Gymnoside I

Apigenin exerts chemopreventive effects on lung injury induced by SiO(2) nanoparticles through the activation of Nrf2.[Pubmed:34480707]

J Nat Med. 2022 Jan;76(1):119-131.

Apigenin (APG) is a flavonoid widely distributed in fruits, vegetables, and herbs, with comprehensive pharmacological effects. In this paper, we report that APG can elicit a protective effect, which is comparable to those induced by Gymnoside II/n-BuOH extracts of Bletilla striata, on SiO(2)-induced lung injury in vitro and in vivo. In vitro experiments showed that APG (25 muM) could restore the SiO(2)-decreased A549 cell viability and lower the apoptotic rate and the production of intracellular reactive oxygen species (ROS) in A549 cells treated with nm SiO(2). Western blot results showed that APG (25 muM) could increase the level of Nuclear factor E2-related factor 2 (Nrf2) and its downstream proteins. In vivo experiments showed that APG (20 mg/kg) could potently alleviate the SiO(2)-elicited lung injury by enhancing the Nrf2 expression and thereby suppressing Bax/Bcl-2 pathway. The present study suggests that APG can significantly alleviate the SiO(2)-induced lung injury both in vitro and in vivo through, at least partially, activating Nrf2 expression.

n-BuOH extract of Bletilla striata exerts chemopreventive effects on lung against SiO(2) nanoparticles through activation of Nrf2 pathway.[Pubmed:33418138]

Phytomedicine. 2021 Feb;82:153445.

BACKGROUND: SiO(2) nanoparticles (nm SiO(2)) are ubiquitous in daily life and are acknowledged to be detrimental to human health. Bletilla striata is a traditional medicine used for generations in China and its polysaccharide has the anti-pulmonary fibrosis effect. PURPOSE: To investigate the lung protective effect of the small molecules (n-BuOH extract) of B. striata and clarify the underlying mechanism. STUDY DESIGN AND METHODS: C57BL/6 mice were subjected to intratracheal instillation with nm SiO(2) nanoparticle suspension (7 mg/kg) to construct the in vivo model of nm SiO(2)-induced lung injury. The chemical profile of the n-BuOH extract of B. striata was investigated by HPLC analysis using authentic samples isolated from B. striata. Gymnoside II with the most potent chemoprotective capacity in the n-BuOH extract was used to clarify the potential bio-active molecular basis of the n-BuOH extract using in vitro experiments. The cytotoxicity, apoptosis, oxidative stress, and the Nrf2 signaling pathway were examined in SiO(2)-induced A549 cells. ML385 was adopted to down-regulate the Nrf2 expression. RESULTS: The n-BuOH extract of B. striata (40 mg/kg) could alleviate the SiO(2)-induced lung injury by increasing Nrf2 expression and thereby suppressing Bax/Bcl-2 pathway in the nm SiO(2)-induced mice model. The chemical profile study showed that militarine, Gymnoside II, and 4-allyl-2, 6-dimethoxyphenol glucoside were the main constituents of n-BuOH extract. Studies on Gymnoside II revealed that it could partially restore the SiO(2)-induced decline in cell viability while did not affect the growth of normal A549 cells within the concentration range of 1-50 muM, suggesting a protective effect against nm SiO(2) in lung A549 cells. The hoechst 33258 staining, flow cytometry, and western blot experiments demonstrated that Gymnoside II (25 muM) could partially reverse the SiO(2)-induced cell apoptosis and ROS production by enhancing Nrf2, HO-1, and gamma-GCSc expressions and Nrf2 silencing by ML385 abrogated the effects of Gymnoside II (25 muM) on apoptosis and ROS production in A549 cells. CONCLUSION: The present study suggests that in addition to the polysaccharide, small molecules (n-BuOH extract) of B. striata can also elicit a protective effect on lung injuries through the Nrf2-dependent mechanism and Gymnoside II is one of the main bio-active constituents contributing to the n-BuOH extract-elicited lung protective effect against nm SiO(2).

Simultaneous Determination of Three Bioactive Constituents from Bletilla striata by UPLC-MS/MS and Application of the Technique to Pharmacokinetic Analyses.[Pubmed:31772602]

Evid Based Complement Alternat Med. 2019 Oct 21;2019:8942512.

Bletilla striata has been widely used as a valuable hemostatic agent for thousands of years due to the high levels of bioactive constituents it contains. Here, we used a sensitive ultrahigh-performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) method for the simultaneous determination of three major active ingredients of the B. striata extract, namely, alpha-isobutylmalic acid, Gymnoside I, and militarine in rat plasma. The three major active ingredients were determined using the multiple reaction monitoring (MRM) mode at m/z 189 ⟶ 129 for alpha-isobutylmalic acid, m/z 457.2 ⟶ 285.1 for Gymnoside I, m/z 725.3 ⟶ 457.2 for militarine, and m/z 417.0 ⟶ 267.0 for the IS puerarin. All calibration curves showed good linearity (R (2) >/= 0.999) over the concentration range with the lower limit of quantification between 0.015 and 0.029 mug/mL. The relative standard deviations of intraday and interday measurements were less than 15%, and the method was accurate within 93.3-100.4%. The extraction recovery was 92.65-100.98%, and no matrix effect was observed. The results indicated that after oral administration of B. striata in rats, the T (max) of alpha-isobutylmalic acid was significantly longer than that of Gymnoside I and militarine and the mean residence time and area under the curve of alpha-isobutylmalic acid and Gymnoside I in rats were significantly higher than those of militarine. Moreover, the blood concentration-time curve of alpha-isobutylmalic acid showed double peaks, suggesting that alpha-isobutylmalic acid could exhibit the phenomenon of enterohepatic circulation or metabolic conversion. We also explored some of the pharmacokinetic characteristics of three ingredients from B. striata extract in vivo, and the data obtained may provide a basis for the further investigation of B. striata.

A Validated HPLC-MS/MS Method for Simultaneous Determination of Militarine and Its Three Metabolites in Rat Plasma: Application to a Pharmacokinetic Study.[Pubmed:31186657]

Evid Based Complement Alternat Med. 2019 May 2;2019:2371784.

A rapid, reliable, and sensitive HPLC-electrospray ionization-tandem mass spectrometry (HPLC-MS/MS) method was established and validated for simultaneous determination of militarine and its three metabolites (gastrodin, alpha-isobutylmalic acid, and Gymnoside I) in rat plasma. Plasma was acidified with formic acid, and protein was precipitated with methanol. MS/MS with ESI and multiple reaction monitoring at m/z 725.3-->457.3, 457.1-->127, 304.3-->107.2, 189-->129, and 417.1-->267.1 was used for determination of militarine, gastrodin, alpha-isobutylmalic acid, Gymnoside I, and puerarin (internal standard), respectively. Chromatographic separation was conducted using an ACE UltraCore SuperC18 (2.1 x 100 mm, 2.5 mum) column with gradient mobile phase (0.1% formic acid in water and acetonitrile). The lower limits of quantitation for militarine, gastrodin, alpha-isobutylmalic acid, and Gymnoside I were 1.02, 2.96, 1.64, and 0.3 ng/mL, respectively. The relative standard deviations of intra- and interday measurements were less than 15%, and the method accuracy ranged from 87.4% to 112.5%. The extraction recovery was 83.52%-105.34%, and no matrix effect was observed. The three metabolites (gastrodin, alpha-isobutylmalic acid, and Gymnoside I) were synchronously detected at 0.83 h, suggesting that militarine was rapidly transformed to gastrodin, alpha-isobutylmalic acid, and Gymnoside I. Moreover, the area under the curve (AUC) and C(max) of militarine were significantly lower than those of gastrodin and alpha-isobutylmalic acid, showing that militarine was largely metabolized to gastrodin and alpha-isobutylmalic acid in vivo. The studies on pharmacokinetics of militarine and its three metabolites were of great use for facilitating the clinical application of militarine and were also highly meaningful for the potential development of militarine.

[Studies on glucosyloxybenzyl 2-isobutylmalates of Pleione bulbocodioides].[Pubmed:26087555]

Zhongguo Zhong Yao Za Zhi. 2015 Mar;40(5):908-14.

Ten glucosyloxybenzyl 2-isobutylmalates and one benzyl alcohol glycoside were isolated from the dry tuber of Pleione bulbocodioides, which is a specie of Orchidaceae family and its dry tuber is one of the main sources of traditional Chinese medicine "shanci-gu", by a combination of various column chromatographic methods, including ODS, macroporous adsorbent resin, Sepheadex LH-20, and preparative HPLC. Their structures were identified on the basis of chemical evidences and spectroscopic analysis asloroglossin (1), grammatophylloside A (2), cronupapine (3), (-)-(2R, 3S)-1-(4-beta-D-glucopyranosyloxybenzyl)-4-methyl-2-isobutyltartrate (4), vandateroside II (5), grammatophylloside B (6), bis [4-(beta-D-glucopyranosyloxy) -benzyl] (S) -2-isopropylmalate (7), Gymnoside I (8), militarine (9), dactylorhin A (10), gastrodin (11). Compounds 1-7 were isolated from this genus for the firt time.