In vitro and in vivo anticancer activity of a novel puerarin nanosuspension against colon cancer, with high efficacy and low toxicity

Unlocking the potential of flavonoids: Natural solutions in the fight against colon cancer

Colorectal cancer (CRC) is a major cause of cancer-related deaths worldwide, underscoring the importance of understanding the diverse molecular and genetic underpinnings of CRC to improve its diagnosis, prognosis, and treatment. This review delves into the adenoma-carcinoma-metastasis model, emphasizing the "APC-KRAS-TP53" signature events in CRC development. CRC is categorized into four consensus molecular subtypes, each characterized by unique genetic alterations and responses to therapy, illustrating its complexity and heterogeneity. Furthermore, we explore the role of chronic inflammation and the gut microbiome in CRC progression, emphasizing the potential of targeting these factors for prevention and treatment. This review discusses the impact of dietary carcinogens and lifestyle factors and the critical role of early detection in improving outcomes, and also examines conventional chemotherapy options for CRC and associated challenges. There is significant focus on the therapeutic potential of flavonoids for CRC management, discussing various types of flavonoids, their sources, and mechanisms of action, including their antioxidant properties, modulation of cell signaling pathways, and effects on cell cycle and apoptosis. This article presents evidence of the synergistic effects of flavonoids with conventional cancer therapies and their role in modulating the gut microbiome and immune response, thereby offering new avenues for CRC treatment. We conclude by emphasizing the importance of a multidisciplinary approach to CRC research and treatment, incorporating insights from genetic, molecular, and lifestyle factors. Further research is needed on the preventive and therapeutic potential of natural compounds, such as flavonoids, in CRC, underscoring the need for personalized and targeted treatment strategies.

Nanosuspensions in ophthalmology: Overcoming challenges and enhancing drug delivery for eye diseases

This review article provides a comprehensive overview of the advancements in using nanosuspensions for controlled drug delivery in ophthalmology. It highlights the significance of ophthalmic drug delivery due to the prevalence of eye diseases and delves into various aspects of this field. The article explores molecular mechanisms, drugs used, and physiological factors affecting drug absorption. It also addresses challenges in treating both anterior and posterior eye segments and investigates the role of mucus in obstructing micro- and nanosuspensions. Nanosuspensions are presented as a promising approach to enhance drug solubility and absorption, covering formulation, stability, properties, and functionalization. The review discusses the pros and cons of using nanosuspensions for ocular drug delivery and covers their structure, preparation, characterization, and applications. Several graphical representations illustrate their role in treating various eye conditions. Specific drug categories like anti-inflammatory drugs, antihistamines, glucocorticoids, and more are discussed in detail, with relevant studies. The article also addresses current challenges and future directions, emphasizing the need for improved nanosuspension stability and exploring potential technologies. Nanosuspensions have shown substantial potential in advancing ophthalmic drug delivery by enhancing solubility and absorption. This article is a valuable resource for researchers, clinicians, and pharmaceutical professionals in this field, offering insights into recent developments, challenges, and future prospects in nanosuspension use for ocular drug delivery.

Preparations of 25 wt% of Pyraclostrobin Nanosuspension Concentrate (SC) Using Lignosulfonate-Based Colloidal Spheres to Improve Its Thermal Storage Stability

Improving the thermal storage stability of nanosuspension concentrate (SC) prepared from low-melting-point pesticide is a recognized problem. In this work, using pyraclostrobin as the raw material, 25 wt% of pyraclostrobin nano-SC was prepared through a water-based grinding method, and the optimal grinding conditions were obtained as follows: a grinding time of 23 h, D-3911 as dispersant and a dispersant dosage of 12 wt%. The pyraclostrobin nano-SC D90 size prepared based on this best formula was 216 nm. Adding glycerin could improve the stability of nano-SC at room temperature, but its thermal storage stability was still poor. For this problem, sodium lignosulfonate and cetyltrimethylammonium bromide (NaLS/CTAB) colloidal spheres were prepared through electrostatic and hydrophobic self-assembly and characterized. The delamination and precipitation of nano-SC can be significantly improved by adding an appropriate amount of colloidal spheres, and the nano-SC D90 size decreased from 2726 to 1023 nm after 7 days of thermal storage. Farmland experiments indicated the control efficiency of pyraclostrobin nano-SC against flowering cabbage downy mildew disease was about 30% higher than that of SC. Especially after adding the wetting agent, the effect of nano-SC could be comparable to that of commercial Kairun (currently the best pyraclostrobin formulation in the world).

Advances in Extraction, Purification, and Analysis Techniques of the Main Components of Kudzu Root: A Comprehensive Review

Kudzu root (Pueraria lobate (Willd.) Ohwi, KR) is an edible plant with rich nutritional and medicinal values. Over the past few decades, an ample variety of biological effects of Pueraria isoflavone have been evaluated. Evidence has shown that Pueraria isoflavone can play an active role in antioxidant, anti-inflammatory, anti-cancer, neuroprotection, and cardiovascular protection. Over 50 isoflavones in kudzu root have been identified, including puerarin, daidzein, daidzin, 3'-hydroxy puerarin, and genistein, each with unambiguous structures. However, the application of these isoflavones in the development of functional food and health food still depends on the extraction, purification and identification technology of Pueraria isoflavone. In recent years, many green and novel extraction, purification, and identification techniques have been developed for the preparation of Pueraria isoflavone. This review provides an updated overview of these techniques, specifically for isoflavones in KR since 2018, and also discusses and compares the advantages and disadvantages of these techniques in depth. The intention is to provide a research basis for the green and efficient extraction, purification, and identification of Pueraria isoflavone and offers investigators a valuable reference for future studies on the KR.

Pharmacokinetics and Anti-Diabetic Studies of Gliclazide Nanosuspension

Gliclazide (GCZ), an antidiabetic medication, has poor solubility and limited oral bioavailability due to substantial first-pass metabolism. Thus, the purpose of the current study was to optimize and formulate a GCZ nanosuspension (NS) employing the antisolvent precipitation technique. A three-factor, three-level Box–Behnken design (BBD) was used to examine the impact of the primary formulation factors (drug concentration, stabilizer, and surfactant %) on particle size. The optimized NS contains 29.6 mg/mL drug, 0.739% lecithin, and 0.216% sodium dodecyl sulfate (SDS). Under scanning microscopy, the topography of NS revealed spherical particles. Furthermore, NS had a much better saturation solubility than the pure material, which resulted in a rapid dissolving rate, which was attributed to the amorphous structure and smaller particle size of the NS particles. Studies on intestinal permeability using the in vitro noneverted intestinal sac gut method (duodenum, jejunum, and ileum) and single-pass intestinal permeability (SPIP) techniques showed that the effective permeability was also increased by more than 3 fold. In the pharmacokinetic study, the C_max and AUC_0–t values of NS were approximately 3.35- and 1.9-fold higher than those of the raw medication and marketed formulation (MF). When compared to plain drug and commercial formulations, the antidiabetic efficacy of NS demonstrated that it had a significant impact on lowering glucose levels.

Puerarin inhibits EMT induced by oxaliplatin via targeting carbonic anhydrase XII

Puerarin is a flavonoid molecule that widely exists in various plants. Puerarin has been reported to exhibit anti-tumor effects in various cancers. However, its exact underlying pharmacological mechanism is unclear. This study evaluated the anticancer effect of puerarin combined with oxaliplatin (OXA) in vitro and in vivo. Our results indicated that puerarin can reverse platinum-based anti-cancer drug resistance, and enhance the OXA’s anticancer effects on breast cancer. Furthermore, puerarin can inhibit migration and reverse the epithelial-mesenchymal transition (EMT) induced by low-dose OXA. Further studies showed that the carbonic anhydrase (CA) XII is a potential target of puerarin. In conclusion, puerarin is expected to become an adjuvant chemotherapy drug and potentially become one of the medicated foods for breast cancer patients.

Formulation and Physicochemical and Biological Characterization of Etoposide-Loaded Submicron Emulsions with Biosurfactant of Sophorolipids

Etoposide (ETO), a traditional anticancer chemotherapeutic agent, is commercialized in oral soft gelatin capsules and non-aqueous parenteral solutions form. Novel formulation application and new excipients exploration are needed to improve the water-solubility and comfort of the drug administration. In the present study, novel etoposide-loaded submicron emulsions (ESE) with the biosurfactants of acidic sophorolipid (ASL) and lactonic sophorolipid (LSL) instead of the chemical surfactant of Tween-80 were prepared and characterized. Firstly, parameters of medium-chain triglyceride: long-chain triglyceride (MCT:LCT), lecithin concentration, homogenization pressure and cycle, and type and concentration of surfactants were investigated to optimize the formation of ESEs. Then the physicochemical properties, antitumor activity, stability, and security of ESEs were compared. The results showed that ASL performed the best properties and activities than Tween-80 and LSL in ESE formation. ASL-ESE showed higher drug loading capacity, slower release rate, and significantly increased antitumor activity against ovarian cancer cell line A2780 via apoptosis than Tween-ESE and commercial ETO injection. Besides, both ASL-ESE and Tween-ESE caused no hemolysis, and the safe dose of ASL was 2.14-fold that of Tween-80 in the hemolysis test, making ASL more reliable for drug delivery applications. Furthermore, ASL-ESE exhibited equivalent long-term and autoclaving stability to Tween-ESE. These results thus suggested the excellent competences of ASL in ESE formation, efficacy enhancement, and safety improvement.

Puerarin: A Potential Therapeutic for Colon Adenocarcinoma (COAD) Patients Suffering From SARS-CoV-2 Infection

Patients with colonic adenocarcinoma (COAD) are at relatively high risk of SARS-CoV-2 infection. However, there is a lack of medical strategies to treat COVID-19/COAD comorbidity. Puerarin, a natural product, is a known antiviral, antitumor, and immunomodulatory effect. Therefore, we hypothesised that puerarin could be used to treat COVID-19/COAD patients. Based on network pharmacology and bioinformatics analysis, the potential targets and pharmacological mechanisms of puerarin in COVID-19/COAD were identified. By intersecting therapeutic target genes for puerarin, COVID-19-related genes and COAD-related genes, 42 target genes of puerarin that could potentially treat COVID-19/COAD comorbidity were obtained. By using the 42 potential target genes to construct the protein-protein interaction (PPI) network, we obtained five core target genes, namely RELA, BCL2, JUN, FOS, and MAPK1. The results of bioinformatics analysis revealed that puerarin could be able to treat COVID-19/COAD comorbidity through apoptosis, antiviral, antioxidant, NF-κB signaling pathway, MAPK signaling pathway, IL-17 signaling pathway, TNF signaling pathway, and HIF-1 signaling pathway etc. This study found that puerarin has the potential to treat COVID-19/COAD patients and that the therapeutic target genes obtained in the study may provide clues for the treatment of COVID19/COAD comorbidity.

Dual-spectrum online monitoring of puerarin and total flavonoids contents during the extraction process of Pueraria lobata

In the extraction process of traditional Chinese medicine (TCM), the rapid detection of the active components of TCM plays a vital role. We pioneered the choice of dual-spectrum technology based on near-infrared (NIR) and ultraviolet-visible (UV-Vis) spectra and applied it to the quantitative monitoring of online extraction of puerarin and total flavonoids from Pueraria lobata. An online monitoring system was constructed to fulfill the dual-spectrum online monitoring. The extraction solution flows from a flask into a pipeline under the control of a peristaltic pump, removing the solid residues contained in the solution with filters. When the extraction solution flows into the cuvette, it will be measured with NIR and UV-Vis portable spectrometers. After finishing the spectra collection, the peristaltic pump will reverse to push the extraction solution back to the flask. The partial least squares (PLS) models were established to quantitatively analyze puerarin and total flavonoids by NIR, UV-Vis, and dual-spectrum data. As for NIR, UV-Vis and dual-spectrum, the RMSEP (mg/mL) of the puerarin models were 0.0803, 0.0500, and 0.0351, and those of the total flavonoids models were 0.4373, 0.2402, and 0.1795, respectively. The results show that the dual-spectrum online monitoring system is simple, stable and fast (a few seconds) in operation, and accurate in prediction. Compared with individual NIR or UV-Vis spectra, the dual-spectra contains more comprehensive information, and the prediction ability is stronger. This method is expected to become a promising tool for the quantitative analysis of other traditional Chinese medicines.

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.

Characterization of Cepharanthin Nanosuspensions and Evaluation of Their In Vitro Activity for the HepG2 Hepatocellular Carcinoma Cell Line

BACKGROUND

Conventional cancer therapeutics has enormous toxicity and severe side effects that generate multi-drug resistance. Therefore, an urgent need exists for new alternative therapeutic agents for cancer treatment. Cepharanthin (CEP) has anti-cancer potential but has poor aqueous solubility, which limits its clinical use. Nanosuspensions (NS) are attractive as insoluble drug delivery systems.

OBJECTIVES

In this study, we used D-alpha Tocopherol acid Polyethylene Glycol Succinate (TPGS), Polyvinylpyrrolidone (PVP) VA64, and Croscamellose Sodium (CCS) as stabilizers to produce TPGS-CEP-NS, PVP VA64-CEP-NS, and CCS-CEP-NS by wet-milling technology, and then characterized the NS and evaluated their functional activities in vitro.

METHODS

CEP Nanosuspensions (CEP-NS) were prepared by the wet-milling method. The prepared NS were characterized by particle size distribution, zeta potential, morphology, surface properties, and molecular interactions. The NS were evaluated for their effects on HepG2 cells in vitro. The evaluations included assessment of cellular cytotoxicity, cellular apoptosis, NS uptake by cells, and mitochondrial membrane potential changes.

RESULTS

CEP-NS showed an appropriate particle size and were physically stable. All CEP-NS exhibited HepG2 enhanced anti-proliferative effects by reducing cell viability, enhanced cellular uptake, induced cellular apoptosis, and mitochondrial membrane potential loss.

CONCLUSIONS

CEP-NS may be effective therapeutic agents for the treatment of hepatocellular carcinoma.

In vivo assessments for predicting the bioavailability of nanoencapsulated food bioactives and the safety of nanomaterials

Use of nano-sized materials to design novel delivery systems is actually a double-edged sword regarding the enhancement of absorption and bioavailability of encapsulated bioactives as well as the unpredictable phenomena inside the living cells causing health concerns. So, comprehensive investigations on the use of nanomaterials in foods and their biological fate are needed. To reach this goal, both in vitro and in vivo techniques have been extensively applied. Besides the in vitro models such as cell culture and yeast/bacteria, different live animal models like mice, rat, Drosophila melanogaster, Caenorhabditis elegans, Zebrafish and dog can be applied to study bioavailability and safety of nanodelivery systems. However, considering the low correlation between the achieved results of in vitro and in vivo assays, in vivo tests are the first priority due to providing a real physiological condition. On the other hand, uncorrelated results by in vivo assays represent a serious problem to compare them. To defeat the issues in setting an in vivo research for the nanodelivery systems, all restrictions and FDA regulations is likely to be considered to improve the assays authenticity. This review takes a comprehensive look at the different types of in vivo assays and model organisms that has been utilized for the investigation of bioavailability, release profile and possible toxicity of food-based nanomaterials so far.

Research progress on nanotechnology for delivery of active ingredients from traditional Chinese medicines

There is growing acceptance of traditional Chinese medicines (TCMs) as potential sources of clinical agents based on the demonstrated efficacies of numerous bioactive compounds first identified in TCM extracts, such as paclitaxel, camptothecin, and artemisinin. However, there are several challenges to achieving the full clinical potential of many TCMs, particularly the generally high hydrophobicity and low bioavailability. Recently, however, numerous studies have attempted to circumvent the limited in vivo activity and systemic toxicity of TCM ingredients by incorporation into nanoparticle-based delivery systems. Many of these formulations demonstrate improved bioavailability, enhanced tissue targeting, and greater in vivo stability compared to the native compound. This review summarizes nanoformulations of the most promising and extensively studied TCM compounds to provide a reference for further research. Combining these natural compounds with nanotechnology-based delivery systems may further improve the clinical utility of these agents, in turn leading to more intensive research on traditional medicinal compounds.

Puerarin alleviates osteoporosis in the ovariectomy-induced mice by suppressing osteoclastogenesis via inhibition of TRAF6/ROS-dependent MAPK/NF-κB signaling pathways

In this study, we investigated the mechanisms by which puerarin alleviates osteoclast-related loss of bone mass in ovariectomy (OVX)-induced osteoporosis model mice. Puerarin-treated OVX mice exhibited higher bone density, fewer tartrate-resistant acid phosphatase (TRAcP)-positive osteoclasts, and levels of lower reactive oxygen species (ROS) within bone tissues than vehicle-treated OVX mice. Puerarin suppressed in vitro osteoclast differentiation, hydroxyapatite resorption activity, and expression of osteoclastogenesis-related genes, such as NFATc1, MMP9, CTSK, Acp5 and c-Fos, in RANKL-induced bone marrow macrophages (BMMs) and RAW264.7 cells. It also reduced intracellular ROS levels by suppressing expression of TRAF6 and NADPH oxidase 1 (NOX1) and increasing expression of antioxidant enzymes such as heme oxygenase-1 (HO-1). Puerarin inhibited TRAF6/ROS-dependent activation of the MAPK and NF-κB signaling pathways in RANKL-induced RAW264.7 cells, and these effects were partially reversed by HO-1 silencing or TRAF6 overexpression. These findings suggest puerarin alleviates loss of bone mass in the OVX-model mice by suppressing osteoclastogenesis via inhibition of the TRAF6/ROS-dependent MAPK/NF-κB signaling pathway.

Preparation of parenteral nanocrystal suspensions of etoposide from the excipient free dry state of the drug to enhance in vivo antitumoral properties

Nanoparticle technology in cancer chemotherapy is a promising approach to enhance active ingredient pharmacology and pharmacodynamics. Indeed, drug nanoparticles display various assets such as extended blood lifespan, high drug loading and reduced cytotoxicity leading to better drug compliance. In this context, organic nanocrystal suspensions for pharmaceutical use have been developed in the past ten years. Nanocrystals offer new possibilities by combining the nanoformulation features with the properties of solid dispersed therapeutic ingredients including (i) high loading of the active ingredient, (ii) its bioavailability improvement, and (iii) reduced drug systemic cytotoxicity. However, surprisingly, no antitumoral drug has been marketed as a nanocrystal suspension until now. Etoposide, which is largely used as an anti-cancerous agent against testicular, ovarian, small cell lung, colon and breast cancer in its liquid dosage form, has been selected to develop injectable nanocrystal suspensions designed to be transferred to the clinic. The aim of the present work is to provide optimized formulations for nanostructured etoposide solutions and validate by means of in vitro and in vivo evaluations the efficiency of this multiphase system. Indeed, the etoposide formulated as a nanosuspension by a bottom-up approach showed higher blood life span, reduced tumor growth and higher tolerance in a murine carcinoma cancer model. The results obtained are promising for future clinical evaluation of these etoposide nanosuspensions.

Development of Polymer and Surfactant Based Naringenin Nanosuspension for Improvement of Stability, Antioxidant, and Antitumour Activity

Nanosuspensions are widely reported to enhance the solubility of poorly soluble drugs. In addition to enhancement in solubility, improvement of stability and therapeutic efficacy would be an added advantage. In the present study, premilling and subsequent high-pressure homogenization were carried out to produce naringenin nanosuspension. Hydroxypropyl methylcellulose and sodium dodecyl sulfate were evaluated for their performance as stabilizers under various homogenization cycles. The prepared nanosuspensions were studied for average particle size and size distribution, zeta potential, solubility, drug release, antioxidant activity, and in vitro antitumor activity. It was observed that both hydroxypropyl methylcellulose-stabilized nanosuspension and sodium dodecyl sulfate-stabilized nanosuspension produced an enhancement in physical stability, antioxidant potential, and in vitro cytotoxicity compared with naringenin. Furthermore, hydroxypropyl methylcellulose-stabilized nanosuspension was found to be better than sodium dodecyl sulfate-stabilized nanosuspension in terms of particle size and size distribution, storage stability, and drug release. This study showed that nanosuspension formulations could be a potential strategy for improving dissolution and antitumor activity of naringenin.

A Critical Review on Anticancer Mechanisms of Natural Flavonoid Puerarin

Cancer is one of the prominent global causes of death and the foremost worldwide health concern. Despite unprecedented progress in cancer chemoprevention, a vast number of cancers, however, remain an undefeatable challenge for treatment modalities. Immense therapeutic activities of puerarin contribute to its use in various health disorders. In this review, we explored the potential molecular mechanisms and targets of puerarin, proving its potential as a novel anticancer agent, for future cancer therapy and chemoprevention. Several mechanisms account for anticancer activity of puerarin which includes downregulation of NF-kB signalling pathway, mTOR signalling pathway, PI3K and BCl-2 proteins and upregulation of miR-16, caspase proteins, c- Jun N terminal kinase and extracellular signal-regulated kinase 1/2. These alterations result in inhibition of cancer cell proliferation and/or induction of apoptosis. Understanding the molecular mechanisms involved in chemotherapy and chemoprevention could aid in the more pronounced exploration of puerarin in effective cancer treatment.

Enhancing Betulinic Acid Dissolution Rate and Improving Antitumor Activity via Nanosuspension Constructed by Anti-Solvent Technique

Purpose

The aim of this study was to prepare and evaluate betulinic acid nanosuspension (BA-NS) for new drug delivery to enhance its solubility and in vitro anti-tumor activity.

Methods

BA-NS was formulated by an anti-solvent precipitation method using the Box-Behnken design (BBD). Particle size (PS) and Zeta potential were measured by laser particle size analysis. The drug solid state after freeze drying was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FTIR) after freeze drying. The saturation solubility and dissolution rate were determined by solubility assay and in vitro dissolution studies, respectively. The in vitro cytotoxicity assay was performed using 3-(4,5-dimethylthiazole)-2,5-diphenltetraazolium bromide (MTT) method.

Results

The PS was 129.7±12.2 nm having a Zeta potential of −28.1±4.5 mV and the polydispersity index (PDI) was 0.231±0.013, which confirmed that the nanosuspension was in the stable amorphous state. A series of characterization experiments demonstrated that nanoparticles retained original effective structure and existed as spherical or near-spherical nanoparticles in the nanosuspension, but the drug transferred from the crystal state to the amorphous state. The form of lyophilized BA-NS was very successful in enhancing the dissolution rate in PH-dependent way. The cytotoxicity assay revealed that BA-NS could significantly enhance the in vitro anti-proliferation against tumor cells compared to the BA suspension (BA-S).

Conclusion

The BA-NS can remarkably improve solubility and in vitro antitumor activity, which seems very promising for the treatment of cancers in practical application.

Colon-specific microspheres loaded with puerarin reduce tumorigenesis and metastasis in colitis-associated colorectal cancer

Colitis-associated colorectal cancer (CAC) is a common malignancy that develops in chronically inflamed mucosa and is usually accompanied by metastases at other sites. Puerarin, a natural isoflavone isolated from the root of the Pueraria lobata (Willd.) Ohwi, has potential anti-colon cancer activity. However, the poor solubility and low bioavailability of puerarin has restricted its application in the pharmaceutical industry. In the present study, pH-responsive alginate microspheres loaded with puerarin were prepared by emulsification/internal gelation for targeted treatment of colitis-associated colorectal cancer. Herein, puerarin, as an active drug, could participate in the construction of alginate microspheres with hydrogen bonding. The microspheres exhibited pH-responsive release behavior with little release of puerarin in simulated gastric fluid and high amounts (approximately 55%) of release in simulated colonic fluid. A fluorescence tracer indicated microspheres had high retention time of more than 20 h in the colon. Meanwhile, puerarin-loaded alginate microspheres not only significantly decreased the inflammatory response by downregulating the levels of pro-tumorigenic cytokines, but they reduced tumorigenesis and metastasis by inhibiting epithelial-mesenchymal transitions in AOM/DSS-induced colitis-associated colorectal cancer in mice. The overall results suggested that puerarin-loaded alginate microspheres could effectively inhibit development of colonic tumors, which could be developed as a promising therapeutic strategy for colitis-associated colorectal cancer.

Bioavailability Enhancement of Poorly Soluble Drugs: The Holy Grail in Pharma Industry

Background:

Bioavailability, one of the prime pharmacokinetic properties of a drug, is defined as the fraction of an administered dose of unchanged drug that reaches the systemic circulation and is used to describe the systemic availability of a drug. Bioavailability assessment is imperative in order to demonstrate whether the drug attains the desirable systemic exposure for effective therapy. In recent years, bioavailability has become the subject of importance in drug discovery and development studies.

Methods:

A systematic literature review in the field of bioavailability and the approaches towards its enhancement have been comprehensively done, purely focusing upon recent papers. The data mining was performed using databases like PubMed, Science Direct and general Google searches and the collected data was exhaustively studied and summarized in a generalized manner.

Results:

The main prospect of this review was to generate a comprehensive one-stop summary of the numerous available approaches and their pharmaceutical applications in improving the stability concerns, physicochemical and mechanical properties of the poorly water-soluble drugs which directly or indirectly augment their bioavailability.

Conclusion:

The use of novel methods, including but not limited to, nano-based formulations, bio-enhancers, solid dispersions, lipid-and polymer-based formulations which provide a wide range of applications not only increases the solubility and permeability of the poorly bioavailable drugs but also improves their stability, and targeting efficacy. Although, these methods have drastically changed the pharmaceutical industry demand for the newer potential methods with better outcomes in the field of pharmaceutical science to formulate various dosage forms with adequate systemic availability and improved patient compliance, further research is required.

Intranasal Zotepine Nanosuspension: intended for improved brain distribution in rats

BACKGROUND

Zotepine (ZTP), an antipsychotic drug is well tolerated and particularly effective for treating negative symptoms of psychosis. But is limited by low oral bioavailability caused by substantial first pass metabolism and thereby less amount of drug reaches the brain due to blood brain barrier (BBB).

OBJECTIVES

Since ZTP displays dose dependent side effects, purpose of the contemporary study is to develop zotepine loaded nanosuspension (ZTP-NS) for increased brain targeting in rats at lower doses.

METHODS

ZTP-NS is prepared by two techniques viz., sonoprecipitation (SP) and combination technique (high pressure homogenization preceded by precipitation) by employing various stabilizers. Optimized ZTP-NS was characterized for particle size, solid state, morphology and solubility. In vitro drug release of ZTP and formulations was conducted using Franz diffusion cell. Stability study was performed at different temperature conditions. Pharmacokinetic study was performed in Wistar rats to determine the bioavailability and brain distribution of ZTP after intra-nasal (IN) and intravenous (IV) administration. Histopathology of brain was done after repeated administration of IN ZTP dispersion and NS up to 14 days.

RESULTS

The optimized ZTP-NS formulated with Pluronic F-127 (0.3%w/v), Hydroxypropyl methyl cellulose E15 (0.3%w/v) and soya lecithin (0.4%w/v) showed particle size of 519.26 ± 10.44 nm & 330.2 ± 12.90 nm and zeta potential of -21.7 ± 1.39 mV and - 18.26 ± 1.64 mV with sonoprecipitation and combination technique respectively. In vitro drug release was high (81.79 ± 3.23%) for ZTP-NS prepared by combination technique. Intranasal NS resulted in high brain concentrations of 8.6 fold (sonoprecipitation) and 10.79-fold hike in AUC_0-24h in contrast to intravenous ZTP solution. Histopathology results reveal no significant changes in brain microscopic images.

CONCLUSION

ZTP-NS was successfully developed, characterized and found that nanosuspension is a favorable approach for intranasal delivery of zotepine. Graphical abstract Graphical abstract representing zotepine drawbacks, nanosuspension preparation, characterization and pharmacokinetic study in rats.

Construction of C-glycosides of heterocycles containing the pyrimidin-2-amine or the 1H-pyrazolo[3,4-b]pyridine moiety and their biological evaluation for anticancer activities

A series of novel C-glycosides of heterocyclic derivatives containing a pyrimidin-2-amine or a 1 H-pyrazolo[3,4- b]pyridine moiety were synthesized using condensation reactions of the substituted puerarin with guanidine or 3-amino-5-hydroxypyrazole in methyl alcohol. Their chemical structures were characterized by Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and high-resolution mass spectrometry. In addition, their biological activity has been demonstrated by in vitro evaluation against the human leukemia cells K562 and human prostate cancer cells PC-3 by MTT-based assays, using the commercially available standard drug of cis-platin as a positive control. The results also demonstrated that most of the compounds showed considerable cytotoxicity to these two cell lines of K562 and PC-3, and indicated that novel C-glycosides of heterocyclic derivatives may be potential leads for further biological screenings and may generate drug-like molecules.

Formulation and evaluation of docetaxel nanosuspensions: In-vitro evaluation and cytotoxicity

OBJECTIVE

The aim of the present study was to formulate the anticancer drug; docetaxel (DOX) as nanoparticles to enhance its biological activity.

METHODOLOGY

Solvent precipitation method was used to prepare DOX-loaded nanoparticles and was stabilized by different concentrations of hydroxypropyl methylcellulose (HPMC, E5) and sodium deoxycholate (SDC).

RESULTS

The results showed that the particle size of the prepared DOX nanoparticles stabilized by SDC was small in comparison to those stabilized by the corresponding HPMC concentrations. The smallest particle size (83.97 nm) was obtained by using SDC as stabilizer at 5% level with zeta potential of -13.6 mV. It was concluded that increasing the stabilizer concentration resulted in increase in both initial and overall cumulative drug release. The release rate in case of nanoparticles stabilized by 5% SDC was 33% and 87% after 1 and 24 h respectively. The results showed that a significant reduction in the viability of FRO cells was observed at all tested time intervals in case of nanoparticles stabilized by 5% SDC at concentrations of 100 and 1000 μM/ml. In contrast, no signs of cytotoxicity was observed for nanoparticles stabilized by 5% HPMC at 10 and 100 μM/ml concentrations.

Effects of three flavonoids from an ancient traditional Chinese medicine Radix puerariae on geriatric diseases

As the worldwide population ages, the morbidity of neurodegenerative, cardiovascular, cerebrovascular, and endocrine diseases, such as diabetes and osteoporosis, continues to increase. The etiology of geriatric diseases is complex, involving the interaction of genes and the environment, which makes effective treatment challenging. Traditional Chinese medicine, unlike Western medicine, uses diverse bioactive ingredients to target multiple signaling pathways in geriatric diseases. Radix puerariae is one of the most widely used ancient traditional Chinese medicines and is also consumed as food. This review summarizes the evidence from in vivo and in vitro studies of the pharmacological effects of the main active components of the tuber of Radix puerariae on geriatric diseases.

Effects and mechanism of puerarin on the human retinoblastoma cells

Puerarin is an isoflavonoid that is extracted from Kudzu root and is considered to have an anti-tumor effect. In the present study, the effects of puerarin on human retinoblastoma (RB) cells and the related pathways was determined. The retinoblastoma RB cell lines were used in this study. Cell viability and colony formation capacity were measured by MTT and colony formation assays. Cell cycle was determined by flow cytometry. Cell migration and invasion were examined by Transwell assay. The expression of cell cycle, EMT, and MAPK/ERK signal pathway-related proteins were detected by western blot following puerarin treatment. The results revealed that cell viability and proliferation of RB cells treated with puerarin were significantly lower in RB cells compared to the control group. Puerarin significantly decreased the proportion of cells during S phase which was accompanied with increase in cells at G0/1 and G2 phases. Moreover, puerarin suppressed cell migration, invasion and up-regulated E-Cadherin expression as well as down-regulated Vimentin and α-SMA expression. Furthermore, puerarin treatment suppressed the expression of p-MEK and p-ERK in RB cells. Our findings suggest that puerarin contributes to in the treatment of RB and other malignant tumors.

Puerarin Inhibits Proliferation and Induces Apoptosis by Upregulation of miR-16 in Bladder Cancer Cell Line T24

Bladder cancer (BC) is a common disease of the urinary system. Puerarin is a flavonoid extracted from Pueraria lobata. However, the role of puerarin in BC remains unclear. Hence, this study aimed to investigate the effect of puerarin on BC cells. Cell viability, proliferation, and apoptosis were measured by CCK-8, BrdU assay, and flow cytometry analysis, respectively. The expressions of miR-16, apoptosis-related factors, and the main factors of the NF-κB pathway were analyzed by qRT-PCR and Western blot. In this study, we found that cell viability and proliferation were significantly reduced, cell apoptosis was enhanced, and the mRNA level of miR-16 was upregulated in puerarin-treated T24 cells. Further, silencing of miR-16 inhibited the decrease in cell viability and the increase in apoptosis. The expression of main factors involved in the NF-κB signaling pathway was downregulated in the puerarin group, while miR-16 silencing alleviated these downregulations. More importantly, puerarin deactivated the NF-κB signaling pathway via upregulation of miR-16. Also, miR-16 downregulated COX-2 expression via deactivation of the NF-κB signaling pathway. This study demonstrated that puerarin could inhibit cell proliferation, promote cell apoptosis, and deactivate NF-κB signaling pathway via upregulation of miR-16 in T24 cells.

Puerarin Suppresses Na+-K+-ATPase-Mediated Systemic Inflammation and CD36 Expression, and Alleviates Cardiac Lipotoxicity In Vitro and In Vivo

Puerarin, a type of isoflavone, was shown to have multiple protective effects on myocardial injury. The objective of this study was to investigate the role of puerarin in the progression of lipotoxic cardiomyopathy. Primary cardiomyocytes were isolated from FATP1 transgenic (Tg) mice with lipotoxic cardiomyopathy, and various concentrations of puerarin were used to incubate with the cardiomyocytes. Our results showed low-dose puerarin (≤20 μM) treatment increased the cell viability and decreased the accumulation of free fatty acid (FFA). The data on enzyme-linked immunosorbent assay indicated that 15 μM puerarin treatment greatly increased Na-K-ATPase activity and decreased C-reactive protein secretion, thus suppressing the expression of CD36, a key contributor to the FFA accumulation. Additionally, low-dose puerarin (≤100 mg/kg body weight) administration improved Na-K-ATPase activity. Our data on serum analysis and histological detection in vivo indicated that systemic inflammation, CD36-induced lipid infiltration, and cardiomyocyte apoptosis were markedly alleviated in Tg mice injected with 90 mg/kg dose of puerarin. Finally, the uptake rates of H-palmitate and C-glucose were monitored on ex vivo working hearts that were obtained from wild-type (WT), Tg-control, and Tg-puerarin mice. Compared with WT hearts, Tg hearts displayed a significant decrease in Na/K-ATPase activity and glucose consumption rate and an increase in palmitate uptake rate and FFA accumulation. In Tg-puerarin hearts, Na/K-ATPase activity and glucose consumption rate were significantly rescued, and palmitate uptake and FFA accumulation were sharply suppressed. In conclusion, low-dose puerarin suppressed Na-K-ATPase-mediated CD36 expression and systemic inflammation and alleviated cardiac lipotoxicity in vitro and in vivo.

Drug nanocrystals for cancer therapy

Drug nanocrystals (NCs) with fascinating physicochemical properties have attracted great attention in drug delivery. High drug-loading efficiency, great structural stability, steady dissolution, and long circulation time are a few examples of these properties, which makes drug NCs an excellent formulation for efficient cancer therapy. In the last two decades, there are a lot of hydrophobic or lipophilic drugs, such as paclitaxel (PTX), camptothecin (CPT), thymectacin, busulfan, cyclosporin A, 2-devinyl-2-(1-hexyloxyethyl) pyropheophorbide (HPPH), and so on, which have been formulated into drug NCs for cancer therapy. In this review, we summarized the recent advances in drug NCs-based cancer treatment. So far, there are main three methods to synthesize drug NCs, including top-down, bottom-up, and combination methods. The characterization methods of drug NCs were also elaborated. Furthermore, the applications and mechanisms of drug NCs were introduced by their administration routes. At the end, we gave a brief conclusion and discussed the future perspectives of drug NCs in cancer therapy. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Cytotoxic and chemosensitization effects of Scutellarin from traditional Chinese herb Scutellaria altissima L. in human prostate cancer cells

Scutellaria altissima L. is a common traditional Chinese medicine used to treat inflammation in some countries. Scutellarin, an active major flavone glycoside isolated from the traditional Chinese medicine Scutellaria altissima L., has been shown to offer various beneficial biochemical effects on cerebrovascular diseases and inflammation. However, the antiproliferative effects of Scutellarin in prostate cancer and the underlying mechanism are not fully elucidated. In the present study, we aimed to ascertain whether Scutellarin inhibits cancer cell growth and to further explore the molecular mechanism. Scutellarin enhanced the sensitivity of prostate cancer cells to cisplatin. MTT assays revealed that cell viability was significantly decreased in the prostate cancer cells treated with Scutellarin. Flow cytometric analysis indicated that Scutellarin suppressed cell proliferation by promoting G2/M arrest and inducing apoptosis. We employed western blotting to delineate the underlying mechanisms involved in the G2/M arrest and apoptosis. Comet assay and γH2AX immunocytochemistry were used to detect levels of DNA damage in PC3 cells exposed to Scutellarin and/or cisplatin. Our data revealed that Scutellarin significantly induced prostate cancer cell apoptosis by activating the caspase cascade. An increase in the Bax/Bcl-2 ratio, depolarization of mitochondrial membrane potential and cell cycle arrest at G2/M phase were accompanied by the apoptosis induction. Additionally, Scutellarin altered the protein expression of cell cycle and apoptosis regulatory genes by downregulating Cdc2, cyclin B1 and Bcl-2 and upregulating caspase-3, caspase-9 and Bax in prostate cancer cells. Furthermore, Scutellarin sensitized PC3 cells to cisplastin treatment in a dose-dependent manner. Taken together, our data confirmed the cytotoxicity of Scutellarin against prostate cancer PC3 cells and provide new findings in regards to Scutellarin sensitizing prostate cancer cells to chemotherapy. Our findings suggest that Scutellarin has potential to be used as a novel antineoplastic therapeutic candidate for prostate cancer patients.

Effects of puerarin on intracellular Ca2+ and cell viability of MDCK renal tubular cells

Puerarin is a natural compound and has been used as herb medication in a number of countries, especially in Asia. The effect of puerarin on Ca²⁺ signaling is unknown in renal cells. This study examined whether puerarin affected Ca²⁺ physiology in MDCK renal tubular cells. Cytosolic free Ca²⁺ levels ([Ca²⁺]_i) were measured using the fluorescent dye fura-2. Cell viability was examined by using WST-1 assay. Puerarin induced [Ca²⁺]_i rises and the response was reduced by removing extracellular Ca²⁺. Puerarin-induced Ca²⁺ entry was not altered by protein kinase C (PKC) activity, but was inhibited by nifedipine. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) or thapsigargin partly inhibited puerarin-evoked [Ca²⁺]_i rises. Inhibition of phospholipase C (PLC) with U73122 did not change puerarin-induced [Ca²⁺]_i rises. Puerarin at 25-50μM caused cytotoxicity, which was not reversed by pretreatment with the Ca²⁺ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Collectively, in MDCK cells, puerarin induced [Ca²⁺]_i rises by evoking PLC-independent Ca²⁺ release from the endoplasmic reticulum and other unknown stores, and Ca²⁺ entry via nifedipine-sensitive, PKC-insensitive Ca²⁺ entry pathways. Puerarin also caused Ca²⁺-independent cell death.

Puerarin attenuates cisplatin-induced rat nephrotoxicity: The involvement of TLR4/NF-κB signaling pathway

Puerarin was a major isoflavonoid derived from the Chinese medical herb radix puerariae (Gegen). In present study effect of puerarin on cisplatin nephrotoxicity was evaluated. Rat model of nephrotoxicity was established by a single intraperitoneal injection of cisplatin (7mg/kg). Puerarin was administrated through caudal vein injection once per day at the dose of 10mg/kg, 30mg/kg and 50mg/kg. Biochemical assays showed that after cisplatin treatment the serum urea and creatinine increased significantly compared with control (P<0.05). Cisplatin treatment significantly increased xanthine oxidase (XO) activity and malondialdehyde (MDA) formation, and significantly decreased the levels and /or activities of enzymatic and non-enzymatic antioxidants (GSH, GPx, GST, GR, SOD, CAT), in the kidney tissues. Renal levels of TNF-α and IL-6, two important inflammatory cytokines, were also upregulated by cisplatin. Histopathological examination indicated that cisplatin treatment resulted in severe necrosis and degeneration, hyaline casts in the tubules, intertubular hemorrhage, congestion and swelling in glomerulus and leukocytes infiltration in the kidney tissues. Western blot results demonstrated that cisplatin increased TLR4 and NF-κB protein expression in the kidney tissues. However, all these changes induced by cisplatin were significantly attenuated by puerarin treatment in dose-dependent manner, which indicated the renal protective effect of puerarin. Cell culture experiments illustrated that puerarin alone treatment concentration-dependently inhibited COLO205 and HeLa tumor cell growth and dose-dependently promoted the antitumor activity of cisplatin in COLO205 and HeLa tumor cells. The promotion effects might be attributed to suppression of cisplatin-increased NF-κB p65 expression by puerarin. Taken together, findings in this study suggested that puerarin exhibited renal protection against cisplatin nephrotoxicity via inhibiting TLR4/NF-κB signaling, with no inhibition but promotion effect on the antitumor activity of cisplatin. Puerarin might be a promising adjuvant agent for cisplatin chemotherapy.

A Novel Microspheres Formulation of Puerarin: Pharmacokinetics Study and In Vivo Pharmacodynamics Evaluations

The aim of this study was to investigate the pharmacokinetics and pharmacodynamics of puerarin loaded carboxymethyl chitosan microspheres (Pue-CCMs). The differences in pharmacokinetics parameters of rats after intragastric administration of Pue-CCMs and puerarin were investigated using HPLC. To assess the protective effect of Pue-CCMs on myocardial injury in rats, serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), total superoxide dismutase (T-SOD), and malondialdehyde (MDA) were measured, in addition to pathological examinations and immunohistochemical staining. Our present study has shown that the AUC_0–t, C_max, T_max, MRT_0–t of Pue-CCMs, and puerarin were 20.176 mg·h/L, 3.778 μg/mL, 1 h, 4.634 h and 9.474 mg·h/L, 2.618 μg/mL, 0.542 h, and 3.241 h, respectively. Pue-CCMs alleviated myocardial ischemic injury. Pretreatment with Pue-CCMs could significantly decrease CK, LDH, and MDA levels and increase T-SOD level in the serum. Pue-CCMs downregulated expression of the Bcl-2 associated X protein (Bax) and upregulated B-cell lymphoma-2 (Bcl-2) expression. Compared with puerarin group, the Pue-CCMs group could improve the oral bioavailability of puerarin. The protective effect of Pue-CCMs against myocardial injury was significantly greater than puerarin at the same dose. In summary, Pue-CCMs should be a qualified and promising candidate as a new oral preparation of puerarin.

Preparation and In Vitro/In Vivo Evaluation of Puerarin Solid Self-Microemulsifying Drug Delivery System by Spherical Crystallization Technique

The aim of this work was to establish a method for preparing stable and controllable solid self-microemulsifying drug delivery system (S-SMEDDS) by spherical crystallization technique, which was explored for promoting the dissolution, oral bioavailability, and process efficiency. Solubility test, preparation of liquid self-microemulsifying drug delivery system (L-SMEDDS), and the obtained ternary phase diagrams test have been performed to screen and optimize the composition of LSMEDDS. The optimized formulation was used to prepare puerarin solid self-microemulsifying drug delivery system (Pue-SSMEDDS) by spherical crystallization technique. Droplet size and morphological analysis of the optimal Pue-SSMEDDS were determined to evaluate the final formulation. And the Pue-SSMEDDS was also assessed by flowability study, angle of repose, Carr's index, and flow velocity. Furthermore, the vitro dissolution and pharmacokinetic profile in vivo were analyzed. The study in vitro showed the Pue-SSMEDDS could disperse in the dispersion medium within 60 s and was spherical with the particle size of 19.66 nm and zeta potential of -28.3 mV. It could keep stable at low temperature and seal condition for 3 months. In vivo pharmacokinetic experiments of rats, the mean plasma concentration of self-microemulsion group was much higher than that of conventional tablets and could play a long-lasting efficacy, while there was no significant difference between the LSMEDDS and S-SMEDDS. The results suggested the potential of S-SMEDDS could improve the oral bioavailability of poorly water-soluble drug, such as puerarin.

A recent trend of drug-nanoparticles in suspension for the application in drug delivery

Persistent development in nanomedicine has enabled successful nanosizing of most drug samples which, in turn, imparts remarkable properties to the drugs such as enhanced solubility and bioavailability for the applications in drug delivery. In this context, several review articles are available in scientific domain covering inorganic nanoparticles such as Au, Ag, SPIONs, Qdots, carbon nanotubes and graphene; however, this review covers the development of drug nanoparticles together with their possibilities and limitation from fabrication (bottom up vs top down) to application in drug delivery during the last 5 years. In addition, some distinguished studies and novel drug particles are presented in order to contribute significantly toward the understanding of drug nanocrystals and its use in drug delivery.

Safety of nanosuspensions in drug delivery

Nanosuspension technology is currently undergoing dramatic expansion in pharmaceutical science research and development. However, most of the research efforts generally focus on formulation and potential beneficial description, while the research into potential toxicological effects and implications (i.e., in vivo safety and health effects) is lacking. This review identifies some of the key factors for studying nanosuspension safety and the potential undesired effects related to nanosuspension exposure. The key factors for discussion herein include particle characterization, preparation approach, composition, and excipients of the formulation and sterilization methods. A few comments on the primary and required safety aspects of each administration route are also reviewed.

Preparation, characterization and bioavailability of oral puerarin nanoparticles by emulsion solvent evaporation method

In this paper, puerarin (PUE) was nanocrystallized by emulsion solvent evaporation (ESE) method, followed by freeze-drying. The solubility, dissolution rate and oral bioavailability of PUENs were significantly improved compared with raw PUE.

Polymeric nanoparticles for colon cancer therapy: overview and perspectives

Colorectal cancer (CRC) is the third-most common malignant tumour and is associated with high morbidity and mortality worldwide.

Developing nanocrystals for cancer treatment

Nanocrystals are carrier-free solid drug particles that are sized in the nanometer range and have crystalline characteristics. Due to high drug loading (as high as 100%) - free of organic solvents or solubilizing chemicals - nanocrystals have become attractive in the field of drug delivery for cancer treatment. Top-down and bottom-up approaches have been developed for preparing anticancer nanocrystals. In this review, preparation methods and in vivo performance of anticancer nanocrystals are discussed first, followed by an introduction of hybrid nanocrystals in cancer theranostics.

The construction of puerarin nanocrystals and its pharmacokinetic and in vivo-in vitro correlation (IVIVC) studies on beagle dog

Puerarin is widely used in clinics in China as a therapeutic agent for cardiovascular diseases by intravenous administration. Adverse drug reactions caused by cosolvents often increase the patients' treatment burden (high drug costs and low compliance). The development of oral formulation is urgently needed and nanocrystal technique has become a preferred way to develop oral dosage form, nowadays. In this study, high pressure homogenization (HPH) was employed to prepare puerarin nanocrystals by employing SDS as the stabilizer, and redispersibility of the nanocrystals powder was also studied. The nanocrystals prepared was characterized using DLS, DSC, XRD and SEM. A preferred in vivo-in vitro correlation was also established in this study. Pharmacokinetic studies on beagle dog showed that comparing to raw puerarin powder, both of the Cmax and AUC of puerarin nanocrystals were enhanced. From the above results, we can conclude that nanocrystal technique is an efficient technology to improve the oral bioavailability of puerarin.

Enrichment and separation of antitumor triterpene acids from the epidermis of Poria cocos by pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography

Triterpene acids were extracted from the epidermis of Poria cocos (Schw.) Wolf. These acids were found to inhibit the growth of lung cancer cells in vitro and in vivo. An efficient method for the preparative separation of antitumor triterpene acids was established that involves the combination of pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography. We used pH-zone-refining counter-current chromatography to concentrate the triterpene acids using a two-phase solvent system composed of petroleum ether/ethyl acetate/methanol/water (3:7:5:5, v/v/v/v), trifluoroacetic acid (10 mM) was added to the upper phase as a retainer, and ammonia (10 mM) was added to the lower phase as an eluter. As a result, 200 mg concentrate of triterpene acids was obtained from 1.0 g of crude extract. The concentrate was further separated by conventional high-speed counter-current chromatography using a solvent system composed of petroleum ether/ethyl acetate/methanol/water (0.8:1.2:1.2:0.9, v/v), yielding 50 mg of poricoic acid A and 5 mg of poricoic acid B from 120 mg concentrate, respectively. The inhibitory activity of the major compound on lung A549 cells was examined and poricoic acid A was found to significantly inhibit the growth of A 549 cells.