Evaluation of Cassia tora Linn. against Oxidative Stress-induced DNA and Cell Membrane Damage

Genome-Wide Mining of the Tandem Duplicated Type III Polyketide Synthases and Their Expression, Structure Analysis of Senna tora

Senna tora is one of the homologous crops used as a medicinal food containing an abundance of anthraquinones. Type III polyketide synthases (PKSs) are key enzymes that catalyze polyketide formation; in particular, the chalcone synthase-like (CHS-L) genes are involved in anthraquinone production. Tandem duplication is a fundamental mechanism for gene family expansion. However, the analysis of the tandem duplicated genes (TDGs) and the identification and characterization of PKSs have not been reported for S. tora. Herein, we identified 3087 TDGs in the S. tora genome; the synonymous substitution rates (Ks) analysis indicated that the TDGs had recently undergone duplication. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the type III PKSs were the most enriched TDGs involved in the biosynthesis of the secondary metabolite pathways, as evidenced by 14 tandem duplicated CHS-L genes. Subsequently, we identified 30 type III PKSs with complete sequences in the S. tora genome. Based on the phylogenetic analysis, the type III PKSs were classified into three groups. The protein conserved motifs and key active residues showed similar patterns in the same group. The transcriptome analysis showed that the chalcone synthase (CHS) genes were more highly expressed in the leaves than in the seeds in S. tora. The transcriptome and qRT-PCR analysis showed that the CHS-L genes had a higher expression in the seeds than in other tissues, particularly seven tandem duplicated CHS-L2/3/5/6/9/10/13 genes. The key active-site residues and three-dimensional models of the CHS-L2/3/5/6/9/10/13 proteins showed slight variation. These results indicated that the rich anthraquinones in S. tora seeds might be ascribed to the PKSs' expansion from tandem duplication, and the seven key CHS-L2/3/5/6/9/10/13 genes provide candidate genes for further research. Our study provides an important basis for further research on the regulation of anthraquinones' biosynthesis in S. tora.

Cassia tora extract alleviates Aβ1-42 aggregation processes in vitro and protects against aluminium-induced neurodegeneration in rats

OBJECTIVES

To examine the ability of Cassia tora extract to produce, in vitro and in vivo, beneficial effects with respect to events occurring during Alzheimer's disease.

METHODS

Previously characterised methanol extract of C. tora was tested for its ability to lessen Aβ₄₂ aggregation processes in vitro and to alleviate aluminium-induced impairments in vivo in rats.

KEY FINDINGS

Cassia tora extract prevents the aggregation of monomeric, oligomeric and fibrillary Aβ_1-42 in vitro. Moreover, the daily ingestion of 100 and 400 milligrams of the extract per kilogram of body weight for 60 days ameliorates the neurobehavioral and cognitive abilities of aluminium-treated rats in vivo. Importantly, treatments with the extract trigger a significant recovery of antioxidant enzymes function, a diminution of lipid peroxidation and acetylcholinesterase activity, a decrease of pro-inflammatory cytokines expression and an increase of brain-derived neurotrophic factor levels in both the hippocampus and the frontal cortex. Finally, we evidence that the extract is able to ameliorate the aluminium-dependent loss of neuronal integrity in the CA1 and CA3 regions of the hippocampus.

CONCLUSIONS

Altogether, our results reveal that methanol extract of C. tora is able to prevent typical AD-related events and therefore stands as a promising mild and natural anti-AD multitarget compound.

Metabolite identification of gut microflora-cassia seed interactions using UPLC-QTOF/MS

Cassia seed is the dried ripe seed of Cassia obtusifolia L. or Cassia tora L., which is widely used as a food or traditional Chinese medicine. The aim of the present study was to detect the components and metabolites in the culture of human or rat intestinal microflora suspension with the water decoction of cassia seed in vitro, using an ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry system equipped with a negative ion scan mode. Initially, ellagic acid was identified in the cassia seed decoction. Subsequently, six different metabolites, including urolithin (uro)-A, uro-B, uro-D, uro-M6, uro-M7 and uro-B-glucuronide (glur), were detected after co-culture of the cassia seed decoction with intestinal microflora, but not in the cassia seed decoction alone. Uro-M6, uro-M7, uro-A and uro-B were common metabolites in the culture of human or rat intestinal microflora suspension with the water decoction of cassia seed. However, uro-D was only detected in the culture of rat intestinal microflora suspension with the water decoction of cassia seed, and uro-B-glur was only detected in the culture of human intestinal microflora with the water decoction of cassia seed. The uro and intermediate metabolites were produced by ellagic acid in the cassia seed decoction under the action of the intestinal microflora. The production of metabolites might be related to the abundance and diversity of the intestinal microflora in humans and rats. The present study provided rationale for further pharmacological and clinical studies on the mechanisms of action of cassia seeds.

Cassia tora prevents Aβ1-42 aggregation, inhibits acetylcholinesterase activity and protects against Aβ1-42-induced cell death and oxidative stress in human neuroblastoma cells

BACKGROUND

Alzheimer's is a complex neurodegenerative disease and is characterized by extraneuronal accumulation of β-amyloid peptide. Because of its complex nature, multi-target directed ligands (MTDLs) are increasingly being considered as promising anti-Alzheimer therapeutic agents. This study is aimed at determining the effects of Cassia tora ethyl acetate fraction on several Alzheimer-associated deleterious events in test tubes as well as in human neuroblastoma SK-N-SH and SH-SY5Y cell lines.

METHOD

Ethyl acetate fraction of C. tora was purified by chromatography, characterized by 1H and 13C NMR, and tested for its ability to prevent Aβ 1-42 aggregation by thioflavin-T fluorescence and transmission electron microscopy. We also analyzed the intracellular ROS level and cytotoxicity in SK-N-SH and SH-SY5Y cell lines.

RESULTS

The extract inhibits the formation of Aβ 1-42 aggregation from monomers and oligomers, as also acetylcholinesterase activity, Aβ 1-42 -induced cell death, and Aβ 1-42 -dependent intracellular ROS production in both SK-N-SH and SH-SY5Y cells. In-depth chromatographic and spectroscopic analysis of the extract revealed that the active molecules are most likely triglycerides of oleic acid (C18H34O2).

CONCLUSION

We demonstrate for the first time that Cassia tora fraction prevents Aβ 1-42 aggregation, inhibits acetylcholinesterase and alleviates Aβ 1-42 -induced oxidative stress in human neuroblastoma cells. We further suggest the possible use of triglycerides of oleic acid as efficient anti-Alzheimer agents.

Neuroprotective effects of Cassia tora against paraquat-induced neurodegeneration: relevance for Parkinson's disease

The aim of the present study was to determine whether Cassia tora extracts could reverse the oxidative stress-induced neurodegeneration in a Parkinson's disease in vitro model. The leaves were treated with ethyl acetate (CtEA) or methanol (CtME). The extracts were first analysed by HPLC for their phenolic content and then tested for their neuroprotective effects in human SK-N-SH neuroblastoma cells. Cells were pre-treated with various concentrations of extracts followed by incubation with paraquat (14 μM). Firstly, pre-treatment of SK-N-SH cells with 100 μg/mL of CtEA or CtME significantly reduced the paraquat-induced production of reactive oxygen species. Furthermore, both CtEA and CtME reduced the paraquat-induced apoptosis. Moreover, there was a significant reduction of paraquat-induced DNA damage in SK-N-SH cells pre-treated with CtEA or CtME. Finally, both extracts significantly inhibited paraquat-dependent lipid peroxidation. Altogether, these in vitro data establish C. tora as a possible anti-Parkinson natural remedy.