Antioxidant and Compositional HPLC Analysis of Three Common Bamboo Leaves.

Bamboo leaves of Phyllostachys nigra (PN), Lophatherum gracile (LG), and Pleioblastus amarus (PA) are three common herbs in China. In this work, a new high performance liquid chromatography (HPLC) method for the simultaneous determination of seven compounds in bamboo leaves has been developed; and PN, LG, and PA leaves were analyzed. PN showed four times as much chlorogenic acid (CA) than the other two, and contained the most isoorientin (iso-ORI) and isovitexin (iso-VIT) as well. The PA presented the most orientin (ORI) and LG covered a majority of cynaroside (CYN). We measured the antioxidant activity by scavenging the stable 2,2-diphenyl-1-pyridinohydrazinyl (DPPH) free radicals, and found that Luteolin (inhibitory concentration (IC)50 = 0.42 µM, LUT) and CYN (IC50 = 0.43 µM) showed 2-3 times higher antioxidant activity than iso-ORI (IC50 = 0.81 µM), ORI (IC50 = 0.84 µM), and other related antioxidant standards such as trolox (IC50 = 0.97 µM) and ascorbic acid (IC50 = 0.93 µM, VC). Among extracts, PN and PA showed considerable antioxidant activity, which was related well with the contents of CA, iso-ORI, and iso-VIT (p < 0.05). This study firstly provides evidence for functional antioxidant compounds of bamboo leaves based on statistical analysis of the HPLC analysis and DPPH assay, and it lays a foundation for its further development or utilization.

Comparison of different methods for extraction of Cinnamomi ramulus: yield, chemical composition and in vitro antiviral activities.

Hydrodistillation (HD), supercritical fluid extraction (SFE) and reflux extraction (RE) were applied to obtain Cinnamomi ramulus extracts. The yields, chemical compositions and antiviral activities of the extracts were investigated. Extracts were analysed using gas chromatography-mass spectrometry and the antiviral activities were evaluated using cytopathic effect inhibition assay. HD, SFE and RE afforded 0.376, 1.227 and 5.914% yields, respectively. Cinnamaldehyde (CA), SFE and ethanol extracts exhibited antiviral activities against herpes simplex virus type 1. Moreover, CA and other three extracts had inhibition efficacy against respiratory syncytial virus. The most efficient antiviral activities were obtained with SFE.

[Optimization of Ethanol Extraction and Water Extraction Technologies of Zuogui Pills by Orthogonal Test].

OBJECTIVE: To optimize the ethanol extraction and water extraction technologies of Luogui Pills. METHODS: An orthogonal test was used to study the influence of ethanol concentration, amount of ethanol and reflux time on hyperoside in Cuscutae Semen, ursolic acid in Corni Fructus and the yield of dry paste. Also, The effect of soaking time, amount of water and extraction time on acteoside in Rehmanniae Radix Praeparata and the yield of dry paste were investigated. All these factors were adopted as the indices for choosing the best ethanol extraction and water extraction technologies. RESULTS: The best ethanol extraction technology for Cuscutae Semen, Corni Fructus and Achyranthis Bidentatae Radix was reflux extracting for 1 h each time for two times with eight times of 70% ethanol. The best water extraction technology for the residue and the rest herbs after the ethanol extraction was soaking for 0. 5 h and then decocting for 0. 5 h each time for two times with twelve times of water. CONCLUSION: The optimal extraction technologies are stable and feasible, the extraction rate of the alcohol soluble and water soluble effective components is high, and it provides the reference basis for the secondary development of Zuogui Pills.

A novel strategy for pharmaceutical cocrystal generation without knowledge of stoichiometric ratio: myricetin cocrystals and a ternary phase diagram.

PURPOSE: To develop a streamlined strategy for pharmaceutical cocrystal preparation without knowledge of the stoichiometric ratio by preparing and characterizing the cocrystals of myricetin (MYR) with four cocrystal coformers (CCF). METHODS: An approach based on the phase solubility diagram (PSD) was used for MYR cocrystals preparation and the solid-state properties were characterized by differential scanning calorimetry (DSC), fourier transform-infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The ternary phase diagram (TPD) was constructed by combining the PSD and nuclear magnetic resonance (NMR) data. After that, the TPD was verified by traditional methods. The dissolution of MYR in the four cocrystals and pure MYR within three different media were also evaluated. RESULTS: A simple research method for MYR cocrystal preparation was obtained as follows: first, the PSD of MYR and CCF was constructed and analyzed; second, by transforming the curve in the PSD to a TPD, a region of pure cocrystals formation was exhibited, and then MYR cocrystals were prepared and identified by DSC, FT-IR, PXRD, and SEM; third, with the composition of the prepared cocrystal from NMR, the TPD of the MYR-CCF-Solvent system was constructed. The powder dissolution data showed that the solubility and dissolution rate of MYR was significantly enhanced by the cocrystals. CONCLUSIONS: A novel strategy for pharmaceutical cocrystals preparation without knowledge of the stoichiometric ratio based on the TPD was established and MYR cocrystals were successfully prepared. The present study provides a systematic approach for pharmaceutical cocrystal generation, which benefits the development and application of cocrystal technology in drug delivery.

Effects of solid dispersion and self-emulsifying formulations on the solubility, dissolution, permeability and pharmacokinetics of isorhamnetin, quercetin and kaempferol in total flavones of Hippophae rhamnoides L.

The aim of this study was to investigate the effects of solid dispersions (SD) and self-emulsifying (SE) formulations on the solubility and absorption properties of active components in total flavones of Hippophae rhamnoides L. (TFH). The solubility, dissolution rate, permeability and pharmacokinetics of isorhamnetin, quercetin and kaempferol in TFH SD/SE formulations and TFH were compared. The results showed that the solubility and dissolution rate of isorhamnetin, quercetin and kaempferol in SD/SE formulations were significantly enhanced compared to those in TFH, however, their intestinal permeability was comparable. The bioavailability of isorhamnetin, quercetin and kaempferol in rats remarkably increased after oral administration of TFH SD formulations compared to TFH, but there was no significant increase after oral administration of TFH SE formulations. The results of this study indicated the SD formulations on the improvement of pharmacokinetic properties of isorhamnetin, quercetin and kaempferol in TFH were much better than those of SE formulations. The improvement of pharmacokinetic properties of isorhamnetin, quercetin and kaempferol in TFH by SD formulations was probably ascribed to the enhancement of the solubility and dissolution of the three components, but was not relevant to the intestinal permeability. Therefore, as for herb extracts containing multiple components, especially for their major components with poor water solubility, solid dispersion formulations might have the better potential to enhance their bioavailability.

Pharmacokinetic properties of isorhamnetin, kaempferol and quercetin after oral gavage of total flavones of Hippophae rhamnoides L. in rats using a UPLC-MS method.

An ultra performance liquid chromatography-mass spectrometric (UPLC-MS) method was developed to investigate the pharmacokinetic properties of isorhamnetin, kaempferol and quercetin from a total flavone extract of Hippophae rhamnoides L. (TFH) after single dose oral administration. Rat plasma samples were pretreated using liquid-liquid extraction, and chromatographic separation was performed on a C(18) column using a linear gradient of methanol and formic acid (0.1%). The pharmacokinetic parameters of isorhamnetin, kaempferol and quercetin from TFH in rats were quantitatively determined by UPLC with photodiode array detection (PDA). The qualitative detection of the three flavones was accomplished by selected ion monitoring in negative ion mode ESI-MS. Results of the pharmacokinetic study indicate that the three flavones in TFH were absorbed by passive diffusion in rats, and no "double-peak" phenomenon was observed in C-t curves of the three flavones from TFH except for quercetin. Results of this study indicate that the pharmacokinetic behaviors of isorhamnetin, kaempferol and quercetin when administered together in a complex herbal extract might be different than the individual behaviors of the same compounds administered in their pure forms. Results of this study also demonstrate that UPLC-MS is a rapid and practical method to determine the pharmacokinetic parameters of flavones present in an herbal extract.

Preparation and in vitro evaluation of solid dispersions of total flavones of Hippophae rhamnoides L.

The purpose of this study was to enhance the dissolution of total flavones of Hippophae rhamnoides L. (TFH) by solid dispersions consisting of the drug and a polymeric carrier, poloxamer 188 (PXM). The solvent evaporation method was used to prepare solid dispersions. A 3(2) full-factorial design approach was used for optimization wherein the amount of solvent (X(1)) and the drug-to-polymer ratio (X(2)) were selected as independent variables and the percentage of TFH dissolved in 10 min (Q(10)) was selected as the dependent variable. Multiple linear regression analysis revealed that a suitable level of (1) and X(2) was required for obtaining higher dissolution of TFH from PXM solid dispersions. Solid dispersions were characterized by differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and dissolution tests. Characterization studies revealed that solid dispersion of TFH-PXM showed enhancement of TFH dissolution due to the conversion of TFH into a less crystalline and/or amorphous form. In conclusion, dissolution enhancement of TFH was obtained by preparing its solid dispersions in PXM using solvent method.

[Studies on self-microemulsifying drug preparations of total flavones of Hippophae rhamnoides].

OBJECTIVE: To develop self-microemulsifying preparations of total flavones of Hippophae Rhamnoides L. (TFH) and the determination method of dissolution. METHOD: The equilibrium solubility of TFH in different compositions of oils, emulsifier and assistant emulsifier was investigated. The self-microemulsion formula was optimized by constructing the pseudo-ternary phase diagrams of blank SMEDDS determining the self-microemulsifying efficiency and the stability of the SMEDDS. The 2 hours dissolution curve of TFH self-microemulsifying preparations was established. The optimal self-microemulsion formula was composed of MIGLYOL 812 N, Cremophor EL and 1,2-Propylene glycol. RESULT: The ratio of them was 0.5:5.7:3.8. The average particle size was 12.1 nm. The dissolution rate at 10 minutes of TFH self-microemulsifying preparation was 131% higher than that of Xinda kang tablets. CONCLUSION: The acquired microemulsion with small particle size is stable. The dissolution rate is evidently improved compared with market dosage forms.

[Studies on the influences of Changan Granule on the model of irritable bowel syndrome rat].

OBJECTIVE: To investigate the influences of Changan Granule on the model of rat with irritable bowel syndrome (IBS) by observing the weight, the content of Nitric Oxide (NO) and 5-hydroxytryptamine (5-HT) in serum of rat. METHODS: The model of IBS rat was established by decoction of Folium Sennae and restraint stress, effects of Changan Granule were studied through observing the influences on rat weight and the content of NO and 5-HT in serum. RESULTS: Compared to those of the model group, Changan Granule could improve diarrhea induced by Folium Sennae and increase body weight obviously (P<0.05 or P<0.01). Compared to the control group, Changan Granule could also increase the content of NO and 5-HT in serum significantly (P<0.05 or P<0.01). Through histological survey, we discovered that the high and middle dose of Changan Granule could change the symptom of inflammation and improve the morphous of epithelium mucosae compared to the model group. And there were no obvious pathological changes on the high and middle dose groups of Changan Granule compared to the control group. CONCLUSION: Changan Granule is effective to cure IBS and has protective effects on the bowel mucosae.