Optimization of Flavonoid Extraction from Xanthoceras sorbifolia Bunge Flowers, and the Antioxidant and Antibacterial Capacity of the Extract

Study on the Phenotypic Diversity of 33 Ornamental Xanthoceras sorbifolium Cultivars

Xanthoceras sorbifolium, belonging to the family Sapindaceae, has a beautiful tree shape, elegant leaves, large and many brightly colored flowers, and a long flowering duration. This plant is widely applied in gardens. In this study, 33 cultivars of Xanthoceras sorbifolium were selected from the perspective of ornamental properties, and their phenotypic traits, such as leaves, flowers, and branches, were measured and analyzed, and their phenotypic diversity was comprehensively evaluated using principal component analysis, in order to investigate the phenotypic diversity characteristics of Xanthoceras sorbifolium. The results showed that the genetic diversity index of the qualitative traits varied from 0.14 to 1.50, and that of quantitative traits varied from 1.76 to 2.05. The quantitative traits were more diverse than the qualitative traits. The coefficient of variation of the qualitative traits ranged from 16.90% to 57.96%, and that of quantitative traits ranged from 12.92% to 32.87%. The phenotypic traits of the tested cultivars had relatively rich variation. Furthermore, the level of the phenotypic diversity index of Xanthoceras sorbifolium was not consistent with the level of coefficient of variation, indicating large variation and uneven distribution of variation. Through principal component analysis, 17 quantitative characters were extracted into five principal components, with a cumulative contribution rate of 79.82%, representing the primary information on the quantitative characters of ornamental Xanthoceras sorbifolium cultivars. The F value of the 33 samples ranged from -2.79 to 1.93, and the comprehensive scores of seven cultivars were greater than 1, indicating that these cultivars had rich phenotypic diversity. Therefore, the screening, development, and utilization of fine germplasm resources of Xanthoceras sorbifolium should focus on these cultivars. The 33 cultivars were subsequently clustered into five categories through systematic clustering. The cluster analysis provided references for breeding ornamental Xanthoceras sorbifolium cultivars with different utilization values, such as large white flowers, small red flowers, large red flowers, large orange flowers, and double-petaled flowers.

A Review of Classification, Biosynthesis, Biological Activities and Potential Applications of Flavonoids

Flavonoids represent the main class of plant secondary metabolites and occur in the tissues and organs of various plant species. In plants, flavonoids are involved in many biological processes and in response to various environmental stresses. The consumption of flavonoids has been known to reduce the risk of many chronic diseases due to their antioxidant and free radical scavenging properties. In the present review, we summarize the classification, distribution, biosynthesis pathways, and regulatory mechanisms of flavonoids. Moreover, we investigated their biological activities and discuss their applications in food processing and cosmetics, as well as their pharmaceutical and medical uses. Current trends in flavonoid research are also briefly described, including the mining of new functional genes and metabolites through omics research and the engineering of flavonoids using nanotechnology. This review provides a reference for basic and applied research on flavonoid compounds.

Antimicrobial effect of quercetin against Streptococcus pneumoniae

Streptococcus pneumoniae is a bacterium that causes serious infections, including pneumonia. The limited range of available vaccines and the rise of antibiotic-resistant bacteria mean that new treatments are needed. This study looked at the potential of quercetin as an antimicrobial agent against S. pneumoniae in both isolation and in biofilms. The researchers used microdilution tests, checkerboard assays, and death curve assays, as well as in silico and in vitro cytotoxicity evaluations. They found that quercetin at a concentration of 125.0 μg/mL had both inhibitory and bactericidal effects against S. pneumoniae, and these effects were increased when quercetin was combined with ampicillin. Quercetin also reduced the growth of pneumococcal biofilms. In addition, quercetin (absence or in combination with ampicillin) reduced the death time of Tenebrio molitor larvae compared to the infection control. The study also demonstrated that quercetin had low toxicity in both in silico and in vivo assays, suggesting that it could be a promising treatment for infections caused by S. pneumoniae.

[Xanthoceras sorbifolium Bunge flower extract inhibits benign prostatic hyperplasia in rats]

OBJECTIVE

To assess the inhibitory effect of the extract of Xanthoceras sorbifolium Bunge flower against benign prostatic hyperplasia (BPH) and explore its possible mechanism.

METHODS

MTT assay was used to examine the effect of the extract of Xanthoceras sorbifolium Bunge flower on proliferation of benign prostatic hyperplasia cells (BPH-1), and cell apoptosis and cell cycle changes following the treatment were analyzed using annexin V/PI double staining and flow cytometry. The protein expression levels of Bcl-2, Bax, caspase-3, PI3K and AKT in the treated cells were detected using Western blotting. A rat model of BPH established by subcutaneous injection of testosterone propionate was treated with the flower extract for 28 days, and pathological changes in the prostate tissue were observed with HE staining. The protein expression levels of Bcl-2, Bax, caspase3 and PI3K/AKT in the prostate tissue were detected with Western blotting.

RESULTS

Within the concentration range of 125-1000 µg/mL, the flower extract of Xanthoceras sorbifolium Bunge significantly inhibited the proliferation of BPH-1 cells and caused obvious cell cycle arrest at G0/G1 phase; the apoptotic rate of the cells was positively correlated with the concentration of the flower extract (P < 0.05). Bcl-2, p-PI3K and p-AKT expression levels were significantly down-regulated and Bax and caspase-3 expression levels were significantly increased in the cells after treatment with the flowers extract (P < 0.05). In the rat models of BPH, the rats treated with the flowers extract at moderate and high doses showed obviously decreased expressions of p-AKT and Bcl-2 and an increased expression of Bax in the prostate tissue; a significantly lowered p-AKT expression was observed in the prostate tissue of rats receiving the low-dose treatment (P < 0.05).

CONCLUSION

The flower extract of Xanthoceras sorbifolium Bunge has a inhibitory effect on BPH both in vitro and in rats, suggesting its potential value in the development of medicinal plant preparations for treatment of BPH.

Optimization of Flavonoid Extraction from Salix babylonica L. Buds, and the Antioxidant and Antibacterial Activities of the Extract

The present study was designed to evaluate the chemical extraction, chemical composition, and antioxidant and antibacterial properties of the total flavonoids in Willow Buds (TFW). We investigated the optimal extraction of TFW using response surface methodology (RSM). Chemical compounds were analyzed using Q-Orbitrap LC-MS/MS. The DPPH radical scavenging capacity, hydroxy radical inhibitory ability, and superoxide anion radical inhibitory ability were explored to determine the antioxidant properties of flavonoid extractions. The antibacterial effect was assessed via minimal inhibitory concentration. The results demonstrated that the optimal extraction conditions were an ethanol concentration of 50%, a time of 35 min, and a liquid/material ratio of 70:1 mL/g. Under these conditions, the yield of TFW was 7.57%. Eight flavonoids, a phenolic glycoside, and an alkaloid were enriched in the Willow Buds. The TFW exhibited significant antioxidant activity, with IC₅₀ values of 0.18-0.24 mg/mL and antimicrobial activity against Escherichia coli, Salmonella enterica, Staphylococcus aureus, and Streptococcus pneumoniae. TFW may be explored as potential and natural compounds in food and pharmacological applications.

Simultaneous capture of hydrophilic and hydrophobic compounds from complex plants by biosurfactant-assisted mechanical amorphous dispersion extraction

A biosurfactant-assisted mechanical amorphous dispersion extraction (BA-MADE) procedure was established for the simultaneous capture of hydrophilic phenolic acids and hydrophobic tanshinones from Salvia miltiorrhiza. Single-factor experiments and the response surface methodology were used to optimize and analyze the crucial parameters for the method, such as the type and amount of amorphous-dispersion extractants, grinding time, extraction time and solid-to-liquid ratio. The optimized parameter values for the BA-MADE process were 407.02 mg of sodium chenodeoxycholate, a grinding time of 4.87 min, an extraction time of 4.92 min, and a solid-to-liquid ratio of 0.5:10 g/mL. The calibration curves of danshensu, rosmarinic acid, lithospermic acid, salvianolic acid B, salvianolic acid A, dihydrotanshinone I, cryptotanshinone, tanshinone I, and tanshinone II A exhibited good linearity in the range of 1-500 μg/mL (R² ≥ 0.9990). The limits of detection of nine analytes ranged from 5.46 to 130 ng/mL, the relative standard deviations (RSDs) of intraday and interday precision were less than 1.95 and 3.56%, respectively, and the recoveries of the real sample were in the range of 85-113%, with RSD% below 3.21%. The BA-MADE method was compared with previously reported methods, such as heating reflux extraction, ultrasonic extraction and microwave-assisted micellar extraction, and the results demonstrated that the developed method has significant advantages in the simultaneous extraction of hydrophilic and hydrophobic active components from Salvia miltiorrhiza.

Pigment of Ceiba speciosa (A. St.-Hil.) Flowers: Separation, Extraction, Purification and Antioxidant Activity

In this work, the extraction procedure of a natural pigment from the flower of Ceiba speciosa (A. St.-Hil.) was optimized by response surface methodology. It is the first time that the extraction of the flower pigment of C. speciosa (FPCS) has been reported, along with an evaluation of its stability and biological activity under various conditions, and an exploration of its potential use as a food additive and in medicine. Specifically, the effects of ethanol concentration, solid-liquid ratio, temperature and time on the extraction rate of FPCS were determined using a Box-Behnken design. The optimum extraction conditions for FPCS were 75% ethanol with a solid-liquid ratio of 1:75 mg/mL) at 66 °C for 39 min. The purification of FPCS using different macroporous resins showed that D101 performed best when the initial mass concentration of the injection solution was 1.50 mg/mL, resulting in a three-fold increase in color value. The yield of dry flowers was 9.75% of fresh petals and the FPCS extraction efficiency was 43.2%. The effects of light, solubility, pH, temperature, sweeteners, edible acids, redox agents, preservatives and metal ions on FPCS were also investigated. Furthermore, the characteristics of FPCS were determined by spectrophotometry at a specific wavelength using the Lambert-Beer law to correlate the mass of FPCS with its absorbance value. An acute toxicological test performed according to Horne's method showed that FPCS is a non-toxic extract and thus may be used as a food additive or in other ingestible forms. Finally, western blotting showed that FPCS prevents lipopolysaccharide-induced hippocampal oxidative stress in mice. The study suggests that FPCS may function as an antioxidant with applications in the food, cosmetics and polymer industries.