver tissue.

CONCLUSION

A WHP-enriched IMD effectively prevented progression of DMN-induced liver fibrosis in rats via a direct hepatocyte-protective effect and an antioxidant effect through glutathione synthesis.

Effect of simvastatin and naringenin coadministration on rat liver DNA fragmentation and cytochrome P450 activity: an in vivo and in vitro study

This study was designed to assess the effect of naringenin (NRG) on simvastatin (SV)-induced hepatic damage in rat and to investigate the effects of these drugs on cytochrome P450 (CYP) 2E1 and 3A1/2 isoforms in order to evaluate the possibility of their coadministration. Hepatic damage in rat was induced by SV (20 and 40 mg/kg/day, po for 30 days). The protective effect of NRG (50 mg/kg/day, po) was identified by estimating liver functions and oxidative stress markers such as lipid peroxidation, reduced glutathione, superoxide dismutase, glutathion s-transferase, and catalase as well as protein profile. DNA fragmentation and histopathological study were carried out to confirm the hepatic damage. An in vitro study was conducted to further evaluate the effect of SV and/or NRG administration on the activities of two microsomal CYP isoenzymes including CYP2E1 and CYP3A1/2. SV exerted an oxidative stress which may contribute to the hepatotoxicity. Administration of NRG in combination with SV significantly improved the liver functions, state of oxidative stress, protein profile, DNA fragmentation, and the histopathological changes. SV and/or NRG have a potential to inhibit CYP3A1/2 and CYP2E1. This study concluded that concurrent administration of NRG with SV provided a protection of liver tissue against the SV-induced hepatic damage. The inhibition of CYP2E1 and CYP3A1/2 by the SV and NRG should be taken into account in order to adjust doses to avoid interaction between SV and NRG and adverse effects of SV.

Effect of simvastatin and naringenin coadministration on rat liver DNA fragmentation and cytochrome P450 activity: an in vivo and in vitro study

This study was designed to assess the effect of naringenin (NRG) on simvastatin (SV)-induced hepatic damage in rat and to investigate the effects of these drugs on cytochrome P450 (CYP) 2E1 and 3A1/2 isoforms in order to evaluate the possibility of their coadministration. Hepatic damage in rat was induced by SV (20 and 40 mg/kg/day, po for 30 days). The protective effect of NRG (50 mg/kg/day, po) was identified by estimating liver functions and oxidative stress markers such as lipid peroxidation, reduced glutathione, superoxide dismutase, glutathion s-transferase, and catalase as well as protein profile. DNA fragmentation and histopathological study were carried out to confirm the hepatic damage. An in vitro study was conducted to further evaluate the effect of SV and/or NRG administration on the activities of two microsomal CYP isoenzymes including CYP2E1 and CYP3A1/2. SV exerted an oxidative stress which may contribute to the hepatotoxicity. Administration of NRG in combination with SV significantly improved the liver functions, state of oxidative stress, protein profile, DNA fragmentation, and the histopathological changes. SV and/or NRG have a potential to inhibit CYP3A1/2 and CYP2E1. This study concluded that concurrent administration of NRG with SV provided a protection of liver tissue against the SV-induced hepatic damage. The inhibition of CYP2E1 and CYP3A1/2 by the SV and NRG should be taken into account in order to adjust doses to avoid interaction between SV and NRG and adverse effects of SV.

Anti-inflammatory effects of total alkaloids from Rubus alceifolius Poir [corrected]. on non-alcoholic fatty liver disease through regulation of the NF-κB pathway

We aimed to explore the anti-inflammatory effects of total alkaloids inRubus alceifolius Poir [corrected]. (TARAP) on non-alcoholic fatty liver disease, and to investigate the possible molecular mechanisms. A rodent non-alcoholic fatty liver disease (NAFLD) model was established by administration of a modified high-fat diet ad libitum for 8 weeks. Rats were treated with polyene phosphatidylcholine (PP), TARAP low‑dose (0.72 g/kg body weight/day) and TARAP high-dose (1.44 g/kg body weight/day). The model group and the control group received distilled water. After treatment for 4 weeks, the blood samples were obtained from the abdominal aorta, and the levels of serum ALT, AST, GGT, ALP, TG, TC, HDL-C and LDL-C were measured. Changes in liver tissue morphology were evaluated by H&E staining. The expression levels of nuclear factor (NF)-κB, cyclooxygenase-2 (COX‑2), interleukin (IL)-6 and tumor necrosis factor (TNF)-α in rat livers were assayed by reverse transcription‑polymerase chain reaction (RT-PCR) and immunohistochemistry. Both TARAP and PP attenuated hepatic steatosis induced by the high-fat diet. The modified high-fat diet caused a significant increase in ALT, AST, GGT, ALP, TG, TC, LDL-C levels and a decrease in HDL-C levels. TARAP and PP treatment abrogated the increase in the levels of liver enzymes and the levels of TG, TC, LDL-C, as well as suppressed the increase in HDL-C levels. The results of RT-PCR and immunohistochemical assay showed that PP and TARAP treatment decreased the expression of NF-κB, COX-2, IL-6 and TNF-α. In conclusion, these results suggest that TARAP may protect against NAFLD through regulation of the NF-κB pathway.

Aminotriazole attenuated carbon tetrachloride-induced oxidative liver injury in mice

Carbon tetrachloride (CCl(4)) has been used extensively to study xenobiotic-induced oxidative liver injury. Catalase (CAT) is a major antioxidant enzyme while aminotriazole (ATZ) is commonly used as a CAT inhibitor. In the present study, the effects of ATZ on CCl(4)-induced liver injury were investigated. Our experimental data showed that pretreatment with ATZ significantly decreased CCl(4)-induced elevation of serum aspartate transaminase (AST) and alanine transaminase (ALT) and improved hepatic histopathological abnormality. ATZ dose-dependently inhibited the activity of CAT, but it reduced the content of H(2)O(2) and the levels of malondialdehyde (MDA) in liver tissues. ATZ decreased plasma level of pro-inflammatory cytokines (TNF-α and IL-6) and reduced hepatic levels of myeloperoxidase (MPO). In addition, posttreatment with ATZ also decreased the level of ALT and AST. These data indicated that ATZ effectively alleviated CCl(4)-induced oxidative liver damage. These findings suggested that ATZ might have potential value in preventing oxidative liver injury.