Simultaneous quantification of two steroidal glycosides after oral gavage ofMarsdenia tenacissimaextract in rats using a LC-MS/MS method

Simultaneous determination of eight bioactive components in Marsdenia tenacissima extract in rat plasma by LC-MS/MS and its application in a pharmacokinetic study

As a traditional Chinese medicine, Marsdenia tenacissima (Roxb.) Wight et Arn. plays an indispensable role in clinical practice owing to its specific efficacy in treating malignant tumors, leukocythemia, cystitis and asthma. This study aimed to establish a novel and scientific LC-MS/MS approach to simultaneously determine tenacissoside B, H, G and I, caffeic acid, cryptochlorogenic acid, chlorogenic acid and neochlorogenic acid from M. tenacissima extract within the rat plasma samples. Digoxin was used as the internal reference. All determinations were carried out using the Eclipse Plus C₁₈ column, and water (containing 0.1% formic acid) was used as the mobile phase A, while acetonitrile was the mobile phase B for gradient elution. The UPLC methods were validated, including calibration curves, accuracy, precision, stability and recovery of the total eight analytes, in accordance with the requirements for biopharmaceutical analysis. Moreover, the proposed approach was also used in comprehensive pharmacokinetic research on those eight analytes in rats following M. tenacissima extract gavage. According to the pharmacokinetic parameters, tenacissoside B, I, H and G are the long-acting and primary bioactive constituents in M. tenacissima extract, with long mean residence times and high concentrations. Our findings shed light on the absorption mechanism and provide significant information for the clinical application of M. tenacissima.

Marsdenia tenacissima extract promotes gefitinib accumulation in tumor tissues of lung cancer xenograft mice via inhibiting ABCG2 activity

ETHNOPHARMACOLOGICAL RELEVANCE

Marsdenia tenacissima extract (MTE) is the water-soluble part of a traditional Chinese medicine Marsdenia tenacissima (Roxb.) Wight & Arn, and is commercially available in China for treating cancers. MTE has been revealed to be effective in improving gefitinib efficacy in treating non-small cell lung cancer (NSCLC). However, the mechanisms remain to be defined.

AIM OF THE STUDY

To determine the effects of MTE on gefitinib metabolism and accumulation in vivo, and to explore the underlying mechanisms.

MATERIALS AND METHODS

MTE or vehicle were intraperitoneally administrated to the H1975 xenograft model, followed by intragastric administration of gefitinib 12 h later. Mice plasma, tumors and liver tissues were harvested for further analysis. Hoechst 33342, a specific substrate of ATP Binding Cassette Subfamily G Member 2 (ABCG2), was used to determine the effects of MTE on activities of ABCG2 in tumor cells.

RESULTS

A higher concentration of plasma gefitinib was detected in MTE-treated mice at 24 h after delivery of gefitinib, however, it became insignificant in another 24 h. By contrast, gefitinib levels were continuously higher in MTE-pretreated mice tumor tissues at 12-48 h post gefitinib administration. MTE suppressed plasma levels of gefitinib metabolites (M523595, M608236 and M537194) in the first 24 h after gefitinib delivery, and inhibited activities of liver CYP2D6 and CYP3A4 at early stage (within 6 h) after gefitinib treatment. Strikingly, the activities of ABCG2, the primary drug transporter for gefitinib, were significantly inhibited by MTE in H1975 lung cancer cells. Further, it was identified that tenacissoside H, but not tenacissoside I, may contribute to the ABCG2-suppressive effects of MTE.

CONCLUSIONS

MTE pretreatment temporarily elevated plasma concentrations of gefitinib via inhibiting CYP450 enzymes. Most importantly, MTE promoted gefitinib accumulation in tumor tissues in a long-lasting manner via decreasing activities of ABCG2, a drug transporter responsible for gefitinib efflux.

The Antitumor Activities of Marsdenia tenacissima

Marsdenia tenacissima (MT), a traditional Chinese herbal medicine, has long been used for thousands of years to treat asthma, tracheitis, rheumatism, etc. An increasing number of recent studies have focused on the antitumor effects of MT. The effects of MT on cancer are the result of various activated signaling pathways and inhibiting factors and the high expression levels of regulatory proteins. MT can inhibit different cancer types including non-small cell lung cancer (NSCLC), malignant tumors, hepatic carcinoma, and so on. This article mainly focuses on the activities and mechanisms of MT. In addition, the efficacy and toxicity of MT are also discussed. Further studies of MT are required for improved medicinal utilization.

Marsdenia tenacissima: A Review of Traditional Uses, Phytochemistry and Pharmacology

The stems and roots of Marsdenia tenacissima (Roxb.) Wight et Arn., a traditional Chinese medicine and Dai herbal medicine, have been widely used for the treatment of asthma, trachitis, tonsillitis, pharyngitis, cystitis, pneumonia and drug or food poisoning. Nowadays, the extract of Marsdenia tenacissima, under the trademark of "Xiao-ai-ping", is widely used in clinic for the treatment of different cancers in China. To date, approximately 196 chemical ingredients covering steroids, triterpenes and organic acids have been identified from different parts of this plant. Steroids are the major characteristic and bioactive constituents of this plant. Modern pharmacology has demonstrated that the crude extracts and steroids have various in vitro and in vivo pharmacological activities, such as multidrug resistance reversal, antitumor, anti-angiogenic, immunomodulation and anti-HIV activities. The multidrug resistance reversal of steroids provided evidence for the use of this herb in clinic. However, despite wide clinical application, clinical trials, quality control method, pharmacokinetic and toxicity research on Marsdenia tenacissima were seldom reported and deserved further efforts. The present review aimed to achieve a comprehensive and up-to-date investigation in ethnopharmacology, phytochemistry, pharmacology, clinical study, pharmacokinetics, toxicology and quality control of Marsdenia tenacissima. In addition, the possible perspectives and trends for future studies of Marsdenia tenacissima have also been put forward. It is believed that this review would provide a theoretical basis and valuable data for future in-depth studies and applications.