Antioxidant Activity In Vitro Guided Screening and Identification of Flavonoids Antioxidants in the Extract from Tetrastigma hemsleyanum Diels et Gilg

Predicting antioxidant activity of compounds based on chemical structure using machine learning methods

Oxidative stress is a well-established risk factor for numerous chronic diseases, emphasizing the need for efficient identification of potent antioxidants. Conventional methods for assessing antioxidant properties are often time-consuming and resource-intensive, typically relying on laborious biochemical assays. In this study, we investigated the applicability of machine learning (ML) algorithms for predicting the antioxidant activity of compounds based solely on their molecular structure. We evaluated the performance of five ML algorithms, Support Vector Machine (SVM), Logistic Regression (LR), XGBoost, Random Forest (RF), and Deep Neural Network (DNN), using a dataset of over 1,900 compounds with experimentally determined antioxidant activity. Both RF and SVM achieved the best overall performance, exhibiting high accuracy (> 0.9) and effectively distinguishing active and inactive compounds with high structural similarity. External validation using natural product data from the BATMAN database confirmed the generalizability of the RF and SVM models. Our results suggest that ML models serve as powerful tools to expedite the discovery of novel antioxidant candidates, potentially streamlining the development of future therapeutic interventions.

Red Grape By-Products from the Demarcated Douro Region: Chemical Analysis, Antioxidant Potential and Antimicrobial Activity against Food-Borne Pathogens

Wine production is one of the most important agricultural activities. The winemaking process generates a considerable volume of different residues characterized as by-products, such as pomace, seeds, stems, and skins. By-products are rich in polyphenols with antioxidant and antibacterial properties and may act as bacteriostatic or bactericidal agents against food-borne pathogens, improving food safety by enhancing antibiotic efficacy and reducing bacterial resistance. The aim of this study was to evaluate the phenolic composition and antioxidant activity of grape components (skins, seeds, and stems) from three red grape varieties (Periquita, Gamay, and Donzelinho Tinto) and determine their antibacterial activity against antibiotic-resistant bacteria, including Escherichia coli in food-producing animals and Listeria monocytogenes from food products and food-related environments. Ten phenolic compounds were quantified in these red grape varieties, with specific compounds found in different parts of the grape, including phenolic acids and flavonoids. Flavonoids are abundant in seeds and stems, malvidin-3-O-glucoside being the main anthocyanin in skins. The ethanolic extract from the seeds showed in vitro concentration-dependent activity against reactive species like •NO and O2•-. Gamay extract was the most effective, followed by Donzelinho Tinto and Periquita. Extracts showed varying antibacterial activity against Gram-positive and Gram-negative bacteria, with stronger effects on Gram-positive bacteria. L. monocytogenes was more susceptible, while E. coli was limited to three strains. Seeds exhibited the strongest antibacterial activity, followed by stems. The results of our study provide evidence of the potential of grape by-products, particularly seeds, as sources of bioactive compounds with antioxidant and antibacterial properties, offering promising avenues for enhancing food safety and combating antibiotic resistance in food production and related environments.

Revealing quality chemicals of Tetrastigma hemsleyanum roots in different geographical origins using untargeted metabolomics and random-forest based spectrum-effect analysis

Tetrastigma hemsleyanum root is a popular functional food in China, and the price varies based on the origin of the product. The link between the origin, metabolic profile, and bioactivity of T. hemsleyanum must be investigated. This study compares the metabolic profiles of 254 samples collected from eight different areas with 49 potential key chemical markers using plant metabolomics. The metabolic pathways of the five critical flavonoid metabolites were annotated and enriched using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Moreover, a random forest model aiding the spectrum-effect relationship analysis was developed for the first time indicating catechin and darendoside B as potential quality markers of antioxidant activity. The findings of this study provide a comprehensive understanding of the chemical composition and bioactive compounds of T. hemsleyanum as well as valuable information on the evaluation of the quality of various samples and products in the market.

Tetrastigma hemsleyanum suppresses neuroinflammation in febrile seizures rats via regulating PKC-δ/caspase-1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tetrastigma hemsleyanum Diels et Gilg (T. hemsleyanum, Sanyeqing) has been used in the prevention and treatment of repetitive Febrile seizures (FS) over the centuries in China.

AIM OF THE STUDY

T. hemsleyanum exerts wide pharmacological action, which has been widely used for treating various diseases, including infantile febrile seizure. However, the systematic study on this herb's material basis and the functional mechanism is lacking. This study intended to systematically elucidate the mechanism of T. hemsleyanum against febrile seizures.

MATERIALS AND METHODS

The efficacy of T. hemsleyanum was estimated by using a hot bath as a model of FS, the onset and duration of seizure, morphological structure changes of hippocampal neurons as well as magnetoencephalography were applied to evaluate the effects. Meanwhile, the bioactive components of T. hemsleyanum responsible for the therapeutic effect of T. hemsleyanum on FS were identified by UPLC-MS/MS. Then we systematically elucidated the mechanism of T. hemsleyanum based on metabonomics, transcriptomics, network pharmacological and experimental validation.

RESULTS

In a hyperthermia-induced FS model of rats, T. hemsleyanum significantly increased the seizure latency and decreased seizure duration, alleviating the abnormal delta and gamma band activity during epileptic discharge. Furthermore, ten chemical components of ethanol extracts from T. hemsleyanum were identified by UPLC-MS/MS, including quercetin, kaempferol, and procyanidin B1 and so on, which was consistent with the network pharmacology prediction. The serum metabolomics indicated that T. hemsleyanum mainly acts on inflammation regulation and neuroprotection by the glycerophospholipid metabolism pathway. Ninety-two potential targets of T. hemsleyanum on FS were identified by network pharmacology, and TNF, IL-6, and IL-1β were considered the pivotal targets. In the hippocampus transcriptomics, 17 KEGG pathways were identified after T. hemsleyanum treatment compared with the FS model group, among which 15 pathways overlapped with those identified by network pharmacology, and the PKC-δ/caspase-1 signaling pathway was a critical node. Finally, in vivo experiments also verified T. hemsleyanum inhibited the activation of microglia and resulted in a significant reduction in the level of PKCδ, NLRC4, caspase-1, IL-1β, IL-6 and TNF-α in hippocampus of FS rats.

CONCLUSIONS

Our study suggested that the therapeutic effect of T. hemsleyanum on FS might be regulated by inhibiting the neuroinflammation, thus exerting an anticonvulsant effect in vivo, and the mechanism might be related to regulating the PKC-δ/caspase-1 signaling pathway.

In Vitro Analysis of Cytotoxic Activities of Monotheca buxifolia Targeting WNT/β-Catenin Genes in Breast Cancer Cells

Breast cancer (BC) is known to be the most common malignancy among women throughout the world. Plant-derived natural products have been recognized as a great source of anticancer drugs. In this study, the efficacy and anticancer potential of the methanolic extract of Monotheca buxifolia leaves using human breast cancer cells targeting WNT/β-catenin signaling was evaluated. We used methanolic and other (chloroform, ethyl acetate, butanol, and aqueous) extracts to discover their potential cytotoxicity on breast cancer cells (MCF-7). Among these, the methanol showed significant activity in the inhibition of the proliferation of cancer cells because of the presence of bioactive compounds, including phenols and flavonoids, detected by a Fourier transform infrared spectrophotometer and by gas chromatography mass spectrometry. The cytotoxic effect of the plant extract on the MCF-7 cells was examined by MTT and acid phosphatase assays. Real-time PCR analysis was performed to measure the mRNA expression of WNT-3a and β-catenin, along with Caspase-1,-3,-7, and -9 in MCF-7 cells. The IC50 value of the extract was found to be 232 μg/mL and 173 μg/mL in the MTT and acid phosphatase assays, respectively. Dose selection (100 and 300 μg/mL) was performed for real-time PCR, Annexin V/PI analysis, and Western blotting using Doxorubicin as a positive control. The extract at 100 μg/mL significantly upregulated caspases and downregulated the WNT-3a and β-catenin gene in MCF-7 cells. Western blot analysis further confirmed the dysregulations of the WNT signaling component (*** p< 0.0001). The results showed an increase in the number of dead cells in methanolic extract-treated cells in the Annexin V/PI analysis. Our study concludes that M. buxifolia may serve as an effective anticancer mediator through gene modulation that targets WNT/β-catenin signaling, and it can be further characterized using more powerful experimental and computational tools.