Preliminary Phytochemical Screening, In Vitro Antidiabetic, Antioxidant Activities, and Toxicity of Leaf Extracts of Psychotria malayana Jack

Acute exposure of zebrafish (Danio rerio) adults to psychotria carthagenensis leaf extracts: chemical profile, lack of genotoxicity and histological changes

Psychotria carthagenensis is a shrubby plant, often consumed by traditional populations in religious rituals. Previous studies have shown that this plant's infusion can inhibit the activity of Acetylcholinesterase (AChE) in rats. Despite the therapeutic potential, there is a lack of research regarding its possible toxicological and genotoxic effects. Hence, this study aimed to analyze the chemical profile of the ethanol extract from P. carthagenensis leaves by LC-DAD-MS and assess its possible toxicity and genotoxicity in zebrafish (Danio rerio). Adult zebrafish (N = 9/group) were exposed at different concentrations and the LC50 was calculated. Frequencies of micronucleus (MN) and nuclear abnormalities (NA) were estimated for genotoxic effects, and degree of tissue changes (DTC) was used to assess the liver and gill histopathology. From the LC-DAD-MS analyses, the identified compounds included N-fructosyl valine, ethyl hexoside, 5-O-E-caffeoylquinic acid, N-feruloylagmatime, roseoside, di-O-deoxyhexoyl-hexosyl quercetin, loiolide, and oleamide. The calculated values of LC50 did not vary significantly during the time of exposure. At the concentrations of 1.25, 2.5, 3.75, 5, 7.5, 10 and 15 mg/L, there was no genotoxicity, and only low to moderate toxicity for the tissues was observed, despite mortality of 100% at doses of 20-100 mg/L of P. carthagenensis ethanolic leaf extract. There were changes in cytoplasm of hepatocytes at 1.25 mg/L, and karyorrhexis, karyolysis and megalocytosis at 10 mg/L. In the gills, the alterations were primary lamellar hyperplasia in all concentrations, and at 10 mg/L, secondary lamellar edema and vascular hyperemia were common. Additionally, the chemical composition of P. carthagenensis was expanded.

Quality Studies on Cynometra iripa Leaf and Bark as Herbal Medicines

Cynometra iripa Kostel. is a Fabaceae species of mangrove used in traditional Ayurvedic medicine for treating inflammatory conditions. The present study aims to establish monographic botanical and chemical quality criteria for C. iripa leaf and bark as herbal substances and to evaluate their in vitro antioxidant potential. Macroscopic and microscopic qualitative and quantitative analyses, chemical LC-UV/DAD-ESI/MS profiling, and the quantification of key chemical classes were performed. Antioxidant activity was evaluated by DPPH and FRAP assays. Macroscopically, the leaf is asymmetrical with an emarginated apex and cuneate base. Microscopically, it shows features such as two-layered adaxial palisade parenchyma, vascular bundles surrounded by 3-6 layers of sclerenchyma, prismatic calcium oxalate crystals (5.89 ± 1.32 μm) along the fibers, paracytic stomata only on the abaxial epidermis (stomatal index-20.15), and non-glandular trichomes only on petiolules. The microscopic features of the bark include a broad cortex with large lignified sclereids, prismatic calcium oxalate crystals (8.24 ± 1.57 μm), and secondary phloem with distinct 2-5 seriated medullary rays without crystals. Chemical profile analysis revealed that phenolic derivatives, mainly condensed tannins and flavonoids, are the main classes identified. A total of 22 marker compounds were tentatively identified in both plant parts. The major compounds identified in the leaf were quercetin-3-O-glucoside and taxifolin pentoside and in the bark were B-type dimeric proanthocyanidins and taxifolin 3-O-rhamnoside. The total phenolics content was higher in the leaf (1521 ± 4.71 mg GAE/g dry weight), while the total flavonoids and condensed tannins content were higher in the bark (82 ± 0.58 mg CE/g and 1021 ± 5.51 mg CCE/g dry weight, respectively). A total of 70% of the hydroethanolic extracts of leaf and bark showed higher antioxidant activity than the ascorbic acid and concentration-dependent scavenging activity in the DPPH assay (IC50 23.95 ± 0.93 and 23.63 ± 1.37 µg/mL, respectively). A positive and statistically significant (p < 0.05) correlation between the phenol content and antioxidant activity was found. The results obtained will provide important clues for the quality control criteria of C. iripa leaf and bark, as well as for the knowledge of their pharmacological potential as possible anti-inflammatory agents with antioxidant activity.

In Vitro Anti-Diabetic, Anti-Inflammatory, Antioxidant Activities and Toxicological Study of Optimized Psychotria malayana Jack Leaves Extract

Psychotria malayana Jack (Family: Rubiaceae, local name: Salung) is a traditional herb used to treat diabetes. A previous study by our research group demonstrated that P. malayana methanolic and water extract exhibits significant potential as an effective agent for managing diabetes. Further research has been performed on the extraction optimization of this plant to enhance its inhibitory activity against α-glucosidase, a key enzyme associated with diabetes, and to reduce its toxicity. The objectives of this study are to evaluate the anti-diabetic, anti-inflammatory, and antioxidant properties of the optimized P. malayana leaf extract (OE), to evaluate its toxicity using a zebrafish embryo/larvae model, and to analyze its metabolites. The anti-diabetic effects were assessed by investigating α-glucosidase inhibition (AGI), while the inflammation inhibitory activity was performed using the soybean lipoxygenase inhibitory (SLOXI) test. The assessment of antioxidant activity was performed utilizing FRAP and DPPH assays. The toxicology study was conducted using the zebrafish embryo/larvae (Danio rerio) model. The metabolites present in the extracts were analyzed using GC-MS and LC-MS. OE demonstrated significant AGI and SLOXI activities, represented as 2.02 and 4.92 µg/mL for IC50 values, respectively. It exhibited potent antioxidant activities as determined by IC50 values of 13.08 µg/mL (using the DPPH assay) and 95.44 mmol TE/mg DW (using the FRAP assay), and also demonstrated an LC50 value of 224.29 µg/mL, which surpasses its therapeutic index of 111.03. OE exhibited a higher therapeutic index compared to that of the methanol extract (13.84) stated in the previous state of the art. This suggests that OE exhibits a lower level of toxicity, making it safer for use, and has the potential to be highly effective in its anti-diabetic activity. Liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) demonstrated the presence of several constituents in this extract. Among them, several compounds, such as propanoic acid, succinic acid, D-tagatose, myo-inositol, isorhamnetin, moracin M-3'-O-β-D-glucopyranoside, procyanidin B3, and leucopelargonidin, have been reported as possessing anti-diabetic and antioxidant activities. This finding offers great potential for future research in diabetes treatment.

Phytochemical analysis, antioxidant, α-glucosidase inhibitory activity, and toxicity evaluation of Orthosiphon stamineus leaf extract

Ocimum aristatum, commonly known as O. stamineus, has been widely studied for its potential as an herbal medicine candidate. This research aims to compare the efficacy of water and 100% ethanolic extracts of O. stamineus as α-glucosidase inhibitors and antioxidants, as well as toxicity against zebrafish embryos. Based on the study findings, water extract of O. stamineus leaves exhibited superior inhibition activity against α-glucosidase, ABTS, and DPPH, with IC50 values of approximately 43.623 ± 0.039 µg/mL, 27.556 ± 0.125 µg/mL, and 95.047 ± 1.587 µg/mL, respectively. The major active compounds identified in the extract include fatty acid groups and their derivates such as linoleic acid, α-eleostearic acid, stearic acid, oleanolic acid, and corchorifatty acid F. Phenolic groups such as caffeic acid, rosmarinic acid, 3,4-Dihydroxybenzaldehyde, norfenefrine, caftaric acid, and 2-hydroxyphenylalanine and flavonoids and their derivates including 5,7-Dihydroxychromone, 5,7-Dihydroxy-2,6-dimethyl-4H-chromen-4-one, eupatorin, and others were also identified in the extract. Carboxylic acid groups and triterpenoids such as azelaic acid and asiatic acid were also present. This study found that the water extract of O. stamineus is non-toxic to zebrafish embryos and does not affect the development of zebrafish larvae at concentrations lower than 500 µg/mL. These findings highlight the potential of the water extract of O. stamineus as a valuable herbal medicine candidate, particularly for its potent α-glucosidase inhibition and antioxidant properties, and affirm its safety in zebrafish embryos at tested concentrations.

Several natural phytochemicals from Chinese traditional fermented food-pickled Raphanus sativus L.: Purification and characterization

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β-Sitosterol, β-sitosterol-3-o-glucose glycosides, α-linolenic acid, 1-monopalmitin and chaenomic acid A were identified from 5-year-old pickled radish.

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Production of the merad product 5-hydroxymethylfurfural in fresh white radish after salting and fermentation.

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β-Sitosterol, β-sitosterol-3-O-glucose glycosides have good affinity with antioxidant enzymes.

In this study, we aimed to isolate and identify the bioactive compounds from 5-year pickled radish. The pickled radish was extracted with methanol or ethyl acetate. Sephadex LH-20, normal phase and reverse phase silica gel column chromatography were used for separation and purification, combined with thin layer chromatography (TLC), high performance liquid chromatography (HPLC), electrospray mass spectrometry (ESI-MS), nuclear magnetic resonance spectroscopy (NMR) technology for structural identification. The results showed that 6 compounds were separated and purified from methanol and ethyl acetate extracts of 5-year-old pickled radish. The structures were identified as 5-hydroxymethylfurfural, β-sitosterol, β-sitosterol-3-O-glucose glycosides, α-linolenic acid, 1-monopalmitin and chaenomic acid A. Using molecular docking, it was determined that β-sitosterol and its derivative β-sitosterol-3-O-glucose glycosides have high affinity for five antioxidant enzymes, and there were multiple hydrogen bonds between them. These results indicated that pickled radishes might be used as an important source of natural chemical substances.