Correlation between in vitro and in vivo erosion behaviour of erodible tablets using gamma scintigraphy

In vitro and in vivo erosion behaviour of erodible tablets consisting of glyceryl behenate and low-substituted hydroxypropylcellulose manufactured using three different methods: direct compression (DC), melt granulation (MG) and direct solidification (DS) was investigated. In vitro erosion behaviour was studied using gravimetric and scintigraphic methods. For scintigraphic investigations, the radiolabel was adsorbed onto activated charcoal and incorporated into tablets at a concentration that did not affect the erosion profile. A clinical study was carried out in six healthy volunteers using gamma scintigraphy. Tablet erosion was affected by the preparation method and was found to decrease in the order of preparation method, DC > MG > DS tablets. The mean in vivo onset time for all tablets (DC: 6.7 ± 3.8 min, MG: 18.3 ± 8.1 min, DS: 67 ± 18.9 min) did not differ significantly from in vitro onset time (DC: 5.3 ± 1 min, MG: 16.8 ± 3.9 min, DS: 61.8 ± 4.7 min). The mean in vivo completion times were found to be 36.6 ± 9.7 (DC tablets), 70 ± 18.3 min (MG tablets) and 192.5 ± 39.9 min (DS tablets). Among the three different erodible tablets, MG tablets showed the highest correlation between in vitro and in vivo mean erosion profile and suggested a potential platform to deliver controlled release of water-insoluble compounds.     

Genotoxic evaluation of titanium dioxide nanoparticles in vivo and in vitro

With the extensive application of titanium dioxide (TiO₂) nanoparticles (NPs) in food industry, there is a rising debate concerning the possible risk associated with exposure to TiO₂ NPs. The purpose of this study is to evaluate the genotoxicity of TiO₂ NPs using in vivo and in vitro test systems. In vivo study, the adult male Sprague-Dawley rats were exposed to anatase TiO₂ NPs (75 ± 15 nm) through intragastric administration at 0, 10, 50 and 200 mg/kg body weight every day for 30 days. The γ-H₂AX assay showed TiO₂ NPs could induce DNA double strand breaks in bone marrow cells after oral administration. However, the micronucleus test revealed that the oral-exposed TiO₂ NPs did not cause damage to chromosomes or mitotic apparatus observably in rat bone marrow cells. In vitro study, Chinese hamster lung fibroblasts (V79 cells) were exposed to TiO₂ NPs at the dose of 0, 5, 10, 20, 50 and 100 μg/mL. Significant decreases in cell viability were detected in all the treated groups after 24 h and 48 h exposure. Significant DNA damage was only observed at the concentration of 100 μg/mL after 24 h treatment using the comet assay. The obvious gene mutation was observed at the concentration of 20 and 100 μg/mL after 2 h treatment using hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene mutation assay. This study presented a comprehensive genotoxic evaluation of TiO₂ NPs, and TiO₂ NPs were shown to be genotoxic both in vivo and in vitro tests. The gene mutation and DNA strand breaks seem to be more sensitive genetic endpoints for the detection of TiO₂ NPs induced genotoxic effects.     

In vitro and in vivo characterization of a novel negative allosteric modulator of neuronal nAChRs

In this study, we compared the in vitro and in vivo neuronal nicotinic acetylcholine receptor (nAChR) properties of 1,2,3,3a,4,8b-hexahydro-2-benzyl-6-N,N-dimethylamino-1-methylindeno[1,2,-b]pyrrole (HDMP, 4) to that of negative allosteric modulator (NAM), PCP. Patch-clamp experiments showed that HDMP exhibited an inhibitory functional activity at α7 nAChRs with an IC₅₀ of 0.07 μM, and was 357- and 414-fold less potent at α4β2 and α3β4 nAChRs, with IC₅₀s of 25.1 and 29.0 μM, respectively. Control patch-clamp experiments showed that PCP inhibited α7, α4β2 and α3β4 nAChRs with IC₅₀s of to 1.3, 29.0 and 6.4 μM, respectively. Further, HDMP did not exhibit any appreciable binding affinity to either α7 or α4β2 nAChRs, suggesting its action via a non-competitive mechanism at these neuronal nAChR subtypes. The in vivo study showed that HDMP was a potent antagonist of nicotine-induced analgesia in the tail-flick (AD₅₀ = 0.008 mg/kg), but not in the hot-plate test. All together, our in vitro and in vivo data suggest that HDMP is a novel NAM of neuronal nAChRs with potent inhibitory activity at α7 nAChR subtype at concentrations ≤1 μM that are not effective for α4β2 and α3β4 nAChRs.     

Estrogenic/antiestrogenic activities of a Epimedium koreanum extract and its major components: in vitro and in vivo studies

The estrogenic and antiestrogenic activities of Epimedii Herba, which is a traditional medicinal herb used in Korea and China were investigated in this study. The in vitro estrogen receptor (ER) mediated estrogenic/antiestrogenic activities of an Epimedii Herba extract (Epi ext) and its major components were determined using an estrogen responsive element driven reporter gene assay in MCF-7/ERE and HEK293T cells. The Epi ext exhibited ERα- and ERβ-mediated estrogenic activity with an EC₅₀ of 5.0 and 17.8 μM in HEK293T cells, respectively. Prenylflavonoid glycosides such as icariin (ICA), epimedin A, B, and C did not show any in vitro estrogenic or antiestrogenic activities. Icaritin (ICT) and quercetin exhibited in vitro ER mediated estrogenic activity with a more potent interaction with ERβ. In vivo estrogenic activities of the Epi ext, ICA and ICT were compared using an uterotrophic assay. Although the potency of in vitro estrogenic activity was in the order of ICT > Epi ext > ICA, ICA had the strongest estrogenic activity and next ICT in ovariectomized rats. These results collectively suggest that phytoestrogens possess both estrogenic and antiestrogenic activity, and that the differential expression of these two compounds with opposing activities is dependent on the physiological environment in terms of estrogen level, which may be the case in humans.     

Controlled non-invasive transdermal iontophoretic delivery of zolmitriptan hydrochloride in vitro and in vivo

The objective was to investigate the transdermal delivery kinetics of zolmitriptan from an iontophoretic patch system in Yorkshire swine in vivo. Preliminary in vitro experiments showed that cumulative drug transport during a 6-h current application (0.25 mA cm⁻²) was independent of patch load (263.7 ± 92.7, 357.2 ± 85.9, 374.9 ± 74.3 and 335.9 ± 27.7 μg cm⁻² for 7.5, 15, 45 and 90 mg patch loads, respectively; ANOVA, p < 0.05); the steady-state flux was ∼92 μg cm⁻² h⁻¹. The in vivo studies used multistep current profiles to demonstrate (i) rapid drug uptake and (ii) the effect of superposing a bolus input on basal drug levels. In both studies, zolmitriptan was detected in the blood after 2.5 min; drug levels were 7.1  1.7 and 10.4 ± 3.5 ng ml⁻¹ at t = 30min in Studies 1 and 2, respectively. In Study 2, increasing current intensity from 0.2 to 1.4 mA (0.05-0.35 mA cm⁻²) at t = 180 min caused zolmitriptan levels to rise from 9.38 ± 0.93 ng ml⁻¹ at t = 180 min to 13.57 ± 1.85 ng ml⁻¹ at t = 190 min; a ∼50% increase in 10 min. Extrapolation of these results to humans suggests the feasibility of delivering therapeutic amounts of zolmitriptan at faster rates than those from existing dosage forms.     

Validation of in vitro screening models for progestagenic activities: Inter-assay comparison and correlation with in vivo activity in rabbits

The PR CALUX® cell line is a stably transfected human U2-OS cell line expressing the human PR and a luciferase reporter construct containing three progesterone-responsive elements coupled to a minimal promoter. The validity of this assay has been studied as an alternative to the McPhail assay in rabbits, an in vivo assay to detect progestins. The PR CALUX assay was characterized by its stable expression of PR protein which leads to induction of endogenous PR target genes by progestins. It was found to have a highly selective response to low levels of different progestins, as well as an insignificant response to other nuclear hormone receptor ligands. As an important step in their validation, the PR CALUX bioassay was compared with another earlier described in vitro bioassay, a Chinese Hamster Ovary (CHO) cell-based PR-CHO reporter gene assay as well as with an in vitro PR-binding (PR-BIN) assay, and the in vivo McPhail assay. This was done using 35 (with the most accurate potency determinations in all tests) and 50 (with less reliable potency determinations in some tests) compounds tested in all assays. The correlation scores between PR CALUX and PR-CHO were r² = 0.77, and 0.93, respectively; between PR CALUX and PR-BIN r² = 0.69 and 0.80. Comparison between either the PR CALUX or the PR-CHO transactivation assay and the in vivo McPhail assay revealed very good correlations of r² = 0.68 (n = 35), and 0.85 (n = 50). The transactivation assays can discriminate very potent, from potent, weak and inactive compounds rather easily. Besides testing the biological activity of pure chemicals and pharmaceuticals in vitro, the PR CALUX and PR-CHO transactivation assays proved to be relatively good predictors of in vivo progestagenic activity, allowing the use of these assays as prescreening methods or in vitro alternatives.     

Preventive effects of a purified extract isolated from Salvia miltiorrhiza enriched with tanshinone I,tanshinone IIA and cryptotanshinone on hepatocyte injury in vitro and in vivo

Salvia miltiorrhiza is traditionally used to treat liver disease in Asia. In this study, we tested the ability of a purified extract of S. miltiorrhiza (PF2401-SF) and its constituents, tanshinone I, tanshinone IIA, and cryptotanshinone, to protect against acute and subacute liver damage induced by carbon tetrachloride by measuring serum transaminase levels, the reduced form of glutathione (GSH), antioxidant enzyme activities, and lipid peroxidation levels in the liver. We also evaluated their ability to protect primary cultured rat hepatocytes from tertiary-butylhydroperoxide (tBH) or d-galactosamine (GalN). PF2401-SF was protective at 50–200 mg/kg per day in acute liver injury and 25–100 mg/kg per day in subacute liver injury. Tanshinone I, tanshinone IIA, and cryptotanshinon (40 μM), inhibited lactate dehydrogenase leakage, GSH depletion, lipid peroxidation and free radical generation in vitro. PF2401-SF and its major constituents, tanshinone I, tanshinone IIA and cryptotanshinone, can protect against liver toxicity in vivo and in vitro due to its antioxidant effects.     

In vivo and in vitro skin absorption of lipophilic compounds,dibutyl phthalate,farnesol and geraniol in the hairless guinea pig

The relationship between in vitro and in vivo skin absorption of lipophilic cosmetic ingredients (dibutyl phthalate (DBP, Log K_ow: 4.45), farnesol (Log K_ow: 5.77) and geraniol (Log K_ow: 3.56) from an oil-in-water emulsion was investigated in the hairless guinea pig. In vivo absorption of DBP, farnesol and geraniol 24 h after dermal application was 62.0 ± 2.0, 39.8 ± 2.5, and 15.1 ± 1.8% of the applied dose (%AD), respectively. In vitro absorption was measured at 24 and 72 h by using flow-through diffusion cells (0.64 cm²) with a receptor fluid consisting of HHBSS + 4% BSA. In vitro studies of DBP, farnesol and geraniol absorption over 24 h found 27.1 ± 1.9, 43.5 ± 3.3 and 45.9 ± 3.2%AD in receptor fluid, respectively, and over 72 h found 59.9 ± 3.2, 77.5 ± 7.1 and 49.0 ± 6.3%AD, respectively. We found that the amount of DBP absorbed in vivo after 24 h closely agreed with the amount of DBP found in the receptor fluid in vitro after 72 h. In contrast, the amount of topically applied farnesol absorbed in vivo after 24 h was similar to the amount of farnesol found in receptor fluid in vitro after 24 h. A direct comparison between the in vivo absorption of geraniol and the in vitro absorption at 24 and 72 h was not meaningful due to the rapid evaporation of geraniol from the skin. Our in vitro results suggest that lipophilic chemicals initially form a reservoir in skin, and the material in the reservoir may ultimately diffuse out of the skin into the receptor fluid within 72 h. Our results also demonstrate the utility of in vivo studies for resolving questions about the fate of lipophilic chemicals remaining in skin after in vitro absorption studies.     

Thermo-responsive shell cross-linked PMMA-b-P(NIPAAm-co-NAS) micelles for drug delivery

Thermo-responsive amphiphilic poly(methyl methacrylate)-b-poly(N-isopropylacrylamide-co-N-acryloxysuccinimide) (PMMA-b-P(NIPAAm-co-NAS)) block copolymer was synthesized by successive RAFT polymerizations. The uncross-linked micelles were facilely prepared by directly dissolving the block copolymer in an aqueous medium, and the shell cross-linked (SCL) micelles were further fabricated by the addition of ethylenediamine as a di-functional cross-linker into the micellar solution. Optical absorption measurements showed that the LCST of uncross-linked and cross-linked micelles was 31.0 °C and 40.8 °C, respectively. Transmission electron microscopy (TEM) showed that both uncross-linked and cross-linked micelles exhibited well-defined spherical shape in aqueous phase at room temperature, while the SCL micelles were able to retain the spherical shape with relatively smaller dimension even at 40 °C due to the cross-linked structure. In vitro drug release study demonstrated a slower and more sustained drug release behavior from the SCL micelles at high temperature as compared with the release profile of uncross-linked micelles, indicating the great potential of SCL micelles developed herein as novel smart carriers for controlled drug release.     

Effects of Areca catechu L. containing procyanidins on cyclooxygenase-2 expression in vitro and in vivo

Polyphenols are widely distributed in plants and known for antioxidant and anti-inflammatory properties. Areca nut, rich in polyphenols, is the major component of betel quid and we have previously shown that the extract of areca nut can induce oxidative stress in vitro. In this study, we have further pinpointed that areca nut extract (ANE) contains catechin based procyanidins which range from dimers to decamers and polymers; this was carried out by HPLC and electrospray ionization/mass spectrometry (ESI/MS). To quantify their antioxidant potential, oligomeric and polymeric procyanidins of ANE were separated and evaluated using the Trolox equivalent antioxidant capacity (TEAC) assay. The results clearly demonstrated that the antioxidant capacity of the ANE procyanidins increased with the degree of polymerization. The anti-inflammatory potential of ANE was also tested using 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated human oral cancer SAS cells. ANE inhibited TPA-induced cyclooxygenase-2 (COX-2) protein expression at low doses, which correlated with the inhibition of ERK phosphorylation in the SAS cells. Furthermore, feeding rats with ANE at 1 and 10 mg/kg/day for 5 days significantly repressed carrageenan-induced inflammatory exudates and PGE₂ formation. In conclusion, ANE, which contains catechins based oligomeric and polymeric procyanidins, regulates COX-2 expression in vitro and possess anti-inflammatory potential in vivo.     

The effect of cimetidine on in vitro and in vivo microsomal drug metabolism in the rat

The effect of cimetidine on rat liver microsomal drug metabolism in vitro and in vivo was studied. Cimetidine inhibits aminopyrine N-demethylation and benzo[a]pyrene hydroxylation in a noncompetitive manner with inhibition constants between 1 and 10 mM. Benzo[a]pyrene hydroxylation in liver microsomes from 3-methylcholanthrene-pretreated rats is not appreciably inhibited by cimetidine indicating some specificity in terms of different cytochrome P-450 forms. Cimetidine gives rise to a type II spectral change with a spectral dissociation constant of about 0.1 mM. The prolonged administration of cimetidine does not result in the induction of hepatic drug metabolism. Pretreatment of rats with cimetidine prolongs aminopyrine half-life and hexobarbital sleeping time. These results demonstrate that cimetidine is an in vitro inhibitor of microsomal drug metabolism in the rat and this inhibition leads to pharmacokinetic drug-drug interactions in vivo.     

Enhanced in vitro transdermal delivery of caffeine using a temperature- and pH-sensitive nanogel,poly(NIPAM-co-AAc)

Temperature- and pH-responsive poly(N-isopropylacrylamide) (polyNIPAM) copolymerised with 5% (w/v) of acrylic acid (AAc), termed as poly(NIPAM-co-AAc) nanogel was investigated as a novel multi-responsive topical drug delivery carrier, using caffeine as a model permeant. The role of a pH modulator (citric acid) on the nanogel system was also studied. The loading was carried out in deionised water at two different temperatures, which were 2–4 °C and 25 °C (room temperature, RT) over 3 days. The loading of caffeine into the poly(NIPAM-co-AAc) nanogel was found to be significantly higher at 2–4 °C than at RT (p = 0.0072). As for the control nanogel (polyNIPAM), a similar pattern of loading level can be observed (p = 0.0005). This enhanced loading at low temperatures could be attributed to the hydrophilic behaviour of the polyNIPAM network in response to temperatures lower than its lower critical solution temperature (LCST). In vitro diffusion studies across epidermis porcine skin were carried out at 32 °C for the saturated solution of caffeine as well as caffeine-loaded poly(NIPAM-co-AAc) and polyNIPAM nanogels. The in vitro permeation data of caffeine-loaded poly(NIPAM-co-AAc) at 2–4 °C were shown to enhance the delivery of the loaded caffeine across the epidermis in comparison to the saturated solution of caffeine, by 3.5 orders of magnitude. Additionally, the study demonstrated that the effect of pH modulator on the release of loaded permeant was insignificant.     

In vitro and in vivo antioxidant activity of Symplocos cochinchinensis S. Moore leaves containing phenolic compounds

Methanol extract of Symplocos cochinchinensis S. Moore leaves was evaluated for its in vitro and in vivo antioxidant activity. The total phenolic content of the extract was 230 mg of gallic acid equivalents/g extract. The extract showed very good scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC₅₀ 620.30 ± 0.14 μg/ml), hydroxyl (IC₅₀ 730.21 ± 1.05 μg/ml), nitric oxide (IC₅₀ 870.31 ± 0.19 μg/ml) radicals, as well as high reducing power. The extract also showed strong suppressive effect on lipid peroxidation. In in vivo study CCl₄ induced oxidative stress produced significant increase in SGOT, SGPT and LDH levels along with reduction in liver SOD, CAT, GSH and GPx levels. Pre-treatment of rats with the extract (250 and 500 mg/kg) for 7 days showed significant reduction in the levels of SGOT, SGPT and LDH compared to CCl₄ treated rats. SOD, CAT, GSH and GPx levels were increased significantly due to treatment with the extract. The activity of the extract was comparable to the standard drug, silymarin (25 mg/kg). The results suggest that the leaves of S. cochinchinensis are a source of natural antioxidants.     

Physicochemical aspects of doxorubicin-loaded pH-sensitive polymeric micelle formulations from a mixture of poly(l-histidine)-b-poly(l-lactide)-b-poly(ethylene glycol)

In this study, doxorubicin (DOX) was physically incorporated into pH-sensitive micelles made from a mixture of poly(l-histidine)-b-poly(ethylene glycol)/poly(l-lactide)-b-poly(ethylene glycol) (75/25, wt.%). The DOX-loaded mixed micelles were formulated using dialysis methods and optimal DOX incorporation was achieved at a drug/polymer feed ratio of 0.2 (wt./wt.) when a proper amount of aqueous phase (0.2, v./v.) was added into the common solvent (DMSO) solution, followed by dialysis at 4 °C. Based on the results obtained from dynamic light scattering, UV-Vis absorption, and fluorescence experiments, it was demonstrated that the encapsulated drugs were mainly located inside the hydrophobic micelle cores, well protected and inaccessible to the exterior molecules. Under in vitro conditions, although the microstructure of the micelles was altered below pH 8.0 by the encapsulated drugs, the drug-loaded micelles still exhibited a desirable ability to control the drug release in response to tumor extracellular pH.     

Cisplatin,oxaliplatin, and carboplatin unequally inhibit in vitro mRNA translation

DNA is considered the preferential target of platinum containing cytostatics such as cisplatin, oxaliplatin, and carboplatin. Despite profound knowledge on the interaction between platinum drugs and DNA, there is little data on the interaction with mRNA and even less on the potential differences among these antineoplastic agents to inhibit protein synthesis. We therefore established an in vitro translation system using in vitro transcribed mRNA encoding green fluorescent protein (GFP) to evaluate the effects of exposure of GFP mRNA to 0–100 μM of cisplatin, oxaliplatin, or carboplatin. We additionally investigated the interaction between these drugs and mRNA through evaluation of crossing-points during quantitative real-time polymerase chain reactions. In contrast to oxaliplatin or carboplatin, 100 μM cisplatin significantly increased crossing-points by about 3 cycles (P < 0.01) and profoundly attenuated translation of GFP mRNA (P < 0.05). Oxaliplatin showed a trend to reduce GFP mRNA translation, whereas carboplatin entirely failed to influence it.     

Evaluation of genotoxicity of multi-walled carbon nanotubes in a battery of in vitro and in vivo assays

The genotoxic potential of two products of multi-walled carbon nanotubes (coded as N-MWCNTs, diameter of 44 nm/BET surface area of 69 m²/g and MWNT-7, diameter of 70 nm/BET surface area of 23 m²/g) was evaluated using a battery of genotoxicity assays, comprising a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and a mammalian erythrocytes micronucleus test. Neither type exerted mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, and TA1537, or in Escherichia coli WP2uvrA, in the absence or presence of metabolic activation. The products of MWCNTs did not increase the number of structural chromosomal aberrations either, regardless of metabolic activation, though they increased the number of numerical chromosomal aberrations, one slightly and the other distinctly, in the absence of metabolic activation. In ICR mice, the two products did not affect the proportion of immature erythrocytes, the total proportion of erythrocytes, or the number of micronuclei in immature erythrocytes.     

Protective effect of Solanum torvum on doxorubicin-induced nephrotoxicity in rats

Nephrotoxicity is one of the important side effects of anthracycline antibiotics. The aim of the study was to determine the protective effect of Solanum torvum on doxorubicin-induced nephrotoxicity in rats using biochemical and histopathological approaches. Oxidative stress is the main factor in doxorubicin (DOX) induced nephrotoxicity. Wistar rats received either DOX (67.75 mg/kg, i.v, 2 days before sacrifice) or S. torvum (100 mg/kg and 300 mg/kg, p.o.) prior to DOX treatment or S. torvum (100 mg/kg and 300 mg/kg, p.o.) extract alone for 4 weeks. Nephrotoxicity was assessed by measuring the abnormal levels of serum creatinine and blood urea nitrogen (BUN). The anti-oxidant defence enzymes superoxide dismutase (SOD) and catalase (CAT) of kidney tissue were also measured at the end of the treatment schedule. Treatment with S. torvum (100 mg/kg and 300 mg/kg) significantly (p < 0.05) decreased the levels of creatinine and BUN and significantly (p < 0.05) increased the anti-oxidant defence enzyme levels of SOD and CAT. Histopathological changes showed that DOX caused significant structural damages to kidneys like tubular necrosis, renal lesions and glomerular congestion which was reversed with S. torvum. The results suggest that S. torvum has the potential in preventing the nephrotoxicity induced by doxorubicin.     

Injury effects of ginkgolide B on maturation of mouse oocytes,fertilization, and fetal development in vitro and in vivo

Ginkgolide B (GKB), the major active component of Ginkgo biloba extracts, exerts both stimulatory and inhibitory effects on apoptotic signaling. Previous studies by our group demonstrated that ginkgolide treatment of mouse blastocysts induces apoptosis, decreases cell number, hinders early postimplantation blastocyst development, and increases early-stage blastocyst death. Here, we further investigate the effects of GKB on oocyte maturation, and subsequent pre- and postimplantation development in vitro and in vivo. In our experiments, GKB induced a significant reduction in the rate of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with 1–6 μM GKB during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased placental and fetal weights. Data obtained using an in vivo mouse model further disclosed that consumption of drinking water containing 3–6 μM GKB led to decreased oocyte maturation and in vitro fertilization, as well as early embryo developmental injury, specifically, inhibition of development to the blastocyst stage in vivo. To our knowledge, this is the first study to investigate the impact of GKB on maturation of mouse oocytes, fertilization, and sequential embryonic development.     

Effect of permeation enhancers on transdermal delivery of fluoxetine: In vitro and in vivo evaluation

The aim of this study was to investigate the feasibility of transdermal fluoxetine (FX) delivery. The effects of chemical forms (base or salt) and permeation enhancers on in vitro skin permeation of FX were assessed using hairless mouse, rat and human cadaver skin. The optimized formulations from the in vitro studies were then evaluated in an in vivo pharmacokinetic study in rats. The in vitro skin permeation studies suggested that the FX base (FXB) and isopropyl myristate (IPM)–limonene mixture could be suitable for transdermal delivery of FX. The permeation parameters of FX through human cadaver skin were well correlated with that through hairless mouse and rat skin, suggesting that these animal models can be used for predicting the permeability of FX through human skin. After transdermal administration of FX with IPM or the IPM–limonene mixture to rats, the mean steady-state plasma concentration (C_ss) was 66.20 or 77.55 ng/mL, respectively, which was maintained over 36 h and had a good correlation with the predicted C_ss from the in vitro data. These in vitro and in vivo data demonstrated that permeation enhancers could be a potential strategy for transdermal delivery of FX.     

Macranthoside B,a hederagenin saponin extracted from Lonicera macranthoides and its anti-tumor activities in vitro and in vivo

Macranthoside B (MB) is a hederagenin saponin extracted from the flower bud of Lonicera macranthoides. In this study, we defined the anticancer effect of MB both in vitro and in vivo using cell proliferation assays and xenograft tumor growth assays. Our data indicate that MB inhibits the proliferation of various kinds of cancer cells with IC₅₀ values in the range of 10–20 μM. Moreover, the volume and weight of xenograft tumors in nude mice treated with 5 mg/kg MB were decreased remarkably compared to those of the vehicle control group. Furthermore, DAPI staining and flow cytometry analysis with Annexin V/PI double staining revealed that more apoptotic cells were observed following MB treatment. In addition, degradation of PARP (poly-ADP-ribose polymerase), and activation of the caspase cascade for intrinsic pathways were observed. We also found that the expression of Bcl-2 protein decreased and the protein level of Bax increased which leading to an increase of the Bax/Bcl-2 ratio. Our results showed that MB exhibited strong anti-tumor effect and mitochondrion-mediated apoptosis induction involved in it.