Cell experiment:

HepAD38 cells are grown to about 80% confluence in 0.3 μg/mL of tetracycline (TET). After the removal of TET, the cells are treated with different doses of Morphothiadin (GLS4), or no drug. Cell viability is monitored by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay[2].

Animal experiment:

ICR mice are used to evaluate the pharmacokinetic (PK) properties of Morphothiadin (GLS4). Following oral administration of 10 mg/kg (of body weight) of Morphothiadin to male mice, the concentration of Morphothiadin in plasma is determined using liquid chromatography-tandem mass spectrometry (LC/MS/MS). For toxicity studies, ICR mice are given Morphothiadin by gavage over a 4-week period and then kept off drug for another 2 weeks. Groups consisting of 20 male plus 20 female mice are administered a vehicle (1% methyl-2-hydroxyethyl cellulose), 35.7, 118.9, or 356.6 mg/kg per day in a volume corresponding to 20 mL/kg. Ten mice per dose group are euthanized 2 weeks after the end of drug treatment. Body weight, food consumption, serum albumin levels, and adverse effects are determined[2].

Morphothiadin is a potent inhibitor on the replication of both wild-type and adefovir-resistant HBV with an IC50 of 12 nM.

Morphothiadin is a potent inhibitor on the replication of both wild-type and adefovir-resistant HBV with an IC50 of 12 nM. Morphothiadin (GLS4) shows no toxicity up to 25 μM. The cytotoxic dose whereby 50% of cells die (CC50) for primary hepatocytes is 115 μM for Morphothiadin (P<0.001). The CC90 is 190 μM for Morphothiadin (P<0.01) in HepAD38 cells. Morphothiadin strongly inhibits virus accumulation in the supernatant of HepAD38 cells at 25 nM to 100 nM (P<0.02). Results show a concentration-dependent decrease of core protein in cells treated with Morphothiadin[2].

The area under the concentration-time curve from 0 to 24 h (AUC0-24) of Morphothiadin (GLS4) is 556 h•ng/mL. After intravenous administration of 10 mg/kg Morphothiadin, the total plasma clearance and apparent volume distribution are 4.2 liters/h/kg and 7.38 liters/kg, respectively. The bioavailability of Morphothiadin is 25.5%. It is found that virus titers have increased 83.5-fold in mice treated with 3.75 mg/kg per day of Morphothiadin, 28.3-fold among mice treated with 7.5 mg/kg per day, but only 3- to 6-fold among mice treated with the higher doses of Morphothiadin. There is generally an inverse relationship between Morphothiadin dose and virus titer, with the greatest rebound seen in mice treated with 3.75 mg/kg per day of Morphothiadin (540-fold) and the smallest rebound in mice treated with 60 mg/kg per day (23-fold) (P7.5 mg/kg per day significantly suppresses the virus replication cycle throughout the treatment period, while Morphothiadin doses of >15 mg/kg per day suppresses virus for up to 2 weeks after the end of treatment[2].

[1]. Zhou X, et al. Effects of ketoconazole and rifampicin on the pharmacokinetics of GLS4, a novel anti-hepatitis B virus compound, in dogs. Acta Pharmacol Sin. 2013 Nov;34(11):1420-6. [2]. Wu G, et al. Preclinical characterization of GLS4, an inhibitor of hepatitis B virus core particle assembly. Antimicrob Agents Chemother. 2013 Nov;57(11):5344-54.