Protective effect of flavonoids from Astragalus complanatus on radiation induced damages in mice

Food Polyphenols in Radiation-Related Diseases: The Roles and Possible Mechanisms

PURPOSE OF REVIEW

As science and technology continue to evolve, the potential harm of radiation to the human body cannot be overlooked. Radiation has the capacity to inflict cellular and body-wide damage. Polyphenols are a group of naturally occurring compounds that are found in an array of plant foods. Scientific studies have demonstrated that these compounds possess noteworthy anti-radiation efficacy. Furthermore, they have been observed to be less toxic at higher doses. In the present review, we discussed the mechanisms of ionizing radiation damage and the progress in the research on the radiation resistance mechanism of polyphenol compounds, to provide guidance for the prevention and treatment of radiation related diseases.

RECENT FINDINGS

Food polyphenols can reduce the oxidative damage caused by ionizing radiation, clear free radicals, reduce DNA damage, regulate NF-KB, MAPK, JAK/STAT, Wnt and other signaling pathways, improve immune function, and have significant protective effects on radiation-induced inflammation, fibrosis, cancer and other aspects. In addition, it also has significant dual effects on radiation sensitization and radiation protection. Food polyphenols come from a wide range of sources, are abundant in daily food, and have no toxic side effects, demonstrating that food polyphenols have great advantages in preventing and treating radiation-related diseases.

Flavonol glycoside complanatoside A requires FOXO/DAF-16, NRF2/SKN-1, and HSF-1 to improve stress resistances and extend the life span of Caenorhabditis elegans

Aging is associated with the increased risk of most age-related diseases in humans. Complanatoside A (CA) is a flavonoid compound isolated from the herbal medicine Semen Astragali Complanati. CA was reported to have potential anti-inflammatory and anti-oxidative activities. In this study, we investigated whether CA could increase the stress resistance capability and life span of Caenorhabditis elegans. Our results showed that CA could extend the longevity of C. elegans in a dosage-dependent manner, while 50 μM of CA has the best effect and increased the life span of C. elegans by about 16.87%. CA also improved the physiological functions in aging worms, such as enhanced locomotor capacity, and reduced the accumulation of the aging pigment. CA could also reduce the accumulation of toxic proteins (α-synuclein and β-amyloid) and delay the onset of neurodegenerative disorders, such as Alzheimer’s disease and Parkinson’s disease, in models of C. elegans. Further investigation has revealed that CA requires DAF-16/FOXO, SKN-1, and HSF-1 to extend the life span of C. elegans. CA could increase the antioxidation and detoxification activities regulated by transcription factor SKN-1 and the heat resistance by activating HSF-1 that mediated the expression of the chaperone heat shock proteins. Our results suggest that CA is a potential antiaging agent worth further research for its pharmacological mechanism and development for pharmaceutical applications.

Characterization of the complete plastid genome of the perennial herb Astragalus complanatus Bunge (Fabales: Fabaceae)

Astragalus complanatus Bunge is a perennial herb with high medicinal value, and is endemic to China. The plastid genome of A. complanatus was determined to be 124,213 bp in length with an A + T-biased nucleotide composition (65.7% A + T). The plastid genome harbors a total of 111 genes, including 75 protein-coding, 32 tRNA, and 4 rRNA genes. The presence of one or two introns was detected in 11 protein-coding genes and 6 tRNA genes. Phylogenetic analysis revealed that A. complanatus failed to cluster together with the seven congeners, implying that its phylogenetic placement may need further investigation.

Bioactive Flavonoid Glycosides and HPLC and UPLC Quantification of Commercial Astragali Complanati Semen

Eleven compounds, including nine known flavonoid glycosides (1-4, 6-8, and 10-11), one isoflavone glycoside (5), and a glansreginic acid (9), were isolated from the 80% ethanol extract of commercial Astragali Complanati Semen (ACS). All chemical structures were determined by spectroscopic analyses, including 1D and 2D NMR. Compounds 2, 4, 5, 6, 9, and 10 were isolated and identified from the title plant for the first time. Biological evaluation revealed that all the isolates showed promising anti-NO production, and 1, 2, 3, and 8 were more potent in antioxidant activity than vitamin E. The major peaks in the UPLC and HPLC profiles identified their chemical structures by comparing their retention time and UV spectra with those of the reference substances. Furthermore, nine of the eleven samples collected from North, Middle, and South regions of Taiwan possessed similar HPLC fingerprints and were identified as Astragali Complanati Semen, whereas the other two samples from southern Taiwan would be the adulterants due to the different fingerprinting patterns. In addition, an HPLC-UV method was employed to determine the content of target compound complanatuside (11) with good linear regression (R2 = 0.9998) for ACS in the Taiwanese market. Of the isolates, flavonol glycosides 1 and 3 were the major peaks in HPLC/UPLC, and showed more potent antioxidant and anti-NO production activities than that of 11, revealing that these compounds can be the available agents for the quality control of ACS.

Identification and quantification of phenolic compounds of Western Siberia Astragalus danicus in different regions

The potential of phenolic compounds of medicinal plants including Astragalus danicus L is determined by but not limited to their antioxidant activity. Their anti-inflammatory, antitumor, and other useful properties are known, which allows using these phytochemicals within preventive activities to reduce the risk of many serious diseases. Chromatographic analysis of the Astragalus danicus L. biomaterial from the plant samples collected in three regions of the Kemerovo region (Western Siberia, Russia) established the presence of compounds of flavonols (isorhamnetin glucoside, kaempferol glucoside), flavones (apigenin 7-glucoside), phenylpropanoids (chlorogenic acid) in the aerial part of plants. The total content of phenolic compounds in plant samples ranged from 100.75 ± 3.87 mg/g (Yashkinsky district) to 190.95 ± 7.34 mg/g (Belovsky district). The content of chlorogenic acid in the studied samples was from 0.14 ± 0.01 mg/g to 1.16 ± 0.04 mg/g. Isorhamnetin glucoside was found only in samples of plants from two districts - Prokopievsky (41.39 ± 1.58 mg/g) and Belovsky (95.0 ± 3.66 mg/g). The content of glucosides of kaempferol ranged from 0.38 ± 0.01 mg/g to 0.55 ± 0.02 mg/g. Its content is almost twice as high as the content in the well-known analogues of Astragalus. Apigenin-7-glucoside was isolated in Astragalus samples for the first time, in a small amount (3.34 ± 0.13 mg/g) in a sample of plants of one growing zone. Studies have confirmed that the content of flavonoids in plants significantly depends not only on the genetic characteristics of plants, but also on the hydrothermal regime, the climatic conditions of different botanical and geographical areas of the habitat. This work shows that Astragalus danicus L. growing in Kemerovo region is a promising raw material for pharmacological preparations.

Effects of astragalus injection on different stages of early hepatocarcinogenesis in a two-stage hepatocarcinogenesis model using rats

To clarify the suppressive effects of astragalus injection (AI) on different stages of early hepatocarcinogenesis induced by weak promotion, SD rats initiated with a single intraperitoneal (i.p.) injection of N-diethylnitrosamine (DEN) at 200 mg/kg body weight and promoted with 0.5% piperonyl butoxide (PBO) in diet were repeatedly administered AI at 5 ml/kg body weight/day in the early postinitiation (EPI) or late postinitiation (LPI) period for 2 or 8 weeks, respectively. The number and area of glutathione S-transferase placental form (GST-P)-immunoreactive ⁽⁺⁾ foci tended to increase in the DEN+PBO group compared with the DEN-alone group. Among the PBO-promoted groups, number and area of GST-P⁺ foci did not visibly change in the DEN+PBO+AI-EPI group compared with the DEN+PBO group. In contrast, number and area of GST-P⁺ foci tended to decrease in the DEN+PBO+AI-LPI group compared with the DEN+PBO group. Number of Ki67⁺ cells was increased in the DEN+PBO group compared with the DEN-alone group and was decreased in both AI-administered groups compared with the DEN+PBO group. Gene expression analysis revealed that the DEN+PBO+AI-LPI group showed increased transcript levels of Ccne1, Cdkn1b, Rb1, Bax, Bcl2, Casp3, and Casp9 compared with the DEN+PBO group; however, the DEN+PBO+AI-EPI group did not show changes in the transcript levels of any genes examined compared with the DEN+PBO. These results suggest that AI administration during the LPI period caused weak suppression of hepatocarcinogenesis under weak promotion with a low PBO dose by the mechanism involving facilitation of cell cycle suppression causing G1/S arrest and apoptosis via the mitochondrial pathway. In addition, the results suggest that AI administration during the EPI period has no effect on weakly promoted hepatocarcinogenesis.

Protective Effects on 60Co-γ Radiation Damage of Pine Cone Polyphenols from Pinus koraiensis-Loaded Chitosan Microspheres In Vivo

A novel chitosan microsphere for encapsulating pine cone polyphenols (PP) from P. koraiensis was successfully prepared using an emulsion crosslinking technique. The characteristics of pine polyphenol-loaded microspheres (PPM) were determined using scanning electron microscopy (SEM) and a laser particle size detector. It was found that PPMs were spherical in shape with uniform particle size distribution patterns. The drug content and encapsulation rate of the microspheres were 7.47% and 73.6%, respectively, at a Ch/GA mass ratio of 0.7. The animal experiments showed that PPM had a stronger radiation protective effect than PP. PPM significantly increased the immune organ indices, the quantity of marrow DNA, the superoxide dismutase (SOD) activity, the splenocyte proliferation index, and the phagocytosis activity of monocytes. PPM also decreased the numbers of micronuclei in bone marrow cells and malondialdehyde (MDA) levels in plasma in mice exposed to 60Co γ-irradiation. In addition, gender differences in biological responses to exposure to radiation were observed.

Whole body radioprotective effect of phenolic extracts from the fruits of Malus baccata (Linn.) Borkh

This study was designed to evaluate the radioprotective effect of phenolics extracted from the fruits of Malus baccata (Linn.) Borkh. (MBP-3b) against damage induced by (60)Co γ-irradiation in vivo. MBP-3b could significantly improve the activity of endogenous antioxidant enzymes and the T-AOC, as well as reduce the MDA level in the liver and kidneys of irradiated mice. In addition, pretreatment with MBP-3b at a dose of 150 mg per kg bw could significantly enhance immunomodulation activity by promoting the proliferation of spenocytes and monocyte phagocytosis. The administration of MBP-3b prevented the decline induced by radiation of haematological parameters (WBC, RBC, PLT and HGB). Furthermore, MBP-3b could protect spenocytes from radiation-induced damage by inhibiting cell apoptosis. The results indicated that MBP-3b possesses strong whole body radioprotective and immunomodulatory activities. The main constituents of MBP-3b were tentatively identified as delphinidin-3,5-diglucoside, cyanidin-3-glucoside, chlorogenic acid, proanthocyanidin C1, quercetin-3-galactoside, quercetin-3-glucoside, quercetin-3-xyloside/arabinoside, phloretin-2-xyloseglucoside, quercetin-3-rhamnoside and phlorizin. MBP-3b could be used as a probable radioprotector against gamma radiation induced oxidative damage.

Flavonoids from the Genus Astragalus: Phytochemistry and Biological Activity

Flavonoids, the most common plant polyphenols are widely distributed in every species and possess a broad range of pharmacological activities. The genus Astragalus is the largest in the Fabaceae family with more than 2,500 species spread. They are known to contain different metabolites such as flavonoids, saponins, and polysaccharides. Plants from the genus have been used in the traditional medicine of many countries for centuries. This paper is focused on the large group of flavonoid compounds. Details on structure as well as information about the pharmacological properties of flavonoids, isolated from Astragalus species have been discussed. This review is based on publications until the first half of 2014 and includes also the results from our phytochemical investigations of the genus.

Quantification of complanatoside A in rat plasma using LC-MS/MS and its application to a pharmacokinetic study

Complanatoside A is a flavonol glycoside isolated from Astragalus complanatus, and currently it is used as a quality control index for A. complanatus in the 2010 edition of the Chinese Pharmacopoeia. For the first time, a simple and sensitive LC-MS/MS method was developed for the determination of complanatoside A in rat plasma over the range of 2.3-575 ng/mL. Complanatoside A was extracted from plasma by a protein precipitation procedure, separated by LC and detected by MS/MS in positive electrospray ionization mode. The method was validated for selectivity, carryover, sensitivity, linearity, extraction recovery, matrix effect, accuracy, precision and stability studies. The lower limit of quantification was established at 2.3 ng/mL. Intra- and inter-day precisions (LLOQ, low-QC, med-QC and high-QC) were <7.9%, and accuracies were between 94.0 and 105.1%. Matrix effect was acceptable (97.9-103.0%) and extraction recovery was reproducible (88.5-94.4%). Complanatoside A was stable in the investigated conditions. The method was applied to the pharmacokinetics of complanatoside A in rats. Copyright © 2015 John Wiley & Sons, Ltd.

Effects and mechanism of flavonoids from Astragalus complanatus on breast cancer growth

Flavonoids from Astragalus complanatus R.Br (FAC) had anticancer effects on many tumor cells. The current study was performed to evaluate the effects of FAC on human breast cell proliferation, apoptosis, and metastasis, as well as their active mechanism. Cell viability and growth were detected using the cell counting kit (CCK)-8 assay in vitro. Assay of FAC on induced breast cancer mortality was counted as survival time of nude mice after breast cell line inoculation. The effect of FAC on cell invasion was investigated by an optimization assay that contains a 96-well Boyden chamber with wells precoated with BME at three different concentrations. The mechanism of its action on apoptosis and metastasis was determined by related gene detection. Proliferation of three breast cell lines was inhibited with FAC treatment in a dose-dependent manner. Survival time of nude mice with breast cancer cell inoculation also was prolonged with increasing FAC dose. Metastasis in FAC-treated breast cells was also significantly inhibited. Real-time polymerase chain reaction (PCR) assay demonstrated that apoptosis-related BCL-2 and caspase-9 gene expression was consistent with their phenotype change. Metastasis-related FAK and BRCA1 gene expression was inversely related to FAC treatment. Western blot analysis indicated that BCL-2 and FAK proteins were reduced, whereas caspase-9 and BRCA1 proteins were increased with a higher dose of FAC treatment. These data suggested that FAC has an important role in breast cancer growth and metastasis suppression in vitro and in vivo. Its active mechanism involves promoting programmed cancer cell death and regulates metastasis-related gene expression.

Radioprotective activity of neutral polysaccharides isolated from the fruiting bodies of Hohenbuehelia serotina

In this study, the radioprotective effect of neutral polysaccharides from Hohenbuehelia serotina (NTHSP) against the damages induced by (60)Co-γ radiation was investigated. The results showed that NTHSP could significantly improve the activity of glutathione peroxidase (GSH-Px) and increase the contents of glutathione (GSH) and ceruloplasmin in plasma after treated with 6 Gy-radiation compared with the radiation controls (p < 0.05). Furthermore, administration with NTHSP could effectively increase the quantity of marrow DNA (p < 0.05) and reduce the rates of chromosome aberration and micronuclei (p < 0.01) in bone marrows of mice. In addition, NTHSP could markedly inhibit the expressions of Bax protein and promote the expressions of Bcl-2 protein, accordingly inhibit the releases of cytochrome c and expressions of activated Caspase-3, and therefore block the mitochondrial apoptotic pathway of splenocytes in mice induced by (60)Co-γ radiation. These results suggested that NTHSP might be a natural radioprotective agent against the injuries induced by radiation.

Synergistic radiation protective effect of purified Auricularia auricular-judae polysaccharide (AAP IV) with grape seed procyanidins

The aim of this study was to investigate the synergistic antioxidant potential and protective effect of grape seed procyanidins (GSP) in combination with Auricularia auricular-judae polysaccharides (AAP IV) on radiation injury in splenocytes. Rat splenocyte irradiation resulted in significantly higher apoptosis rate, malondialdehyde (MDA) (p < 0.005), reactive oxygen species (ROS) (p < 0.01); cell viability, total superoxide dismutase (T-SOD) (p < 0.01), catalase (CAT) (p < 0.01), glutathione peroxidase (GSH-PX) (p < 0.05), activity and glutathione (GSH) (p < 0.01) levels were significantly reduced, compared with the control group. "GSP + AAP IV" treatment of rat splenocytes at doses of "GSP (0.3 μg/mL) + AAP IV (50 μg/mL)" displayed higher radioprotective and antioxidative effects than the administration of either GSP or AAP IV, as evident by lower levels of MDA (p < 0.001) concentration, as well as higher cell viability and T-SOD (p < 0.05), CAT (p < 0.005), GSH-PX (p < 0.01) and GSH content compared to the radiation group. In addition, in vivo studies have shown that "GSP + AAP IV" significantly ameliorated the decrease of spleen index (p < 0.005) and spleen GSH (p < 0.005) levels and significantly inhibited the increase of MDA (p < 0.005) levels of spleen with radiation-induced damage, compared with the non-treated group. The in vivo and in vitro results suggested that GSP and AAP IV have a synergistic protective effect against radiation-induced injury by improving the antioxidant and immunomodulation activities.

Pharmaceutical properties of calycosin, the major bioactive isoflavonoid in the dry root extract of Radix astragali

CONTEXT

Radix astragali (Fabaceae astragalus propinquus Schischkin) is a Chinese medicinal herb traditionally used for the treatment of several diseases. Calycosin is the major bioactive chemical in the dry root extract of this medical plant.

OBJECTIVE

This work presents a brief overview of recent reports on the potential effects of calycosin on several diseases and the possible mechanisms of action of this chemical.

MATERIALS AND METHODS

This review gathers information from the scientific literature (before 1 June 2013) that was compiled from various databases, such as Science Direct, PubMed, Google Scholar, and Scopus.

RESULTS

The potential pharmaceutical properties of calycosin in the treatment of tumors, inflammation, stroke, and cardiovascular diseases have gained increasing attention in the recent years. The literature survey showed that calycosin exhibits promising effects for the treatment of several diseases and that these effects may be due to its isoflavonoid and phytoestrogenic properties. The effects of calycosin most likely result from its interaction with the ER receptors on the cell membrane and the modulation of the MAPK signaling pathway.

CONCLUSION

Calycosin exhibits great potential as a therapeutic drug and may be a successful example of the standardization and modernization of traditional Chinese herbal medicine.

Semen Astragali Complanati: an ethnopharmacological, phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Semen Astragali Complanati (SAC), the dried ripe seed of Flatstem Milkvetch (Astragalus complanatus Bunge) (Leguminosae), is commonly used in traditional Chinese medicine (TCM) for treating muscle, liver, kidney, blood, skin and reproductive system diseases.

MATERIALS AND METHODS

Relevant information about SAC was gathered via "Google Scholar", "ISI Web of Knowledge", "PubMed", "ScienceDirect", "Medline Plus", "ACS", "CNKI" and "Wiley Online Library" and from books in local libraries.

RESULTS

The major contents of SAC include fatty acids, amino acids, polysaccharides, flavonoids, triterpene glycosides and trace elements. Previous scientific studies have reported that SAC exhibits a number of therapeutic effects on chronic diseases such as cardiovascular diseases, diabetes mellitus and cancers. It has been found that flavonoids are the main bioactive component in SAC. However most of the previous studies have shown the effects brought by the total flavonoid fraction extracted from SAC only; further studies are warranted for the biological effects produced by individual components. There are only a few studies on the toxicity of SAC and the overall results show that its toxicity is quite low or even non-existent.

CONCLUSIONS

SAC is a valuable TCM herb with multiple pharmacological effects for treating some chronic diseases. More studies on SAC will help us to have a better understanding of its pharmacological mechanisms so as to provide more scientific evidence to explain its traditional uses, identify its therapeutic potential on other diseases and understand its possible harmful effects. Based on previous studies, it is easy to identify that antioxidant effect of SAC might play an important role on its pharmacological effects. Studying the effects of SAC on handling intracellular reactive oxygen species may be a potential direction to help understanding the molecular mechanisms of SAC on preventing and/or treating chronic diseases.

Hepatoprotective effects of loach (Misgurnus anguillicaudatus) lyophilized powder on dimethylnitrosamine-induced liver fibrosis in rats

This study investigates the hepatoprotective effects and the potential therapeutic mechanisms of loach (Misgurnus anguillicaudatus) lyophilized powder (MLP) on dimethylnitrosamine (DMN) induced liver fibrosis in rats. After treatment with MLP (50, 100, 200 mg/kg), alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (Alb), total protein (TP) and hydroxyproline (Hyp) levels were detected, to assess the destruction of hepatocytes and the extent of liver fibrosis. Matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), hyaluronic acid (HA), Laminin (LN), procollagen type-III (PC-III), collagen type-IV (C-IV), and transforming growth factor-β₁ (TGF-β₁) contents in serum were all tested using ELISA kits. Alpha-smooth muscle actin (α-SMA) and the tissue inhibitor of metalloproteinase-1 (TIMP-1) protein contents and distribution were evaluated using western blot and immunohistochemical analysis. MLP significantly decreased the serum concentrations of ALT, AST, Hyp, HA, LN, PC-III, C-IV, MMP-2, TIMP-1, α-SMA and TGF-β₁, while increasing the contents of Alb and MMP-9. No significant changes on TP serum concentrations were observed. These results suggest that MLP has anti-hepatic fibrosis effects and its mechanism may be associated with the attenuation of extracellular matrix (ECM) synthesis, the acceleration of ECM degradation, inhibition of hepatic stellate cells (HSCs) activation and TGF-β₁ expression.

Garlic oil suppressed the hematological disorders induced by chemotherapy and radiotherapy in tumor-bearing mice

Although the anticancer effects of garlic and its products have been demonstrated by a variety of studies; however, few studies were conducted to investigate the effects of garlic on the adverse effects of chemo/radiotherapy. In order to clarify the above question and make a more comprehensive understanding of the anticancer effects of garlic, tumor xenograft mice model was established by subcutaneous injection of H22 tumor cells, and was used for the investigation of effects of garlic oil (GO) on the chemo/radiotherapy. In the chemotherapy test, tumor-bearing mice were treated with cyclophosphamide (CTX) or CTX plus GO (25 or 50 mg/kg bw) for 14 d, while the mice received a single 5 Gy total body radiation or radiation plus GO (25 or 50 mg/kg bw) in radiotherapy test. The results showed that GO did not increase the tumor inhibitory rate of CTX/radiation, which indicated that GO could not enhance the chemo/radiosensitivity of cancer cells. However, the decrease of the peripheral total white blood cells (WBCs) count induced by CTX/radiation was significantly suppressed by GO cotreatment. Furthermore, GO cotreatment significantly inhibited the decrease of the DNA contents and the micronuclei ratio of the bone marrow. Lastly, the reduction of the endogenous spleen colonies induced by CTX/radiation was significantly suppressed by GO cotreatment. These findings support the idea that GO consumption may benefit for the cancer patients receiving chemotherapy or radiotherapy.

Comparative tissue distribution profiles of five major bio-active components in normal and blood deficiency rats after oral administration of Danggui Buxue Decoction by UPLC-TQ/MS

Astragali Radix (AR) and Angelicae Sinensis Radix (ASR) were frequently combined and used in China as herbal pair called as Danggui Buxue Decoction (DBD) for treatment of blood deficiency syndrome, such as women's ailments. This study is to investigate the tissue distribution profiles of five major bio-active constituents (ferulic acid, caffeic acid, calycosin-7-O-β-glucoside, ononin and astragaloside IV) in DBD after oral administration of DBD in blood deficiency rats, and to compare the difference between normal and blood deficiency rats. The blood deficiency rats were induced by bleeding from orbit at the dosages of 5.0mLkg(-1) every day, and the experimental period was 12 days. At the finally day of experimental period, both normal and blood deficiency rats were orally administrated with DBD, and then the tissues samples were collected at different time points. Ferulic acid, caffeic acid, calycosin-7-O-β-glucoside, ononin and astragaloside IV in different tissues were detected simultaneously by UPLC-TQ/MS, and the histograms were drawn. The results showed that the overall trend was CLiver>CKidney>CHeart>CSpleen>CLung, CC-30min>CM-30min>CM-60min>CC-5min>CM-5min>CC-60min>CM-240min>CC-240min. The contents of the detected compounds in liver were more than that in other tissues no matter in normal or blood deficiency rats. Compared to normal rats, partial contents of the compounds in blood deficiency rats' tissues at different time points had significant difference (P<0.05). This study was the first report about tissue distribution investigation in blood deficiency animals which is conducted by bleeding. And the results demonstrated that the five DBD components in normal and blood deficiency rats had obvious differences in some organs and time points, suggesting that the blood flow and perfusion rate of the organ were altered in blood deficiency animals.

Astragalus polysaccharide reduces inflammatory response by decreasing permeability of LPS-infected Caco2 cells

As the major constituent of Radix Astragali, Astragalus polysaccharide (APS) is known for its anti-inflammation and immunomodulatory functions. The objective of this study was to investigate the effect of APS on inflammatory response and structural changes in lipopolysaccharide (LPS)-infected Caco2 cells. Caco2 cells were co-cultured with APS and LPS, with APS added after the addition of LPS (post-addition), before the addition of LPS (pre-addition), or simultaneously with the addition of LPS (simultaneous addition). The mRNA expression of inflammatory indicators and tight junctions was measured by RT-qPCR. Short circuit current (Isc) was recorded by an Ussing chamber system. Addition of APS significantly down-regulated the expression of TNF-α, IL-1β and IL-8 (P<0.05) and the Isc levels (P<0.05) of LPS-infected Caco2 cells for all three administration treatments. The minimum anti-inflammatory concentration of APS was 50, 100, and 100 μg/mL for pre-, post-, and simultaneous additions of APS, respectively. The mRNA expression of zonula occludens-1 (ZO-1) and occludin was significantly up-regulated for post- and pre-additions of APS, respectively (P<0.05). Results suggested that APS had anti-inflammatory and structure protective properties for LPS-infected Caco2 cells, and may be used as a preventative treatment for intestine cells.

Baicalein attenuates impaired hippocampal neurogenesis and the neurocognitive deficits induced by γ-ray radiation

BACKGROUND AND PURPOSE

Whole-brain irradiation (WBI) therapy produces learning and memory deficits in patients with brain tumours. Although the pathological cascade of cognitive deficits remains unknown, it may involve reduced neurogenesis within the hippocampus. Baicalein is a flavonoid derived from the roots of Huangqin, Scutellaria baicalensis Georgi, and has been shown to have antioxidant effects. Here, we have investigated the protective effects of baicalein on irradiation-induced impairments in hippocampal neurogenesis and cognitive function.

EXPERIMENTAL APPROACH

Radioprotective effects of baicalein were evaluated in C17.2 neural progenitor cells and 6-week-old male C57BL/6 mice during hippocampal neurogenesis. Mice were given a single dose of 5 Gy WBI. Changes in hippocampal neurogenesis, oxidative stress and BDNF-pCREB signalling were evaluated. Morris water maze and passive avoidance test were used to assess learning and memory.

KEY RESULTS

Baicalein protected neural progenitor cells against irradiation-induced necrotic cell death. Pretreatment with baicalein attenuated the irradiation-induced impairment of hippocampal neurogenesis by modulating oxidative stress and elevating BDNF-pCREB signalling. Furthermore, baicalein prevented the spatial learning and memory retention deficits follwing WBI.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that baicalein can be viewed as a potential therapeutic agent that protects against the impaired neurogenesis induced by WBI, and its neurocognitive consequences.

Protective effect of anthocyanin from Lonicera Caerulea var. Edulis on radiation-induced damage in mice

The radioprotective effect of anthocyanin extracted from Lonicera caerulea var. edulis (ALC), was studied in ICR mice. Different doses of ALC were intragastrically administered to mice once a day, prior to radiation. After two weeks, the mice received a one-time 5 Gy whole body (60)Coγ radiation. The spleen index, thymus index, activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), malondialdehyde (MDA) content, and glutathione (GSH) content in liver tissue were measured. Compared with the radiation control group, the levels of MDA in all ALC treated groups decreased significantly (p < 0.05). Moreover, the GSH content, activities of SOD and GSH-Px in liver tissue were enhanced significantly (p < 0.05) in all ALC groups. These results demonstrate that ALC may be a potential radioprotector, and a further study of the molecular mechanism is needed for further application.