Panaxadiol and panaxatriol derivatives as anti-hepatitis B virus inhibitors

Panaxadiol Attenuates Brain Damage by Inhibiting Ferroptosis in a Rat Model of Cerebral Hemorrhage

Intracerebral hemorrhage (ICH) is the most common subtype of hemorrhage stroke, with a high disability, morbidity and mortality rate globally. Panaxadiol (PD), a triterpenoid sapogenin monomer, is isolated from the roots of ginseng, which has shown a variety of biological properties, such as anti-inflammation, anti-cancer, and neuroprotection. However, its effect and mechanism on ICH were still unknown. Thirty-six rats were randomly divided into six group (n = 6), namely, sham, ICH, ICH + 5 mg/kg PD, ICH + 10 mg/kg PD, ICH + 20 mg/kg PD, and ICH + 10 mg/kg PD + 50 mg/kg vismodegib. Rats were treated with type IV collagenase to induce an in vivo model of ICH, and then intraperitoneally injected with PD (5, 10 and 20 mg/kg) and 50 mg/kg vismodegib (an inhibitor of hedgehog signal). The effect and potential mechanism of PD on ICH were explored by behavioral test, brain water content measurement, Evans blue detection, hematoxylin-eosin (HE) staining, iron level examination, Prussian blue staining, western blot and immunohistochemistry, respectively. An increase in the mNSS (13.17 ± 1.17), and a decrease in the rotarod latency (40.67 ± 9.31), modified Garcia score (9.83 ± 1.47), forelimb use times (3.33 ± 0.82), left forepaw placements (29.90 ± 4.38) and left turns (17.34 ± 3.55) in ICH rats were reversed with the PD treatment (6.83 ± 0.75, 113.5 ± 11.95, 17.50 ± 1.87, 8.17 ± 0.98, 63.56 ± 9.84, and 42.13 ± 4.52 respectively). PD treatment reduced the brain water content (73.13 ± 3.16 vs. 86.82 ± 4.74), the level of Evans blue (2.14 ± 0.25 vs. 4.03 ± 0.20) and cerebral hemorrhage in ICH rats. Also, PD injection decreased the iron level (0.06 ± 0.005 vs. 0.17 ± 0.02) and the expression of ACSL4 (0.56 ± 0.07 vs. 1.23 ± 0.16), with the increased expression of GPX4 (1.14 ± 0.08 vs. 0.21 ± 0.03) in ICH rats. Mechanically, PD treatment restored the decreased expression of SHH (0.96 ± 0.13 vs. 0.20 ± 0.03), GLI1 (0.89 ± 0.13 vs. 0.06 ± 0.007) and PTCH (0.75 ± 0.05 vs. 0.10 ± 0.01) in ICH rats. Inhibition of SHH signaling by vismodegib reversed the ameliorative effect of PD on ICH rats. PD improved brain damage by suppressing ferroptosis via the activation of the SHH/GLI signaling pathway, which could lay a theoretical foundation for the treatment of ICH.

Dammarane-type leads panaxadiol and protopanaxadiol for drug discovery: Biological activity and structural modification

Based on the definite therapeutic benefits, such as neuroprotective, cardioprotective, anticancer, anti-diabetic and so on, the Panax genus which contains many valuable plants, including ginseng (Panax ginseng C.A. Meyer), notoginseng (Panax notoginseng) and American ginseng (Panax quinquefolius L.), attracts research focus. Actually, the biological and pharmacological effects of the Panax genus are mainly attributed to the abundant ginsenosides. However, the low membrane permeability and the gastrointestinal tract influence seriously limit the absorption and bioavailability of ginsenosides. The acid or base hydrolysates of ginsenosides, 20 (R,S)-panaxadiol and 20 (R,S)-protopanaxadiol showed improved bioavailability and diverse pharmacological activities. Moreover, relative stable skeletons and active hydroxyl group at C-3 position and other reactive sites are suitable for structural modification to improve biological activities. In this review, the pharmacological activities of panaxadiol, protopanaxadiol and their structurally modified derivatives are comprehensively summarized.

(R)-panaxadiol by whole cells of filamentous fungus Absidia coerulea AS 3.3382

The microbial transformation of 20(R)-panaxadiol (PD) by the fungus Absidia coerulea AS 3.3382 afforded three new and three known metabolites. The structures of the metabolites were characterized as 3-oxo-20(R)-panaxadiol (1), 3-oxo-7β- hydroxyl-20(R)-panaxadiol (2), 3-oxo-22β-hydroxyl-20(R)-panaxadiol (3), 3-oxo- 7β,22β-dihydroxyl-20(R)-panaxadiol (4), 3-oxo-7β,24β-dihydroxyl-20(R)-panaxadiol (5), and 3-oxo-7β,24α-dihydroxyl-20(R)-panaxadiol (6). Among them, 2-4 were new compounds. In addition, compounds 3 and 4 exhibited significant anti-hepatic fibrosis activity.

Biotransformation of 20(R)-panaxatriol by the fungus Aspergillus flavus Link AS 3.3950

Microbial transformation of 20(R)-panaxatriol by the fungus Aspergillus flavus Link AS 3.3950 was performed. Four new (1-4), along with two previously reported metabolites (5 and 6), were obtained. Their chemical structures were elucidated on the basis of extensive spectroscopic analyses. Furthermore, the inhibitory effects of those compounds on K562/ADR, Du-145, Hela, MCF-7 and HepG2 cell lines were evaluated by MTT assay. Among them, compound 15β-hydroxy-20(R)-panaxatriol (4) exhibited selective inhibitory effects on human leukaemic progenitor cells K562/ADR through arresting cell cycle, which was associated with obvious decrease of cyclin B1, cyclin D1 and cyclin-dependent kinase (CDK) 1/2/4/6 protein expression.