Maculosin,a non-toxic antioxidant compound isolated from Streptomyces sp. KTM18

ContextStreptomyces species are prolific sources of bioactive secondary metabolites known especially for their antimicrobial and anticancer activities.ObjectiveThis study sought to isolate and characterize antioxidant molecules biosynthesized by Streptomyces sp. KTM18. The antioxidant potential of an isolated compound and its toxicity were accessed.Materials and methodsThe compound was purified using bioassay-guided chromatography techniques. Nuclear magnetic resonance (NMR) experiments were carried out for structure elucidation. The antioxidant potential of the isolated compound was determined using DPPH free radical scavenging assay. The toxicity of the isolated compound was measured using a brine shrimp lethality (BSL) assay.ResultsEthyl acetate extract of Streptomyces sp. KTM18 showed more than 90% inhibition of DPPH free radical at 50 µg/mL of the test concentration. These data were the strongest among 13 Streptomyces isolates (KTM12–KTM24). The active molecule was isolated and characterized as maculosin (molecular formula, C₁₄H₁₆N₂O₃ as determined by the [M + H]⁺ peak at 261.1259). The DPPH free radical scavenging activity of pure maculosin was higher (IC₅₀, 2.16 ± 0.05 µg/mL) than that of commercial butylated hydroxyanisole (BHA) (IC₅₀, 4.8 ± 0.05 µg/mL). No toxicity was observed for maculosin (LD₅₀, <128 µg/mL) in brine shrimp lethality assay (BSLA) up to the compound’s antioxidant activity (IC₅₀) concentration range. The commercial standard, berberine chloride, showed toxicity in BSLA with an LD₅₀ value of 8.63 ± 0.15 µg/mL.ConclusionsMaculosin may be a leading drug candidate in various cosmetic and therapeutic applications owing to its strong antioxidant and non-toxic properties.     

UPLC-PDA-ESI-QTOF-MS/MS fingerprint of purified flavonoid enriched fraction of Bryophyllum pinnatum; antioxidant properties,anticholinesterase activity and in silico studies

ContextBryophyllum pinnatum (Lam.) Oken (Crassulaceae) is used traditionally to treat many ailments.ObjectivesThis study characterizes the constituents of B. pinnatum flavonoid-rich fraction (BPFRF) and investigates their antioxidant and anticholinesterase activity using in vitro and in silico approaches.Materials and methodsMethanol extract of B. pinnatum leaves was partitioned to yield the ethyl acetate fraction. BPFRF was isolated from the ethyl acetate fraction and purified. The constituent flavonoids were structurally characterized using UPLC-PDA-MS². Antioxidant activity (DPPH), Fe²⁺-induced lipid peroxidation (LP) and anticholinesterase activity (Ellman’s method) of the BPFRF and standards (ascorbic acid and rivastigmine) across a concentration range of 3.125–100 μg/mL were evaluated in vitro for 4 months. Molecular docking was performed to give insight into the binding potentials of BPFRF constituents against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE).ResultsUPLC-PDA-MS² analysis of BPFRF identified carlinoside, quercetin (most dominant), luteolin, isorhamnetin, luteolin-7-glucoside. Carlinoside was first reported in this plant. BPFRF significantly inhibited DPPH radical (IC₅₀ = 7.382 ± 0.79 µg/mL) and LP (IC₅₀ = 7.182 ± 0.60 µg/mL) better than quercetin and ascorbic acid. Also, BPFRF exhibited potent inhibition against AChE and BuChE with IC₅₀ values of 22.283 ± 0.27 µg/mL and 33.437 ± 1.46 µg/mL, respectively compared to quercetin and rivastigmine. Docking studies revealed that luteolin-7-glucoside, carlinoside and quercetin interact effectively with crucial amino acid residues of AChE and BuChE through hydrogen bonds.Discussion and conclusionsBPFRF possesses an excellent natural source of cholinesterase inhibitor and antioxidant. The material could be further explored for the potential treatment of oxidative damage and cholinergic dysfunction in Alzheimer’s disease.     

α-Amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory effects of Melicope latifolia bark extracts and identification of bioactive constituents using in vitro and in silico approaches

ContextMelicope latifolia (DC.) T. G. Hartley (Rutaceae) was reported to contain various phytochemicals including coumarins, flavonoids, and acetophenones.ObjectiveThis study investigates the antidiabetic and antioxidant effects of M. latifolia bark extracts, fractions, and isolated constituents.Materials and methodsMelicope latifolia extracts (hexane, chloroform, and methanol), fractions, and isolated constituents with varying concentrations (0.078–10 mg/mL) were subjected to in vitro α-amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory assay. Molecular docking was performed to study the binding mechanism of active compounds towards α-amylase and DPP-4 enzymes. The antioxidant activity of M. latifolia fractions and compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching assays.ResultsMelicope latifolia chloroform extract showed the highest antidiabetic activity (α-amylase IC₅₀: 1464.32 μg/mL; DPP-4 IC₅₀: 221.58 μg/mL). Fractionation of chloroform extract yielded four major fractions (CF₁–CF₄) whereby CF₃ showed the highest antidiabetic activity (α-amylase IC₅₀: 397.68 μg/mL; DPP-4 IC₅₀: 37.16 μg/mL) and resulted in β-sitosterol (1), halfordin (2), methyl p-coumarate (3), and protocatechuic acid (4). Isolation of compounds 2–4 from the species and their DPP-4 inhibitory were reported for the first time. Compound 2 showed the highest α-amylase (IC₅₀: 197.53 μM) and β-carotene (88.48%) inhibition, and formed the highest number of molecular interactions with critical amino acid residues of α-amylase. The highest DPP-4 inhibition was exhibited by compound 3 (IC₅₀: 911.44 μM).Discussion and conclusionsThe in vitro and in silico analyses indicated the potential of M. latifolia as an alternative source of α-amylase and DPP-4 inhibitors. Further pharmacological studies on the compounds are recommended.     

Ethanol extract of Gynura bicolour reduces atherosclerosis risk by enhancing antioxidant capacity and reducing adhesion molecule levels

ContextGynura bicolour (Roxb. and Willd.) DC (Asteraceae) leaf is a common vegetable. Ethanol extracts of fresh G. bicolour leaves (GBEE) have several physiological effects, but studies on atherosclerosis are limited.ObjectiveWe investigated the oxidant scavenging ability and vascular adhesion molecule expression of these extracts.Materials and methodsThe antioxidant effects of 0.05–0.4 mg/mL GBEE were analyzed in vitro. Intracellular antioxidant capacity and adhesion molecule levels were detected in EA.hy926 cells pre-treated with 10–100 μg/mL GBEE for 8 h, then TNF-α for 3 h. The antioxidant capacity of red blood cells and the adhesion molecule levels in the thoracic aorta were detected in high-fat diet (HFD)-fed Sprague–Dawley rats treated with GBEE for 12 weeks.ResultsThe in vitro EC₅₀ values of GBEE based on its DPPH radical-scavenging ability, reducing power, and ferrous ion-chelating ability were 0.20, 3.21 and 0.49 mg/mL, respectively. In TNF-α-treated EA.hy926 cells, the thiobarbituric acid-reactive substance levels were decreased after 10, 50, or 100 μg/mL GBEE treatments (IC₅₀: 19.1 mg/mL). When HFD-fed rats were co-treated with GBEE, the GBEE-H group exhibited 25% higher glutathione levels than the HFD group (p < 0.05). E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion protein-1 levels were decreased in TNF-α-treated EA.hy926 cells after GBEE treatment (by approximately 11–73%; p < 0.05), and the above three adhesion molecules levels were decreased in HFD-fed rats with combined GBEE treatment (by approximately 30–77%; p < 0.05).ConclusionsGBEE can protect the vascular endothelium by reducing adhesion molecule expression and regulating antioxidants. It may have the potential to prevent atherosclerosis.     

Anti-allergic actions of a Chinese patent medicine,huoxiangzhengqi oral liquid,in RBL-2H3 cells and in mice

ContextHuoxiangzhengqi oral liquid (HXZQ-OL), a traditional Chinese medicine formula, has antibacterial, anti-inflammation and gastrointestinal motility regulation effects.ObjectiveThe study investigates the anti-allergic activity and underlying mechanism of HXZQ-OL.Materials and methodsIgE/Ag-mediated RBL-2H3 cells were used to evaluate the anti-allergic activity of HXZQ-OL (43.97, 439.7 and 4397 μg/mL) in vitro. The release of cytokines and eicosanoids were quantified using ELISA. RT-qPCR was used to measure the gene expression of cytokines. The level of intracellular Ca²⁺ was measured with Fluo 3/AM. Immunoblotting analysis was performed to investigate the mechanism of HXZQ-OL. In the passive cutaneous anaphylaxis (PCA), BALB/c mice (5 mice/group) were orally administrated with HXZQ-OL (263.8, 527.6 and 1055 mg/kg/d) or dexamethasone (5 mg/kg/d, positive control) for seven consecutive days.ResultsHXZQ-OL not only inhibited degranulation of mast cells (IC₅₀, 123 μg/mL), but also inhibited the generation and secretion of IL-4 (IC₅₀, 171.4 μg/mL), TNF-α (IC₅₀, 88.4 μg/mL), LTC4 (IC₅₀, 52.9 μg/mL) and PGD2 (IC₅₀, 195.8 μg/mL). Moreover, HXZQ-OL suppressed the expression of IL-4 and TNF-α mRNA, as well as the phosphorylation of Fyn, Lyn and multiple downstream signalling proteins including MAPK and PI3K/NF-κB pathways. In addition, HXZQ-OL (527.5 mg/kg) attenuated the IgE-mediated PCA with 55% suppression of Evans blue exudation in mice.ConclusionsHXZQ-OL attenuated the activation of mast cell and PCA. Therefore, HXZQ-OL might be used as an alternative treatment for allergic diseases.     

Cytotoxic activity of standardized extracts,a fraction,and individual secondary metabolites from fenugreek seeds against SKOV-3, HeLa and MOLT-4 cell lines

ContextTrigonella foenum-graecum L. (Fabaceae) has many therapeutic properties and anticancer potential.ObjectiveThe cytotoxic activities of standardized extracts and a fraction from fenugreek seeds and their compounds (sapogenins, flavone C-glycosides, alkaloid trigonelline) against human cancer SKOV-3, HeLa and MOLT-4 cells were evaluated.Materials and methodsFenugreek seeds were extracted with 70% methanol (A) or water (B). Furthermore, the seeds were purified with petroleum ether and chloroform and next extracted with methanol to obtain fraction (C). The quantitative analysis of saponins and flavonoids in the extracts was done with HPLC methods. The extracts (5–120 µg/mL) and compounds (1–50 µg/mL) were tested on the cells by MTT assay and RTCA system. The effect of a fraction on ROS production, mitochondrial membrane potential and caspase-3/7 activity in HeLa and SKOV-3 cells was also evaluated by flow cytometry.ResultsThe strongest cytotoxic activity on cancer cells showed the fraction C (IC₅₀ was 3.91 ± 0.03 for HeLa, 3.97 ± 0.07 for SKOV-3, and 7.75 ± 0.37 for MOLT-4) with the highest content of steroidal saponins (163.18 ± 11.03 μg/mg) and flavone C-glycosides (820.18 ± 0.05 μg/mg). The fraction significantly increased ROS production (up to four times higher than in keratinocytes as control) and caspases activity in the cells. The examined flavonoids did not exhibit the cytotoxic activity in contrast to yamogenin, tigogenin, and diosgenin.ConclusionsThe obtained results complement the data on the cytotoxic activity of Foenugraeci Semen and synergistic effect of flavonoids and saponins complex contained in the plant.     

Yang-Yin-Jie-Du decoction overcomes gefitinib resistance in non-small cell lung cancer via down-regulation of the PI3K/Akt signalling pathway

ContextYang-Yin-Jie-Du Decoction (YYJDD) was used to improve gefitinib efficacy in our clinical practice, but its mechanism remains unclear.ObjectiveThis study explored if YYJDD could reverse gefitinib resistance.Materials and methodsH1975 cells were exposed to control, 10 μM gefitinib, 3.2 mg/mL YYJDD or combination treatment. Cell viability was detected by MTT during 0–96 h. Apoptosis and the PI3K/Akt proteins were tested by flow cytometry and western-blot at 24 h. LY294002 was applied to further determine the role of the PI3K/Akt. 23 BALB/c nude xenograft mice received normal saline (n = 5), 80 mg/kg gefitinib (n = 6), 2.35 g/kg lyophilised powder of YYJDD (n = 6) or combination treatment (n = 6) by gavage for 4 weeks and submitted to TUNEL, immunohistochemistry, and western-blot.ResultsIn vitro, gefitinib (IC₅₀: 20.68 ± 2.06 μM) and YYJDD (IC₅₀: 6.6 ± 0.21 mg/mL) acted in a moderate synergistic way. Combination treatment inhibited cell viability from 100% to 25.66%. Compared to gefitinb (33.23 ± 3.99%), cell apoptosis was increased with combination treatment (54.11 ± 7.32%), accompanied by down-regulation of the PI3K/Akt. LY294002 further inhibited cell viability, increased apoptosis, and down-regulated p-Akt/Akt. In vivo, the tumour sizes in the combination group (1165.13 ± 157.79 mm³) were smaller than gefitinib alone (1630.66 ± 208.30 mm³). The positive rate of TUNEL staining was increased by combination treatment (22.33 ± 2.75%) versus gefitinib (7.37 ± 0.87%), while the PI3K/Akt was down-regulated.Discussion and conclusionYYJDD has potential to overcome gefitinib resistance. Future investigations should be focussed on its specific targets.     

Cytotoxic furanosesquiterpenoids and steroids from Ircinia mutans sponges

ContextIrcinia mutans Wilson (Irciniidae) is a sponge with antimicrobial and cytotoxic constituents.ObjectiveOur objective was to characterise the cytotoxic constituents of two seasonal collections of I. mutans.Materials and methodsThe sponges were extracted in methanol-dichloromethane and their constituents were purified and characterised using column chromatography, GC-MS, 1 D and 2 D NMR. Anti-proliferative activities of the compounds, were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay (0.25–100 μg/mL, 72 h) against leukaemia (MOLT-4), breast (MCF-7) and colon cancer (HT-29) human cells.ResultsThree furanosesquiterpoids; furodysin (1), ent-furodysinin (2) and furoircin (3) and ten sterols were characterised in I. mutans, for the first time. Cholesterol (4), cholesta-5, 7-dien-3β-ol (5) and ergosterol (6) were determined in the sponge from the winter collections, while cholesta-5, 22-dien-3β-ol (7), 24-methyldesmosterol (8), campesterol (9), stigmasterol (10), γ-ergostenol (11), chondrillasterol (12) and γ-sitosterol (13) were detected in the summer samples. The steroids from the winter collection exhibited cytotoxic activity with IC₅₀ values of 13.0 ± 0.9, 11.1 ± 1.7 and 1.1 ± 0.4 µg/mL, against the mentioned cancer cell lines, respectively, while those from the summer sample, showed greater activity, IC₅₀ = 1.1 ± 0.2 μg/mL against MOLT-4. The purified steroids showed potent MOLT-4 cytotoxic activity, IC₅₀ values = 2.3–7.8 µg/mL.Discussion and conclusionThe present study suggests that I. mutans is a rich source of cytotoxic steroids, and introduces 3 as new natural product. Considering the high cytotoxic activity of the steroids, these structures could be candidates for anticancer drug development in future research.     

QiShenYiQi pills,a Chinese patent medicine,increase bioavailability of atorvastatin by inhibiting Mrp2 expression in rats

ContextAtorvastatin (ATV) and QiShenYiQi pills (QSYQ), a Chinese patent medicine, are often co-prescribed to Chinese cardiovascular patients. The effects of QSYQ on the pharmacokinetics of ATV have not been studied.ObjectiveWe investigated the influence of QSYQ on the pharmacokinetics of ATV and its metabolites upon oral or intravenous administration of ATV to rats.Materials and methodsSprague-Dawley rats (n = 5/group) were pre-treated with oral QSYQ (675 mg/kg) or vehicle control for 7 days and then orally administrated ATV (10 mg/kg) or intravenously administrated ATV (2 mg/kg). Serum concentrations of ATV and metabolites were determined by ultra-high performance liquid chromatography tandem mass spectrometry. Expression of metabolic enzymes and transporters in jejunum and ileum were measured by quantitative real-time PCR and Western blot.ResultsQSYQ resulted in an increase of AUC_0-12 h of ATV from 226.67 ± 42.11 to 408.70 ± 161.75 ng/mL/h and of C_max of ATV from 101.46 ± 26.18 to 198.00 ± 51.69 ng/mL and in an increased of para-hydroxy atorvastatin from 9.07 ± 6.20 to 23.10 ± 8.70 ng/mL in rats administered ATV orally. No change was observed in rats treated intravenously. The expression of multidrug resistance-associated protein 2 mRNA and protein decreased in ileum, and the mRNA of P-glycoprotein decreased in jejunum, though no change in protein expression was found.Discussion and conclusionsQSYQ increased bioavailability of ATV administered orally through inhibiting the expression of Mrp2 in ileum. Clinicians should pay close attention to potential drug-drug interactions between ATV and QSYQ.     

Antioxidant and antifatigue effect of a standardized fraction (HemoHIM) from Angelica gigas,Cnidium officinale,and Paeonia lactiflora

ContextHemoHIM is an herbal preparation containing Angelica gigas Nakai (Apiaceae), Cnidium officinale Makino (Umbelliferae), and Paeonia lactiflora Pallas (Paeoniaceae) developed for immune regulation. To date, studies on the antifatigue effects of HemoHIM have not been conducted.ObjectiveThe antifatigue effects of HemoHIM using models of citrinin and exercise-induced chronic fatigue syndrome were investigated.Materials and methodsCitrinin-induced L6 skeletal muscle cells were treated with HemoHIM (125, 250, and 500 μg/mL). The antioxidant factors were analysed. ICR mice were divided into four groups (n = 10): control, HemoHIM 250, 500 mg/kg, and creatine 300 mg/kg, respectively. Mice were orally administered HemoHIM or creatine for three weeks; during this time, both rotarod test and forced swimming test (FST) were conducted. The latency time was investigated and antioxidant, antifatigue factors were analysed.ResultsHemoHIM significantly restored reduced antioxidant enzymes (SOD, CAT, Txn, GPx, GSr, and GCLC in HemoHIM 500 μg/mL) compared to the citrinin group in L6 cells. In vivo, HemoHIM significantly improved the latency time (FST; 279.88 ± 50.32 sec, rotarod test; 552.35 ± 23.50 sec in HemoHIM 500 mg/kg). Moreover, the FST-induced reduction in glucose and glutathione significantly increased by 3-fold (HemoHIM 500 mg/kg) and increase in LDH and MDA were significantly inhibited by 1.6, 2.1-fold in the HemoHIM 500 mg/kg compared to the control group.     

Response surface optimization of enzymatic hydrolysis and ROS scavenging activity of silk sericin hydrolysates

ContextSericin, a protein found in wastewater from the silk industry, was shown to contain a variety of biological activities, including antioxidant. The enzymatic conditions have been continuously modified to improve antioxidant effect and scavenging capacity against various free radicals of silk sericin protein.ObjectiveVariables in enzymatic reactions, including pH, temperature and enzyme/substrate ratio were analysed to discover the optimum conditions for antioxidant activity of sericin hydrolysates.Materials and methodsHydrolysis reaction catalysed by Alcalase^® was optimized through response surface methodology (RSM) in order to generate sericin hydrolysates possessing potency for % inhibition on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, ferric-reducing power and peroxyl scavenging capacity. Flow cytometry was performed to evaluate cellular ROS level in human HaCaT keratinocytes and melanin-generating MNT1 cells pre-treated either with 20 mg/mL RSM-optimized sericin hydrolysates or 5 mM N-acetyl cysteine (NAC) for 60 min prior exposure with 1 mM hydrogen peroxide (H₂O₂).ResultsAmong these three variables, response surface plots demonstrate the major role of temperature on scavenging capacity of sericin hydrolysates. Sericin hydrolysates prepared by using Alcalase^® at RSM-optimized condition (enzyme/substrate ratio: 1.5, pH: 7.5, temperature: 70 °C) possessed % inhibition against H₂O₂ at 99.11 ± 0.54% and 73.25 ± 8.32% in HaCaT and MNT1 cells, respectively, while pre-treatment with NAC indicated the % inhibition only at 30.26 ± 7.62% in HaCaT and 51.05 ± 7.14% in MNT1 cells.Discussion and conclusionsThe acquired RSM information would be of benefit for further developing antioxidant peptide from diverse resources, especially the recycling of waste products from silk industry.     

Taxifolin,a novel food,attenuates acute alcohol-induced liver injury in mice through regulating the NF-κB-mediated inflammation and PI3K/Akt signalling pathways

ContextTaxifolin (TAX) has effective anti-inflammatory, antioxidant and hepatoprotective activities, but its potential mechanism has not been revealed.ObjectiveTo evaluate the potential protective effect of TAX on acute alcohol-induced liver injury in mice.Materials and methodsAlcoholic liver injury model was established by oral alcohol in mice, and randomly distributed in five groups (n = 10): Normal group (oral saline only); Alcohol group (concentration of fermented alcohol: 56%, 6 mL/kg); TAX groups, mice were orally administered with alcohol, and then TAX with doses of 20, 40, 80 mg/kg, respectively. Oral administration was conducted for 6 weeks.ResultsTAX treatment illustrated that the level of alanine aminotransferase (ALT) was reduced to 65.90 ± 2.26 U/L and aspartate aminotransferase (AST) to 33.28 ± 5.62 U/L compared with alcohol group (ALT 124.51 ± 4.40 U/L, AST 61.70 ± 4.09 U/L), while superoxide dismutase (SOD) was increased to 49.81 ± 2.39 U/mg and glutathione (GSH) to 8.16 ± 0.44 μmol/g, but MDA was reversed to 2.53 ± 0.24 nmol/mg. Histopathological examination showed TAX treatment alleviated alcohol-induced hepatocyte necrosis and inflammatory infiltration. Meanwhile, Western blot and rt-PCR indicated TAX reduced IL-6 to 2.49 ± 0.25 pg/mL and TNF-α to 1.79 ± 0.20 pg/mL, and inhibiting NF-κB activation in liver. Moreover, TAX reversed alcohol-induced apoptosis by regulating the expression of PI3K/Akt and its downstream apoptotic factors.ConclusionsThe research provides novel evidence of the hepatoprotective effect of TAX on alcohol-induced liver injury, while also providing the possibility for future treatment of alcoholic liver disease.     

Streblus asper attenuates alloxan-induced diabetes in rats and demonstrates antioxidant and cytotoxic effects

ContextStreblus asper Lour. (Moraceae) is used for the treatment of different ailments, including diabetes, and requires scientific validation.ObjectiveThe study evaluates antidiabetic effects, antioxidant potential, and cytotoxicity of leaf and bark extracts of S. asper.Materials and methodsAntidiabetic effects were assessed by inducing diabetes in Wistar albino rats (n = 5, six groups included 30 rats) by injecting alloxan [0.25 mg/kg body weight (bw)] intraperitoneally, and efficacy of methanol extracts of leaf and bark, and aqueous extract of leaves were evaluated by oral administration of 300 mg/kg bw of extracts for 3 weeks. Glibenclamide (Dibenol™) was used as a control (10 mg/kg bw). Antioxidant properties were examined by DPPH free radical scavenging activity, and cytotoxicity was investigated using a brine shrimp lethality assay.ResultsMethanol extracts of leaves and bark, and the aqueous extract of leaves of S. asper, caused significant reductions in blood glucose levels in diabetic rats of 36.83, 70.33, and 52.71%, respectively, after 21 days of treatment. IC₅₀ values in DPPH radical scavenging assessment for those extracts were 58.92, 88.54, and 111.36 µg/mL, respectively. LC₅₀ values for brine shrimp lethality for the extracts were 173.80, 32.36, and 3235.9 µg/mL, respectively.Discussion and conclusionsThe methanol bark extract of S. asper showed significant antidiabetic activity. This study will significantly contribute to establishing the plant as an alternative medicinal resource for rural populations of Bangladesh and provides an opportunity for further research to identify the primary active compound(s) and establish new drug candidates.     

Comparative pharmacokinetic analysis of raw and steamed Panax notoginseng roots in rats by UPLC-MS/MS for simultaneously quantifying seven saponins

ContextAfter being steamed, the restorative effects of Panax notoginseng (Burk.) F. H. Chen (Araliaceae) will be strengthened. However, the underlying mechanism remains elusive.ObjectiveTo compare the pharmacokinetics of ginsenosides Rg₁, Rb₁, Rd, Re, Rg₅, Rk₁, notoginsenoside R₁ (GRg₁, GRb₁, GRd, GRe, GRg₅, GRk₁ and NGR₁) in the raw and steam-processed P. notoginseng (RPN and SPN).Materials and methodsThe pharmacokinetics of seven components after oral administration of SPN and RPN extracts (1.0 g/kg) were investigated, respectively, in SD rats (two groups, n = 6) using UPLC-MS/MS.ResultsThe approach elicited good linear regression (r² > 0.991). The accuracy, precision and stability were all within ± 15%. The extraction recoveries and matrix effects were 75.0–100.8% and 85.1–110.3%, respectively. Compared with the RPN group, AUC_0–t of GRg₁ (176.63 ± 42.49 ng/h/mL), GRb₁ (5094.06 ± 1453.14 ng/h/mL), GRd (1396.89 ± 595.14 ng/h/mL), and NGR₁ (135.95 ± 54.32 ng/h/mL), along with C_max of GRg₁ (17.41 ± 5.43 ng/mL), GRb₁ (361.48 ± 165.57 ng/mL), GRd (62.47 ± 33.65 ng/mL) and NGR₁ (23.97 ± 16.77 ng/mL) decreased remarkably with oral administration of the SPN extracts, while GRe showed no significantly difference. Of note, GRg₅ and GRk₁ could not be detected in the plasma.ConclusionsInfluence of the processing reduced the systemic exposure levels to GRg₁, GRb₁, GRd and NGR₁. It is the first report of comparative pharmacokinetic study of multiple saponins analysis after oral administration of RPN and SPN extract, which might be helpful for further studies on its steam-processing mechanism.     

Pharmacokinetic study on the interaction between pachymic acid and bavachin and its potential mechanism

ContextPachymic acid and bavachin are commonly used drugs in the therapy of lung cancer.ObjectiveThe co-administration of pachymic acid and bavachin was investigated to evaluate their potential drug-drug interaction.Materials and methodsThe pharmacokinetics of bavachin (10 mg/kg) was studied in male Sprague-Dawley (SD) rats in the presence of pachymic acid (5 mg/kg) (n = 6). The rats without pre-treatment of pachymic acid were set as the control and the pre-treatment of pachymic acid was conducted for 7 days before the administration of bavachin. The effect of pachymic acid on the activity of CYP2C9 was also estimated in rat liver microsomes with corresponding probe substrates.ResultsPachymic acid influenced the pharmacokinetic profile of bavachin with the increased AUC (32.82 ± 4.61 vs. 19.43 ± 3.26 μg/L/h), the prolonged t_1/2 (3.21 ± 0.65 vs. 2.32 ± 0.28 h), and the decreased CLz/F (307.25 ± 44.35 vs. 523.81 ± 88.67 L/h/kg) in vivo. The metabolic stability of bavachin was enhanced by pachymic acid and the transport of bavachin was inhibited by pachymic acid. Pachymic acid was found to inhibit the activity of CYP2C9 with the IC₅₀ of 21.25 µM as well as the activity of P-gp.Discussion and conclusionThe interaction between pachymic acid and bavachin results from the inhibition of CYP2C9 and P-gp. The dose of bavachin should be adjusted when combining with pachymic acid. The study design can be generalized to a broader study population with adjustment in the dose.     

The anti-breast cancer property of physcion via oxidative stress-mediated mitochondrial apoptosis and immune response

ContextPhyscion (Phy) exerts several pharmacological effects including anti-inflammatory, antioxidant, and antitumor properties.ObjectiveThis study investigates the cytotoxicity and its underlying mechanisms of Phy on breast cancer.Materials and methodsHuman breast cancer cell MCF-7 was treated with 5–400 µM Phy for 24 h, MCF-7-xenografted BALB/c nude mice and immunosuppressive mice model induced by cyclophosphamide were intraperitoneally injected with 0.1 mL/mouse normal saline (control group) and 30 mg/kg Phy every other day for 14 or 28 days, and pathological examination, ELISA and western blot were employed to investigate the Phy anti-breast cancer property in vitro and in vivo.ResultsIn MCF-7 cells, Phy 24 h treatment significantly reduced the cell viability at dose of 50–400 µM and 24 h, with an IC₅₀ of 203.1 µM, and 200 µM Phy induced 56.9, 46.9, 36.9, and 46.9% increment on LDH and caspase-3, −8 and −9. In MCF-7-xenograft tumour nude mice and immunosuppressive mice, 30 mg/kg Phy treatment inhibited tumour growth from the 8th day, and reduced Bcl-2 and Bcl-xL >50%, HO-1 and SOD-1 > 70% in tumour tissues of immunosuppressive mice. In addition, Phy reduced nuclear factor erythroid 2-related factor 2 > 30% and its downstream proteins, and enhanced the phosphorylation of nuclear factor-kappa B > 110% and inhibitor of NF-кB α > 80% in the tumour tissues of BALB/c mice.Discussion and conclusionsThis research demonstrated that Phy has an anti-breast cancer property via the modulation of oxidative stress-mediated mitochondrial apoptosis and immune response, which provides a scientific basis for further research on its clinical applications.     

Discovery of new angiotensin converting enzyme (ACE) inhibitors from medicinal plants to treat hypertension using an in vitro assay

Background and purpose of the study

Angiotensin converting enzyme (ACE) inhibitors plays a critical role in treating hypertension. The purpose of the present investigation was to evaluate ACE inhibition activity of 50 Iranian medicinal plants using an in vitro assay.

Methods

The ACE activity was evaluated by determining the hydrolysis rate of substrate, hippuryl-L-histidyl-L-leucine (HHL), using reverse phase high performance liquid chromatography (RP-HPLC). Total phenolic content and antioxidant activity were determined by Folin-Ciocalteu colorimetric method and DPPH radical scavenging assay respectively.

Results

Six extracts revealed > 50% ACE inhibition activity at 330 μg/ml concentration. They were Berberis integerrima Bunge. (Berberidaceae) (88.2 ± 1.7%), Crataegus microphylla C. Koch (Rosaceae) (80.9 ± 1.3%), Nymphaea alba L. (Nymphaeaceae) (66.3 ± 1.2%), Onopordon acanthium L. (Asteraceae) (80.2 ± 2.0%), Quercus infectoria G. Olivier. (Fagaceae) (93.9 ± 2.5%) and Rubus sp. (Rosaceae) (51.3 ± 1.0%). Q. infectoria possessed the highest total phenolic content with 7410 ± 101 mg gallic acid/100 g dry plant. Antioxidant activity of Q. infectoria (IC₅₀ value 1.7 ± 0.03 μg/ml) was more than that of BHT (IC₅₀ value of 10.3 ± 0.15 μg/ml) and Trolox (IC₅₀ value of 3.2 ± 0.06 μg/ml) as the positive controls.

Conclusions

In this study, we introduced six medicinal plants with ACE inhibition activity. Despite the high ACE inhibition and antioxidant activity of Q. infectoria, due to its tannin content (tannins interfere in ACE activity), another plant, O. acanthium, which also had high ACE inhibition and antioxidant activity, but contained no tannin, could be utilized in further studies for isolation of active compounds.     

Cyanidin attenuates the apoptosis of rat nucleus pulposus cells and the degeneration of intervertebral disc via the JAK2/STAT3 signal pathway in vitro and in vivo

ContextCyanidin has been shown to have therapeutic potential in osteoarthritis. However, it is unclear whether cyanidin prevents the progression of intervertebral disc degeneration (IVDD).ObjectiveThis study evaluates the effects of cyanidin on IVDD in vitro and in vivo.Materials and methodsNucleus pulposus cells (NPCs) isolated from lumbar IVD of 4-week-old male Sprague-Dawley (SD) rats were exposed to 20 ng/mL IL-1β, and then treated with different doses (0-120 µM) of cyanidin for 24 h. SD rats were classified into three groups (n = 8) and treated as follows: control (normal saline), IVDD (vehicle), IVDD + cyanidin (50 mg/kg). Cyanidin was administered intraperitoneally for 8 weeks.ResultsThe IC₅₀ of cyanidin for NPCs was 94.78 µM, and cyanidin had no toxicity at concentrations up to 500 mg/kg in SD rats. Cyanidin inhibited the apoptosis of NPCs induced by IL-1β (12.73 ± 0.61% vs. 18.54 ± 0.60%), promoted collagen II (0.82-fold) and aggrecan (0.81-fold) expression, while reducing MMP-13 (1.02-fold) and ADAMTS-5 (1.40-fold) expression. Cyanidin increased the formation of autophagosomes in IL-1β-induced NPCs, and promoted LC3II/LC3I (0.83-fold) and beclin-1 (0.85-fold) expression, which could be reversed by chloroquine. Cyanidin inhibited the phosphorylation of JAK2 (0.47-fold) and STAT3 (0.53-fold) in IL-1β-induced NPCs. The effects of cyanidin could be enhanced by AG490. Furthermore, cyanidin mitigated disc degeneration in IVDD rats in vivo.Discussion and conclusionsCyanidin improved the function of NPCs in IVDD by regulating the JAK2/STAT3 pathway, which may provide a novel alternative strategy for IVDD. The mechanism of cyanidin improving IVDD still needs further work for in-depth investigation.