A validated liquid chromatography-tandem mass spectrometry method for the determination of methyl gallate and pentagalloyl glucopyranose: application to pharmacokinetic studies

A novel nanocarrier based on natural polyphenols enhancing gemcitabine sensitization ability for improved pancreatic cancer therapy efficiency

Pancreatic cancer (PC) is a highly lethal malignancy with rapid progression and poor prognosis. Despite the widespread use of gemcitabine (Gem)-based chemotherapy as the first-line treatment for PC, its efficacy is often compromised by significant drug resistance. 1,2,3,4,6-Pentagaloyl glucose (PGG), a natural polyphenol, has demonstrated potential in sensitizing PC cells to Gem. However, its clinical application is limited by poor water solubility and bioavailability. In this study, we developed a novel PGG-based nanocarrier (FP) using a straightforward, one-step self-assembly method with Pluronic F127 and PGG. Our results showed that FP induced DNA damage and immunogenic cell death (ICD) in both in vitro cell experiments and patient-derived organoid models, exhibiting potent anti-tumor effects. Furthermore, in mouse KPC and PDX models, FP, when combined with Gem, showed enhanced Gem sensitization compared to pure PGG, largely due to increased DNA damage and ICD induction. These findings demonstrate the potential of FP to improve the stability and utilization of PGG as effective Gem sensitizers in the treatment of pancreatic cancer, providing a promising pathway for clinical application and translational research.

Terminalia bellirica (Gaertn.) Roxb. Extracts reshape the perifollicular microenvironment and regulate the MAPK pathway for androgenetic alopecia treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia bellirica (Gaertn.) Roxb. (TBR), a popular herbal remedy in India and Southeast Asia, has been demonstrated to possess multiple pharmacological activities. However, systematic studies on the medicinal effects and mechanism of TBR for the androgenetic alopecia (AGA) treatment are deficient.

MATERIALS AND METHODS

Human Umbilical Vein Endothelial Cells (HUVECs) and testosterone-induced AGA mice were used to evaluate the hair regrowth activity of TBR extracts. Chemical constituents and potential active components of TBR extracts were analyed by UPLC-Q-TOF-MS in vitro/vivo. The hair regrowth mechanisms of TBR were elucidated through network pharmacology and experimental validation.

RESULTS

Totally 28 chemical constituents in TBR were identified, of which 15 were predicted as potential active components for AGA therapy. TBR could significantly scavenge ROS, promote VEGF level/cell migration of HUVECs, and inhibiting type II 5α-reductase activity (the inhibit rate: 82.35 ± 1.02 %). Pharmacodynamic evaluation suggested that TBR effectively led to hair regrowth in C57BL6 mice compared to minoxidil. TBR promoted the hair follicle (HF) transition from the telogen phase to anagen phase by decreasing MDA levels, increasing VEFG expression and up-regulating phosphorylated P38/ERK protein levels in the MAPK signalling pathway.

CONCLUSIONS

TBR reversed AGA via inhibiting SRD5A2 activity and stimulating the MAPK pathway. Meantime, TBR could remodel the follicle microenvironment by reducing oxidative stress and increasing angiogenesis.

Targeting UBE2T suppresses breast cancer stemness through CBX6-mediated transcriptional repression of SOX2 and NANOG

Breast cancer stem cells (BCSCs) are the main cause of breast cancer recurrence and metastasis. While the ubiquitin-proteasome system contributes to the regulation of BCSC stemness, the underlying mechanisms remain unclear. Here, we identified ubiquitin-conjugating enzyme E2T (UBE2T) as a pivotal ubiquitin enzyme regulating BCSC stemness through systemic screening assays, including single-cell RNA sequencing (scRNA-seq) and stemness-index analysis. We found that patients with high UBE2T expression exhibited worse prognosis than those with low expression (10-year PFS: 55.95 % vs. 85.08 %), which are consistent across various subtypes of breast cancers. Genetic ablation of UBE2T suppresses BCSC stemness and tumor progression in organoids and spontaneous MMTV-PyMT mice, dependent on the transcriptional inactivation of pluripotency genes SOX2 and NANOG. Mechanically, UBE2T collaborates with the E3 ligase TRIM25 to perform K48-linked polyubiquitination and degradation of CBX6 at K214, which deficiency helps to promote the transcription of SOX2 and NANOG and enhances BCSC stemness. The pharmacological inhibitor of UBE2T significantly reduced the expression of NANOG and SOX2, suppressed tumor progression, and demonstrated synergistic effects when combined with chemotherapeutics, but not with other treatments. Collectively, our study revealed that the UBE2T-TRIM25-CBX6 axis can regulate BCSC stemness and offers a potentially therapeutic strategy to combat breast cancer in a clinical translation setting.

Dual-Drug Nanomedicine Assembly with Synergistic Anti-Aneurysmal Effects via Inflammation Suppression and Extracellular Matrix Stabilization

Abdominal aortic aneurysm (AAA) represents a critical cardiovascular condition characterized by localized dilation of the abdominal aorta, carrying a significant risk of rupture and mortality. Current treatment options are limited, necessitating novel therapeutic approaches. This study investigates the potential of a pioneering nanodrug delivery system, RAP@PFB, in mitigating AAA progression. RAP@PFB integrates pentagalloyl glucose (PGG) and rapamycin (RAP) within a metal-organic-framework (MOF) structure through a facile assembly process, ensuring remarkable drug loading capacity and colloidal stability. The synergistic effects of PGG, a polyphenolic antioxidant, and RAP, an mTOR inhibitor, collectively regulate key players in AAA pathogenesis, such as macrophages and smooth muscle cells (SMCs). In macrophages, RAP@PFB efficiently scavenges various free radicals, suppresses inflammation, and promotes M1-to-M2 phenotype repolarization. In SMCs, it inhibits apoptosis and calcification, thereby stabilizing the extracellular matrix and reducing the risk of AAA rupture. Administered intravenously, RAP@PFB exhibits effective accumulation at the AAA site, demonstrating robust efficacy in reducing AAA progression through multiple mechanisms. Moreover, RAP@PFB demonstrates favorable biosafety profiles, supporting its potential translation into clinical applications for AAA therapy.

Optimization and Validation of Procyanidins Extraction and Phytochemical Profiling of Seven Herbal Matrices of Nutraceutical Interest

Several medicinal herbal plants are extensively used as sources of bioactive compounds with beneficial effects on human health. This study assessed the procyanidin and polyphenol profiles together with the antioxidant potential of seven herbal medical matrices. To achieve this aim, procyanidin extraction from grape pomace was optimized and validated by monitoring monomeric-trimeric procyanidins. The proposed quantification method was applied to the seven medical herbs, and it proved to be a very efficient protocol for procyanidin-rich extracts analysis. In addition, the Paullinia cupana Kunth. seed was identified as a very rich source of procyanidins (about 5 mg/g dry matrix of each dimeric and about 3 mg/g dry matrix trimeric) with high antioxidant properties. The polyphenolic profile was assessed by HPLC-HESI-MS/MS analysis. The in vitro antioxidant activity was evaluated by DPPH assay to explore the antioxidant properties of the extracts, which were substantially higher in Peumus boldus Molina leaves extracts (935.23 ± 169 μmol of Trolox equivalent/g of dry weight) concerning the other matrices. Moreover, a high Pearson coefficient value was observed between the total flavonoid content (TFC) and DPPH in comparison with the total polyphenol content (TPC) and DPPH, indicating flavonoids as the principal bioactive with antioxidant activity in the extracts.

Phytochemical profiling and neuroprotective activity of Callistemon subulatus leaves against cyclophosphamide-induced chemobrain

Cyclophosphamide (CPA) is a chemotherapeutic drug used for various types of cancers. However, patients receiving CPA for long periods suffer cognitive impairment associated with difficulties in learning, decreased concentration, and impaired memory. Chemotherapy-induced cognitive impairment, known as chemobrain, has been attributed to enhanced oxidative stress and inflammatory response. The current study aimed to identify the phytoconstituents of Callistemon subulatus extract (CSE) using HPLC-ESI/MS-MS analysis and evaluate its neuroprotective activity against CPA-induced chemobrain in rats. Fourteen compounds were identified following HPLC analysis including, five phlorglucinols, four flavonol glycosides, a triterpene, and a phenolic acid. Forty rats were divided into five groups treated for ten days as follows; group I (control group), group II received CPA (200 mg/kg, i.p.) on the 7th day, groups III and IV received CSE (200 and 400 mg/kg respectively, orally) for ten days and CPA (200 mg/kg, i.p.) on the 7th day, and group V received only CSE (400 mg/kg, orally) for ten days. The administration of CSE effectively ameliorated the deleterious effects of CPA on spatial and short-term memories, as evidenced by behavioral tests, Y-maze and passive avoidance. Such findings were further confirmed by histological examination. In addition, CSE counteracted the effect of CPA on hippocampal acetylcholinesterase (AChE) activity enhancing the level of acetylcholine. Owing to the CSE antioxidant properties, it hindered the CPA-induced redox imbalance, which is represented by decreased catalase and reduced glutathione levels, as well as enhanced lipid peroxidation. Therefore, CSE may be a promising natural candidate for protection against CPA-induced chemobrain in cancer patients.

Pentagalloyl Glucose-Targeted Inhibition of P-Glycoprotein and Re-Sensitization of Multidrug-Resistant Leukemic Cells (K562/ADR) to Doxorubicin: In Silico and Functional Studies

Combining phytochemicals with chemotherapeutic drugs has demonstrated the potential to surmount drug resistance. In this paper, we explore the efficacy of pentagalloyl glucose (PGG) in modulating P-gp and reversing multidrug resistance (MDR) in drug-resistant leukemic cells (K562/ADR). The cytotoxicity of PGG was evaluated using a CCK-8 assay, and cell apoptosis was assessed using flow cytometry. Western blotting was used to analyze protein expression levels. P-glycoprotein (P-gp) activity was evaluated by monitoring the kinetics of P-gp-mediated efflux of pirarubicin (THP). Finally, molecular docking, molecular dynamics simulation, and molecular mechanics with generalized Born and surface area solvation (MM-GBSA) calculation were conducted to investigate drug-protein interactions. We found that PGG selectively induced cytotoxicity in K562/ADR cells and enhanced sensitivity to doxorubicin (DOX), indicating its potential as a reversal agent. PGG reduced the expression of P-gp and its gene transcript levels. Additionally, PGG inhibited P-gp-mediated efflux and increased intracellular drug accumulation in drug-resistant cells. Molecular dynamics simulations and MM-GBSA calculation provided insights into the binding affinity of PGG to P-gp, suggesting that PGG binds tightly to both the substrate and the ATP binding sites of P-gp. These findings support the potential of PGG to target P-gp, reverse drug resistance, and enhance the efficacy of anticancer therapies.

Methyl gallate: Review of pharmacological activity

Methyl gallate (MG) is a polyphenolic compound widely found in natural plants. MG has been shown to have a variety of biological functions, including anti-tumor, anti-inflammatory, anti-oxidant, neuroprotective, hepatoprotective and anti-microbial activities, and has broad research and development prospects. A total of 88 articles related to MG were searched using the PubMed, Science Direct, and Google Scholar databases, systematically investigating the pharmacological activity and molecular mechanisms of MG. There were no restrictions on the publication years, and the last search was conducted on June 5, 2023. MG can exert pharmacological effects through multiple pathways and targets, such as PI3K/Akt, ERK1/2, Caspase, AMPK/NF-κB, Wnt/β-catenin, TLR4/NF-κB, MAPK, p53, NLRP3, ROS, EMT. According to the literature, MG has the potential to be a prospective adjuvant for anticancer therapy and deserves further study.

Pentagalloyl Glucose: A Review of Anticancer Properties, Molecular Targets, Mechanisms of Action, Pharmacokinetics, and Safety Profile

Pentagalloyl glucose (PGG) is a natural hydrolyzable gallotannin abundant in various plants and herbs. It has a broad range of biological activities, specifically anticancer activities, and numerous molecular targets. Despite multiple studies available on the pharmacological action of PGG, the molecular mechanisms underlying the anticancer effects of PGG are unclear. Here, we have critically reviewed the natural sources of PGG, its anticancer properties, and underlying mechanisms of action. We found that multiple natural sources of PGG are available, and the existing production technology is sufficient to produce large quantities of the required product. Three plants (or their parts) with maximum PGG content were Rhus chinensis Mill, Bouea macrophylla seed, and Mangifera indica kernel. PGG acts on multiple molecular targets and signaling pathways associated with the hallmarks of cancer to inhibit growth, angiogenesis, and metastasis of several cancers. Moreover, PGG can enhance the efficacy of chemotherapy and radiotherapy by modulating various cancer-associated pathways. Therefore, PGG can be used for treating different human cancers; nevertheless, the data on the pharmacokinetics and safety profile of PGG are limited, and further studies are essential to define the clinical use of PGG in cancer therapies.

Comparative Assessment of the Antioxidant and Anticancer Activities of Plicosepalus acacia and Plicosepalus curviflorus: Metabolomic Profiling and In Silico Studies

This study presents a comparison between two mistletoe plants—P. acacia and P. curviflorus—regarding their total phenolic contents and antioxidant and anticancer activities. P. curviflorus exhibited a higher total phenolics content (340.62 ± 19.46 mg GAE/g extract), and demonstrated higher DPPH free radical scavenging activity (IC₅₀ = 48.28 ± 3.41µg/mL), stronger reducing power (1.43 ± 0.54 mMol Fe⁺²/g) for ferric ions, and a greater total antioxidant capacity (41.89 ± 3.15 mg GAE/g) compared to P. acacia. The cytotoxic effects of P. acacia and P. curviflorus methanol extracts were examined on lung (A549), prostate (PC-3), ovarian (A2780) and breast (MDA-MB-231) cancer cells. The highest anticancer potential for the two extracts was observed on PC-3 prostate cancer cells, where P. curviflorus exhibited more pronounced antiproliferative activity (IC₅₀ = 25.83 μg/mL) than P. acacia (IC₅₀ = 34.12 μg/mL). In addition, both of the tested extracts arrested the cell cycle at the Pre-G1 and G1 phases, and induced apoptosis. However, P. curviflorus extract possessed the highest apoptotic effect, mediated by the upregulation of p53, Bax, and caspase-3, 8 and 9, and the downregulation of Bcl-2 expression. In the pursuit to link the chemical diversity of P. curviflorus with the exhibited bioactivities, its metabolomic profiling was achieved by the LC-ESI-TOF-MS/MS technique. This permitted the tentative identification of several phenolics—chiefly flavonoid derivatives, beside some triterpenes and sterols—in the P. curviflorus extract. Furthermore, all of the metabolites in P. curviflorus and P. acacia were inspected for their binding modes towards both CDK-2 and EGFR proteins using molecular docking studies in an attempt to understand the superiority of P. curviflorus over P. acacia regarding their antiproliferative effect on PC-3 cancer cells. Docking studies supported our experimental results; with all of this taken together, P. curviflorus could be regarded as a potential prospect for the development of chemotherapeutics for prostate cancer.

The attenuation of antibiotic resistant non-albicans Candida species, cytotoxicity, anti-inflammatory effects and phytochemical profiles of five Vachellia species by FTIR and UHPLC-Q/Orbitrap/MS

This work investigated the antifungal, cytotoxic and LPS-induced anti-inflammatory effects of five Vachellia species (V. karroo, V. kosiensis, V. sieberiana, V. tortalis and V. xanthophloea). The antifungal activity of the aqueous-methanolic extracts were performed using the broth dilution method against four non-albicans Candida species (C. glabrata, C. auris, C. tropicalis and C. parapsilosis). The cytotoxic and anti-inflammatory effects of the extracts were evaluated on African green monkey Vero kidney cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay and the 2ʹ,7ʹ-dichlorofluorescin diacetate (H₂DCF-DA) method. The fourier-transform infrared spectroscopy (FTIR) and Q Exactive plus orbitrap™ Ultra-high-performance liquid chromatography-mass spectrometer (UHPLC-MS) analysis was conducted to evaluate phytochemical constituents of the extracts. The plant extracts selected in this study displayed potency against the Candida species tested, with MIC values ≤0.62 mg/mL for V. karroo, V. kosiensis and V. xanthophloea. A dose-dependent cell viability was observed on Vero cells with all extracts showing LC₅₀ values >20 μg/mL. Extracts tested at 10 μg/mL elicited a significant decrease in lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) in Vero cells with V. sieberiana, V. tortilis, V. karroo, V. kosiensis and V. xanthophloea displaying inhibitory percentages of 35%, 32%, 55%, 52% and 49%, respectively. Characterisation of functional groups representing compounds in the extracts demonstrated the presence of different classes of compounds of the aliphatic, sugar and aromatic types. The Q Exactive plus orbitrap™ mass spectrometer enabled tentative identification of three major compounds in the extracts, including epigallocatechin, methyl gallate and quercetin amongst others. Based on the mass spectrometer results, it is postulated that quercetin found mostly in active extracts of V. karroo, V. xanthophloea, and V. kosiensis may be responsible for the observed antifungal and anti-inflammatory activity. This data demonstrates that the Vachellia species that were investigated could potentially be promising candidates for the management of fungal infections and related inflammation.

The High Content of Quercetin and Catechin in Airen Grape Juice Supports Its Application in Functional Food Production

Ensuring healthy lives and well-being constitutes one of the Sustainable Development Goals of the UN 2030 agenda. Consequently, research into how natural products may promote health is essential for the new generation of nutraceuticals and functional foods that are in high demand today. Grape juice is a natural foodstuff composed of water, sugars, minerals, vitamins and a wide array of polyphenols. Polyphenols are bioactive compounds of great interest due to their antioxidant properties and benefits to health, supporting antimicrobial, anti-aging, and anticarcinogenic activity. The majority of grape juice produced in the world is used for the production of wine, although a small part is used in the food industry, mainly in baby food and sports drinks. The aim of this work is to determine the polyphenol content in the natural and concentrated juice of Airen grapes, the main white grape variety produced in Spain. For this, fresh juices from five grape varietals (Airen, Sauvignon Blanc, Gewürztraminer, Verdejo and Tempranillo) and concentrated Airen juice were analyzed and compared. Results showed similar contents of phenolic acids and stilbenes in all grape varietals studied, although the Airen variety demonstrated a higher concentration of two flavonoids: quercetin and catechin. It can be concluded that the grape juice concentration process negatively affects the stability of these compounds, causing a reduction in the polyphenol content that ranges between 54–71%, with the exception of quercetin and catechin.

Simultaneous determination of gallic acid, methyl gallate, and 1,3,6-tri-O-galloyl-β-d-glucose from Turkish galls in rat plasma using liquid chromatography-tandem mass spectrometry and its application to pharmacokinetics study

Turkish galls (TG) is a traditional Uygur medicine typically used in clinics for dental disease and chronic ulcerative colitis. In this study, a novel liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous quantification of gallic acid, methyl gallate, and 1,3,6-tri-O-galloyl-β-d-glucose in rat plasma, which are the major bioactive compounds of TG. After a feasible protein precipitation using acetonitrile for sample preparation, chromatographic separation was performed with a BDS Hypersil C18 column (2.1 × 100 mm, 5 μm) at 30°C, and water containing 10 mmol of ammonium acetate and acetonitrile was used as the mobile phase with a flow rate of 0.3 mL/min. The MS detector was operated in the selective reaction monitoring with negative-ionization mode. The results of the method validation, including selectivity, linearity, accuracy, precision, extraction recovery, matrix effect, and stability of the compounds in the biosamples, were all within the current acceptance criteria. The established method was successfully applied to the pharmacokinetics study of three analytes in rats after an oral administration of TG extract and laid the foundation for studying the active components and mechanism of TG in vivo.

Bergenia pacumbis from Nepal, an astonishing enzymes inhibitor

BACKGROUND

The Bergenia species are perennial herbs native to central Asia, and one of the most promising medicinal plants of the family Saxifragaceae which are popularly known as 'Pashanbheda'. The aim of this study was to evaluate antioxidant and α-amylase, α-glucosidase, lipase, tyrosinase, elastase, and cholinesterases inhibition potential of Bergenia pacumbis of Nepali origin collected from the Karnali region of Nepal.

METHODS

The sequential crude extracts were made in hexane, ethyl acetate, methanol, and water. Antioxidant activities were analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The α-amylase, α-glucosidase, lipase, tyrosinase, elastase, acetylcholinesterase, and butyrylcholinesterase inhibition were analyzed by the 3,5-Dinitrosalicylic acid (DNSA), p-Nitrophenyl-α-D-glucopyranoside (p-NPG), 4-nitrophenyl butyrate (p-NPB), l-3,4-dihydroxyphenylalanine (L-DOPA), N-Succinyl-Ala-Ala-p-nitroanilide (AAAPVN), acetylthiocholine, and butyrylcholine as a respective substrate. The major metabolites were identified by high performance liquid chromatography with electron spray ionization- quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS) profiling.

RESULTS

Our results revealed the great antioxidant ability of crude extract of B. pacumbis in ethyl acetate extract against both DPPH (IC50 = 30.14 ± 0.14 μg/mL) and ABTS (IC50 = 17.38 ± 1.12 μg/mL). However, the crude methanol extract of B. pacumbis showed the comparable enzymes inhibitions with standard drugs; α-amylase (IC50 = 14.03 ± 0.04 μg/mL), α-glucosidase (IC50 = 0.29 ± 0.00 μg/mL), lipase (IC50 = 67.26 ± 0.17 μg/mL), tyrosinase (IC50 = 58.25 ± 1.63 μg/mL), elastase (IC50 = 74.00 ± 3.03 μg/mL), acetylcholinesterase (IC50 = 31.52 ± 0.58 μg/mL), and butyrylcholinesterase (IC50 = 11.69 ± 0.14 μg/mL). On the basis of HPLC-ESI-QTOF-MS profiling of metabolites, we identified major compounds such as Bergenin, Catechin, Arbutin, Gallic acid, Protocatechuic acid, Syringic acid, Hyperoside, Afzelechin, Methyl gallate, Paashaanolactone, Astilbin, Quercetin, Kaempferol-7-O-glucoside, Diosmetin, Phloretin, and Morin in methanol extract which has reported beneficial bioactivities.

CONCLUSION

Our study provides a plethora of scientific evidence that the crude extracts of B. pacumbis from Nepalese origin in different extracting solvents have shown significant potential on inhibiting free radicals as well as enzymes involved in digestion, skin related problems, and neurological disorders compared with the commercially available drugs.

Evaluation of the pharmacokinetic-pharmacodynamic integration of marbofloxacin in combination with methyl gallate against Salmonella Typhimurium in rats

Fluoroquinolone resistance in Salmonella Typhimurium is becoming a major concern. Hence, an intervention to limit the growth in resistance is inevitable. One way to combat this challenge is through combination therapy. The combination of antibiotics with phytochemicals has become an ideal means of preventing antimicrobial resistance. Recently, in an in vitro study, the combination of methyl gallate (MG) with marbofloxacin (MAR) has shown to prevent Salmonella Typhimurium invasion. It is also worth to study the effects of plant extracts on the pharmacokinetics of antibiotics. Hence, the objective of this study was to determine the effect of MG on the pharmacokinetics of MAR and pharmacokinetics/pharmacodynamics integration of MG and MAR. The micro-broth dilution method was used to obtain the minimum inhibitory concentration (MIC), and fractional inhibitory concentration (FIC) of MAR and MG. Whereas, the pharmacokinetic was conducted in rats by administering either MAR alone or combined with MG through oral and/or intravenous routes. The results indicated that the MIC of MAR and MG against standard strain Salmonella Typhimurium (ATCC 14028) was 0.031 and 500 μg/mL, respectively. The FIC_index of the combination of MAR and MG was 0.5. For orally administered drugs, the C_max and AUC_24h of MAR were 1.04 and 0.78 μg/mL and 5.98 and 6.11 h.μg/mL when MAR was given alone and in combination with MG, respectively. The intravenous administration of MAR showed a half-life of 3.8 and 3.9 h; a clearance rate of 1.1 and 0.73 L/h/kg and a volume of distribution of 5.98 and 4.13 L/kg for MAR alone and in combination with MG, respectively. The AUC₂₄/MIC for MAR alone and in combination with MG was 192.8 and 381.9 h, respectively. In conclusion, MG has shown to increase the antimicrobial activity of MAR in vitro and ex vivo experiments without affecting the pharmacokinetics of MAR in rats.

Anti-influenza virus phytochemicals from Radix Paeoniae Alba and characterization of their neuraminidase inhibitory activities

ETHNOPHARMACOLOGICAL RELEVANCE

Bai Shao (Radix Paeoniae Alba, BS), the root of Paeonia lactiflora Pall., in ancient China was used for Wen Bing (Warm Disease) treatment. Wen Bing has the symptoms of influenza. Ethanol extract of the root has recently been shown to possess anti-influenza activity. However, the active compounds have not yet been identified.

AIM

We showed that BS aqueous extract was potent in inhibiting influenza A virus in infected cells. We aimed to isolate the bioactive compounds and characterize the anti-influenza mechanism.

MATERIALS AND METHODS

Plaque reduction assay was performed for fractions isolated from BS. Hemagglutination inhibition assay and neuraminidase inhibition assay were performed to find the target protein. Molecular docking and reverse genetics were used to confirm the action site of gallic acid on the neuraminidase protein.

RESULTS

We identified three tannin compounds gallic acid (GA), methyl gallate (MG) and pentagalloylglucose (PGG) in BS aqueous extract that could inhibit the replication of influenza A virus in MDCK cells. While only PGG was found to inhibit the influenza virus-induced hemagglutination of chicken erythrocytes, all three compounds significantly reduced the activity of the neuraminidase. The results from molecular docking and reverse genetics showed that GA interacted with Arg152 of neuraminidase protein.

CONCLUSION

Three compounds GA, MG and PGG isolated from BS were found to inhibit influenza A virus in MDCK cells. GA interacts with amino acid Arg152 of the viral neuraminidase. Our study identified anti-influenza compounds of BS and demonstrated their antiviral mechanism, thus providing scientific evidence for using this herb for clinical treatment.

A Review on Liquid Chromatography-Tandem Mass Spectrometry Methods for Rapid Quantification of Oncology Drugs

In the last decade, the tremendous improvement in the sensitivity and also affordability of liquid chromatography-tandem mass spectrometry (LC-MS/MS) has revolutionized its application in pharmaceutical analysis, resulting in widespread employment of LC-MS/MS in determining pharmaceutical compounds, including anticancer drugs in pharmaceutical research and also industries. Currently, LC-MS/MS has been widely used to quantify small molecule oncology drugs in various biological matrices to support preclinical and clinical pharmacokinetic studies in R&D of oncology drugs. This mini-review article will describe the state-of-the-art LC-MS/MS and its application in rapid quantification of small molecule anticancer drugs. In addition, efforts have also been made in this review to address several key aspects in the development of rapid LC-MS/MS methods, including sample preparation, chromatographic separation, and matrix effect evaluation.

In vitro glucuronidation of methyl gallate and pentagalloyl glucopyranose by liver microsomes

Methyl gallate (MG) and pentagalloyl glucopyranose (PGG) are bioactive phenolic compounds that possess various pharmacological activities. However, the knowledge of hepatic metabolism of MG and PGG is limited. The purpose of this study was to investigate the in vitro glucuronidation of MG and PGG using liver microsomes from human (HLMs) and rats (Sprague-Dawley, SDRLMs; Wistar, WRLMs; and Gunn, GRLMs), and recombinant human uridine 5'-diphospho-glucuronosyltransferases (UGT) 1A1 and 1A9. The results demonstrated that liver microsomes catalyzed two mono-glucuronided MG (M1 and M2) formations but that UGT1A1 and 1A9 catalyzed only M1 formation. For PGG, a mono-glucuronided metabolite was mediated by liver microsomes or UGT1A9. However, a PGG glucuronide was absent in the UGT1A1 system. Additionally, all metabolites showed susceptibility to β-glucuronidases. Furthermore, the glucuronidation activities of PGG were lower than those of MG. The kinetic parameters of MG glucuronidation demonstrated that the SDRLMs and GRLMs were more similar to the HLMs than the WRLMs for the formations of M1 and M2, respectively and that the SDRLMs and HLMs preferentially contributed to M1, whereas the WRLMs and GRLMs showed the favored formation of M2. In conclusion, MG and PGG were subjectively glucuronided by liver microsomes to demonstrate species- and strain-dependent metabolism.

Factors Influencing Oral Bioavailability of Thai Mango Seed Kernel Extract and Its Key Phenolic Principles

Mango seed kernel extract (MSKE) and its key components (gallic acid, GA; methyl gallate, MG; and pentagalloyl glucopyranose, PGG) have generated interest because of their pharmacological activities. To develop the potential use of the key components in MSKE as natural therapeutic agents, their pharmacokinetic data are necessary. Therefore, this study was performed to evaluate the factors affecting their oral bioavailability as pure compounds and as components in MSKE. The in vitro chemical stability, biological stability, and absorption were evaluated in Hanks' Balanced Salt Solution, Caco-2 cell and rat fecal lysates, and the Caco-2 cell model, respectively. The in vivo oral pharmacokinetic behavior was elucidated in Sprague-Dawley rats. The key components were unstable under alkaline conditions and in Caco-2 cell lysates or rat fecal lysates. The absorptive permeability coefficient followed the order MG > GA > PGG. The in vivo results exhibited similar pharmacokinetic trends to the in vitro studies. Additionally, the co-components in MSKE may affect the pharmacokinetic behaviors of the key components in MSKE. In conclusion, chemical degradation under alkaline conditions, biological degradation by intestinal cell and colonic microflora enzymes, and low absorptive permeability could be important factors underlying the oral bioavailability of these polyphenols.