YELLOW CAMELLIAS: A REVIEW OF CHEMICAL CONSTITUENTS AND BIOLOGICAL ACTIVITIES

To date, 69 species of yellow Camellia have been found in South China and Vietnam, and they have attracted substantial attention from scientists. Chemical and biological studies have only been carried out on a few species, with the main focus on the Chinese species Camellia nitidissima, but have shown that the main active ingredients of these yellow camellia species include flavonoids, phenolic compounds, saponins, triterpenoids, phytosterols, essential oils, amino acids, and polysaccharides. Many pharmacological studies have proved that the total extracts, fractions, and isolated substances from yellow camellia species possess antioxidant, anticancer, hypolipidemic, hypoglycemic, antiallergic, hepatoprotective, neuroprotective, anxiolytic, and antidepressant activities. This review systematically summarizes recent research results in order to provide a comprehensive and up-to-date understanding of the chemical composition and biological activities of yellow camellia species, creating a basis for research of the yellow camellia species in Vietnam and development of new products from this source.Cho đến nay, đã có 69 loài trà hoa vàng (Yellow Camellias) được tìm thấy ở Nam Trung Quốc và Việt Nam và thu hút được sự chú ý rất lớn của các nhà khoa học. Các nghiên cứu hóa học và tác dụng sinh học mới chỉ được thực hiện trên một số loài, trong đó tập trung chủ yếu vào loài Camellia nitidissima ở Trung Quốc nhưng đã cho thấy thành phần hoạt chất chính của các loài trà hoa vàng này bao gồm flavonoid, các hợp chất phenol, saponin, triterpenoid, phytosterol, tinh dầu, acid amin và polysaccharid. Nhiều nghiên cứu dược lý đã chứng minh các dịch chiết toàn phần, dịch chiết phân đoạn và các chất phân lập được từ các loài trà hoa vàng có tác dụng chống oxy hóa, chống ung thư, hạ lipid máu, hạ đường huyết, bảo vệ gan, bảo vệ thần kinh, chống lo ấu và chống trầm cảm. Bài tổng quan này hệ thống hóa các kết quả nghiên cứu gần đây để có một cái nhìn toàn cảnh về thành phần hóa học và tác dụng sinh học của các loài trà hoa vàng, tạo cơ sở cho việc định hướng nghiên cứu phát triển các loài trà hoa vàng ở Việt Nam tạo các sản phẩm có giá trị phục vụ cộng đồng

Pinoresinol and 3,4',5,7-tetrahydroxy-3'-methoxyflavanone from the fruits of Silybum marianum (L.) Gaertn

From the fruits of Silybum marianum (L.) Gaertn. cultivated in the North of Vietnam, (±)2,6-bis(4′-hydroxy-3′-methoxy-phenyl)-3,7-dioxabicyclo[3.3.0]octane (pinoresinol) (1) and 3,4′,5,7-tetrahydroxy-3′-methoxyflavanone (2) were isolated. Their structures were elucidated by analyses of the NMR and mass spectra in comparison with the reported data. This is the first report of both 1 and 2 from Silybum species

Silychristin and isosilychristin from the fruits of Silybum marianum (L.) Gaertin

By various chromatography methods, two flavonolignan silychristin (1) and isosilychristin (2)were isolated from the fruits of Silybum marianum (L.) Gaertn. cultivated in the North of Vietnam. Their structures were elucidated by analyses of the NMR (1D-, 2D-NMR) and ESI spectra. This is the first report of both 1 and 2 from S. marianum cultivated in Vietnam

Advances in Nucleic Acid Amplification-Based Microfluidic Devices for Clinical Microbial Detection

Accurate and timely detection of infectious pathogens is urgently needed for disease treatment and control of possible outbreaks worldwide. Conventional methods for pathogen detection are usually time-consuming and labor-intensive. Novel strategies for the identification of pathogenic nucleic acids are necessary for practical application. The advent of microfluidic technology and microfluidic devices has offered advanced and miniaturized tools to rapidly screen microorganisms, improving many drawbacks of conventional nucleic acid amplification-based methods. In this review, we summarize advances in the microfluidic approach to detect pathogens based on nucleic acid amplification. We survey microfluidic platforms performing two major types of nucleic acid amplification strategies, namely, polymerase chain reaction (PCR) and isothermal nucleic acid amplification. We also provide an overview of nucleic acid amplification-based platforms including studies and commercialized products for SARS-CoV-2 detection. Technologically, we focus on the design of the microfluidic devices, the selected methods for sample preparation, nucleic acid amplification techniques, and endpoint analysis. We also compare features such as analysis time, sensitivity, and specificity of different platforms. The first section of the review discusses methods used in microfluidic devices for upstream clinical sample preparation. The second section covers the design, operation, and applications of PCR-based microfluidic devices. The third section reviews two common types of isothermal nucleic acid amplification methods (loop-mediated isothermal amplification and recombinase polymerase amplification) performed in microfluidic systems. The fourth section introduces microfluidic applications for nucleic acid amplification-based detection of SARS-CoV-2. Finally, the review concludes with the importance of full integration and quantitative analysis for clinical microbial identification

In vitro erythrocyte oxidative damage of Morinda citrifolia L (noni) leaves extract

Slight decrease of hemoglobin and erythrocyte count was observed previously after subchronic oral dosing of Morinda citrifolia L leaves extract in rats. Induction of erythrocyte membrane damage could be the cause for these effects. Aims: The objective of this investigation was to assess the in vitro cytotoxicity of Morinda citrifolia L leaves extract and fractions on rat erythrocytes. Methods: Hemolytic damage was assayed in rat erythrocytes. Oxidative stress was assessed by measuring methemoglobin formation, thiobarbituric acid reactive substances (TBARS) and enzyme antioxidant activities, superoxide dismutase (SOD) and catalase (CAT). Results: Morinda citrifolia L extract caused no hemolysis and induced oxidative damage to red cells in vitro. Methemoglobin increase was observed at concentration between 2 and 8 mg/ml of the extract. Lipid peroxidation was increased and CAT and SOD activities were depleted indicating a possible increase of hydrogen peroxide and superoxide radicals in erythrocytes. Ethyl acetate, dichloromethane and butanol fraction did not cause methemoglobin formation while water fraction increased methemoglobin level at doses up to 6 mg/ml. Conclusions: We concluded that high doses of Morinda citrifolia L extract promote erythrocyte oxidative damage due to metabolites present in water fraction. These could be the cause of decreased erythrocyte and hemoglobin levels observed. [J Intercult Ethnopharmacol 2013; 2(3.000): 135-140

Free-floating magnetic microstructures by mask photolithography

International audienc

Optical lithography of three-dimensional magnetophotonic microdevices

International audienc

In vitro antiviral activities of ethanol and aqueous extracts of Vietnamese traditional medicinal plants against Porcine Epidemic Diarrhea virus: a coronavirus family member

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