Therapeutic Potential of Polyscias fruticosa (L.) Harms Leaf Extract for Parkinson's Disease Treatment by Drosophila melanogaster Model.

Parkinson's disease (PD) is characterized by progressive locomotive defects and loss of dopaminergic neurons. Polyscias fruticosa leaves are used by Vietnamese as herbal medicines to support the treatment of some diseases related to neurodegeneration such as Parkinson's and Alzheimer's diseases. However, recent scientific data have not provided sufficient evidence for the use of P. fruticosa leaves to treat PD or decelerate PD progression. In the present study, the capacity of P. fruticosa leaf extract for PD treatment on the dietary supplementation was investigated using dUCH-knockdown Drosophila model. The results indicated that P. fruticosa leaf extract decelerated dopaminergic neuron degeneration induced by dUCH knockdown in not only the larval stage but also the adult stage, which might result in the amelioration in locomotor ability of dUCH-knockdown larvae and flies. Furthermore, antioxidant activities and some key phytochemicals such as saponins, polyphenols, and flavonoids that might contribute to the effects of the P. fruticosa leaf extract were identified.

Evaluating the Potential of Portulaca oleracea L. for Parkinson's Disease Treatment Using a Drosophila Model with dUCH-Knockdown.

Parkinson's disease (PD), which is characterized by the decreased motor function and the loss of dopaminergic neurons, is a common neurodegenerative disorder in elders. There have been numerous in vitro and in vivo models developed to study mechanisms of PD and screen potential drug. Recently, dUCH-knockdown Drosophila model has been established and showed potential for screening antioxidants for PD treatment. The dUCH-knockdown Drosophila model of PD mimics most of main PD pathologies such as dopaminergic neurons degeneration, locomotor dysfunction, and shortage of dopamine in the brain. Common purslane (Portulaca oleracea L.) is a nutritious vegetable containing a variety of antioxidants, levodopa, and dopamine, a neurotransmitter closely related to PD. Purslane has been reported to exert neuroprotective effects against several neurotoxins including rotenone and 6-OHDA in PD models. However, the recent data have not provided sufficient evidence for using purslane to treat PD or decelerate disease progression. Therefore, in this study, we utilized dUCH-knockdown fly to evaluate the capacity of purslane extracts for PD treatment. The results showed that purslane extracts improved locomotor ability in the larval stage and decelerated disease progression in the adult stage. Additionally, purslane extracts also reduced dopaminergic neuron degeneration. Taken together, our data strongly demonstrated that purslane extracts effectively rescued PD-like phenotypes in the fly model. This result contributed a foundation for further study on the application of purslane in PD treatment.

Curcumin Effectively Rescued Parkinson's Disease-Like Phenotypes in a Novel Drosophila melanogaster Model with dUCH Knockdown.

The relationship between oxidative stress and neurodegenerative diseases has been extensively examined, and antioxidants are considered to be a promising approach for decelerating disease progression. Parkinson's disease (PD) is a common neurodegenerative disorder and affects 1% of the population over 60 years of age. A complex combination of genetic and environmental factors contributes to the pathogenesis of PD. However, since the onset mechanisms of PD have not yet been elucidated in detail, difficulties are associated with developing effective treatments. Curcumin has been reported to have neuroprotective properties in PD models induced by neurotoxins or genetic factors such as α-synuclein, PINK1, DJ-1, and LRRK2. In the present study, we investigated the effects of curcumin in a novel Drosophila model of PD with knockdown of dUCH, a homolog of human UCH-L1. We found that dopaminergic neuron-specific knockdown of dUCH caused impaired movement and the loss of dopaminergic neurons. Furthermore, the knockdown of dUCH induced oxidative stress while curcumin decreased the ROS level induced by this knockdown. In addition, dUCH knockdown flies treated with curcumin had improved locomotive abilities and less severe neurodegeneration. Taken together, with studies on other PD models, these results strongly suggest that treatments with curcumin are an appropriate therapy for PD related to oxidative stress.

Wound healing activity of Streptocaulon juventas root ethanolic extract.

Streptocaulon juventas is a well-known plant that has antimicrobial activity, in vitro antiplasmodial activity, anti-proliferative activity, and antioxidant activity. In this study, we showed experimental evidence that proved that S. juventas root ethanolic extract has wound healing activities. First, in a mouse excision wound model, S. juventas root ethanolic extract at a dose of 100 mg/kg/day significantly reduced the wound closure time. After 7 days, the wound granulation tissue in mice treated with the extract exhibited a 2.3-fold decrease in inflammatory cells, a 1.7-fold increase in fibroblasts and enhanced angiogenesis. Molecular analysis also revealed that after wounds were treated with S. juventas root ethanolic extract, TNF-α and NF-κB1 gene expression were down-regulated by 4.7 and 3.7 times, respectively. In contrast, TGF-ß1 and VEGF gene expression were up-regulated by 1.9 and 6.5 times, respectively. Taken together, our experimental data strongly show that the ethanolic extract from S. juventas root displays remarkable wound healing activity.