Oil-Based Curcuminoid Phospholipid Formulation Mimicking Natural Digestion Enhances Oral Bioavailability of Curcuminoids in Healthy Subjects.

Curcumin, the fat-soluble active ingredient and major compound of curcuminoids contained in the curcuma root, is known for its physiological low absorption and bioavailability. Various formulations and galenic technologies are currently available on the market. In this study, the product tested was provided as a soft gelatin capsule containing curcuminoids in an oily matrix mixed with phospholipids (oil/phospholipids [PL]-based, no new technologies applied or artificial excipients added). This was intended to improve bioavailability of curcuminoids as well as to mimic the natural digestion process of fat-soluble substances. In particular, the oral bioavailability of curcuminoids in the oil/PL-based formulation was compared with the pure curcuminoids extract alone (reference product), in a randomized, cross-over, single oral dose study design. Twelve healthy subjects were administered 200 mg curcuminoids under fasting conditions. Pharmacokinetic parameters were analyzed from individual concentration-time curves of total curcuminoids, as well as the curcumin metabolite tetrahydrocurcumin (THC). Results showed significantly higher AUC0-8h levels after the intake of the oil/PL-based formulation for total curcuminoids (205.60 vs. 112.50 ng/mL*h, P = .0001) as well as for THC (347.30 vs. 118.90 ng/mL*h, P < .0001) in comparison to the pure curcuminoids extract. Cmax was also significantly higher for both parameters analyzed (total curcuminoids: 47.54 vs. 21.16 ng/mL, P = .0001; THC: 96.69 vs. 29.83 ng/mL, P < .0001). In addition, the uptake kinetic of total curcuminoids was significantly fastened with the oil/PL-based curcuminoids formulation compared with the pure curcuminoids extract (P = .0446). These data suggest an improved impact on curcuminoids uptake of the oil/PL-based formulation and confirms its good tolerability.

Enhanced Oral Bioavailability of ß-Caryophyllene in Healthy Subjects Using the VESIsorb® Formulation Technology, a Novel Self-Emulsifying Drug Delivery System (SEDDS).

ß-Caryophyllene (BCP), a common constituent of many spice and food plants, is gaining increased attention due to recent research identifying numerous potential health benefits. Due to limited oral bioavailability observed in preclinical models, the described benefits of BCP may be maximized by using a suitable delivery system. Additionally, human pharmacokinetics (PK) remain unknown. This study evaluates the relative oral bioavailability of BCP formulated in a self-emulsifying drug delivery system (SEDDS) based on VESIsorb® formulation technology (BCP-SEDDS) compared to BCP neat oil. Hence, a randomized, double-blind, cross-over design, single oral dose study (100 mg BCP) in 24 healthy subjects (12 men/12 women) was performed under fasting conditions. Pharmacokinetic parameters were analyzed from individual concentration-time curves. The data show that BCP-SEDDS resulted in a 2.2/2.0-fold increase in AUC0-12h/AUC0-24h and a 3.6-fold increase in Cmax compared to BCP neat oil. Moreover, BCP was absorbed faster from BCP-SEDDS (Tmax: 1.43 h) compared to BCP neat oil (Tmax: 3.07 h). Gender analysis revealed that there is no significant difference between men and women for both the investigated formulations and all investigated PK endpoints. In conclusion, BCP-SEDDS offers a well-tolerated and effective oral delivery system to significantly enhance the oral bioavailability of BCP in humans.

A Novel Self-Emulsifying Drug Delivery System (SEDDS) Based on VESIsorb® Formulation Technology Improving the Oral Bioavailability of Cannabidiol in Healthy Subjects.

Cannabidiol (CBD), a phytocannabinoid compound of Cannabis sativa, shows limited oral bioavailability due to its lipophilicity and extensive first-pass metabolism. CBD is also known for its high intra- and inter-subject absorption variability in humans. To overcome these limitations a novel self-emulsifying drug delivery system (SEDDS) based on VESIsorb® formulation technology incorporating CBD, as Hemp-Extract, was developed (SEDDS-CBD). The study objective was to evaluate the pharmacokinetic profile of SEDDS-CBD in a randomized, double-blind, cross-over design in 16 healthy volunteers under fasted conditions. As reference formulation, the same Hemp-Extract diluted with medium-chain triglycerides (MCT-CBD) was used. CBD dose was standardized to 25 mg. Pharmacokinetic parameters were analyzed from individual concentration-time curves. Single oral administration of SEDDS-CBD led to a 4.4-fold higher Cmax and a 2.85-/1.70-fold higher AUC0-8h/AUC0-24h compared to the reference formulation. Tmax was substantially shorter for SEDDS-CBD (1.0 h) compared to MCT-CBD (3.0 h). Subgroup analysis demonstrated a higher bioavailability in women compared to men. This difference was seen for MCT-CBD while SEDDS-CBD mitigated this gender effect. Overall, SEDDS-CBD showed a significant improvement for all determined pharmacokinetic parameters: increased CBD plasma values (Cmax), favorably enhanced bioavailability (AUC) and fast absorption (Tmax). No safety concerns were noted following either administration.

Bioavailability Study of Maqui Berry Extract in Healthy Subjects.

Several health promoting effects have been reported for maqui berry, rich in anthocyanins. Direct effects of anthocyanins as well as bioactive metabolites might be involved. Within the study, bioavailability of a proprietary standardized maqui berry extract Delphinol® was investigated based on two selected anthocyanins (delphinidin-3-O-glucoside (DS) + cyanidin-3-O-sambubioside (CS)) and two breakdown products (protocatechuic acid (PCA) + gallic acid (GA)) after a single-dose supplementation in humans. Pharmacokinetic parameters were calculated from individual concentration time curves. In all 12 subjects a significant increase was noted in plasma values of DG and CS after intake of maqui berry extract. Maximum concentration of DG was observed after 1.0 ± 0.3 h and CS after 2.0 ± 1.1 h. Within 8 h, concentrations nearly returned to baseline levels. The results confirm a fast uptake and metabolism of the two selected key substances. Additionally, the phenolic acids GA and PCA were observed as breakdown products of anthocyanins. In summary, the study clearly confirms the bioavailability of maqui berry extract and its specific anthocyanin compounds and related breakdown products in healthy subjects.

The use of total antioxidant capacity as surrogate marker for food quality and its effect on health is to be discouraged.

Attempts have been made to use non-compositional parameters, such as total antioxidant capacity (TAC), determined by assays such as oxygen radical absorbance capacity, ferric-reducing ability of plasma, and trolox-equivalent antioxidant capacity, as surrogate markers for food quality and for monitoring food-related changes in human plasma in dietary intervention studies. Increased TAC of plasma is often indiscriminately, and therefore incorrectly, interpreted as being favorable to human health. Whether or not dietary compounds may indeed exert health effects depends on factors other than mere presence in food or body fluids. Many phytochemicals, for example, are poorly absorbed and rapidly metabolized into molecules with altered physicochemical, and therefore biological, properties. Consequently, the use of TAC assays for the in vitro assessment of antioxidant quality of food, which often is employed as a marketing argument or for the assessment of the "wholesomeness" of food, is to be discouraged.

Complete structure determination of N-acetyl-D-galactosamine-binding mistletoe lectin-3 from Viscum album L. album.

The primary structure of the B chain of the N-acetyl-D-galactosamine-recognizing mistletoe lectin-3 (ML-3B) has been deduced from proteolytic digest peptides of the purified glycoprotein, their HPLC-separation and Edman degradation and confirmation of the peptide sequences by MALDI-MS. ML-3B consists of 262 amino acid residues including 10 cysteine moieties. The structure and linkage of the carbohydrate side chains, connected to two N-glycosylation sites at positions Asn(95) and Asn(135) of the lectin, were determined by a combination of glycosidase treatment and MALDI-MS of corresponding glycopeptide fragments. The sequence alignment reveals a high homology with other B chains of type-II RIPs, although there are remarkable differences in the D-galactose-specific mistletoe lectin-1B chain. The recently published primary structure of the mistletoe lectin-3A chain1 and the now available primary sequence of the 3B chain allowed the construction of a preliminary homology model of ML-3. The model demonstrates, unequivocally, that ML-3 is a member of the type-II RIP family with rigid conservation of the enzymatic active site of the A chain and an identical overall protein fold. Specific amino acid residue exchanges and the different glycosylation pattern in comparison with ML-1 are discussed and related to the properties of the two glycoproteins. The knowledge of the complete primary structure of mistletoe lectin-3 is a major contribution towards more insight into the mechanism of the biological activity of commercial mistletoe preparations.

Mistletoe lectin I in complex with galactose and lactose reveals distinct sugar-binding properties.

The structures of mistletoe lectin I (ML-I) from Viscum album complexed with lactose and galactose have been determined at 2.3 A resolution and refined to R factors of 20.9% (Rfree = 23.6%) and 20.9 (Rfree = 24.6%), respectively. ML-I is a heterodimer and belongs to the class of ribosome-inactivating proteins of type II, which consist of two chains. The A-chain has rRNA N-glycosidase activity and irreversibly inhibits eukaryotic ribosomes. The B-chain is a lectin and preferentially binds to galactose-terminated glycolipids and glycoproteins on cell membranes. Saccharide binding is performed by two binding sites in subdomains alpha1 and gamma2 of the ML-I B-chain separated by approximately 62 A from each other. The favoured binding of galactose in subdomain alpha1 is achieved via hydrogen bonds connecting the 4-hydroxyl and 3-hydroxyl groups of the sugar moiety with the side chains of Asp23B, Gln36B and Lys41B and the main chain of 26B. The aromatic ring of Trp38B on top of the preferred binding pocket supports van der Waals packing of the apolar face of galactose and stabilizes the sugar-lectin complex. In the galactose-binding site II of subdomain gamma2, Tyr249B provides the hydrophobic stacking and the side chains of Asp235B, Gln238B and Asn256B are hydrogen-bonding partners for galactose. In the case of the galactose-binding site I, the 2-hydroxyl group also stabilizes the sugar-protein complex, an interaction thus far rarely detected in galactose-specific lectins. Finally, a potential third low-affinity galactose-binding site in subunit beta1 was identified in the present ML-I structures, in which a glycerol molecule from the cryoprotectant buffer has bound, mimicking the sugar compound.

Isolation and quantification of chitin-binding mistletoe lectin from mistletoe extracts and validation of this method.

A method was established to isolate and quantify small amounts of chitin-binding mistletoe lectin (cbML) from extracts of the mistletoe (Viscum album L.) by affinity and reverse phase high performance liquid chromatography. A validation, according to ICH guidelines, of this analytical method was carried out and showed that specificity, robustness and precision are guaranteed. In addition, linearity is ensured for a content between 0.6 and 4.1 microg/ml of cbML in the extracts and recovery was calculated to be in the range of 94 to 100%. So, accuracy of the method is guaranteed as well. As far as the range of the analytical method is concerned, a minimum of 1.2 microg and a maximum of 8.2 microg cbML can be incubated with the affinity material. Detection and quantitation limits were calculated to be 0.13 and 0.46 microg/ml cbML, respectively.

Complete structure determination of the A chain of mistletoe lectin III from Viscum album L. ssp. album.

The complete primary structure of the A chain of mistletoe lectin III (ML3A), a type II ribosome-inactivating protein, was determined using proteolytic digests of ML3A, HPLC separation of the peptides, Edman degration and MALDI-MS. Based on our results, ML3A consists of 254 amino acid residues, showing a high homology to the A chain of isolectin ML1 with only 24 amino acid residue exchanges. A striking important structural difference compared with ML1A is the lack of the single N-glycosylation site in ML3A due to an amino acid exchange at position 112 (ML1A: NL112GS ==> ML3A: T112GS). The alignment of ML3A with the A chains of ML1, isoabrins, ricin D, Ricinus communis agglutinin and three lectins, identified from the Korean mistletoe Viscum album ssp. coloratum, demonstrates the rigid conservation of all amino acid residues, responsible for the RNA-N-glycosidase activity as reported for ricin D. In addition, the fully determined primary structure of ML3A will give further information about the biological mechanism of mistletoe lectin therapy.

Enhanced biocompatibility for SAOS-2 osteosarcoma cells by surface coating with hydrophobic epoxy resins.

BACKGROUND AND AIMS: Implants for surgical needs are produced from different materials including metals, alloys, ceramics or polymers. Metal implants are preferred in those disciplines where sufficient mechanical strength is needed, including traumatology, orthopedic or dental surgery. Further, modern tissue engineering techniques require scaffold materials to generate shape and stability for in vitro generated transplants. However, the biocompatibility and surface contact of most implants or scaffold materials to vital bone or other tissues are not optimal. Therefore we investigated the biocompatibility of different polymer surfaces to an osteoblastic cell line as a function of wettability or hydrophobicity to describe some of the surface parameters influencing the cell to implant or cell to scaffold contact. METHODS: Glass slides were coated with different polymers and in some cases physically or chemically modified. SAOS-2 osteosarcoma cells were used for the biocompatibility tests on 16 different polymers and modifications thereof. The viability of the adherent cells was investigated by MTT assay. Commercially available tissue culture vessels served as controls. RESULTS: We report that excellent biocompatibility to SAOS-2 osteoblastic cells can be obtained with hydrophobic surfaces generated for instance by epoxy resins. Chemical modification of epoxy resin surfaces yielded even a further increased viability index surpassing the viability index obtained with cell culture vessels. CONCLUSION: We conclude that modified hydrophobic surfaces represent an interesting group of compounds for coating endoprosthetic implants or scaffolds for the purposes of tissue engineering.