Berry anthocyanins and anthocyanidins exhibit distinct affinities for the efflux transporters BCRP and MDR1

BACKGROUND AND PURPOSE

Dietary anthocyanins hold great promise in the prevention of chronic disease but factors affecting their bioavailability remain poorly defined. Specifically, the role played by transport mechanisms at the intestinal and blood-brain barriers (BBB) is currently unknown.

EXPERIMENTAL APPROACH

In the present study, 16 anthocyanins and anthocyanidins were exposed to the human efflux transporters multidrug resistance protein 1 (MDR1) and breast cancer resistance protein (BCRP), using dye efflux, ATPase and, for BCRP, vesicular transport assays.

KEY RESULTS

All test compounds interacted with the BCRP transporter in vitro. Of these, seven emerged as potential BCRP substrates (malvidin, petunidin, malvidin-3-galactoside, malvidin-3,5-diglucoside, cyanidin-3-galactoside, peonidin-3-glucoside, cyanidin-3-glucoside) and 12 as potential inhibitors of BCRP (cyanidin, peonidin, cyanidin-3,5-diglucoside, malvidin, pelargonidin, delphinidin, petunidin, delphinidin-3-glucoside, cyanidin-3-rutinoside, malvidin-3-glucoside, pelargonidin-3,5-diglucoside, malvidin-3-galactoside). Malvidin, malvidin-3-galactoside and petunidin exhibited bimodal activities serving as BCRP substrates at low concentrations and, at higher concentrations, as BCRP inhibitors. Effects on MDR1, in contrast, were weak. Only aglycones exerted mild inhibitory activity.

CONCLUSIONS AND IMPLICATIONS

Although the anthocyanidins under study may alter pharmacokinetics of drugs that are BCRP substrates, they are less likely to interfere with activities of MDR1 substrates. The present data suggest that several anthocyanins and anthocyanidins may be actively transported out of intestinal tissues and endothelia, limiting their bioavailability in plasma and brain.

Tea catechins' affinity for human cannabinoid receptors

Among the many known health benefits of tea catechins count anti-inflammatory and neuroprotective activities, as well as effects on the regulation of food intake. Here we address cannabimimetic bioactivity of catechin derivatives occurring in tea leaves as a possible cellular effector of these functionalities. Competitive radioligand binding assays using recombinant human cannabinoid receptors expressed in Chem-1 and CHO cells identified (-)-epigallocatechin-3-O-gallate, EGCG (K(i)=33.6 microM), (-)-epigallocatechin, EGC (K(i)=35.7 microM), and (-)-epicatechin-3-O-gallate, ECG (K(i)=47.3 microM) as ligands with moderate affinity for type 1 cannabinoid receptors, CB1. Binding to CB2 was weaker with inhibition constants exceeding 50 microM for EGC and ECG. The epimers (+)-catechin and (-)-epicatechin exhibited negligible affinities for both CB1 and CB2. It can be concluded that central nervous cannabinoid receptors may be targeted by selected tea catechins but signaling via peripheral type receptors is less likely to play a major role in vivo.

[Retrospective analysis of healing problems after reamed and unreamed nailing of femoral shaft fractures]

168 fractures of the femoral shaft treated by intramedullary nailing were analyzed retrospectively. From 1986-1992 116 fractures had been treated with the reamed AO universal nail (RFN) and from 1993-1996 52 fractures with the AO unreamed femoral nail (UFN). In 24% of the RFN-group and in 2% of the UFN-group (p < 0.0001) open reduction of the fracture had been necessary. The time to radiological consolidation was similar in both groups (18.1 weeks +/- 6.1 vs. 18.3 weeks +/- 5.7, [mean +/- SD]). Delayed unions were less frequent in the RFN-group than in the UFN-group (3% vs. 13%, p = 0.01). Non-unions occurred in the RFN-group in 4%, in the UFN-group in 8%, the difference is not statistically significant (p = 0.46). Fractures with impaired consolidation (delayed-unions and non-unions) in the RFN group were distributed randomly along the femoral diaphysis, whereas all 11 fractures with retarded healing in the UFN group were short transverse or oblique fractures localized immediately distal to the femoral isthmus. We believe that there is mainly a mechanical reason for this phenomen, in addition to fracture type and fracture localization the (insufficient) length of the unreamed nails might have impaired stability further. The different factors should be investigated in larger series. As a consequence we now treat transverse and short oblique fractures of diaphyseal femoral fractures distal to the femoral isthmus with a RFN whereas in other types and localizations of diaphyseal femoral fractures we continue to use the UFN with special attention to maximal nail diameter and length.

[Fever of unknown origin, head and muscle pain, hemoptysis, hepatosplenomegaly and icterus. 2 case reports]

Die Leptospirose kommt in der Schweiz aufgrund der klimatischen Verhältnisse selten vor, trotzdem wird die Inzidenz dieser Krankheit unterschätzt. Das klinische Bild ist vielfältig. Die Differentialdiagnose reicht von einer grippeähnlichen Erkrankung bis hin zur akut verlaufenden Systemerkrankung. Diese Tatsache erfordert aufgrund der therapeutischen Konsequenz, die Durchführung einer intensiven und häufig auch invasiven Diagnostik, welche letztlich oft unergiebig bleibt. Neue und vor allem schnellere diagnostische Möglichkeiten mittels PCR aus Blut, Liquor und Urin werden diskutiert, sind aber noch nicht etabliert. Eine antibiotische Therapie wird je nach Verlaufsform kontrovers beurteilt.

[MR-Arthrography with radial sequences for visualization of early hip pathology not visible on plain radiographs]

AIM

We wanted to improve MRI visualization of early hip pathology invisible on plain radiographs.

METHOD

An MR arthrography of the hip with radial sequences is described. The standard MR technique is improved by 1) using a small flexible surface coil to show selectively the hip joint to be examined, 2) application of gadolinium intra-articularly and 3) by radial imaging sequences perpendicular to the true plane of the acetabulum.

CONCLUSION

By this technique it is possible to achieve an undistorted image of each aspect of the acetabular rim. Regions of special interest can be defined and their pathologies possibly related to morphologies of the proximal end of the femur.

[Inadequate detectability of early stages of coxarthrosis with conventional roentgen images]

AIM

The study was undertaken to determine the value of standard radiographs in the early stages of osteoarthritis.

METHODS

Standard radiographs and arthro-MRI's from thirty hips operated on for early arthrosis (age 25-57 years) were independently analyzed by two orthopaedic surgeons and one radiologist blinded from the intra-operative findings. The radiographs were read on two occasions two months apart. The radiographic findings were then compared to the intra-operative findings.

RESULTS

Intra-operatively, all cases had a labral lesion and, in all but three of the cases, there was a major acetabular cartilage lesion. Each investigator diagnosed all of the labral and/or cartilage lesions on the arthro-MRI. However, on average, the investigators judged 20% (10-35%) of the hips to be normal on the standard radiographs. The probability of detecting an abnormal hip joint was statistically significantly better with arthro-MRI in four of six readings (p < 0.05) and there was a trend in favor of the arthro-MRI in the other two readings (p < 0.1). Intra-observer agreement when using the Tönnis classification of arthrosis on standard radiographs was 0.26 (-0.1-0.62), 0.69 (0.42-0.96) and 0.83 (0.53-1) [kappa-statistic, (95% confidence interval)]. The interobserver agreement was 0.24 (-0.07-0.55).

CONCLUSION

Plain radiographs in the early stages of osteoarthrosis of the hip are neither reliable nor valid to diagnose the onset of disease. Therefore, in the case of a normal radiograph and clinical suspicion of arthrosis, a "normal" radiograph does not exclude the diagnosis and an artho-MRI should be obtained for further evaluation.

[Blood loss in total hip prosthesis implantation: lateral versus supine position]

We performed a prospective randomized study to determine blood loss differences between supine or lateral patient position, during surgery in elective total hip replacement. Between January and October 1996, 64 consecutive cases of total hip replacements were randomly scheduled for a procedure either in the supine or in the lateral position. Of the 56 cases evaluated, 29 were operated in the supine position (SP) and 27 in the lateral position (LP). The standardized implantations were performed without cement and the blood loss was measured. The calculated loss of Hb on the day of operation was 235 g Hb +/- 17 (mean +/- s.e.) in the SP group and 177 g Hb +/- 14 in the LP group, respectively, (unpaired t-test p = 0.01). The calculated loss of Hb after five postoperative days was 227 g Hb +/- 24 (mean +/- s.e.) in the SP group and 179 g Hb +/- 24 in the LP group, respectively, p < 0.2. The net loss of Hb after five postoperative days was calculated by subtracting all perioperative blood substitutions (Cellsaver, autologous and homologous blood) resulting in 340 g Hb +/- 21 (mean +/- s.e.) in the SP group and 272 g Hb +/- 21 in the LP group, respectively, p = 0.02. The blood loss in primary cementless total hip replacement surgery can be significantly reduced by performing the procedure in the lateral position compared to that in the supine position. The blood loss is limited to the day of operation, as indicated by the stable Hb-levels thereafter.

[Acute liver and kidney failure following sorbitol infusion in a 28-year-old patient with undiagnosed fructose intolerance]

In connection with nephrectomy fatal liver and renal failure occurred after infusion of 50 g sorbitol in a 28 years old patient with undiagnosed fructose intolerance. A marked hypoglycemia and lactacidosis, an increase in uric acid, an acute liver failure with breakdown of excretory and synthetic function and disorder of hemostasis were typical of fructose/sorbitol infusion in hereditary fructose intolerance. Under adequate diet, as indicated in our case, HFI could be undiagnosed up to adult age. Therefore, fructose intolerance should be excluded by anamnesis before infusion of fructose/sorbitol. In unknown anamnesis (unconsciousness) fructose/sorbitol containing infusions should not be used. Fructose/sorbitol containing infusions should not be given routinely, but only with certain indication.