Development and validation of a highly sensitive LC-ESI-MS/MS method for the determination of hyperoside in beagle dog plasma: application to a pharmacokinetic study

Paris saponin VII, a Hippo pathway activator, induces autophagy and exhibits therapeutic potential against human breast cancer cells

Dysregulation of the Hippo signaling pathway seen in many types of cancer is usually associated with a poor prognosis. Paris saponin VII (PSVII) is a steroid saponin isolated from traditional Chinese herbs with therapeutic action against various human cancers. In this study we investigated the effects of PSVII on human breast cancer (BC) cells and its anticancer mechanisms. We showed that PSVII concentration-dependently inhibited the proliferation of MDA-MB-231, MDA-MB-436 and MCF-7 BC cell lines with IC₅₀ values of 3.16, 3.45, and 2.86 μM, respectively, and suppressed their colony formation. PSVII (1.2-1.8 μM) induced caspase-dependent apoptosis in the BC cell lines. PSVII treatment also induced autophagy and promoted autophagic flux in the BC cell lines. PSVII treatment decreased the expression and nuclear translocation of Yes-associated protein (YAP), a downstream transcriptional effector in the Hippo signaling pathway; overexpression of YAP markedly attenuated PSVII-induced autophagy. PSVII-induced, YAP-mediated autophagy was associated with increased active form of LATS1, an upstream effector of YAP. The activation of LATS1 was involved the participation of multiple proteins (including MST2, MOB1, and LATS1 itself) in an MST2-dependent sequential activation cascade. We further revealed that PSVII promoted the binding of LATS1 with MST2 and MOB1, and activated LATS1 in the BC cell lines. Molecular docking showed that PSVII directly bound to the MST2-MOB1-LATS1 ternary complex. Microscale thermophoresis analysis and drug affinity responsive targeting stability assay confirmed the high affinity between PSVII and the MST2-MOB1-LATS1 ternary complex. In mice bearing MDA-MB-231 cell xenograft, administration of PSVII (1.5 mg/kg, ip, 4 times/week, for 4 weeks) significantly suppressed the tumor growth with increased pLATS1, LC3-II and Beclin 1 levels and decreased YAP, p62 and Ki67 levels in the tumor tissue. Overall, this study demonstrates that PSVII is a novel and direct Hippo activator that has great potential in the treatment of BC.

Potential clinical applications of phytopharmaceuticals for the in-patient management of coagulopathies in COVID-19

Thrombotic complications occur in many cardiovascular pathologies and have been demonstrated in COVID‐19. The currently used antithrombotic drugs are not free of adverse reactions, and COVID‐19 patients in particular, when treated with a therapeutic dose of an anticoagulant do not receive mortality benefits. The clinical management of COVID‐19 is one of the most difficult tasks for clinicians, and the search for safe, potent, and effective antithrombotic drugs may benefit from exploring naturally bioactive molecules from plant sources. This review describes recent advances in understanding the antithrombotic potential of herbal drug prototypes and points to their future clinical use as potent antithrombotic drugs. Although natural products are perceived to be safe, their clinical and therapeutic applications are not always apparent or accepted. More in‐depth studies are necessary to demonstrate the clinical usefulness of plant‐derived, bioactive compounds. In addition, holistic approaches in systematic investigations and the identification of antithrombotic mechanisms of the herbal bioactive molecule(s) need to be conducted in pre‐clinical studies. Moreover, rigorous studies are needed to compare the potency of herbal drugs to that of competitor chemical antithrombotic drugs, and to examine their interactions with Western antithrombotic medicines. We have also proposed a road map to improve the commercialization of phytopharmaceuticals.

The Pharmacokinetics and Tissue Distributions of Nine Steroidal Saponins from Paris polyphylla in Rats

BACKGROUND AND OBJECTIVES

Paris polyphylla (P. polyphylla) is a herb widely used in traditional Chinese medicine to treat various diseases. This study used ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to study the pharmacokinetics and tissue distributions of nine steroidal saponins from P. polyphylla.

METHODS

P. polyphylla extract was administered to rats intravenously (i.v.) and orally (p.o.). The concentrations of the nine main bioactive components of the extract were determined in plasma and tissue samples using UPLC-MS/MS. The nine saponin compounds were also incubated in an anaerobic environment with intestinal flora suspension solution to investigate hydrolysis by intestinal flora.

RESULTS

After oral administration of the P. polyphylla extract, polyphyllin VII was found to have the highest maximum concentration (C_max, 17.0 ± 2.24 µg/L) of all nine components, followed by the C_max values of dioscin (16.17 ± 0.64 µg/L) and polyphyllin H (11.75 ± 1.28 µg/L), while the C_max values of polyphyllin I, polyphyllin II, progenin III, polyphyllin IV, gracillin, and polyphyllin were less than 10 µg/L. The bioavailabilities of all nine components were less than 1%. All the compounds were hydrolyzed by intestinal flora and were predominantly distributed in the liver and lungs.

CONCLUSIONS

The nine compounds presented different pharmacokinetic parameter values, and multiple administrations did not accumulate in the body. The bioavailabilities of the compounds were low, partly because of hydrolysis by intestinal flora. The nine compounds were mainly distributed in the liver and lungs, which may be target organs.

Natural Polyphyllins (I, II, D, VI, VII) Reverses Cancer Through Apoptosis, Autophagy, Mitophagy, Inflammation, and Necroptosis

Cancer is the second leading cause of mortality worldwide. Conventional therapies, including surgery, radiation, and chemotherapy, have limited success because of secondary resistance. Therefore, safe, non-resistant, less toxic, and convenient drugs are urgently required. Natural products (NPs), primarily sourced from medicinal plants, are ideal for cancer treatment because of their low toxicity and high success. NPs cure cancer by regulating different pathways, such as PI3K/AKT/mTOR, ER stress, JNK, Wnt, STAT3, MAPKs, NF-kB, MEK-ERK, inflammation, oxidative stress, apoptosis, autophagy, mitophagy, and necroptosis. Among the NPs, steroid saponins, including polyphyllins (I, II, D, VI, and VII), have potent pharmacological, analgesic, and anticancer activities for the induction of cytotoxicity. Recent research has demonstrated that polyphyllins (PPs) possess potent effects against different cancers through apoptosis, autophagy, inflammation, and necroptosis. This review summarizes the available studies on PPs against cancer to provide a basis for future research.

UPLC-MS/MS Method for the Determination of Hyperoside and Application to Pharmacokinetics Study in Rat After Different Administration Routes

A rapid and sensitive UPLC-MS/MS method was developed and fully validated for the quantification of hyperoside in rat plasma after intragastric, intraperitoneal and intravenous administration. Geniposide was used as an internal standard, and simple liquid–liquid extraction by ethyl acetate was utilized for to extracting the analytes from the rat plasma samples. Chromatographic separation was carried out on an InfinityLab Poroshell 120EC-C18column (2.1 mm × 50 mm, 1.9-Micro, Agilent technologies, USA). The mobile phase consisted of methanol (A) and water (B) (containing 0.1% acetic acid) at a flow rate of 0.4 mL/min. A run time of 3 min for each sample made it possible to analyze more than 300 plasma samples per day. The validated linear ranges of hyperoside were 2–1000 ng/mL in rat plasma. The intra-day and inter-day precision were within 2.6–9.3%, and accuracy were ± 8.6%. And the results of recovery and matrix interference studies were well within the accepted variability limits. Finally, this method was fully validated and successfully applied to the pharmacokinetic studies of hyperoside via different administration routes in rats.

Sample preparation for liquid chromatographic analysis of phytochemicals in biological fluids

INTRODUCTION

Natural products have been used traditionally for the treatment and prevention of diseases for thousands of years and are nowadays consumed as dietary supplements and herbal medicine. To ensure the safe and effective use of these herbal products, information about bioavailability of active compounds in plasma or target tissues should be provided via validated analytical methods combined with appropriate sampling methods.

OBJECTIVE

To provide comprehensive and abridged information about sample preparation methods for the quantification of phytochemicals in biological samples using liquid chromatography analysis.

METHODS

Sample pre-treatment procedures used in analytical methods for in vivo pharmacokinetic studies of natural compounds or herbal medicines were reviewed. These were categorised according to the biological matrices (plasma, bile, urine, faeces and tissues) and sample clean-up processes (protein precipitation, liquid-liquid extraction and solid-phase extraction).

RESULTS

Although various kinds of sample pre-treatment methods have been developed, liquid-liquid extraction is still widely used and solid-phase extraction is becoming increasingly popular because of its efficiency for extensive clean up of complex matrix samples. However, protein precipitation is still favoured due to its simplicity.

CONCLUSION

Sample treatment for phytochemical analysis in biological fluids is an indispensable and critical step to obtain high quality results. This step could dominate the overall analytical process because both the duration of the process as well as the reliability of the data depend in large part on its efficiency. Thus, special attention should be given to the choice of a proper sample treatment method that targets analytes and their biomatrix.