Oxidative stress and ER stress may contribute to drug-induced hepatitis in tuberculous meningitis

A novel approach combining network pharmacology and experimental validation to study the protective effect of ginsenoside Rb1 against cantharidin-induced hepatotoxicity in mice

Cantharidin (CTD) is a widely used anticancer compound, but its clinical use is mainly limited due to hepatotoxicity. Ginsenoside Rb1 (GRb1) shows potential hepatoprotective effects. Nonetheless, the protective effect and underlying mechanism of GRb1 against CTD-induced hepatotoxicity in mice have not been investigated. This study aims to elucidate the effect and mechanism of GRb1 on CTD-induced hepatotoxicity using network pharmacology and in vivo experiments. Network pharmacology studies have shown that 263 targets were the main mechanisms by which GRb1 alleviates CTD-induced hepatotoxicity. KEGG enrichment analysis revealed that 75 hub genes were mainly enriched in TNF, IL-17 and apoptosis signalling pathways. Molecular docking analysis showed that GRb1 exhibited high affinity with Akt1, Tnf, Il6, Bcl2 and Caspase3. In addition, results from animal studies demonstrated that GRb1 could ameliorate CTD-induced hepatotoxicity by inhibiting protein expression of Caspase-3, Caspase-8, Bcl-2/Bax, GRP78, ATF6, ATF4, CHOP, IRE1α and PERK. This research revealed the mechanism of GRb1 against CTD-induced hepatotoxicity by inhibiting apoptosis and endoplasmic reticulum stress (ERS) and it may provide a scientific rationale for the potential use of GRb1 in the treatment of hepatotoxicity induced by CTD.

Rosiglitazone Protects against Acetaminophen-Induced Acute Liver Injury by Inhibiting Multiple Endoplasmic Reticulum Stress Pathways

Background

Excessive acetaminophen (APAP) use can lead to acute liver injury (ALI) by inducing endoplasmic reticulum stress (ERS). We previously found that pretreatment with the peroxisome proliferator-activated receptor-γ (PPAR-γ) ligand rosiglitazone (RSG) alleviated ALI in APAP-treated mice.

Objective

To examine if RSG-mediated hepatoprotection is associated with ERS suppression.

Methods

Forty-eight male CD-1 mice were randomly divided into control, RSG, APAP 4 h, APAP 24 h, RSG + APAP 4 h, and RSG + APAP 24 h groups. The RSG and RSG + APAP groups received RSG (20 mg/kg) by gavage 48, 24, and 1 h before intraperitoneal injection of 300 mg/kg APAP, while the APAP group received APAP alone and the control group received only normal saline. Animals were sacrificed immediately (RSG and control groups), 4 h (APAP 4 h and RSG + APAP 4 h), or 24 h (APAP 24 h and RSG + APAP 24 h) post-APAP injection. Liver tissues were collected for hematoxylin-eosin staining, TUNEL staining, and Western blotting for ERS-associated proteins. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were also measured. A second cohort received APAP or RSG + APAP as described and were monitored for survival over one week.

Results

At 4 and 24 h following APAP injection alone, serum ALT and AST levels were significantly elevated, and central lobular necrosis of the liver was observed. Necrosis area reached 21.7% at 4 h and 32.1% at 24 h post-APAP, while apoptotic fractions reached 25.6% and 32.4%. Further, 50% of mice in the survival analysis cohort died within one week post-APAP. At 4 h post-APAP, the ERS marker glucose-regulated protein-78 (GRP78) and ERS-associated proteins pJNK, GRP78, p-eIF2α, pPERK, and pIRE were all significantly upregulated. Pretreatment with RSG significantly reduced serum ALT and AST, liver necrosis area, apoptosis rate, and expression of ERS-associated proteins compared to APAP alone, while increasing survival to 80%.

Conclusions

Rosiglitazone pretreatment can alleviate APAP-induced ALI by suppressing three branches of ERS signaling.

Oxidative stress and ER stress are related to severity of tubercular infection

To report the markers of oxidative stress and endoplasmic reticulum (ER) stress in tuberculosis of differing severity. Ninety patients with tuberculosis, 30 each with pulmonary tuberculosis (PTB), Pott's spine (PS) and tuberculous meningitis (TBM) were included. The diagnosis and severity of the respective group was based on pre-defined criteria. Six-months outcome and complications (Hyponatremia, paradoxical worsening and Drug induced hepatitis(DIH)) were recorded. Serum Melanodehyde (MDA) , glutathione (GSH), total antioxidant capacity (TAC), ER stress markers ATF-4,GRP-78 and CHOP, were measured using spectrophotometry and real time PCR. The oxidative and ER stress markers were correlated with different subgroups, severity of TBM, complications and outcome. The severity of TBM correlated with alteration in oxidative and ER stress markers. MDA was related to hyponatremia (P = 0.045), paradoxical worsening (P = 0.035) and DIH (P = 0.038), TAC correlated with paradoxical worsening (P = 0.047) and DIH (P = 0.015). In PS, MDA correlated with paradoxical worsening (P = 0.032) and DIH (P = 0.032); and in PTB, MDA correlated with hyponatremia (P = 0.025) and DIH (P = 0.037). Changes in stress marker levels were more marked in TBM compared to PS and PTB. Outcome of TBM correlated with MDA (P = 0.002), PS to MDA(P = 0.004), TAC(P = 0.05) CHOP(P = 0.004), GRP78(P = 0.001), ATF4(P = 0.045) and PTB to MDA(P = 0.0450), TAC(P = 0.014), CHOP(P = 0.025) and GRP78(P = 0.035). Oxidative and ER stress markers seem to be related to severity of TB, its complications and outcome.

Role of Caspase- 3, TNF-α, and IL6 mRNA Expression in Intracranial Tuberculoma

The development of tuberculoma is a process of inflammation, necrosis, and apoptosis. Therefore, the pro-inflammatory cytokines and apoptosis biomarkers are likely to play an important role. In this study, we report the expression of TNFα, IL6, and caspase-3 at the mRNA level in the patients with tuberculous meningitis (TBM) and compare these biomarkers in the patients with and without tuberculoma. A total of 134 patients with TBM and 35 matched healthy controls were included. The clinical, cerebrospinal fluid (CSF), and cranial magnetic resonance imaging (MRI) findings were noted. The mRNA expression of TNFα, IL6, and caspase-3 in peripheral blood mononuclear cells was evaluated by reverse transcriptase polymerase chain reaction. On cranial MRI, 89 (64.2%) patients had tuberculoma, and their level of consciousness, severity of meningitis, CSF findings, and blood counts were not significantly different from those without tuberculoma. Patients with tuberculoma had a higher expression of TNFα and IL6 compared to the controls, but had lower expression compared to the patients without tuberculoma. TNFα expression positively correlated with the expression of caspase-3, but not with IL6. Twenty-five (18.6%) patients died: 12 (13.5%) in tuberculoma and 13 (28.9%) in the non-tuberculoma group. Death was related to higher expression of TNFα and caspase-3. The lower expression of TNFα and IL6 in intracranial tuberculoma suggests that these patients are unlikely to be benefited with TNFα blockers.

Standard versus sequential anti-tubercular treatment in patients with tuberculous meningitis: a randomized controlled trial

BACKGROUND

To compare the safety and efficacy of sequential anti-tubercular treatment (ATT) regimen with the standard regimen in tuberculous meningitis (TBM).

METHODS

This single-centre, open-label, parallel group randomized controlled trial was conducted from May 2017 to June 2019 in India. Treatment-naïve patients with TBM fulfilling the inclusion criteria were randomized to four drug ATT regimens (rifampicin, isoniazid, ethambutol and pyrazinamide) administered either simultaneously (standard arm) or one after another (sequential arm) in a 1 : 1 ratio. The primary endpoint was drug-induced hepatitis (DIH) and the secondary endpoints were in-hospital death and disability at 3 and 6 months using a modified Rankin Scale.

RESULTS

A total of 97 patients with TBM were recruited; 15 did not meet the inclusion criteria and 2 refused to participate. The median age of the patients was 26 y (range 15-75) and 37 (46.2%) were males. The patients in the sequential arm had fewer cases of DIH (20% vs 42.5%; p=0.03). The patients in the sequential arm had lower in-hospital mortality (2.5% vs 17.5%; p=0.025) and better 6-month outcomes (25.0% vs 50.0%; p=0.02) compared with the standard arm.

CONCLUSIONS

Sequential ATT was associated with a lower frequency of DIH, lower in-hospital mortality and better 6-month outcome.

TRIAL REGISTRATION

Clinical Trials Registry of India (ctri.nic.in) identifier: REF/2016/09/012214/CTRI/2017/10/010072.

Is cerebral salt wasting related to sympathetic dysregulation in tuberculous meningitis?

BACKGROUND

Cerebral Salt wasting (CSW) is common in Tuberculous Meningitis (TBM) and is suggested to be due to sympathetic dysregulation of renal blood supply but has not been proven.

OBJECTIVE

To evaluate plasma Catecholamines in TBM patients with CSW and correlate with the markers of stress.

MATERIALS AND METHODS

The diagnosis of TBM was based on clinical, CSF and MRI criteria. Catecholamines level was measured by LC-MS on admission, at the time of hyponatremia and on correction of hyponatremia. Catecholamine levels were correlated with clinical and laboratory markers of stress, hyponatremia and severity of CSW using pre-defined criteria.

RESULTS

There were 24 patients with TBM (12 with CSW) and 12 controls. The median age of patients was 31 (18-75) years and 12 (50 %) were females. TBM patients with CSW had significantly higher levels of catecholamines compared to controls (p < 0.001). TBM patients with CSW had higher levels of norepinephrine than those without CSW (p = 0.034). Sequential studies revealed that dopamine and epinephrine increased at the time of hyponatremia and declined on its correction. Severity of TBM was related to dopamine (p = 0.04) and severity of CSW was related to epinephrine (p = 0.016).

CONCLUSION

CSW in TBM seems to be related to catecholamine dysregulation.