The Isolation and Preparation of Samwinol from Dracocephalum heterophyllum and Prevention on Aβ25-35-Induced Neuroinflammation in PC-12 Cells

Investigating the neuroprotective effects of Dracocephalum moldavica extract and its effect on metabolomic profile of rat model of sporadic Alzheimer's disease

Alzheimer's disease (AD) is a progressive condition marked by multiple underlying mechanisms. Therefore, the investigation of natural products that can target multiple pathways presents a potential gate for the understanding and management of AD. This study aimed to assess the neuroprotective effects of the hydroalcoholic extract of Dracocephalum moldavica (DM) on cognitive impairment, biomarker changes, and putative metabolic pathways in a rat model of AD induced by intracerebroventricular streptozotocin (ICV-STZ). The DM extract was standardized and quantified based on examining total phenolic, total flavonoid, rosmarinic acid, and quercetin contents using colorimetry and high-performance liquid chromatography (HPLC) methods. The antioxidant potential of the extract was evaluated by 2,2-Diphenyl-1-picrylhydrazyl and nitric oxide radical scavenging assays. Male Wistar rats were injected with STZ (3 mg/kg, single dose, bilateral ICV) to induce a sporadic AD (sAD) model. Following model induction, rats were orally administered with DM extract (100, 200, and 400 mg/kg/day) or donepezil (5 mg/kg/day) for 21 days. Cognitive function was assessed using the radial arm water maze behavioral test. The histopathological evaluations were conducted in the cortex and hippocampus regions. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to assess metabolite changes in various brain regions. DM extract significantly attenuated cognitive dysfunction induced by ICV-STZ according to behavioral and histopathological investigations. Thirty-two discriminating metabolites related to the amino acid metabolism; the glutamate/gamma-aminobutyric acid/glutamine cycle; nucleotide metabolism; lipid metabolism (glycerophospholipids, sphingomyelins, ceramides, phosphatidylserines, and prostaglandins), and glucose metabolic pathways were identified in the brains of rats with sAD simultaneously for the first time in this model. Polyphenols in DM extract may contribute to the regulation of these pathways. After treatment with DM extract, 10 metabolites from the 32 identified ones were altered in the brain tissue of a rat model of sAD, most commonly at doses of 200 and 400 mg/kg. In conclusion, this study demonstrates the neuroprotective potential of DM by upregulation/downregulation of various pathophysiological biomarkers such as adenine, glycerophosphoglycerol, inosine, prostaglandins, and sphingomyelin induced by ICV-STZ in sAD. These findings are consistent with cognitive behavioral results and histopathological outcomes.

Pharmacophylogenetic relationships of genus Dracocephalum and its related genera based on multifaceted analysis

The Lamiaceae genus Dracocephalum, with over 30 species, is believed to have considerable medicinal properties and is widely used in Eurasian ethnomedicine. Numerous studies have researched on the geographical distribution, metabolite identification, and bioactivity of Dracocephalum species, especially amidst debates concerning the taxonomy of its closely related genera Hyssopus and Lallemantia. These discussions present an opportunity for pharmacophylogenetic studies of these medicinal plants. In this review, we collated extensive literature and data to present a multifaceted view of the geographical distribution, phylogenetics, phytometabolites and chemodiversity, ethnopharmacological uses, and pharmacological activities of Dracocephalum, Hyssopus, and Lallemantia. We found that these genera were concentrated in Europe, with species adapted to various climatic zones. These genera shared close phylogenetic relationships, with Dracocephalum and Hyssopus displaying intertwined patterns in the phylogenetic tree. Our review assessed more than 900 metabolites from these three genera, with terpenoids and flavonoids being the most abundant. Researchers have recently identified novel metabolites within Dracocephalum, expanding our understanding of its chemical constituents. Ethnopharmacologically, these genera have been traditionally used for treating respiratory, liver and gall bladder diseases. Extracts and metabolites from these genera exhibit a range of pharmacological activities such as hepatoprotective, anti-inflammation, antimicrobial action, anti-hyperlipidaemia, and anti-tumour properties. By integrating phylogenetic analyses with network pharmacology, we explored the intrinsic links between metabolite profiles, traditional efficacy, and modern pharmacology of Dracocephalum and its related genera. This study contributes to the discovery of potential medicinal value from closely related species of Dracocephalum and aids in the development and sustainable use of medicinal plant resources.

Neuroprotective Effect of Codonopsis pilosula Polysaccharide on Aβ25-35-Induced Damage in PC12 Cells via the p38MAPK Signaling Pathways

OBJECTIVES

Plant polysaccharides have attracted increasing attention due to their high efficiency and low toxicity. Codonopsis pilosula polysaccharide (CPP) is an essential substance extracted from Codonopsis pilosula, known for its excellent antioxidant and neuroprotective effects. However, it is still unclear how CPP improves nerve protection and what its underlying molecular mechanisms are. This study aimed to investigate the neuroprotective effect of CPP on Aβ25-35-induced damage in PC12 cells and its underlying molecular mechanisms.

METHODS

The neuroprotective effect of CPP was evaluated using Aβ25-35-induced damage in pheochFfromocytoma (PC12) cells as an in vitro cell model. The cells were treated with CPP alone or in combination with SB203580 (an inhibitor of p38MAPK) in Aβ25-35 culture. The cell viability was assessed using a 3-(4,5-Dimethylthiazol-2-yl)-2,diphenyltetrazolium (MTT) assay. Furthermore, reactive oxygen species (ROS) were detected using flow cytometry. The production levels of intracellular superoxide dismutase (SOD), dismutase (SOD), glutathione (GSH), catalase (CAT), and malondialdehyFde (MDA) were determined using the colorimetric method. Annexin V-FITC and propidium iodide (PI) staining, as well as 33258 were performed using fluorescence microscopy. Moreover, the effect of adding SB203580 was studied to determine the changes in cell apoptosis induced by CPP treatment and Aβ25-35 induction.

RESULTS

The CPP markedly inhibited Aβ25-35-induced reduction in the viability and apoptosis of PC12 cells. CPP also reduced the Aβ25-35-induced increase in the expression of the apoptosis factors and the levels of free radicals (ROS and MDA) and reversed the Aβ25-35-induced suppression of antioxidant activity. Additionally, inhibition of p38MAPK via the addition of their antagonists reversed the observed anti-apoptosis effects of CPP.

CONCLUSIONS

CPP can efficiently provide neuroprotection against Aβ25-35-induced damage in PC12 cells brought about via oxidation and apoptosis reactions, and the underlying mechanisms involve the p38MAPK pathways. Therefore, CPP could potentially be useful as a neuroprotective agent in natural medicine, pharmacy, and the food industry.

Characterization of Polysaccharides from the Pericarp of Zanthoxylum bungeanum Maxim by Saccharide Mapping and Their Neuroprotective Effects

The pericarp of Zanthoxylum bungeanum maxim (PZM) is a commonly used spice and herbal medicine in China. In the present study, the structural characteristics of PPZM were investigated by saccharide mapping after enzymatic digestion by using high-performance thin layer chromatography (HPTLC) and polysaccharide analysis by using carbohydrate gel electrophoresis (PACE). The mechanisms of protective effects of PPZM on Aβ_25-35-induced oxidative damage were explored in PC12 cells. The results showed that PPZM contained 1,4-α-D-galactosidic, 1,4-α-D-galactosiduronic, and (1→4)-β-D-glucosidic linkages. Pretreatment with PPZM significantly increased the cell viability of Aβ_25-35-injured PC12 cells. Flow cytometry and Hoechst/PI staining indicated that PPZM gradually relieved the apoptosis of the Aβ_25-25-treated cells. PPZM markedly decreased the ROS level of PC12 cells and suppressed Aβ_25-35-induced oxidative stress by increasing the SOD level, and decreasing the level of MDA and LDH. The mRNA expressions of caspase-3 and Bax were significantly downregulated, and Bcl-2 expression was upregulated by treatment with PPZM. PPZM significantly increased the mRNA expression of Nrf2 and HO-1 in Aβ_25-35 treated cells. The results indicated that PPZM alleviated apoptosis and oxidative stress induced by Aβ_25-25 through the inhibition of mitochondrial dependent apoptosis and activation of Nrf2/HO-1 pathway. PPZM can be used as a potential protective agent against Aβ_25-25-induced neurotoxicity.

Medium- and High-Pressure Integrated Chromatographic Strategies for the Isolation and Purification of Free Radical Inhibitors from Dracocephalum heterophyllum

Dracocephalum heterophyllum has been reported as a traditional Tibetan medicine with diverse therapeutic benefits for the effective treatment of various diseases. However, only a few reports on its free radical inhibitors are limited due to its complex chemical composition and difficult isolation and purification processes. In this study, five free radical inhibitors are isolated by an integrated chromatographic method from Dracocephalum heterophyllum, followed by an investigation of the in vitro antioxidant activity utilizing 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Medium-pressure liquid chromatography was used for the pretreatment of the crude extract of Dracocephalum heterophyllum and targeted separation and purification of the free radical inhibitors using high-pressure liquid chromatography; the antioxidant peaks are recognized by the separation and purification process in combination with an online HPLC-DPPH system. Five free radical inhibitors with purity higher than 95% were obtained, namely xanthotoxol, 5-hydroxy-8-methoxypsoralen, luteolin, methyl rosmarinate, and ethyl rosmarinate. Finally, DPPH assays are performed, and their IC50 values for isolated compounds are 250.39 ± 13.32 μM, 26.91 ± 1.93 μM, 66.87 ± 14.33 μM, 21.99 ± 3.17 μM, and 36.96 ± 1.72 μM, respectively. This method is effective in isolating free radical inhibitors from Dracocephalum heterophyllum, and it has the potential to be adopted for the isolation of antioxidants from other plants of medicinal value as well.