Pharmacokinetic assessment of rifampicin and des-acetyl rifampicin in carbon tetrachloride induced liver injury model in Wistar rats.

OBJECTIVES: Preclinical evidence is needed to assess drug-metabolite behaviour in compromised liver function for developing the best antitubercular treatment (ATT) re-introduction regimen in drug-induced liver injury (DILI). The pharmacokinetic behavior of rifampicin (RMP) and its active metabolite des-acetyl-rifampicin (DARP) in DILI's presence is unknown. To study the pharmacokinetic behavior of RMP and DARP in the presence of carbon tetrachloride (CCl4) plus ATT-DILI in rats. METHODS: Thirty rats used in the experiment were divided equally into six groups. We administered a single 0.5 mL/kg CCl4 intraperitoneal injection in all rats. Groups II, III, IV, and V were started on daily oral RMP alone, RMP plus isoniazid (INH), RMP plus pyrazinamide (PZA), and the three drugs INH, RMP, and PZA together, respectively, for 21-days subsequently. Pharmacokinetic (PK) sampling was performed at 0, 0.5, 1, 3, 6, 12, and 24 h post-dosing on day 20. We monitored LFT at baseline on days-1, 7, and 21 and sacrificed the rats on the last day of the experiment. RESULTS: ATT treatment sustained the CCl4-induced liver injury changes. A significant rise in mean total bilirubin levels was observed in groups administered rifampicin. The triple drug combination group demonstrated 1.43- and 1.84-times higher area-under-the-curve values of RMP (234.56±30.66 vs. 163.55±36.14 µg h/mL) and DARP (16.15±4.50 vs. 8.75±2.79 µg h/mL) compared to RMP alone group. Histological and oxidative stress changes supported underlying liver injury and PK alterations. CONCLUSIONS: RMP metabolism inhibition by PZA, more than isoniazid, was well preserved in the presence of underlying liver injury.

Scopoletin a potential phytochemical therapy for antitubercular treatment drug induced liver injury (ATT-DILI) model in Wistar rats.

OBJECTIVES: The hepatoprotective properties of scopoletin have been explored in carbon tetrachloride (CCl4) induced liver injury but not in drug-induced liver injury (DILI) scenarios. Only N-acetyl-cysteine (NAC) has proven efficacy in DILI treatment. Accordingly, we conducted a study to assess the hepatoprotective action of scopoletin in the anti-tubercular treatment (ATT)-DILI model in Wistar rats, if any. METHODS: A total of 36 rats were evaluated, with six in each group. A 36-day ATT at 100 mg/kg dose for isoniazid, 300 mg/kg for rifampicin and 700 mg/kg for pyrazinamide were fed to induce hepatotoxicity in rats. Group I and II-VI received normal saline and ATT, respectively. Oral scopoletin (1,5 and 10 mg/kg) and NAC 150 mg/kg were administered in groups III, IV, V and VI, respectively, once daily for the last 15 days of the experiment. LFT monitoring was performed at baseline, days 21, 28, and 36. Rats were sacrificed for the histopathology examination. RESULTS: Aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and bilirubin levels were significantly increased in group II (receiving ATT) compared to normal control on day 28 and day 36 (p<0.05). All three doses of scopoletin and NAC groups led to the resolution of AST, ALT, ALP, and bilirubin changes induced by ATT medications effect beginning by day 28 and persisting on day 36 (p<0.01). An insignificant effect was observed on albumin and total protein levels. The effect was confirmed with antioxidants and histopathology analysis. CONCLUSIONS: The study confirms the hepatoprotective efficacy of scopoletin in a more robust commonly encountered liver injury etiology.

Dose-Response Evaluation of Scopoletin, a Phytochemical, in a High-Fructose High-Fat Diet-Induced Dyslipidemia Model in Wistar Rats.

The putative hypolipidemic properties of scopoletin have not been fully confirmed due to a lack of validation in an irreversible chronic hyperlipidemia animal model. The druggability also needs to be studied in terms of bioavailability in the vascular compartment. Accordingly, we conducted a study to assess the hypolipidemic and pharmacokinetic behavior of scopoletin in the high-fructose high-fat diet (HFHFD)-induced dyslipidemia model in Wistar rats. A total of 42 rats were studied, with 6 in each of the 7 groups. A 60-day HFHFD opted for induction of dyslipidemia. Group I and groups II-VII received normal rat chow diet and HFHFD, respectively. Oral scopoletin (1, 5, 10 mg/kg) and atorvastatin 5 mg/kg were administered in groups III-VI, respectively, once daily for the next 15 days. A separate group, group VII, was used for the pharmacokinetic assessment comparing the scopoletin 10 mg/kg intraperitoneally (IP) in group VII versus the oral (group V). Pharmacokinetic blood sampling was performed on the 10th day of continuous once-daily therapy. Rats were sacrificed for the histological examination. All three scopoletin dosages significantly decreased the total cholesterol, low-density lipoproteins, and triglycerides (P < .05 for all), but not in a dose-dependent manner. Atherogenic Index of plasma, Castelli's risk indices, and histopathological findings confirmed the protective effect of scopoletin. The IP administration showed a 23.18% higher exposure than the oral route (P < .001 for area under the curve and P < .05 for concentration-maximum). This study confirms the hypolipidemic efficacy of scopoletin in a more robust irreversible model of dyslipidemia. Scopoletin's gut absorption in the disease state may also boost the initial phase exploratory clinical trial.

Scopoletin Improves Glucose Homeostasis in the High-Fructose High-Fat Diet-Induced Diabetes Model in Wistar Rats.

Antihyperglycemic action of scopoletin needs to be validated before considering it for clinical trials. The present study explored antihyperglycemic action of scopoletin in high-fructose high-fat diet (HFHFD)-induced diabetes in rats. The animal study was performed using 48 rats, 6 in each group. HFHFD was administered for model induction for 74 days. Rats in Group I (normal control [NC]) and group II (experimental control [EC]) received normal saline and HFHFD, respectively, throughout the study. Groups III, IV, V, and VI received oral scopoletin (1 mg/kg [low dose, LD], 5 mg/kg [medium dose, MD], 10 mg/kg [high dose, HD]), and metformin (250 mg/kg; positive control [PC] for efficacy), respectively, once daily from day 60 to 74, in addition to HFHFD. Group VII (10 mg/kg oral scopoletin safety group) and VIII (0.1 mg/kg oral warfarin; PC for safety) were separately used for bleeding time-clotting time (BTCT) assessment on days 60, 68, and 74. Groups I, VII, and VIII rats were studied for safety assessment. Later, animals were sacrificed for histological examination. Scopoletin-treated groups showed a significant decline in glucose levels, especially in the MD (5.18 ± 0.12) and HD group (5.271 ± 0.11) in comparison to the EC (6.37 ± 0.05) on day 74 (P < .05). Two weeks after scopoletin treatment, ß-cell function significantly improved (53.073 ± 4.67) in the MD group versus 29.323 ± 8.505 in the NC group (P < .05). A statistically significant difference was observed when the MD group (53.07 ± 4.67) was compared to the metformin-treated group (24.80 ± 3.24; P < .05). The safety assessment in the form of BTCT findings did not observe a difference among groups I, VII, and VIII (P > .05). The study showed that scopoletin dose-independently reversed insulin resistance. Consequently, scopoletin can be a potential candidate for antidiabetic drug development.

Essential oil nebulization in mild COVID-19(EONCO): Early phase exploratory clinical trial.

Background: Medications studied for therapeutic benefits in coronavirus disease 2019 (COVID-19) have produced inconclusive efficacy results except for steroids. Objective: A prospective randomized open-label, parallel-arm Phase I/II clinical trial was planned to compare essential oil (EO) blend versus placebo nebulization in mild COVID-19. Methods: A Phase I safety evaluation was carried out in a single ascending and multiple ascending dose study designs. We assessed Phase II therapeutic efficacy on COVID-19 and general respiratory symptoms on days 0, 3, 5, 7, 10, and 14 on the predesigned case record form. Viremia was evaluated on day 0, day 5, and day 10. Results: Dose-limiting toxicities were not reached with the doses, frequencies, and duration studied, thus confirming the formulation's preliminary safety. General respiratory symptoms (p < 0.001), anosmia (p < 0.05), and dysgeusia (p < 0.001) benefited significantly with the use of EO blend nebulization compared to placebo. Symptomatic COVID-19 participants with mild disease did not show treatment benefits in terms of symptomatic relief (p = 1.0) and viremia clearance (p = 0.74) compared to the placebo. EO blend was found to be associated with the reduced evolution of symptoms in previously asymptomatic reverse transcription polymerase chain reaction (RT-PCR)-positive study participants (p = 0.034). Conclusion: EO nebulization appears to be a safer add-on symptomatic relief approach for mild COVID-19. However, the direct antiviral action of the EO blend needs to be assessed with different concentrations of combinations of individual phytochemicals in the EO blend.