Exploring the therapeutic potential of triterpenoid saponins from Gymnema sylvestre: Mechanistic insights into hepatoprotection, immunomodulation, anticancer activities, molecular docking, and pharmacokinetics

The study comprehensively investigated the therapeutic potential of Gymnema sylvestre triterpenoid saponin extract (GST), encompassing its hepatoprotective, immunomodulatory, and anticancer activities. The study employed a Prednisolone (PRD)-induced immunosuppressed rat model to assess the hepatoprotective and immunomodulatory effects of GST. Using this model, GST was found to modulate haematopoiesis, improving RBC, platelet, and WBC counts, underscoring its potential in hematopoietic homeostasis. Organ atrophy, a hallmark of immunosuppression in spleen, thymus, liver, and kidneys, was reversed with GST treatment, reinforcing its hepatotrophic and organotropic capabilities. Elevated hepatic biomarkers, including alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and lipid peroxidase (LPO), indicative of hepatocellular injury and oxidative stress, were reduced with GST, underscoring its hepatoprotective and antioxidative effects. Additionally, GST restored depleted antioxidants glutathione (GSH) and superoxide dismutase (SOD), highlighting its strong antioxidative capabilities. Molecular insights revealed a downregulation of interleukin-2 (IL-2) and interleukin-4 (IL-4) mRNA in the spleen of immunosuppressed rats, while GST treatment significantly upregulated IL-2 and IL-4 mRNA expression, showcasing its immunomodulatory potential. Increased levels of tumor necrosis factor-α (TNF-α) associated with immune dysregulation were effectively decreased by GST, underscoring its role in modulating inflammatory responses and restoring immune balance. Molecular docking studies indicated strong inhibition of TNF-α by GST compounds. In terms of anticancer activity, GST demonstrated significant cytotoxicity against MCF-7, and MDA-MB-231 (breast cancer cell lines). Notably, GST demonstrated biocompatibility with normal CHO (Chinese hamster ovary cell line) and HUVEC (Human umbilical vein endothelial cells) cell lines. Molecular docking studies indicated strong inhibition of breast cancer proteins HER1 and HER2 (human epidermal growth factor receptors) by GST compounds. Additionally, pharmacokinetics, bioavailability, drug-likeness, and toxicity risk predictions suggest that GST compounds are pharmacologically favourable with no adverse effects.

Synergistic Protective Effect of Fermented Schizandrae Fructus Pomace and Hoveniae Semen cum Fructus Extracts Mixture in the Ethanol-Induced Hepatotoxicity

Schizandrae Fructus (SF), fruits of Schisandra chinensis (Turcz.) Baill. and Hoveniae Semen cum Fructus (HSCF), the dried peduncle of Hovenia dulcis Thunb., have long been used for alcohol detoxification in the traditional medicine of Korea and China. In the current study, we aimed to evaluate the potential synergistic hepatoprotective effect of a combination mixture (MSH) comprising fermented SF pomace (fSFP) and HSCF hot water extracts at a 1:1 (w:w) ratio against ethanol-induced liver toxicity. Subacute ethanol-mediated hepatotoxicity was induced by the oral administration of ethanol (5 g/kg) in C57BL/6J mice once daily for 14 consecutive days. One hour after each ethanol administration, MSH (50, 100, and 200 mg/kg) was also orally administered daily. MSH administration significantly reduced the serum activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and γ-glutamyl transpeptidase. Histological observation indicated that MSH administration synergistically and significantly decreased the fatty changed region of hepatic parenchyma and the formation of lipid droplet in hepatocytes. Moreover, MSH significantly attenuated the hepatic triglyceride accumulation through reducing lipogenesis genes expression and increasing fatty acid oxidation genes expression. In addition, MSH significantly inhibited protein nitrosylation and lipid peroxidation by lowering cytochrome P450 2E1 enzyme activity and restoring the glutathione level, superoxide dismutase and catalase activity in liver. Furthermore, MSH synergistically decreased the mRNA level of tumor necrosis factor-α in the hepatic tissue. These findings indicate that MSH has potential for preventing alcoholic liver disease through inhibiting hepatic steatosis, oxidative stress, and inflammation.

Synthesis of nigranoic acid and manwuweizic acid derivatives as HDAC inhibitors and anti-inflammatory agents

As a successful anti-tumor drug target, the family of histone deacetylases (HDACs) is also a critical player in immune response, making the research of anti-inflammatory HDAC inhibitors an attractive new focus. In this report, triterpenoids nigranoic acid (NA) and manwuweizic acid (MA) were identified as HDAC inhibitors through docking-based virtual screening and enzymatic activity assay. A series of derivatives of NA and MA were synthesized and assessed for their biological effects. As a result, hydroxamic acid derivatives of NA and MA showed moderately increased activity for HDAC1/2/4/6 inhibition (the lowest IC₅₀ against HDAC1 is 1.14 μM), with no activity against HDAC8. In J774A.1 macrophage, compound 1-3, 13 and 17-19 demonstrated inhibitory activity against lactate dehydrogenase (LDH) and IL-1β production, without affecting cell viability. Compound 19 increased the histone acetylation level in J774A.1 cells, as well as inhibited IL-1β maturation and caspase-1 cleavage. These results indicated that compound 19 blocks the activation of NLRP3 inflammasome, probably related to HDAC inhibition. This work provided a natural scaffold for developing low-cytotoxic and anti-inflammatory HDAC inhibitors, as well as a class of tool molecules for studying the relationship between HDACs and NLRP3 activation.

Hepatoprotective effects of chamazulene against alcohol-induced liver damage by alleviation of oxidative stress in rat models

Liver injury and disease caused by alcohol is a common complication to human health worldwide. Chamazulene is a natural proazulene with antioxidant and anti-inflammatory properties. This study aims to investigate the hepatoprotective effects of chamazulene against ethanol-induced liver injury in rat models. Adult Wistar rats were orally treated with 50% v/v ethanol (8-12 mL/kg body weight [b.w.]) for 6 weeks to induce alcoholic liver injury. Chamazulene was administered orally to rats 1 h prior to ethanol administration at the doses of 25 and 50 mg/kg b.w. for 6 weeks. Silymarin, a commercial drug for hepatoprotection, was orally administered (50 mg/kg b.w.) for the positive control group. Chamazulene significantly reduced (p < 0.05) the levels of serum alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and malondialdehyde, whereas the levels of antioxidant enzymes (glutathione peroxidase, catalase, and superoxide dismutase) and reduced glutathione were significantly restored (p < 0.05) in contrast to the ethanol model group. The levels of pro-inflammatory cytokines (tumour necrosis factor-α and interleukin-6) were suppressed by chamazulene (p < 0.05) with relevance to ethanol-induced liver injury. Histopathological alterations were convincing in the chamazulene-treated groups, which showed protective effects against alcoholic liver injury. Chamazulene has a significant hepatoprotective effect against ethanol-induced liver injury through alleviation of oxidative stress and prevention of inflammation.

Protective effect of centella triterpene saponins against cyclophosphamide-induced immune and hepatic system dysfunction in rats: its possible mechanisms of action

This study was designed to investigate the protective effects of the centella triterpene saponins (EXT) on cyclophosphamide (CYP)-induced hepatotoxicity and immunosuppression in rats. The phytochemical profile of EXT was analyzed for centella saponins by using high-performance liquid chromatographic (HPLC). Therapeutic efficacy of EXT (250 mg/kg/day p.o) on hematological profile of blood, liver function markers, and cytokine profiles in CYP (10 mg/kg/day p.o)-treated rats. In addition, weights of immune organs (spleen and thymus) and histopathological changes in the liver, intestine, and spleen were also evaluated. The active principles in EXT were identified as madecassoside, asiaticoside, and asiatic acid by HPLC analysis. Upon administration of EXT, enhanced levels of glutamate pyruvate transaminase, alkaline phosphatase, and lipid peroxidation were found reduced while the levels of reduced glutathione and hematological parameters and relative weights of immune organs were restored to normal in CYP-treated rats. The hepatic mRNA level of TNF-α, which was increased during CYP administration, was significantly decreased by the EXT treatment. The decreased levels of mRNA expression of other cytokines like IFN-γ, IL-2, GM-CSF, after CYP treatment, were also found elevated upon administration of the EXT. Histopathological examination of the intestine, liver, and spleen indicated that the extract could attenuate the CYP-induced hepatic and immune organ damage. These results indicated that EXT modulated the immune and hepatic system function of rats against CYP-induced immunosuppression and hepatotoxicity by restoring the cytokine production, antioxidant system, and multiorgan injury. Thus, triterpene saponins may provide protective and/or therapeutic alternative against the immune-mediated liver diseases.