Green extraction of bioactive flavonoids in Scutellariae Radix using deep eutectic solvents-based ultrasound-assisted matrix solid phase dispersion combined with computer-aided analysis

An efficient and sustainable deep eutectic solvents-based ultrasound-assisted matrix solid phase dispersion (DES-UAMSPD) method was proposed for extracting the bioactive flavonoids in Scutellariae Radix (SR), with molecular sieve (ZSM-5) as dispersant and betaine-levulinic acid (Bet-Lea (1:2, 50 % water content)) as the effective extractant. The interaction mechanism of DES formation and extraction process was comprehensively elucidated by computer simulation techniques such as electrostatic potential (ESP) distributions, independent gradient model based on hirshfeld partition (IGMH) and frontier molecular orbitals theory. The response surface methodology experiments were conducted to optimize the extraction conditions. Under optimal extraction conditions, the total content of five analytes (baicalin, oroxyloside, wogonoside, baicalein and wogonin) reached 182.66 mg g-1, which was 1.50-2.19 folds higher than conventional extraction solvents. The greenness and environmental friendliness of the proposed method were evaluated through Green Analytical Procedure Index and Analytical Eco-Scale. Additionally, this quantitative method exhibited reliable linearity for the analytes (r2 > 0.9997) and excellent recovery (95.4 %-102 %, RSD < 2.72 %). The limits of detection ranged from 0.02 to 0.04 μg mL-1. Overall, these results highlighted the excellent extraction and quantification capability of the proposed approach, which offered an environmentally friendly strategy for effective extraction of bioactive compounds from natural products.

Production of secondary metabolites in callus cultures of Scutellaria baicalensis L. and assessment of their anti-inflammatory and antioxidant efficacy in ulcerative colitis rats

Baikal skullcap or Chinese (Scutellaria baicalensis L.) is an interesting plant with promising medicinal properties; however, traditional cultivation methods are time-consuming, and yield variations can be significant; callus culture is considered one of the solutions to overcome these limitations because the callus culture provides an effective, alternative for the consistent production of secondary metabolites. For callus production of S. baicalensis L., the in vitro germinating seedlings were cultured on MS medium containing 1.0 mg/L 6-benzyladenine (BAP) and 1.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D). Three culture lines were established, and the best growth index represented in fresh and dry weight was obtained from line No. 1. S. baicalensis L. callus extract was performed on the best callus line in the stationary phase for in vitro assays. The chemical analysis, antioxidant tests, proline, flavonoids, phenolics, and macronutrient content were assessed. Therefore, this paper aims to evaluate the effectiveness of secondary metabolites in S. baicalensis L. callus and to study its biological effect on recurrent ulcerative colitis (UC). Conventional treatment of UC has focused on suppressing immunological responses instead of addressing which are (UC) underlying causes. Recurrent UC is caused by oxidative stress and inflammation that lead to chronic inflammation of the inner lining of the colon and rectum. According to the findings, secondary metabolites in S. baicalensis L. callus cultures increased antioxidant activity. This improvement in oxidative activity was positively correlated with the potential to reduce UC in vivo.

Biotechnological strategies for controlled accumulation of flavones in hairy root culture of Scutellaria lateriflora L

Accumulation of medicinally important flavones and acteoside was evaluated in Scutellaria lateriflora hairy root cultures subjected to different experimental strategies - feeding with precursors of phenolics biosynthesis (phenylalanine, cinnamic acid, and sodium cinnamate), addition of elicitors (chitosan, jasmonic acid) and Amberlite XAD-4 and XAD-7 resins and permeabilization with dimethyl sulfoxide (DMSO) and methanol. The production profile of S. lateriflora cultures changed under the influence of the applied strategies. Hairy roots of S. lateriflora were found to be a rich source of wogonoside or wogonin, depending on the treatment used. The addition of sodium cinnamate (1.0 mg/L) was the most effective approach to provide high production of flavonoids, especially wogonoside (4.41% dry weight /DW/; 566.78 mg/L). Permeabilization with DMSO (2 µg/ml for 12 h) or methanol (30% for 12 h) resulted in high biosynthesis of wogonin (299.77 mg/L and 274.03 mg/L, respectively). The obtained results provide new insight into the selection of the optimal growth conditions for the production of in vitro biomass with a significant level of flavone accumulation. The data may be valuable for designing large-scale cultivation systems of hairy roots of S. lateriflora with high productivity of bioactive compounds - wogonin or wogonoside.

Baicalin-Current Trends in Detection Methods and Health-Promoting Properties

Baicalin (7-D-glucuronic acid-5,6-dihydroxyflavone) belongs to natural flavonoids extracted from the roots of Scutellaria baicalensis, the plant used in traditional Chinese medicine. It has been proven that baicalin has various pharmacological activities, such as antioxidant, anti-inflammatory, anticancer, antibacterial, and anti-apoptotic ones. However, it is essential not only to determine the medical usefulness of baicalin, but also to find and develop the most effective methods for its extraction and detection. Therefore, the aim of this review was to summarize the current methods of detection and identification of baicalin and to present the medical applications of baicalin and the underlying mechanisms of its action. Based on the review of the latest literature, it can be concluded that liquid chromatography alone or together with mass spectrometry is the most commonly used method for the determination of baicalin. Recently, also new electrochemical methods have been established, e.g., biosensors with fluorescence, which have better detection limits, sensitivity, and selectivity.

Biologically active compounds in Scutellaria baicalensis L. callus extract: Phytochemical analysis and isolation

Plant cells and tissue cultures are sources of secondary plant metabolites. Substances produced by callus cultures can expand the raw material base in pharmacy and food production. However, isolating biologically active substances from medicinal plants is a labor- and time-consuming process. As a result, new and efficient technological processes adapted for extraction from callus cultures are in high demand, and new algorithms of isolation and purification of biologically active substances remain a relevant task. This research featured callus cultures of Scutellaria baicalensis. The procedures for phytochemical analysis and isolation of biologically active substances involved such physicochemical research methods as high-performance chromatography (HPLC), thin-layer chromatography (TLC), UV spectrometry, and IR spectrometry. The high performance liquid chromatography confirmed the presence of flavonoids represented by baicalein (5,6,7-trioxyflavone), baicalin (baicalein 7-O-glucuronide), scutellarein (5,6,7,4-tetraoxyflavone), scutellarin (7-O-glucuronide scutellarein), vagonin, and oroxylin. The spectral analyses also detected skutebaicalin. The highest total content of diterpene belonged to the samples extracted with 70% ethanol at 70°C. The content of diterpene was 0.09 mg/cm3 in terms of betulin. The biologically active substances were isolated from the callus extracts of S. baicalensis with a recovery rate of ≥ 80%. The purification scheme made it possible to obtain highly-pure individual biologically active compounds: trans-cinnamic acid, baicalin, and oroxylin A had a purity of ≥ 95%; baicalein had a purity of ≥ 97%; scutellarin and luteolin reached ≥ 96%. The new technological extraction method made it possible to obtain extracts from S. baicalensis callus cultures, which were tested for the component composition. The developed isolation algorithm and purification scheme yielded biologically active substances with a purification degree of ≥ 95%.

Baicalin mediated regulation of key signaling pathways in cancer

Baicalin has been widely investigated against different types of malignancies both at the cellular and molecular levels over the past few years. Due to its remarkable anti-proliferative potential in numerous cancer cell lines, it has created immense interest as a potential chemotherapeutic modality compared to other flavonoids. Thus, this review focuses on the recent accomplishments of baicalin and its limitations in cancer prevention and treatment. Further, combination studies and nanoformulations using baicalin to treat cancer along with the metabolism, bioavailability, toxicity, and pharmacokinetics have been discussed. The present review explains biological source, and anti-proliferative potential of baicalin against cancers including breast, colon, hepatic, leukemia, lung, and skin, as well as the relevant mechanism of action to modulate diverse signaling pathways including apoptosis, cell cycle, invasion, and migration, angiogenesis, and autophagy. The anticancer mechanism of baicalin in orthotropic and xenograft mice models have been deliberated. The combination studies of baicalin in novel therapies as chemotherapeutic adjuvants have also been summarized. The low bioavailability, fast metabolism, and poor solubility, and other significant factors that limit the clinical use of baicalin have been examined as a challenge. The improvement in the pharmacokinetics and pharmacodynamics of baicalin with newer approaches and the gaps are highlighted, which could establish baicalin as an effective and safe compound for cancer treatment as well as help to translate its potential from bench to bedside.

Assembly of black phosphorus quantum dots-doped MOF and silver nanoclusters as a versatile enzyme-catalyzed biosensor for solution, flexible substrate and latent fingerprint visual detection of baicalin

In this work, a versatile enzyme-catalyzed biosensor was developed by using the assembled nanohybrids of black phosphorus quantum dots (BPQDs)-doped metal-organic frameworks (MOF) and silver nanoclusters (AgNCs). The nanohybrids of AgNCs/BPQDs/MOF exhibit dual-emissive fluorescence (FL) centers at 630 nm (red) and 535 nm (blue) under excitation at 440 nm. Baicalin enhances the activity of catalase and catalytic decomposition of H₂O₂. With increase of baicalin contents in the mixture containing nanohybrids, catalase and H₂O₂, the catalase-caused decomposition of H₂O₂ was accelerated and the excessive H₂O₂ was consumed. Baicalin can restrain the oxidation capability of H₂O₂. The red-FL (response signal) of AgNCs adhering to MOF increases, while blue-FL (reference signal) of BPQDs doped into MOF has negligible changes. A new ratiometric FL biosensor was designed based on nanohybrids and enzyme-catalyzed reaction. This biosensor enables the detection of baicalin in the range of 0.01-500 μg mL^-1, with a limit of detection of 3 ng mL^-1. This biosensor has high sensitivity, selectivity and stability for baicalin detection in practical samples. Especially, it performed the solution, flexible substrate and latent fingerprint visual detection of baicalin through direct observation of FL color shades with naked eyes. This work explored a facile and efficient semi-quantitative method for versatile FL visual detection, which can promote the development of advanced chemo/bio-sensors and analysis methods.