Saikosaponins: a review of pharmacological effects

Ultrasonic extraction and antioxidant evaluation of oat saponins

The aim of this study is to optimize the extraction process of oat saponins (Os) and to evaluate their antioxidant potential. Single factor experiment, response surface optimization design, and orthogonal test were employed to optimize the process of ultrasonic-assisted extraction of Os, and the optimal extraction conditions were as followed: ethanol volume fraction of 80 %, material-solvent ratio of 1:14, ultrasonic power of 400 W, ultrasonic time of 25 min, extraction temperature of 60℃, extraction time of 180 min, and the extraction rate of Os was 0.317 %±0.105 %. Using the method, the crude extract of Os was prepared and its abilities of scavenging radicals in vitro and inhibiting protein oxidation in pork were determined, with ascorbic acid (Vc) as the control. Results revealed that the scavenging ability of Os against DPPH radical, hydroxyl radical (·OH) and superoxide anion (O2-) increased with the concentration of Os. Interestingly, the scavenging abilities of Os against DPPH and O2- were far lower than that of Vc, but its scavenging ability against ·OH was very close to that of Vc, reaching 84.59 % and 96.33 %, respectively. Furthermore, the experiments of pork storage and Fenton oxidation system showed that Os with 0.09-0.72 mg/mL could reduce the production of carbonyl (8.49 %-50.05 %) and the oxidation of total sulfhydryl (1.29 %-25.86 %), and effectively inhibit the oxidation of protein in pork by 7.82 %-22.53 %. The results of this study will provide a theoretical basis for the application of oat saponins as a natural anti-protein oxidant in meat processing and storage.

The therapeutic effects of saikosaponins on depression through the modulation of neuroplasticity: From molecular mechanisms to potential clinical applications

Depression is a major global health issue that urgently requires innovative and precise treatment options. In this context, saikosaponin has emerged as a promising candidate, offering a variety of therapeutic benefits that may be effective in combating depression. This review delves into the multifaceted potential of saikosaponins in alleviating depressive symptoms. We summarized the effects of saikosaponins on structural and functional neuroplasticity, elaborated the regulatory mechanism of saikosaponins in modulating key factors that affect neuroplasticity, such as inflammation, the hypothalamic-pituitary-adrenal (HPA) axis, oxidative stress, and the brain-gut axis. Moreover, this paper highlights existing gaps in current researches and outlines directions for future studies. A detailed plan is provided for the future clinical application of saikosaponins, advocating for more targeted researches to speed up its transition from preclinical trials to clinical practice.

Reducing effect of intragastrically administered saikosaponin A on alcohol and sucrose self-administration in rats

Saikosaponin A (SSA) is an active ingredient of the Asian medicinal herb, Bupleurum falcatum L. When administered via the intraperitoneal (i.p.) route, SSA suppressed multiple addictive-like behaviours, including operant alcohol self-administration, in rodents. It is unknown whether these effects are retained after intragastric (i.g.) administration, a desirable prerequisite for a compound with therapeutic potential. To fill this gap, i.g. SSA (0, 50, and 100 mg/kg) was tested in Sardinian alcohol-preferring (sP) rats trained to lever-respond for oral alcohol. SSA reduced lever-responding and amount of self-administered alcohol. However, when compared to i.p. SSA, i.g. SSA resulted to be markedly less potent and effective, suggestive of reduced bioavailability after i.g. treatment. Finally, and in agreement with previous data on the suppressing effect of i.p. SSA on behaviours motivated by highly palatable foods, i.g. SSA (0, 50, and 100 mg/kg) reduced oral sucrose self-administration in a separate set of sP rats.

Simultaneous Extraction and Analysis of Seven Major Saikosaponins from Bupleuri Radix and the Exploration of Antioxidant Activity and Its Mechanism

Saikosaponins (SS) are the main active components of Bupleuri Radix. In this study, the yields of SS a, b1, b2, c, d, e, and f were simultaneously determined using the HPLC-DAD dual wavelength method, and the ultrasound-assisted extraction process of saikosaponins was optimized using the response surface methodology. The antioxidant effect of saikosaponins was investigated using the scavenging rate of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2-diazo-bis (3-ethyl-benzothiazole-6-sulfonic acid) diammonium salt (ABTS), and hydroxyl (-OH) groups, and the mechanism was clarified via network pharmacological analysis. The results showed that the optimal extraction process of SS was a 5% ammonia-methanol solution as an extraction solvent, a material-liquid ratio of 1:40, a temperature of 46.66 °C, an extraction time of 65.07 min, and an ultrasonic power of 345.56 W. The total content of the seven saikosaponins under this condition was up to 6.32%, which was close to the model's predicted value of 6.56%, where the yields of the seven saikosaponins a, b1, b2, c, d, e, and f were 1.18%, 0.11%, 0.26%, 1.02%, 3.02%, 0.38%, and 0.44%, respectively. The saikosaponins have an obvious scavenging ability for DPPH, ABTS, and -OH radicals. The interactions of seven saikosaponins with antioxidant targets were studied, and a database was used to collate the core of saikosaponins and antioxidants through network pharmacology. The mechanisms of the antioxidant effects of the saikosaponins were derived via GO enrichment analysis and KEGG pathway analysis. Finally, the binding energy of the saikosaponins to the antioxidant targets was found to be less than -5.0 kcal·mol-1 via molecular docking, indicating that the antioxidant capacity of the saikosaponins are good. Therefore, this study developed a rapid and efficient method for the extraction of saikosaponins, which provides a theoretical basis for an in-depth understanding of the rational utilization of saikosaponins and the development of their medicinal value.

Extraction, purification, structure characteristics, biological activities and pharmaceutical application of Bupleuri Radix Polysaccharide: A review

Bupleuri Radix (BR), as a well-known plant medicine of relieving exterior syndrome, has a long history of usage in China. Bupleuri Radix Polysaccharide (BRP), as the main component and an important bioactive substance of BR, has a variety of pharmacological activities, including immunoregulation, antioxidant, antitumor, anti-diabetic and anti-aging, etc. In this review, the advancements on extraction, purification, structure characteristics, biological activities and pharmaceutical application of BRP from different sources (Bupleurum chinense DC., Bupleurum scorzonerifolium Willd., Bupleurum falcatum L. and Bupleurum smithii Woiff. var. Parvifolium Shan et Y. Li.) are summarized. Meanwhile, this review makes an in-depth discussion on the shortcomings of the research on BRP, and new valuable insights for the future researches of BRP are proposed.

Nanodrug rescues liver fibrosis via synergistic therapy with H2O2 depletion and Saikosaponin b1 sustained release

Hypoxia and hydrogen peroxide (H₂O₂) accumulation form the profibrogenic liver environment, which involves fibrogenesis and chronic stimulation of hepatic stellate cells (HSCs). Catalase (CAT) is the major antioxidant enzyme that catalyzes H₂O₂ into oxygen and water, which loses its activity in different liver diseases, especially in liver fibrosis. Clinical specimens of cirrhosis patients and liver fibrotic mice are collected in this work, and results show that CAT decrease is closely correlated with hypoxia-induced transforminmg growth factor β1 (TGF-β1). A multifunctional nanosystem combining CAT-like MnO₂ and anti-fibrosis Saikosaponin b1 (Ssb1) is subsequently constructed for antifibrotic therapy. MnO₂ catalyzes the accumulated H₂O₂ into oxygen, thereby ameliorating the hypoxic and oxidative stress to prevent activation of HSCs, and assists to enhance the antifibrotic pharmaceutical effect of Ssb1. This work suggests that TGF-β1 is responsible for the diminished CAT in liver fibrosis, and our designed MnO₂@PLGA/Ssb1 nanosystem displays enhanced antifibrotic efficiency through removing excess H₂O₂ and hypoxic stress, which may be a promising therapeutic approach for liver fibrosis treatment.

Saponins: Research Progress and Their Potential Role in the Post-COVID-19 Pandemic Era

In the post-COVID-19 pandemic era, the new global situation and the limited therapeutic management of the disease make it necessary to take urgent measures in more effective therapies and drug development in order to counteract the negative global impacts caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new infectious variants. In this context, plant-derived saponins-glycoside-type compounds constituted from a triterpene or steroidal aglycone and one or more sugar residues-may offer fewer side effects and promising beneficial pharmacological activities. This can then be used for the development of potential therapeutic agents against COVID-19, either as a therapy or as a complement to conventional pharmacological strategies for the treatment of the disease and its prevention. The main objective of this review was to examine the primary and current evidence in regard to the therapeutic potential of plant-derived saponins against the COVID-19 disease. Further, the aim was to also focus on those studies that highlight the potential use of saponins as a treatment against SARS-CoV-2. Saponins are antiviral agents that inhibit different pharmacological targets of the virus, as well as exhibit anti-inflammatory and antithrombotic activity in relieving symptoms and clinical complications related to the disease. In addition, saponins also possess immunostimulatory effects, which improve the efficacy and safety of vaccines for prolonging immunogenicity against SARS-CoV-2 and its infectious variants.

Transcriptome Level Reveals the Triterpenoid Saponin Biosynthesis Pathway of Bupleurum falcatum L

Bupleurum falcatum L. is frequently used in traditional herbal medicine in Asia. Saikosaponins (SSs) are the main bioactive ingredients of B. falcatum, but the biosynthetic pathway of SSs is unclear, and the biosynthesis of species-specific phytometabolites is little known. Here we resolved the transcriptome profiles of B. falcatum to identify candidate genes that might be involved in the biosynthesis of SSs. By isoform sequencing (Iso-Seq) analyses of the whole plant, a total of 26.98 Gb of nucleotides were obtained and 124,188 unigenes were identified, and 81,594 unigenes were successfully annotated. A total of 1033 unigenes of 20 families related to the mevalonate (MVA) pathway and methylerythritol phosphate (MEP) pathway of the SS biosynthetic pathway were identified. The WGCNA (weighted gene co-expression network analysis) of these unigenes revealed that only the co-expression module of MEmagenta, which contained 343 unigenes, was highly correlated with the biosynthesis of SSs. Comparing differentially expressed gene analysis and the WGCNA indicated that 130 out of 343 genes of the MEmagenta module exhibited differential expression levels, and genes with the most "hubness" within this module were predicted. Manipulation of these genes might improve the biosynthesis of SSs.

A Review of Antidepressant Effects and Mechanisms of Three Common Herbal Medicines: Panax ginseng, Bupleurum chinense, and Gastrodia elata

OBJECTIVES

Major depressive disorder (MDD) has been reported to affect an increasing number of individuals due to the modern lifestyle. Because of its complicated mechanisms and recurrent attacks, MDD is considered a refractory chronic disease. Although the mainstream therapy for MDD is chemical drugs, they are not a panacea for MDD because of their expensiveness, associated serious adverse reactions, and endless treatment courses. Hence, we studied three kinds of herbal medicines, namely, Panax ginseng C. A. Mey (PGM), Bupleurum chinense DC (BCD), and Gastrodia elata Blume (GEB), and reviewed the mechanisms underlying their antidepressant properties to provide a reference for the development of antidepressants and clinical medications.

METHODS

An extensive range of medicinal, clinical, and chemistry databases and search engines were used for our literature search. We searched the literature using certain web literature search engines, including Google Scholar, PubMed, Science Direct, CNKI (China National Knowledge Infrastructure), and Web of Science.

RESULTS

Experimental research found that active compounds of these three medicines exhibited good antidepressant effects in vivo and in vitro. Clinical investigations revealed that single or combined treatment of these medicines improved certain depressive symptoms. Antidepressant mechanisms are summarized based on this research.

CONCLUSION

The antidepressant mechanism of these three medicines includes but is not limited to ameliorating inflammation within the brain, reversing the hypothalamic-pituitary adrenal axis (HPA) system hyperfunction, inhibiting monoamine neurotransmitters reuptake, anti-neuron apoptosis and preventing neurotoxicity, and regulating depressive-related pathways such as the BDNF pathway and the PI3K/Akt/mTOR pathway.

Analgesic effects of saikosaponin A in a rat model of chronic inflammatory pain

Saikosaponin A (SSA) is the main active ingredient of roots of the East Asian medicinal plant, Bupleurum falcatum L. The present study was aimed at delving into the analgesic properties of SSA in a model of chronic inflammatory pain. To this end, rats were initially treated intraplantarly with complete Freund's adjuvant for induction of hyperalgesia. Twenty-four hours later, rats were acutely treated with SSA (0, 1 and 2 mg/kg, i.p.) and exposed to the Von Frey monofilament test or Randall-Selitto paw pressure test for assessment of mechanical hyperalgesia. Treatment with 2 mg/kg SSA had analgesic effects: the nocifensive reaction (paw withdrawal) occurred later and required application of the nociceptive stimulus at a stronger pressure. The analgesic effects of SSA were of magnitude comparable to that of the effects exerted by the reference compound, acetyl salicylic acid (100 mg/kg, i.p.). The well-described anti-inflammatory properties of SSA likely underlie its analgesic effects.

The Role of Saponins in the Treatment of Neuropathic Pain

Neuropathic pain is a chronic pain caused by tissue injury or disease involving the somatosensory nervous system, which seriously affects the patient's body function and quality of life. At present, most clinical medications for the treatment of neuropathic pain, including antidepressants, antiepileptic drugs, or analgesics, often have limited efficacy and non-negligible side effects. As a bioactive and therapeutic component extracted from Chinese herbal medicine, the role of the effective compounds in the prevention and treatment of neuropathic pain have gradually become a research focus to explore new analgesics. Notably, saponins have shown analgesic effects in a large number of animal models. In this review, we summarized the most updated information of saponins, related to their analgesic effects in neuropathic pain, and the recent progress on the research of therapeutic targets and the potential mechanisms. Furthermore, we put up with some perspectives on future investigation to reveal the precise role of saponins in neuropathic pain.

Plant-Derived Natural Products as Lead Agents against Common Respiratory Diseases

Never has the world been more challenged by respiratory diseases (RDs) than it has witnessed in the last few decades. This is evident in the plethora of acute and chronic respiratory conditions, ranging from asthma and chronic obstructive pulmonary disease (COPD) to multidrug-resistant tuberculosis, pneumonia, influenza, and more recently, the novel coronavirus (COVID-19) disease. Unfortunately, the emergence of drug-resistant strains of pathogens, drug toxicity and side effects are drawbacks to effective chemotherapeutic management of RDs; hence, our focus on natural sources because of their unique chemical diversities and novel therapeutic applications. This review provides a summary on some common RDs, their management strategies, and the prospect of plant-derived natural products in the search for new drugs against common respiratory diseases.

Screening saikosaponin d (SSd)-producing endophytic fungi from Bupleurum scorzonerifolium Willd

Saikosaponin d (SSd) is an important bioactive compound of traditional Chinese medicinal plant Bupleurum scorzonerifolium Willd. and exhibits many effects, such as anti-tumor, anti-inflammation and immunomodulatory. Since endophytic fungi possess the natural capacity to produce the similar secondary metabolite to that of their host plants, they are promising as alternative sources of plant bioactive natural products. In this study, in order to search for SSd-producing strains, endophytes were isolated from B. scorzonerifolium and were authenticated by the ITS sequence and the translation elongation factor-1alpha gene (TEF-1α) sequence analysis. The profile of metabolites present in the crude exacts was carried out by ultra performance liquid chromatography time-of-flight mass spectrometry (UPLC/Q-TOF-MS) analysis. The results showed that two strains, CHS₂ and CHS₃ from B. scorzonerifolium could produce SSd by UPLC/Q-TOF-MS analysis, and the amount of SSd produced by strain CHS₂ and CHS₃ were about 2.17 and 2.40 µg/mL, respectively. CHS₂ and CHS₃ showed a close phylogenetic relationship to Fusarium oxysporum and Fusarium acuminatum, respectively. According to our concern, no endophytic fungi capable of producing SSd from B. scorzonerifolium have been found before. Our clear intention was to isolate and identify these endophytic fungi that produce important active secondary metabolites, and then study the strains that produce this compound on a large scale through fermentation or even genetic study, to provide a feasible and more convenient way for the production of SSd.

Saikosaponin D alleviates DOX-induced cardiac injury in vivo and in vitro

ABSTRACT

As a highly efficient anticancer agent, Doxorubicin (DOX) is used for various cancers' treatment, but DOX-induced oxidative damages contribute to a degenerative irreversible cardiac toxicity. Saikosaponin D (SSD), which is a triterpenoid saponin with many biological activities including anti-inflammatory effects and antioxidant properties, provides protection against pathologic cardiac remodeling and fibrosis. In present study, we investigated the work of SSD for DOX-induced cardiotoxicity and the involved mechanisms. We observed that DOX injection induced cardiac injury, malfunction and decreased survival rate. Besides, DOX treatment increased lactate dehydrogenase (LDH) leakage, cardiomyocyte apoptosis, myocardium fibrosis and decrease of cardiomyocytes' sizes. Meanwhile, all the effects were notably attenuated by SSD treatment. In vitro, we found that 1μM SSD could enhance the proliferation of H9c2 cells, and inhibit DOX-induced apoptosis. It was found that the levels of MDA and reactive oxygen species (ROS) were significantly reduced by improving the activities of the endogenous antioxidative enzymes including catalase (CAT), and glutathione peroxidase (GSH-Px). Furthermore, SSD treatment could downregulate the DOX-induced p38 phosphorylation. Our results suggested that SSD efficiently protected the cardiomyocytes from DOX-induced cardiotoxicity by inhibiting the excessive oxidative stress via p38 MAPK signaling pathway.

Comparative permeability of three saikosaponins and corresponding saikogenins in Caco-2 model by a validated UHPLC-MS/MS method

Saikosaponins (SSs) are the main active components extracted from Bupleuri Radix (BR) which has been used as an important herbal drug in Asian countries for thousands of years. It has been reported that the intestinal bacteria plays an important role in the in vivo disposal of oral SSs. Although the deglycosylated derivatives (saikogenins, SGs) of SSs metabolized by the intestinal bacteria are speculated to be the main components absorbed into the blood after oral administration of SSs, no studies have been reported on the characteristics of SGs for their intestinal absorption, and those for SSs are also limited. Therefore, a rapid UHPLC-MS/MS method was developed to investigate and compare the apparent permeability of three common SSs (SSa, SSd, SSb₂) and their corresponding SGs (SGF, SGG, SGD) through a bidirectional transport experiment on Caco-2 cell monolayer model. The method was validated according to the latest FDA guidelines and applied to quantify the six analytes in transport medium samples extracted via liquid-liquid extraction (LLE). The apparent permeability coefficient (P _app ) determined in this study indicated that the permeability of SGs improved to the moderate class compared to the corresponding parent compounds, predicting a higher in vivo absorption. Moreover, the efflux ratio (ER) value demonstrated an active uptake of SSd and the three SGs, while a passive diffusion of SSa and SSb₂.

Saikosaponin a promotes sleep by decreasing neuronal activities in the lateral hypothalamus

Insomnia is one of the most prevalent sleep disorders, which imparts tremendous societal and economic impact. However, the present pharmacotherapy is greatly limited by adverse effects, so it is necessary to explore new drugs for the treatment of insomnia. Radix Bupleuri (RB) has been widely used in traditional Chinese medicine for >2000 years; it has many pharmacological effects, including sedation and anticonvulsant properties. The present study investigated the effects of saikosaponin a (SSa), an active component of RB, on sleep and locomotion. Male C57BL/6j mice received intraperitoneal injections of SSa at three different dosages (0.625, 1.25, and 2.5 mg/kg). Sleep parameters were analysed by electroencephalography and electromyography. The open-field test was used to measure locomotor activities. Our present results showed that SSa treatment significantly increased the duration of non-rapid eye movement sleep and shortened sleep latency in a dose-dependent manner. A high dose of SSa (2.5 mg/kg) also decreased locomotor activities. Moreover, by measuring c-Fos expression and the calcium signal in the lateral hypothalamus (LH), we found that SSa treatment decreased neuronal activity in the LH. In conclusion, SSa might be the sleep-promoting component in RB and its mechanism may be related to the modulation of neuronal activity in the LH.

Combination of natural antivirals and potent immune invigorators: A natural remedy to combat COVID-19

The flare‐up in severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) that emerged in December 2019 in Wuhan, China, and spread expeditiously worldwide has become a health challenge globally. The rapid transmission, absence of anti‐SARS‐CoV‐2 drugs, and inexistence of vaccine are further exacerbating the situation. Several drugs, including chloroquine, remdesivir, and favipiravir, are presently undergoing clinical investigation to further scrutinize their effectiveness and validity in the management of COVID‐19. Natural products (NPs) in general, and plants constituents specifically, are unique sources for various effective and novel drugs. Immunostimulants, including vitamins, iron, zinc, chrysin, caffeic acid, and gallic acid, act as potent weapons against COVID‐19 by reinvigorating the defensive mechanisms of the immune system. Immunity boosters prevent COVID‐19 by stimulating the proliferation of T‐cells, B‐cells, and neutrophils, neutralizing the free radicals, inhibiting the immunosuppressive agents, and promoting cytokine production. Presently, antiviral therapy includes several lead compounds, such as baicalin, glycyrrhizin, theaflavin, and herbacetin, all of which seem to act against SARS‐CoV‐2 via particular targets, such as blocking virus entry, attachment to host cell receptor, inhibiting viral replication, and assembly and release.

Computational assessment of saikosaponins as adjuvant treatment for COVID-19: molecular docking, dynamics, and network pharmacology analysis

Saikosaponins are major biologically active triterpenoids, usually as glucosides, isolated from Traditional Chinese Medicines (TCM) such as Bupleurum spp., Heteromorpha spp., and Scrophularia scorodonia with their antiviral and immunomodulatory potential. This investigation presents molecular docking, molecular dynamics simulation, and free energy calculation studies of saikosaponins as adjuvant therapy in the treatment for COVID19. Molecular docking studies for 23 saikosaponins on the crystal structures of the extracellular domains of human lnterleukin-6 receptor (IL6), human Janus Kinase-3 (JAK3), and dehydrogenase domain of Cylindrospermum stagnale NADPH-oxidase 5 (NOX5) were performed, and selected protein-ligand complexes were subjected to 100 ns molecular dynamics simulations. The molecular dynamics trajectories were subjected to free energy calculation by the MM-GBSA method. Molecular docking and molecular dynamics simulation studies revealed that IL6 in complex with Saikosaponin_U and Saikosaponin_V, JAK3 in complex with Saikosaponin_B4 and Saikosaponin_I, and NOX5 in complex with Saikosaponin_BK1 and Saikosaponin_C have good docking and molecular dynamics profiles. However, the Janus Kinase-3 is the best interacting partner for the saikosaponin compounds. The network pharmacology analysis suggests saikosaponins interact with the proteins CAT Gene CAT (Catalase) and Checkpoint kinase 1 (CHEK1); both of these enzymes play a major role in cell homeostasis and DNA damage during infection, suggesting a possible improvement in immune response toward COVID-19.

Utility of Basophil Activation Test in a Case of Daisaikoto- and Yokukansan-induced Lung Injury

Drug-induced lung injury is defined as a respiratory disorder. The usefulness of the basophil activation test (BAT) for drug allergy-related cases was recently reported. The patient was an 82-year-old woman who had been taking Daisaikoto and Yokukansan (herbal medicines) 3 months before developing dry cough. She was admitted to our hospital with an initial diagnosis of pneumonia with elevated serum LDH, KL-6, and IgE. Chest CT showed bilateral ground-glass opacities. Her bronchoalveolar lavage fluid showed increased eosinophils. Finally, a BAT was positive for both medications. Based on the findings, the patient was diagnosed with Daisaikoto- and Yokukansan-induced lung injury. The current case suggests that the BAT may be useful for the diagnosis of drug-induced lung injury.

Harmonizing Formula Prescription Patterns in Patients With Chronic Kidney Disease: A Population-Based Cross-Sectional Study

Objective: Harmonizing formulas are associated with beneficial renal outcomes in chronic kidney disease (CKD), but the therapeutic mechanisms are unclear. The study aims to explore the associations of intentions and independent factors with harmonizing formulas prescriptions for patients with CKD. Methods: We conducted a population-based cross-sectional study to explore factors associated with harmonizing formulas prescription. Patients who had been prescribed harmonizing formulas after CKD diagnosis was defined as the using harmonizing formulas group. Disease diagnoses when having harmonizing formula prescriptions and patient characteristics related to these prescriptions were collected. Results: In total, 24,971 patients were enrolled in this analysis, and 5,237 (21%) patients were prescribed harmonizing formulas after CKD diagnosis. The three most frequent systematic diseases and related health problems for which harmonizing formula prescriptions were issued in CKD were symptoms, signs, and ill-defined conditions (24.5%), diseases of the digestive system (20.67%), and diseases of the musculoskeletal system (12.9%). Higher likelihoods of harmonizing formula prescriptions were associated with young age (adjusted odds ratio: 0.98, 95% confidence interval: 0.97-0.98), female sex (1.79, 1.68-1.91), no diabetes (1.20, 1.06-1.36), no hypertension (1.38, 1.27-1.50), no cerebrovascular disease (1.34, 1.14-1.56), less disease severity (0.85, 0.83-0.88), using nonsteroidal anti-inflammatory drugs (NSAIDs) (1.65, 1.54-1.78), and using analgesic drugs other than NSAIDs (1.47, 1.35-1.59). Conclusion: Harmonizing formulas are commonly used for treating symptoms of the digestive and musculoskeletal systems in CKD cases. Further research on harmonizing formula effectiveness with regard to particular characteristics of CKD patients is warranted.

Active components of Bupleurum chinense and Angelica biserrata showed analgesic effects in formalin induced pain by acting on Nav1.7

ETHNOPHARMACOLOGY RELEVANCE

Pain is an unpleasant sensory and emotional experience, often accompanied by the occurrence of a variety of diseases. More than 800 kinds of traditional Chinese medicines (TCM) has now been reported for pain relief and several monomers have been developed into novel analgesic drugs. Bupleurum chinense and Angelica biserrata were representatives of the TCM that are currently available for the treatment of pain.

AIM OF THE STUDY

The study aims to detect the potential analgesic activity of each monomer of Bupleurum chinense and Angelica biserrata and to explore whether Nav1.7 is one of the targets for its analgesic activity.

MATERIALS AND METHODS

In this study, five monomers from Bupleurum chinense (Saikosaponin A, Saikosaponin B1, Saikosaponin B2, Saikosaponin C, Saikosaponin D) and five monomers from the Angelica biserrata (Osthole, Xanthotoxin, Imperatorin, Isoimperatorin, Psoralen) were examined by whole-cell patch-clamp on Nav1.7, which was closely associated with pain. Classical mouse pain models were also used to further verify the analgesic activity in vivo.

RESULTS

The results showed that monomers of Saikosaponins and Angelica biserrata all inhibited the peak currents of Nav1.7, indicating that Nav1.7 might be involved in the analgesic mechanism of Saikosaponins and Angelica biserrata. Among them, Saikosaponin A and Imperatorin showed the strongest inhibitory effect on Nav1.7. Furthermore, both Saikosaponin A and Imperatorin showed inhibitory effects on thermal pain and formalin-induced pain in phase II in vivo.

CONCLUSION

The results provide valuable information for future studies on the potential of TCM in alleviating pain.

Facile Synthesis of Saikosaponins

Saikosaponin A (SSa) and D (SSd) are typical oleanane-type saponins featuring a unique 13,28-epoxy-ether moiety at D ring of the aglycones, which exhibit a wide range of biological and pharmacological activities. Herein, we report the first synthesis of saikosaponin A/D (1-2) and their natural congeners, including prosaikosaponin F (3), G (4), saikosaponin Y (5), prosaikogenin (6), and clinoposaponin I (7). The present synthesis features ready preparation of the aglycones of high oxidation state from oleanolic acid, regioselective glycosylation to construct the β-(1→3)-linked disaccharide fragment, and efficient gold(I)-catalyzed glycosylation to install the glycans on to the aglycones.

Protective effect of dietary supplementation of Bupleurum falcatum L saikosaponins on ammonia exposure-induced ileum injury in broilers

Ammonia (NH3) at a high concentration has been recognized as a highly poisonous pollutant affecting both air and water quality. NH3, as a stimulus, exerts negative impact on broiler growth and production, but the molecular mechanisms are not clear yet. This study was designed to evaluate the effects of dietary supplementation of Bupleurum falcatum L saikosaponins (SP) on the growth and ileum health status in broilers exposed to NH3. Day-old Arbor Acers broilers (n = 480) were randomly allocated into 1 of 4 treatments. The main factors were dietary SP supplementation (0 or 80 mg/kg of diet) and NH3 challenge (with or without 70 ± 5 ppm NH3). The data of growth, intestinal morphology, and mRNA expression related to ileal function were collected from broilers exposed to NH3 for 7 d. Results showed that NH3 remarkably suppressed growth performance and intestinal development as well as induced biological injuries in the ileum of broilers, resulting from oxidative stress, mucous barrier damage, and immune dysfunction as well as upregulated apoptosis. These negative effects of NH3 were alleviated by the SP supplement. In conclusion, dietary supplementation of SP may be helpful in alleviating the detrimental effects of NH3 on the ileum development in broilers.

Herbal Medicine in the Treatment of Epilepsy

Epilepsy is one of the most common disorders of the central nervous system. Although epilepsy is common worldwide, approximately 80% of epileptic patients live in the developing countries or those with low-middle income. Up until the second decade of the 20th century, epilepsy was treated mostly by traditional remedies. Today, antiepileptic drugs are used as a general treatment instead to prevent and control epileptic seizures. However, patient access to these drugs is hindered due to the healthcare systems of their countries and a number of other reasons, such as cultural, socio-demographic, and financial poverty. In addition, approximately 30-40%of epileptic patients suffer from refractory epilepsy, additionally, AEDs have adverse side-effects that can lead to treatment failure or reduce the patient's quality of life. Despite recent advances in the treatment of epilepsy, there is still a need for improving medical treatment with a particular focus on efficacy, safety, and accessibility. Since herbal medicines have been used for many centuries around the world for treating epilepsy, it is, therefore, plausible that a rigorous study on herbal medicine and phytochemical components within plants of various species and origin may lead to the discovery of novel AEDs. Nowadays, many medicinal plants used in different cultures and regions of the world have been identified. Most phytochemical components of these plants have been identified and, in some cases, their targets located. Therefore, it is possible that new, effective, and accessible anticonvulsants drugs can be obtained from a medicinal plant.

Phytomedicine and the COVID-19 pandemic

Coronavirus disease broke out as unexplained pneumonia in Wuhan, China. The disease soon became a pandemic and was formally named as coronavirus disease or COVID-19. The causative virus has been named as SARS-CoV-2 by the International Committee on Taxonomy of Viruses. The most common complication in COVID-19-affected patients appears to be acute respiratory distress syndrome. At present, mainly symptomatic treatments are being given to COVID-19 patients, and no drug has been proved to cure the disease. There has been vying among pharmaceutical and researcher to devise a cure. The phytotherapy or the phytomedicines have been acknowledged as effective immunity booster and potential to eliminate the viral infection. The Chinese approach toward traditional herbal medicines has already being acknowledged as antiviral and RNA synthesis inhibitors globally. The secondary metabolites of plants such as alkaloids, flavonoids, phenolic acids, and terpenoids have been the source of countless medicinal compounds. For example, well-known antimalarial chloroquine phosphate (analogue of quinine, originally extracted from the bark of cinchona tree) has broad-spectrum antiviral activities. Antiviral phytomedicines have already been used in past two coronavirus outbreaks, that is, SARS-CoV and MERS-CoV. Ethnobotany or the folklore knowledge of medicinal plants, for instance, has also played a major role in the development of new drugs for centuries. Some species such as Lycoris radiata, Artemisia annua, Lindera aggregata, Isatis indigotica, Torreya nucifera, and Houttuynia cordata have already have proven their efficacies against certain ailments. Different plant parts can be consumed as raw or be modified into decoctions and tea for maximizing their effectivity. Moreover, phytochemicals can be regarded as best source of alternative and cheaper counterparts to synthetic medicines. Specifically, plants possessing antiinfluenza and antimalarial activities are potential candidates. Therefore this chapter will elucidate the phytoactive compounds and their sources and efficiencies in mitigating the COVID-19. This chapter will also serve a guideline to phytotherapy-based industries and public health.

Effects of saikosaponin-d on CYP3A4 in HepaRG cell and protein-ligand docking study

Saikosaponin-d (SSd) is a major bioactive triterpenoid saponin extracted from Bupleurum, which has anti-inflammatory, anticancer, antioxidative and anti-hepatic fibrosis effects. Due to the effects of Bupleurum-related formulations on cytochrome P450 (CYPs) expression still remain unclear, the combination therapies involved formulations containing Bupleurum may sometimes lead to unexpected drug-drug interactions in clinical practice. These interactions can limit the clinical applications of related formulations. In this study, we tried to explore the effects of SSd on CYP3A4 mRNA, protein expression and the enzyme activity in HepaRG cells by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), Western blot (WB) and HPLC method, respectively. The interaction between SSd and CYP3A4 was analysed by molecular docking. HepaRG cells were cultured with different concentrations of SSd (0.5, 1, 5 and 10 μmol/L) for 72 hours. It is revealed that SSd can inhibit CYP3A4 mRNA and its protein expression, and also the enzyme activity. Molecular docking study demonstrated that SSd can bind to several key active sites of amino acid residues of CYP3A4 protein with hydrogen bonds and hydrophobic interactions. Thus, drug-drug interactions resulted by SSd inhibiting CYP3A4 need attention when formulations containing SSd or Bupleurum are co-administrated with drugs metabolized by CYP3A4.

Effects of Saikosaponin D on CYP1A2 and CYP2D6 in HepaRG Cells

Background

Bupleurum is one of the most important traditional Chinese medicines and an ingredient in many compound preparations. It is widely used together with other drugs in clinical practice, and thus there is great potential for drug–drug interactions. Saikosaponin D (SsD) is a major bioactive triterpenoid saponin extracted from Bupleurum with anti-inflammatory, anticancer, antioxidative, and antihepatic fibrosis effects. Effects of the main components of Bupleurum on cytochromes P450 (CYPs) need to be clarified in the clinical application of combination therapies of formulations containing SsD or Bupleurum.

Purpose

This study aimed to investigate the effects of SsD on the CYP1A2 and CYP2D6 mRNAs, protein expression, and relative enzyme activities in HepaRG cells.

Methods

HepaRG cells were cultured with SsD at concentrations of 0.5, 1, 5 and 10 μM for 72 hours. mRNA and protein expression of CYP1A2 and CYP2D6 were analyzed with real-time PCR and Western blot analysis. Relative enzyme activities were analyzed with HPLC based on consumption of the specific probe substrate.

Results

SsD significantly induced expression of mRNA and increased relative activity of CYP1A2 in HepaRG cells after the cells had been treated with SsD at concentrations of 1, 5 and 10 μM. SsD also induced protein expression of CYP1A2 at concentrations of 5 and 10 μM. SsD exhibited an inductive effect on CYP2D6 mRNA and protein expression, while increasing the relative activity of CYP2D6 at concentrations of 5 and 10 μM.

Conclusion

This study is the first to investigate the effect of SsD on CYP1A2 and CYP2D6 in HepaRG cells, and the results may provide some useful information on potential drug–drug interactions related to clinical preparations containing SsD or Bupleurum.

"Fei Yan No. 1" as a Combined Treatment for COVID-19: An Efficacy and Potential Mechanistic Study

There has been a large global outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), representing a major public health issue. In China, combination therapy, including traditional Chinese medicine (TCM) as a treatment for COVID-19 has been used widely. “Fei Yan No. 1” (QFDYG) is a formula recommended by the Hubei Government to treat COVID-19. A retrospective study of 84 COVID-19 patients from Hubei Provincial Hospital of TCM and Renmin Hospital of Hanchuan was conducted to explore the clinical efficacy of QFDYG combination therapy. TCMSP and YaTCM databases were used to determine the components of all Chinese herbs in QFDYG. Oral bioavailability (OB) ≥ 30% and drug-like (DL) quality ≥ 0.18 were selected as criteria for screening the active compounds identified within the TCMSP database. The targets of active components in QFDYG were determined using the Swiss TargetPrediction (SIB) and Targetnet databases. The STRING database and the Network Analyzer plugin in Cytoscape were used to obtain protein-protein interaction (PPI) network topology parameters and to identify hub targets. Gene Ontology (GO) enrichment was conducted using FunRich version 3.1.3, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment using ClueGO version 2.5.6 software. PPI and compound-pathway (C-T) networks were constructed using Cytoscape 3.6.0. Compared with the control group, combined treatment with QFDYG resulted in a significantly higher rate of patients recovering from symptoms and shorter the time. After 14 days of treatment, QFDYG combined treatment increased the proportion of patients testing negative for SARS-CoV-2 nucleic acid by RT-PCR. Compared with the control group, promoting focal absorption and inflammation as viewed on CT images. GO and KEGG pathway enrichment indicated that QFDYG principally regulated biological processes, such as inflammation, an immune response, and apoptosis. The present study revealed that QFDYG combination therapy offered particular therapeutic advantages, indicating that the theoretical basis for the treatment of COVID-19 by QFDYG may play an antiviral and immune response regulation through multiple components, targets, and pathways, providing reference for the clinical treatment of COVID-19.

Saikosaponin D Inhibits Proliferation and Promotes Apoptosis Through Activation of MKK4-JNK Signaling Pathway in Pancreatic Cancer Cells

Introduction

Pancreatic cancer remains one of the most lethal malignancies and has few treatment options. Saikosaponin D (SSD), a major bioactive triterpene saponin isolated from Bupleurum chinense, has been reported to exert cytotoxicity properties toward many cancer cells. However, the effects of SSD on pancreatic cancer have been little scrutinized.

Methods

Here, we investigated the effect of SSD on the proliferation and apoptosis of human pancreatic cancer BxPC3 and PANC1 cells and the mouse pancreatic cancer cell line Pan02. Cell viability was determined by MTT assays and cell apoptosis analyzed by DAPI staining and flow cytometry. Expression levels of apoptosis-regulating markers and activity of the MKK4–JNK signaling pathway were determined by Western blotting. The inhibitor SP600125 was applied to confirm the role of the JNK pathway in SSD efficiency.

Results

SSD significantly inhibited the proliferation of BxPC3, PANC1, and Pan02 cells in a concentration- and time-dependent manner. Flow-cytometry analysis indicated obvious apoptosis induction after SSD exposure. Furthermore, SSD significantly triggered cleavage of caspase 3 and caspase 9 proteins and increased the expression of FoxO3a. In addition, activity of the MKK4–JNK pathway was dramatically increased after treatment with SSD in BxPC3 cells. SSD obviously stimulated phosphorylation of JNK, cJun, and SEK1/MKK4 proteins within 30 minutes. The addition of SP600125 blocked the activation of SSD on the MKK4–JNK regulatory pathway and reversed the effects of SSD on proliferation inhibition and apoptosis induction in BxPC3 cells.

Conclusion

These results revealed that SSD was capable of suppressing tumor growth and promoting apoptosis of pancreatic cancer cells via targeting the MKK4–JNK signaling pathway, indicating the possibility of further developing SSD as a potential therapeutic candidate for pancreatic cancer.

Saikosaponin D inhibits proliferation and induces apoptosis of non-small cell lung cancer cells by inhibiting the STAT3 pathway

OBJECTIVE

To study the effects of saikosaponin D (SSD) on proliferation and apoptosis in human non-small cell lung cancer cell lines, and to explore underlying mechanisms.

METHODS

Following treatment with saikosaponin D, A549 and H1299 cells were assessed for anti-proliferation effects using cell cycle kit-8 assays, changes in nuclear morphology using 4',6-diamidino-2-phenylindole (DAPI) staining, and cell apoptosis using annexin V/propidium iodide double staining. Proliferation- and apoptosis-related proteins were detected by immunoblotting.

RESULTS

Saikosaponin D had dose-dependent inhibitory effects on A549 cells (IC₅₀, 3.57 µM) and H1299 cells (IC₅₀, 8.46 µM). DAPI staining revealed decreased cell numbers, and most H1299 cells became round after treatment with 20 µM saikosaponin D. As saikosaponin D concentration increased, the proportions of cells in G0/G1 phase, and cells undergoing apoptosis, increased. Levels of phosphorylated p44/42 and signal transducer and activator of transcription (STAT)3 were significantly downregulated in both cell lines, while total STAT3 levels were not significantly affected. The cleaved form of caspase 3 was significantly upregulated.

CONCLUSIONS

Saikosaponin D inhibits proliferation, inducing cell cycle arrest and apoptosis, in lung cancer cells in a dose-dependent manner, possibly through inhibition of STAT3 phosphorylation and activation of caspase 3.

Traditional Chinese medicine Xiaosheng Powder for dry eye disease: A protocol for systematic review and meta analysis

BACKGROUND

Dry eye disease (DED) has shown a significant increase in recent years, which seriously affects people's work and life. Xiaosheng Powder, a traditional Chinese medicine decoction, has been widely used in treating DED. However, there is no systematic review of the results of the study on this therapeutic effect. The purpose of this review is to evaluate the effectiveness and safety of Xiaosheng Powder in the treatment of DED.

METHODS AND ANALYSIS

The electronic databases to be searched will include MEDLINE (PubMed), Cochrane Central Register of Controlled Trials in the Cochrane Library, Excerpta Medica Database, China National Knowledge Infrastructure, China Scientific Journal Database, Wanfang Database and Chinese Biomedical Literature Database. Papers in English or Chinese published from inception to 2020 will be included without any restrictions. Improvement in Ocular Surface Disease Index will be assessed as the primary outcomes. Tear break-up time, Schirmer I test, fluorescent, adverse events, and the recurrence rate after at least 3 months of the treatment will be evaluated as secondary outcomes. We will conduct a meta-analysis of randomized controlled trial if possible. The methodological qualities, including the risk of bias, will be evaluated using the Cochrane risk of bias assessment tool, while confidence in the cumulative evidence will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation approach.

ETHICS AND DISSEMINATION

It is not necessary for a formal ethical approval because the data is not individualized. The results of this review will offer implications for the use of Xiaosheng Powder as a treatment for DED. This knowledge will inform recommendations by ophthalmologist and researchers who are interested in the treatment of DED. The findings of this systematic review will be disseminated through peer-reviewed publications and conference presentations.

TRAIL REGISTRATION NUMBER

PROSPERO CRD42020147709.

Cognitive improvements and reduction in amyloid plaque deposition by saikosaponin D treatment in a murine model of Alzheimer's disease

Alzheimer's disease (AD), is a severe neurodegenerative disease that currently lacks an optimally effective therapeutic agent for its management. Saikosaponin D (SSD) is a component extracted from the herb Bupleurum falcatum that is commonly used in Chinese medicine. Although SSD has been reported to exert neuroprotective effects, its pharmacological role in AD has not been previously elucidated. Therefore, the aim of the present study was to investigate whether SSD treatment improves the cognitive function and pathological features of 3xTg mice, a triple-transgenic mouse model of AD that displays classical pathological features of AD. The effects of SSD treatment on the behavioral, histological and physiological features of the animal were quantified. Results from the behavioral experiments on the SSD-treated 3xTg mice identified a significant reduction in memory impairment. In addition, histological staining results indicated that SSD application could preserve the morphology of neurons, reduce apoptosis and significantly inhibit amyloid-β deposition in the hippocampus of 3xTg mice. SSD treatment also decelerated the activation of microglia and astrocytes in the hippocampus of 3xTg mice, possibly via the inhibition of the NF-κB signal transduction pathway. Therefore, the present study demonstrated the protective effects of SSD against progressive neurodegeneration and identified the potential underlying pharmacological mechanism. It was speculated that SSD may serve as a possible therapeutic agent in AD treatment in the future.

Aromatic Herbs, Medicinal Plant-Derived Essential Oils, and Phytochemical Extracts as Potential Therapies for Coronaviruses: Future Perspectives

After its recent discovery in patients with serious pneumonia in Wuhan (China), the 2019 novel coronavirus (2019-nCoV), named also Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has spread quickly. Unfortunately, no drug or vaccine for treating human this coronavirus infection is available yet. Numerous options for controlling or preventing emerging 2019-nCoV infections may be predicted, including vaccines, interferon therapies, and small-molecule drugs. However, new interventions are likely to require months to years to develop. In addition, most of the existing antiviral treatments frequently lead to the development of viral resistance combined with the problem of side effects, viral re-emergence, and viral dormancy. The pharmaceutical industry is progressively targeting phytochemical extracts, medicinal plants, and aromatic herbs with the aim of identifying lead compounds, focusing principally on appropriate alternative antiviral drugs. Spices, herbal medicines, essential oils (EOs), and distilled natural products provide a rich source of compounds for the discovery and production of novel antiviral drugs. The determination of the antiviral mechanisms of these natural products has revealed how they interfere with the viral life cycle, i.e., during viral entry, replication, assembly, or discharge, as well as virus-specific host targets. Presently, there are no appropriate or approved drugs against CoVs, but some potential natural treatments and cures have been proposed. Given the perseverance of the 2019-nCoV outbreak, this review paper will illustrate several of the potent antiviral chemical constituents extracted from medicinal and aromatic plants, natural products, and herbal medicines with recognized in vitro and in vivo effects, along with their structure-effect relationships. As this review shows, numerous potentially valuable aromatic herbs and phytochemicals are awaiting assessment and exploitation for therapeutic use against genetically and functionally different virus families, including coronaviruses.

Differential Effects of Saikosaponins A, B2, B4, C and D on Alcohol and Chocolate Self-Administration in Rats

AIMS

Treatment with saikosaponin A (SSA)-an ingredient of the medicinal herb, Bupleurum falcatum-has been reported to suppress several addictive-like behaviors, including morphine, cocaine, alcohol and chocolate self-administration in male rats. The aim of this investigation was to investigate whether saikosaponins of B. falcatum other than SSA affect alcohol and chocolate self-administration in rats.

METHODS

Ovariectomized female Sardinian alcohol-preferring (sP) and Wistar rats were trained to self-administer alcohol (15%, v/v) and a chocolate solution [5% (w/v) Nesquik® in water], respectively, under fixed ratio schedules of reinforcement. The following saikosaponins were compared to SSA: saikosaponin D (SSD; epimer of SSA), saikosaponin C (SSC), saikosaponin B2 (SSB2) and saikosaponin B4 (SSB4). All saikosaponins were tested acutely at the doses of 0, 0.25, 0.5 and 1 mg/kg (i.p.).

RESULTS

Treatment with SSA and SSD resulted in highly similar, marked reductions in alcohol self-administration; SSC failed to alter lever-responding for alcohol, while SSB2 and SSB4 produced intermediate reductions. Only SSA and SSD reduced chocolate self-administration, with SSC, SSB2 and SSB4 being ineffective.

CONCLUSIONS

The wide spectrum of efficacy of saikosaponins in reducing alcohol and chocolate self-administration suggests that even relatively small structural differences are sufficient to produce remarkable changes in their in vivo pharmacological profile. Together, these results confirm that roots of B. falcatum may be an interesting source of compounds with anti-addictive potential.

Not all saponins have a greater antiprotozoal activity than their related sapogenins

The antiprotozoal effect of saponins varies according to both the structure of the sapogenin and the composition and linkage of the sugar moieties to the sapogenin. The effect of saponins on protozoa has been considered to be transient as it was thought that when saponins were deglycosilated to sapogenins in the rumen they became inactive; however, no studies have yet evaluated the antiprotozoal effect of sapogenins compared to their related saponins. The aims of this study were to evaluate the antiprotozoal effect of eighteen commercially available triterpenoid and steroid saponins and sapogenins in vitro, to investigate the effect of variations in the sugar moiety of related saponins and to compare different sapogenins bearing identical sugar moieties. Our results show that antiprotozoal activity is not an inherent feature of all saponins and that small variations in the structure of a compound can have a significant influence on their biological activity. Some sapogenins (20(S)-protopanaxatriol, asiatic acid and madecassic acid) inhibited protozoa activity to a greater extent than their corresponding saponins (Re and Rh₁ and asiaticoside and madecassoside), thus the original hypothesis that the transient nature of the antiprotozoal action of saponins is due to the deglycosilation of saponins needs to be revisited.

Proposed mechanisms for the extracellular release of PD-L1 by the anticancer saponin platycodin D

Platycodin D (PTD) is an oleanane-type terpenoid saponin, isolated from the plant Platycodon grandiflorus. PTD displays multiple pharmacological effects, notably significant anticancer activities in vitro and in vivo. Recently, PTD was shown to trigger the extracellular release of the immunologic checkpoint glycoprotein PD-L1. The reduction of PD-L1 expression at the surface of cancer cells leads to interleukin-2 secretion and T cells activation. In the present review, we have analyzed the potential origin of this atypical PTD-induced PD-L1 release to propose a mechanistic explanation. For that, we considered all published scientific information, as well as the physicochemical characteristics of the natural product (a modeling analysis of PTD and the related saponin β -escin is provided). On this basis, we raise the hypothesis that the capacity of PTD to induce PD-L1 extracellular release derives from two main mechanisms: (i) a drug-promoted shedding of membrane PD-L1 by metalloproteases or more likely, (ii) a cholesterol binding-related effect, that would lead to perturbation of membrane raft domains, limiting the recruitment of proteins like TLR4. The drug-induced membrane effects (frequently observed with saponin drugs), associated with a production of interferon-γ,can favor the release of proteins like PD-L1 into membrane vesicles. Our analysis supports the hypothesis that PTD is a cholesterol-dependent lipid raft-modulating agent able to promote the formation of PD-L1 containing extracellular vesicles. The anticancer potential of PTD and its capacity to modulate the functioning of the PD-1/PD-L1 checkpoint should be further considered.

An in-silico evaluation of different Saikosaponins for their potency against SARS-CoV-2 using NSP15 and fusion spike glycoprotein as targets

The Public Health Emergency of International Concern declared the widespread outbreak of SARS-CoV-2 as a global pandemic emergency, which has resulted in 1,773,086 confirmed cases including 111,652 human deaths, as on 13 April 2020, as reported to World Health Organization. As of now, there are no vaccines or antiviral drugs declared to be officially useful against the infection. Saikosaponin is a group of oleanane derivatives reported in Chinese medicinal plants and are described for their anti-viral, anti-tumor, anti-inflammatory, anticonvulsant, antinephritis and hepatoprotective activities. They have also been known to have anti-coronaviral property by interfering the early stage of viral replication including absorption and penetration of the virus. Thus, the present study was undertaken to screen and evaluate the potency of different Saikosaponins against different sets of SARS-CoV-2 binding protein via computational molecular docking simulations. Docking was carried out on a Glide module of Schrodinger Maestro 2018-1 MM Share Version on NSP15 (PDB ID: 6W01) and Prefusion 2019-nCoV spike glycoprotein (PDB ID: 6VSB) from SARS-CoV-2. From the binding energy and interaction studies, the Saikosaponins U and V showed the best affinity towards both the proteins suggesting them to be future research molecule as they mark the desire interaction with NSP15, which is responsible for replication of RNA and also with 2019-nCoV spike glycoprotein which manage the connection with ACE2.

Communicated by Ramaswamy H. Sarma

Sikyungbanha-Tang Suppressing Acute Lung Injury in Mice Is Related to the Activation of Nrf2 and TNFAIP3

Sikyungbanha-Tang (SKBHT) is a Chinese traditional medicine popularly prescribed to patients with respiratory inflammatory symptoms in Korea. Although the Korea Food and Drug Administration approved SKBHT as a therapeutics for relieving the symptoms, experimental evidence for SKBHT suppressing inflammation is scarce. Here, we presented evidence that SKBHT can suppress inflammation in an acute lung injury (ALI) mouse model and explored the possible underlying mechanisms of SKBHT's anti-inflammatory activity. Single intratracheal (i.t.) injection of SKBHT (1 mg/kg or 10 mg/kg body weight) into mouse lungs decreased prototypic features of lung inflammation found in ALI, such as a high level of proinflammatory cytokines, neutrophil infiltration, and the formation of hyaline membrane, which were induced by a single i.t. LPS (2 mg/kg body weight). When added to a murine macrophage RAW 264.7 cells, SKBHT activated an anti-inflammatory factor Nrf2, increasing the expression of genes regulated by Nrf2. SKBHT suppressed the ubiquitination of Nrf2, suggesting that SKBHT increases the level of and thus activates Nrf2 by blunting the ubiquitin-dependent degradation of Nrf2. SKBHT induced the expression of tumor necrosis factor α-induced protein 3 (TNFAIP3), an ubiquitin-modulating protein that suppresses various cellular signals to NF-κB. Concordantly, SKBHT suppressed NF-κB activity and the expression of inflammatory cytokine genes regulated by NF-κB. Given that Nrf2 and TNFAIP3 are involved in regulating inflammation, our results suggest that SKBHT suppresses inflammation in the lung, the effect of which is related to SKBHT activating Nrf2 and TNFAIP3.

Saikosaponin B2 attenuates kidney fibrosis via inhibiting the Hedgehog Pathway

BACKGROUND

Renal interstitial fibrosis is a common pathway through which chronic kidney disease progresses to end-stage renal disease. There are currently no effective drugs available to treat kidney fibrosis, so traditional medicine is likely to be a candidate. The therapeutic potential of saikosaponin B2 (SSB2), a biologically active ingredient of Radix Bupleuri, on renal fibrosis has not been reported.

METHODS

A unilateral ureteral obstruction (UUO) model was conducted to induce renal interstitial fibrosis in mice. SSB2's effect was valuated by histological staining and exploring the changes in expression of relative proteins and mRNAs. A conditional medium containing sonic hedgehog variant protein stimulating normal rat kidney interstitial fibroblast cells (NRK-49F) was used in an in vitro model to determine the possible mechanism. The molecular target of SSB2 was verified using several mutation plasmids.

RESULTS

SSB2 administration reduced kidney injury and alleviated interstitial fibrosis by decreasing excessive accumulation of extracellular matrix components in UUO mice. It could also reduce the expression of α-SMA, fibronectin and Gli1, a crucial molecule of the hedgehog (Hh) signaling pathway both in vivo and in vitro. In NIH-3T3 cells simulated by conditional medium containing sonic hedgehog variant protein, SSB2 showed the ability to decrease the expression of Gli1 and Ptch1 mRNA. Using a dual-luciferase reporter assay, SSB2 suppressed the Gli-luciferase reporter activity in NIH-3T3 cells, and the IC₅₀ was 0.49 μM, but had no effect on the TNF-α/NF-κB and Wnt/β-catenin signaling pathways, indicating the inhibition selectivity on the Hh signaling pathway. Furthermore, SSB2 failed to inhibit the Hh pathway activity evoked by ectopic expression of Gli2ΔN and Smo D473H, suggesting that SSB2 might potentially act on smoothened receptors.

CONCLUSION

SSB2 could attenuate renal fibrosis and decrease fibroblast activation by inhibiting the Hh signaling pathway.

Comparative Effect of Aqueous and Methanolic Bupleuri Radix Extracts on Hepatic Uptake of High-Density Lipoprotein and Identification of the Potential Target in HFD-Fed Mice

Our previous study found saikosaponin b₂ (SSb₂) increased high-density lipoprotein (HDL) uptake in HepG2 cells. SSb₂ is only found in aqueous Bupleuri Radix extract, and it is one of the secondary saponins derived from saikosaponin d (SSd), which exists in the methanolic extract. This study aimed to compare the effect of aqueous extract of Bupleuri Radix on hepatic uptake of HDL with methanolic extract and to reveal the underlying mechanism of enhancing HDL uptake in mice fed with high-fat diet (HFD). Cellular HDL uptake in each group was quantified by flow cytometry. Bioactive components bound to the HepG2 cytomembrane were detected with HPLC-DAD. RNA sequencing was performed to screen the underlying target on hepatic HDL-uptake, and western blotting was conducted to verify differential protein expression. Significant increases of HDL uptake by HepG2 cells were observed in all groups of aqueous extract of Bupleuri Radix, while no effect or negative effect was observed in the methanolic extract. Saikosaponin b₁ (SSb₁) and SSb₂ were detected in the desorption elute of the aqueous extract from the HepG2 cytomembrane, while saikosaponin a (SSa) and SSd were not found. Remarkable upregulation of FGF21 in HFD-fed mice liver was affirmed after treatment with aqueous extract. This study suggested that aqueous Bupleuri Radix extract could promote hepatic HDL uptake in vitro but methanolic extract could not, and FGF21 might be the potential target.

Recent Advances in Biotransformation of Saponins

Saponins are a class of glycosides whose aglycones can be either triterpenes or helical spirostanes. It is commonly recognized that these active ingredients are widely found in various kinds of advanced plants. Rare saponins, a special type of the saponins class, are able to enhance bidirectional immune regulation and memory, and have anti-lipid oxidation, anticancer, and antifatigue capabilities, but they are infrequent in nature. Moreover, the in vivo absorption rate of saponins is exceedingly low, which restricts their functions. Under such circumstances, the biotransformation of these ingredients from normal saponins—which are not be easily adsorbed by human bodies—is preferred nowadays. This process has multiple advantages, including strong specificity, mild conditions, and fewer byproducts. In this paper, the biotransformation of natural saponins—such as ginsenoside, gypenoside, glycyrrhizin, saikosaponin, dioscin, timosaponin, astragaloside and ardipusilloside—through microorganisms (Aspergillus sp., lactic acid bacteria, bacilli, and intestinal microbes) will be reviewed and prospected.

Saikosaponin D suppresses enterovirus A71 infection by inhibiting autophagy

The dysregulation of autophagy, an evolutionarily conserved lysosomal degradation process, has been implicated in a wide variety of human diseases, and thus, small chemicals that modulate autophagy have therapeutic potential. Here, we assessed the ability of active components isolated from Bupleurum falcatum, a popular Chinese herb, to modulate autophagy. We found that saikosaponin D (SsD) and A (SsA) but not C (SsC) potently and reversibly inhibited the fusion of autophagosomes and lysosomes, resulting in the accumulation of autophagosomes, an increased lysosomal pH, and TFEB nuclear translocation. RAB5A knockdown or the expression of a dominant-negative RAB5 mutant significantly reduced the ability of SsD or SsA to block autophagy. Enterovirus A71 (EV-A71), the cause of hand-foot-mouth disease, has been shown to induce autophagy. We found that SsD potently inhibited EV-A71 RNA replication and subsequent viral protein synthesis, thereby preventing EV-A71-induced cell death. ATG5 knockdown inhibited EV-A71 viral protein synthesis, whereas autophagy induction by rapamycin promoted synthesis. Taken together, our data indicate that SsD and SsA are potent late-stage autophagy inhibitors that can be used to prevent EV-A71 infection.

Components of a popular Chinese herb known as Chaihu may inhibit the ability of the virus that causes hand-foot-and-mouth disease (HFMD) to infect cells by interfering with the natural process cells use to dispose of dysfunctional and unwanted components. Dysregulated autophagy has been implicated in various human diseases, included viral infections. Previous studies have suggested that Enterovirus A71 (EV-71), which causes HFMD, might subvert this process to aid its replication. Saikosaponins are active components of the herb Bupleurum falcatum, which appear to modulate autophagy. Jianbo Yue at the City University of Hong Kong and colleagues discovered that two such molecules, saikosaponin A and D, inhibited a key step in the autophagy process: the fusion of autophagosomes and lysosomes. This inhibited EV-A71 protein synthesis and the death of infected cells.

Network pharmacology and RNA sequencing studies on triterpenoid saponins from Bupleurum chinense for the treatment of breast cancer

Breast cancer remains the most commonly diagnosed malignancy among women, which is frequently associated with adverse side-effects and high metastasis. Bupleurum chinense DC. has been empirically and extensively used as the core prescription for more than half of Chinese formulations for the adjuvant therapy of breast cancer, and its biological activity against breast cancer has been proven by both in vitro and in vivo experiments. Saikosaponin compounds are the characteristic constituent of B. chinense, which exhibit significant cytotoxicity toward several cancer cells. However, the specific mechanisms of these compounds in the treatment of breast cancer have not been comprehensively understood. Therefore, we aimed to determine more potentially therapeutic targets and investigate the biological mechanisms of B. chinense. In the present study, we adopted network pharmacology and bioinformatics analysis to facilitate this requirement. Consequently, the network analysis revealed that saikosaponin-f (39), saikosaponin-d (14), saikosaponin-c (26), saikosaponin-h (54), saikosaponin-g (41), 3′′,6′′-O-diacetylsaikosaponin-d (20), 11α-methoxy-saikosaponin-f (40), and 6′′-O-acetylsaikosaponin-b₁ (48) might play important roles in the treatment of breast cancer. In addition, the apoptosis regulator Bcl-2 (BCL-2), C-X-C chemokine receptor type 4 (CXCR4), probable ATP-dependent RNA helicase DDX5 (DDX5), protein kinase C alpha (PRKCA), and proto-oncogene tyrosine-protein kinase Src (SRC) were the potential therapeutic targets that exhibited intense interactions. Mechanistically, a gene enrichment analysis revealed that the action of B. chinense against breast cancer was achieved by the regulation of several biological signaling pathways, such as pathways in cancer, PI3K-Akt signaling pathway, EGFR tyrosine kinase inhibitor resistance, microRNAs in cancer, etc. More importantly, we verified that the predictions involving saikosaponin-d by the cytotoxicity assay, apoptosis analysis, and RNA sequencing methods were partly consistent with those obtained from the network pharmacology prediction.

The network pharmacology and RNA sequencing studies were used to explore potential therapeutic targets and biological mechanisms of B. chinense for the treatment of breast cancer.