Amentoflavone acts as a radioprotector for irradiated v79 cells by regulating reactive oxygen species (ROS), cell cycle and mitochondrial mass

Insights Into Amentoflavone: A Natural Multifunctional Biflavonoid

Amentoflavone is an active phenolic compound isolated from Selaginella tamariscina over 40 years. Amentoflavone has been extensively recorded as a molecule which displays multifunctional biological activities. Especially, amentoflavone involves in anti-cancer activity by mediating various signaling pathways such as extracellular signal-regulated kinase (ERK), nuclear factor kappa-B (NF-κB) and phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), and emerges anti-SARS-CoV-2 effect via binding towards the main protease (Mpro/3CLpro), spike protein receptor binding domain (RBD) and RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2. Therefore, amentoflavone is considered to be a promising therapeutic agent for clinical research. Considering the multifunction of amentoflavone, the current review comprehensively discuss the chemistry, the progress in its diverse biological activities, including anti-inflammatory, anti-oxidation, anti-microorganism, metabolism regulation, neuroprotection, radioprotection, musculoskeletal protection and antidepressant, specially the fascinating role against various types of cancers. In addition, the bioavailability and drug delivery of amentoflavone, the molecular mechanisms underlying the activities of amentoflavone, the molecular docking simulation of amentoflavone through in silico approach and anti-SARS-CoV-2 effect of amentoflavone are discussed.

Amentoflavone protects the hematopoietic system of mice against γ-irradiation

Some flavonoids have been shown to exhibit good antioxidant activity and protect mice from damage induced by radiation. Amentoflavone (AMF), a biflavonoid derived from the traditional herb-Selaginella tamariscina, has been reported to have antioxidant properties. The protective effects and mechanism of action of AMF against radiation injury remain unknown. In this study, male C57BL/6 mice were subjected to total-body ⁶⁰Co γ-irradiation at 7.5 or 3.0 Gy. The survival rate and mean survival time were evaluated to determine the radioprotective effect of AMF. Number of peripheral blood cells, frequency of colony forming unit-granulocytes, monocytes and micronuclei were measured to assess the protective effects of AMF on the hematopoietic system. Levels of superoxide dismutase and glutathione, and pathological changes in the bone marrow were determined. Additionally, next-generation sequencing technology was used to explore potential targets of AMF. We observed that AMF markedly extends average survival time, reduces injury to the hematopoietic system and promotes its recovery. Furthermore, treatment with AMF significantly attenuated radiation-induced oxidative stress. In addition, AMF had a significant effect on gene tumor necrosis factor alpha-induced protein 2. Together, the results of this study suggest that AMF is a potential protective agent against radiation injury.

Protective Effects of IMOD and Cimetidine against Radiation-induced Cellular Damage

Radiation damage is to a large extent caused by overproduction of reactive oxygen species (ROS). Radioprotectors are agents or substances that reduce the effects of radiation in healthy normal tissues while maintaining the sensitivity to radiation damage in tumor cells. Radioprotectors are agents or substances that reduce the effects of radiation in healthy normal tissues while maintaining the sensitivity to radiation damage in tumor cells Cimetidine was found more effective when used in vivo; this effect might be due to the augmentation of the presence of Sulphur atom in the compound which is ýimportant for their scavenging activity. Recently, a new herbal-based medicine with immunomodulatory capacities, Setarud (IMOD), was introduced as an additional therapy in various inflammatory diseases and HIV infection. IMOD is a mixture of herbal extracts enriched with selenium. Selenium confers protection by inducing or activating cellular free-radical scavenging systems and by enhancing peroxide breakdown. This article suggests that nontoxic amount of IMOD and cimetidine have radioprotective properties and could reduce cytotoxic effects of radiation.

A Review on the Phytochemistry, Pharmacology, and Pharmacokinetics of Amentoflavone, a Naturally-Occurring Biflavonoid

Amentoflavone (C30H18O10) is a well-known biflavonoid occurring in many natural plants. This polyphenolic compound has been discovered to have some important bioactivities, including anti-inflammation, anti-oxidation, anti-diabetes, and anti-senescence effects on many important reactions in the cardiovascular and central nervous system, etc. Over 120 plants have been found to contain this bioactive component, such as Selaginellaceae, Cupressaceae, Euphorbiaceae, Podocarpaceae, and Calophyllaceae plant families. This review paper aims to profile amentoflavone on its plant sources, natural derivatives, pharmacology, and pharmacokinetics, and to highlight some existing issues and perspectives in the future.

Anticytotoxin Effects of Amentoflavone to Pneumolysin

Pneumolysin (PLY) is a devastating bacterial protein toxin of Streptococcus pneumoniae that punctures the cytomembrane, leading to pathological reactions, such as cell disruption and inflammation. Drugs capable of closely impacting the toxin are considered advantageous in the treatment of bacterial infections. Amentoflavone (AMF) is a chemical substance extracted from traditional Chinese herbs. Previous studies have demonstrated that AMF has multiple pharmacological effects and mentioned without attenuating pneumolysin-mediated cytotoxicity. This work focuses on the influence of AMF on inhibitory hemolytic mechanisms. AMF interacts with the toxin at Ser254, Glu277, Arg359, and effectively weakens the oligomerization of wild-type PLY and provides considerable protection against pneumolysin-mediated human alveolar epithelial (A549) cell damage. The results of our study demonstrate that AMF could be a candidate against pneumolysin-related injury.

Fangchinoline inhibits the proliferation of SPC-A-1 lung cancer cells by blocking cell cycle progression

Fangchinoline (Fan) is a bioactive compound isolated from the Chinese herb Stephania tetrandra S. Moore (Fen Fang Ji). The aim of the present study was to investigate the effect of Fan on the proliferation of SPC-A-1 lung cancer cells, and to define the associated molecular mechanisms. Following treatment with Fan, Cell Counting Kit-8, phase contrast imaging and Giemsa staining assays were used to detect cell viability; flow cytometry was performed to analyze the cell cycle distribution; and reverse transcription-quantitative polymerase chain reaction and western blot assays were used to investigate changes in the expression levels of cell cycle-associated genes and proteins. In the present study, treatment with Fan markedly inhibited the proliferation of SPC-A-1 lung cancer cells and significantly increased the percentage of cells in the G₀/G₁ phase of the cell cycle in a dose-dependent manner (P<0.05 for 2.5-5 µm; P<0.01 for 10 µm), whereas the percentage of cells in the S and G₂/M phases were significantly reduced following treatment (P<0.05 for 5 µm; P<0.01 for 10 µm). Mechanistically, Fan significantly reduced the mRNA expression levels of cyclin D1, cyclin-dependent kinase 4 (CDK4) and CDK6 (P<0.05 for 2.5-5 µm; P<0.01 for 10 µm), which are key genes in the regulation of the G₀/G₁ phase of the cell cycle. Furthermore, treatment with Fan also decreased the expression of phosphorylated retinoblastoma (Rb) and E2F transcription factor-1 (E2F-1) proteins (P<0.05 for 5 µm; P<0.01 for 10 µm). In summary, the present study demonstrated that Fan inhibited the proliferation of SPC-A-1 lung cancer cells and induced cell cycle arrest at the G₀/G₁ phase. These effects may be mediated by the downregulation of cellular CDK4, CDK6 and cyclin D1 levels, thus leading to hypophosphorylation of Rb and subsequent suppression of E2F-1 activity. Therefore, the present results suggest that Fan may be a potential drug candidate for the prevention of lung cancer.