Rhododendron anthopogonoides Maxim, a kind of traditional Tibetan medicine, has been used to remove body heat, body detoxification, cough, asthma, stomachic and swelling, eliminate abundant phlegm and inflammatory for a long time. In the present study, the total phenols and total flavonoid contents as well as antioxidative properties of the crude extract and solvent fractions of R. anthopogonoides were determined using seven antioxidant assays. Additionally, the protective effect of the extracts on hypoxia-induced injury in PC12 cells was also investigated. The content of total flavonoid and total phenolic was determined by the aluminum colorimetric method and Folin-Ciocalteu assay, respectively. In vitro antioxidant study, the effect of the crude extract and solvent fractions on total antioxidant activity, reducing power, DPPH radical scavenging, ABTS radical scavenging, superoxide radical scavenging, hydroxyl radical scavenging and nitric oxide radical scavenging were examined. The correlation between the phenolic and flavonoid content of the extracts and their antioxidant properties also analyzed. Furthermore, the protective effect of extracts on hypoxia-induced damage on PC12 cells was investigated by cell viability, lactate dehydrogenase (LDH) release, malondialdehyde (MDA) production and the activities of antioxidant enzymes. Our results showed that ethyl acetate and n-butanol fractions had higher content of phenolics and flavonoid compounds than other fractions. Except ABTS radical assay, n-butanol fraction exhibited the strongest antioxidant activity. While the hexane fraction showed the lowest antioxidant activity. Ethyl acetate also presented excellent antioxidant activity, which was just lower than n-butanol fraction. Significant correlation between the phenolic, flavonoid content of the extract and fractions with antioxidant assay excluding ABTS, OH scavenging assay was observed. Moreover, ethyl acetate and n-butanol fractions showed protective effect in PC12 cell under hypoxia condition, while crude extract and water fraction had no protective effect. In contrast, hexane fraction exhibited strong cytoprotective effect. Further study indicated that pretreatment of PC12 cells with ethyl acetate and n-butanol fractions, prior to hypoxia exposure, significantly increased the survival of cells and the activities of SOD, CAT, GSH-Px and T-AOC, as well as reduced the level of LDH and MDA. The gathered data demonstrated that ethyl acetate and n-butanol fractions were able to protect PC12 cells against hypoxia induced injury through direct free radical scavenging and modulation of endogenous antioxidant enzymes. These findings suggested that ethyl acetate and n-butanol fractions of R. anthopogonoides had significant antioxidant activity and could prevent PC12 cells against hypoxia-induced injury. So it might be regarded as an excellent source of antioxidants and had great potential to explore as therapeutic agent for preventing hypoxia related sickness in future.

Normal tissue and immune organ protection are critical parts of the tumor radiation therapy process. Radiation-induced immune organ damage (RIOD) causes several side reactions by increasing oxidative stress and inflammatory responses, resulting in unsatisfactory curability in tumor radiation therapy. The aim of this study was to develop a novel and efficient anti irradiation nanoparticle and explore its mechanism of protecting splenic tissue from radiation in mice. Nanoparticles of triphenylphosphine cation NIT radicals (NPs-TPP-NIT) were prepared and used to protect the spleens of mice irradiated with X-rays. Splenic tissue histopathology and hematological parameters were investigated to evaluate the protective effect of NPs-TPP-NIT against X-ray radiation. Proteomics was used to identify differentially expressed proteins related to inflammatory factor regulation. In addition, in vitro and in vivo experiments were performed to assess the impact of NPs-TPP-NIT on radiation therapy. NPs-TPP-NIT increased superoxide dismutase, catalase, and glutathione peroxidase activity and decreased malondialdehyde levels and reactive oxygen species generation in the spleens of mice after exposure to 6.0 Gy X-ray radiation. Moreover, NPs-TPP-NIT inhibited cell apoptosis, blocked the activation of cleaved cysteine aspartic acid–specific protease/proteinase, upregulated the expression of Bcl-2, and downregulated that of Bax. We confirmed that NPs-TPP-NIT prevented the IKK/IκB/NF-κB activation induced by ionizing radiation, thereby alleviating radiation-induced splenic inflammatory damage. In addition, when used during radiotherapy for tumors in mice, NPs-TPP-NIT exhibited no significant toxicity and conferred no significant tumor protective effects. NPs-TPP-NIT prevented activation of IKK/IκB/NF-κB signaling, reduced secretion of pro-inflammatory factors, and promoted production of anti-inflammatory factors in the spleen, which exhibited radiation-induced damage repair capability without diminishing the therapeutic effect of radiation therapy. It suggests that NPs-TPP-NIT serve as a potential radioprotective drug to shelter immune organs from radiation-induced damage.

Two new compounds 1 and 2 have been isolated from the aerial parts of Urena lobata L. The structures of the two new compounds were established as ceplignan-4-O-β-d-glucoside (1) and 2,5-dihydroxy benzoic acid-7-(2,6-dimethyl-6-hydroxy-2,7-octadienoic acid) anhydride-5-O-β-d-apiofuranosyl(1 → 2)-β-d-glucoside (urenoside A) (2), on the basis of chemical and spectral evidence, including 1D and 2D NMR spectroscopic data as well as mass spectrometry (HR-ESI-MS).