THAT Egypt is 'the gift of the Nile' may be true from the point of view of human civilization but such a phrase would be misleading if applied to the plant-life of the country. Even the weed flora of the canals and cultivated land is not uniform, and to this must be added the ephemeral flora of the deserts, and the mountains and mountain valleys of Sinai and the Elba mountains. Many botanists have explored Egypt and much has been published regarding both the wild and cultivated flora. However, the need for an accurate and up-to-date taxonomic account cannot be gainsaid, and the present work* by Mrs. Tackholm and the late Prof. G. Tackholm is intended to meet this need.

Flora of egypt

BACKGROUND Besides the numerous biologic and pharmacologic functions in the human body that act as potent antioxidants, flavonoids (flavones, flavanones, flavonols, flavanols and isoflavones) are noted as cancer preventive or therapeutic agents. METHODS This review summarizes the published data using PubMed, Science Direct, and Scopus. RESULTS In this context, recognition and introduction of the most active cytotoxic flavonoids as promising agents for cancer therapy gives insight for further evaluations. However, there are some critical points that may affect the entering of flavonoids as active cytotoxic phytochemicals in the clinical phase. Issues such as the abundance of active species in nature, the methods of extraction and purification, solubility, pharmacokinetic profile, presence of the chiral moieties, method of synthesis, and structure modification may limit the entry of a selected compound for use in humans. Although plenty of basic evidence exists for cytotoxic/antitumor activity of the versatility of flavonoids for entry into clinical trials, the above-mentioned concerns must be considered. CONCLUSION This review is an effort to introduce cytotoxic natural flavonoids (IC50< 10 µM) that may have the potential to be used against various tumor cells. Also, active constituents, molecular mechanisms, and related clinical trials have been discussed as well as the limitations and challenges of using flavonoids in clinic.

Potent Cytotoxic Natural Flavonoids: The Limits of Perspective.

Flavonoids are a category of plant-derived compounds which exhibit a large number of health-related effects. One of the most well-known and studied flavonoids is kaempferol, which can be found in a wide variety of herbs and plant families. Apart from their anticarcinogenic and anti-inflammatory effects, kaempferol and its associated compounds also exhibit antibacterial, antifungal, and antiprotozoal activities. The development of drugs and treatment schemes based on these compounds is becoming increasingly important in the face of emerging resistance of numerous pathogens as well as complex molecular interactions between various drug therapies. In addition, many of the kaempferol-containing plants are used in traditional systems all over the world for centuries to treat numerous conditions. Due to its variety of sources and associated compounds, some molecular mechanisms of kaempferol antimicrobial activity are well known while others are still under analysis. This paper thoroughly documents the vegetal and food sources of kaempferol as well as the most recent and significant studies regarding its antimicrobial applications.

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Kaempferol: Antimicrobial Properties, Sources, Clinical, and Traditional Applications

Eugenia uniflora leaves are a rich source of phenolic compounds with biological activities. In this study, the chemical profile of samples obtained from three sample preparation methods, liquid/liquid extraction from a methanol extract of the leaves (LLE), solid phase dispersion of the leaves in silica gel (SESi) and direct mass analysis on the cleaned leaf surface (LMDA), was evaluated from spectra generated by ultra-high resolution mass spectrometry (Fourier Transform Ion Cyclotron Resonance, FT-ICR) coupled with three different ionization methods, electrospray (ESI), paper spray (PS), and leaf spray (LS). Several flavonoids and phenolic acids were detected in their deprotonated form in the regions from m/z 150 to 1300. Myricitrin ([C21H20O12 − H]−, m/z 463.08831, 0.24), its chloride adduct ([C21H20O12 + Cl]−m/z 499.06499, 0.11) and other myricitrin derivatives, gallic acid ([C7H6O5 − H]−, m/z 169.01415, 0.58) and O-methyl gallic acid ([C8H8O5 − H]−, m/z 183.02998, 0.47), were the main compounds detected. Generally, the use of the ESI(−) source is considered the best ionization method along with LLE as the sample preparation method, producing more intense signals in the mass spectra of myricitrin and its derivatives. LS is an ionization method with negligible sample preparation, but in this case, it provided less intense signals for the compounds of interest when compared to ESI(−)MS. Considering phenolic compounds of Eugenia uniflora, electrospray proved to be the most efficient mass ionization method for the identification of biologically active substances.

Identification of phenolic compounds in Eugenia uniflora leaves by FTICR MS in association with different ionization sources

The bioactive content, antioxidant properties, and enzyme inhibition properties of extracts of Alcea fasciculiflora from Turkey prepared with different solvents (water, methanol, ethyl acetate) and extraction methods (maceration, soxhlet, homogenizer assisted extraction, and ultrasound assisted extraction) were examined in this study. UHPLC-HRMS analysis detected or annotated a total of 50 compounds in A. fasciculiflora extracts, including 18 hydroxybenzoic and hydroxycinnamic acids, 7 Hexaric acids, 7 Coumarins, 15 Flavonoids, and 3 hydroxycinnamic acid amides. The extracts had phenolic and flavonoid levels ranging from 14.25 to 24.87 mg GAE/g and 1.68 to 25.26 mg RE/g, respectively, in the analysis. Both DPPH and ABTS tests revealed radical scavenging capabilities (between 2.63 and 35.33 mg TE/g and between 13.46 and 76.27 mg TE/g, respectively). The extracts had reducing properties (CUPRAC: 40.38–78 TE/g and FRAP: 17.51–42.58 TE/g). The extracts showed metal chelating activity (18.28–46.71 mg EDTAE/g) as well as total antioxidant capacity (phosphomolybdenum test) (0.90–2.12 mmol TE/g). DPPH, ABTS, FRAP, and metal chelating tests indicated the water extracts to be the best antioxidants, while the ethyl acetate extracts had the highest overall antioxidant capacity regardless of the extraction technique. Furthermore, anti-acetylcholinesterase activity was identified in all extracts (0.17–2.80 mg GALAE/g). The water extracts and the ultrasound-assisted ethyl acetate extract were inert against butyrylcholinesterase, but the other extracts showed anti-butyrylcholinesterase activity (1.17–5.80 mg GALAE/g). Tyrosine inhibitory action was identified in all extracts (1.79–58.93 mg KAE/g), with the most effective methanolic extracts. Only the ethyl acetate and methanolic extracts produced by maceration and homogenizer aided extraction showed glucosidase inhibition (0.11–1.11 mmol ACAE/g). These findings showed the overall bioactivity of the different extracts of A. fasciculiflora and provided an overview of the combination of solvent type and extraction method that could yield bioactive profile and pharmacological properties of interest and hence, could be a useful reference for future studies on this species.

https://www.mdpi.com/1420-3049/27/15/5011/pdf?version=1660005471

Nevin M Abdel-Rahman

Papers

Flavonoids of Alcea rosea L. and their immune stimulant, antioxidant and cytotoxic activities on hepatocellular carcinoma HepG-2 cell line.

Phytochemical and pharmacological appraisal of the aerial parts of Lotus corniculatus L. growing in Egypt