Schisandra chinensis (Turcz.) Baill neutral polysaccharides alleviate Parkinson's disease via effectively activating MCL-1 expression regulation of autophagy signaling

The purified neutral polysaccharide fraction, namely SBP-1, was isolated and characterized from Schisandra chinensis (Turcz.) Baill crude Polysaccharides, which have anti-Parkinson's disease activity were investigated in vivo and in vitro. Experiments have shown that the main chain of SBP-1 was Glcp-(1→, →4)-Glcp-(1→ and →4,6)-Glcp-(1→. We also revealed the effect of SBP-1 on the PD mice model and the potential underlying molecular mechanism. The results showed that SBP-1 administration improved behavioral deficits, increased tyrosine hydroxylase-positive cells, attenuated loss of dopaminergic neurons in MPTP-exposed mice, and reduced cell death induced by MPP⁺. The Mcl-1 was identified as the target of SBP-1 by the combination of docking-SPR-ITC, WB, and IF experiments. Subsequently, the study showed that SBP-1 could target Mcl-1 to enhance Autophagy with a change in the apoptotic response, which was further demonstrated by a change in LC3/p62, PI3K/Akt/mTOR, and possesses a change in the expression of BCL2/Bax/Caspase3. These results demonstrate that SBP-1 may protect neurons against MPP⁺ or MPTP-induced damage in vitro and in vivo through enhancing Autophagy. In summary, these findings indicate that SBP-1 and S. chinensis show potential as effective candidates for further investigation in the prevention and treatment of PD or associated illnesses, specifically through Autophagy apoptotic-based mechanisms.

Autophagy; Parkinson's disease; Polysaccharide structure; Schisandra chinensis (Turcz.) Baill.