In situ growth of dual-responsive polymer as coating for open tubular capillary electrochromatographic separation of epimedins

Recently, open tubular capillary electrochromatography (OT-CEC) has captured considerable interest; its efficient separation capability hinges on the interactions between analytes and polymer coatings. However, in situ growth of stimuli-responsive polymers as coatings has been rarely studied and is crucial for expanding the OT-CEC technique and its application. Herein, following poly(styrene-maleicanhydride) (PSM) chemically bonded onto the inner surface of the capillary, a dual pH/temperature stimuli-responsive block copolymer, P(SMN-COOH), was prepared by in situ polymerizing poly(N-isopropylacrylamide) carboxylic acid terminated [P(N-COOH)] in PSM. An OT-CEC protocol was first explored using the coated capillary for epimedins separation. As a proof of concept, the developed OT-CEC system facilitated hydrogen bonding and tuning the hydrophilic/hydrophobic interactions between the test analytes and the P(SMN-COOH) coating by varying buffer pH and environmental temperature. Four epimedins with similar chemical structures were baseline separated under 40 °C at pH 10.0, exhibiting dramatical improvement in separation efficiency in comparison to its performance under 25 °C at pH 4.0. In addition, the coated capillary showed good repeatability and reusability with relative standard deviations for migration time and peak area between 0.7 and 1.7% and between 2.9 and 4.6%, respectively, and no significant changes after six runs. This work introduces a paradigm for efficient OT-CEC separation of herbal medicines through adjusting the interactions between analytes and smart polymer coatings, addressing polymer coating design and OT-CEC challenges.

Phytochemical Profiles, Antioxidant, Cytotoxic, and Anti-Inflammatory Activities of Traditional Medicinal Plants: Centaurea pichleri subsp. pichleri, Conyza canadensis, and Jasminum fruticans

Centaurea pichleri subsp. pichleri, Conyza canadensis, and Jasminum fruticans are traditionally used plants grown in Turkey. Methanol extracts were obtained from these plants and pharmacological activity studies and phytochemical analyses were carried out. To evaluate the phytochemical composition, spectrophotometric and chromatographic techniques were used. The extracts were evaluated for antioxidant activity by DPPH^●, ABTS^●+ radical scavenging, and FRAP assays. The cytotoxic effects of the extracts were investigated on DU145 prostate cancer and A549 lung cancer cell lines. The anti-inflammatory effects of extracts were investigated on the NO amount, TNF-α, IFN-γ, and PGE 2 levels in lipopolysaccharide-stimulated Raw 264.7 cells. The richest extract in terms of phenolic compounds (98.19 ± 1.64 mg_GAE/g_extract) and total flavonoids (21.85 ± 0.64 mg_CA/g_extract) was identified as C. pichleri subsp. pichleri methanol extract. According to antioxidant activity determinations, the C. pichleri subsp. pichleri extract was found to be the most active extract. Finally, the C. pichleri subsp. pichleri methanol extract was revealed to be the most effective inhibitor of viability in the cytotoxic activity investigation, and the extract with the best anti-inflammatory action. The findings point to C. pichleri subsp. pichleri as a promising source of bioactive compounds in the transition from natural sources to industrial uses, such as new medications, cosmeceuticals, and nutraceuticals.

Zein-Stabilized Nanospheres as Nanocarriers for Boosting the Aphrodisiac Activity of Icariin: Response Surface Optimization and In Vivo Assessment

Icariin (ICA), a main active compound of the Epimedium genus, is used as an aphrodisiac in traditional Chinese herbal medicine. Despite its therapeutic efficacy, ICA displays reduced oral absorption, and therefore, low bioavailability hindered its clinical application. Implementing nanotechnology in the field of formulation has been a focus to improve the efficacy of ICA. In this regard, polymeric nanoparticles find a potential application as drug delivery systems. A nanosphere formula was designed, aiming to improve the drug’s efficacy. The proposed ICA nanosphere formula (tocozeinolate) was optimized using D-optimal response surface design. The concentrations of ICA (X₁), D-α-tocopherol polyethylene glycol 1000 succinate (TPGS, X₂), zein (X₃), and sodium deoxycholate (SDC, X₄) expressed as percentages were investigated as quantitative independent variables. As per the experimental design, 23 formulations were developed, which were investigated for particle size (PS, nm), zeta potential (ZP, mV), and entrapment efficiency (EE, %) as response parameters. Numerical optimization and desirability approach were employed to predict the optimized variable levels that, upon combination, could result in minimized size and maximized zeta potential and ICA entrapment. The optimized ICA–tocozeinolate nanospheres showed a particle size of 224.45 nm, zeta potential of 0.961 mV, and drug entrapment of 65.29% that coincide well with the predicted values. The optimized ICA–tocozeinolate nanospheres were evaluated for sexual behavior in Wistar male rats compared to raw ICA at equivalent doses (20 mg/kg). In vivo assessment results showed significant sexual behavior enhancement by the optimized formulation, as evidenced by decreased average time of both mount latency (ML) and ejaculation latency (EL) to almost half those of raw ICA. Additionally, intromission latency (IL) time was reduced by 41% compared to the raw ICA. These results highlighted the potential of the proposed ICA–tocozeinolate nanospheres as a promising platform for improving the delivery and efficacy of therapeutic agents.

Identification of phosphodiesterase type-5 (PDE-5) inhibitors in herbal supplements using a tiered approach and associated consumer risk

The use of herbal supplements for improved sexual performance is a common practice amongst the youth and some senior citizens in Ghana. These products are considered 'natural' and greatly preferred over synthetic alternatives due to the assurance of little to no adverse effects by producers. However, the high rate of adulteration often compromises their safety. Forty herbal supplements, of which 25 were previously shown to result in medium to high intake of phosphodiesterase type-5 (PDE-5) inhibitors using a PDE-Glo bioassay, were further investigated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to examine the reliability of the bioassay and whether the observed higher responses could be ascribed to inherent plant constituents or adulterants. Results showed significant amounts of vardenafil, tadalafil and especially sildenafil, in 2, 1 and 10 samples, respectively, with total concentration levels resulting in estimated daily intakes (EDIs) above 25 mg sildenafil equivalents with six supplements even having EDIs above 100 mg sildenafil equivalents. Only one sample contained a natural ingredient (icariin), but its concentration (0.013 mg g^-1) was too low to explain the observed potency in the bioassay. The estimated concentrations of PDE-5 inhibitors in 35 supplements, according to the bioassay, were in line with those of the LC-MS/MS analysis. However, discrepancies were observed for five supplements. Further examination of one of the latter supplements using the PDE-Glo bioassay to select the positive fraction and further examination with LC-MS/MS and ¹H-NMR revealed the presence of hydroxythiohomosildenafil, a sildenafil analogue not yet included in the liquid chromatography-mass spectrometry reference library. This study demonstrates the significance of applying a tiered approach, where the use of a bioassay is followed by chemical analysis of bioactive samples in order to identify unknown bioactive compounds.

HPLC-DAD Fingerprints Combined With Multivariate Analysis of Epimedii Folium From Major Producing Areas in Eastern Asia: Effect of Geographical Origin and Species

The growth location and plant variety may influence the active components and biological activities of plants used in phytomedicine. In this study, nine sets of different Epimedii Folium, from different representative cultivation locations and Epimedium species, were collected for comparison, using HPLC-DAD combined with multivariate analysis. The objective was to investigate the influence of geographical origin and Epimedium species on the quality of Epimedii Folium, and provide applicable guidance for cultivation and quality control of Epimedii Folium. Several Epimedium spp. sets were used to establish the HPLC-DAD fingerprints and 91 peaks (compounds) were selected for the multivariate analysis. Major compounds were analyzed by HPLC-DAD combined with principal component analysis (PCA). HPLC quantitative analysis of known bioactive compounds was performed. Application of PCA to HPLC data showed that Epimedium samples sharing the same geographical origin or species clustered together, indicating that both species and geographical origin have impacts on the quality of Epimedii Folium. The major bioactive flavonoid compounds, epimedin C, icariin and baohuoside I, were identified and quantified. The concentration of bioactive compounds was significantly influenced both by species and geographical origin. E. sagittatum from Sichuan showed the highest content of bioactive compounds. The results showed that both Epimedium species and geographical origin have strong impact into quality of Epimedii Folium. HPLC data combined with multivariate analysis is a suitable approach to inform the selection of cultivation areas and choose Epimedium spp. most suitable for different geographical areas, resulting in improved quality of Epimedii Folium.

Development and Evaluation of Icariin-Loaded PLGA-PEG Nanoparticles for Potentiation the Proapoptotic Activity in Pancreatic Cancer Cells

Therapeutic efficacy of antineoplastic agents possessing a selective target to the nucleus of the cancer cells could be enhanced through novel formulation approaches. Thus, towards improvement of anticancer potential of icariin (ICA) on pancreatic cancer, the drug was entrapped into the polymeric poly lactic-co-glycolic acid (PLGA) with polyethylene glycol (PEG) as diblock copolymer. Optimization of the formulation was done using Statgraphics software to standardize percentages of PEG-PLGA and tween 80 (TW80) to obtain the smallest particle size. The optimized formulation was found to be in nanometer size and low PDI (0.321). Optimized formula enhanced cytotoxicity and apoptotic potential, compared with ICA-raw, against pancreatic cancer cell lines (aspc-1). The entrapment efficiency of the polymeric micelles was 72.34 ± 2.3% with 93.1 ± 6.5% release of ICA within 72 h. There was a twofold increase in apoptosis and sevenfold increase in necrosis of aspc-1 cells when incubated with raw ICA compared to control cells. Further, loss of mitochondrial membrane potential (⁓50-fold) by the ICA-loaded PMs and free drug compared to control cells was found to be due to the generation of ROS. Findings of cell cycle analysis revealed the significant arrest of G2-M phase of aspc-1 cells when incubated with the optimized formulation. Simultaneously, a significantly increased number of cells in pre-G1 revealed maximum apoptotic potential of the drug when delivered via micellar formulation. Finally, upregulation of caspase-3 established the superiority of the PMs approach against pancreatic cancer. In summary, the acquired results highlighted the potentiality of PMs delivery tool for controlling the growth of pancreatic cancer cells for improved efficacy.