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Published on: August 30, 2014
Pharmacokinetics of natural mistletoe lectins after subcutaneous injection
Roman Huber1, Jürgen Eisenbraun, Barbara Miletzki
1Department of Environmental Health Sciences, University Hospital Freiburg, Breisacher Str. 115b, 79106 Freiburg, Germany. roman.huber@uniklinik-freiburg.de
Purpose:
Knowledge of natural mistletoe lectins (nML) pharmacokinetics can be regarded as essential for further rational studies with mistletoe preparations. Studies with intravenous application of a recombinant type II ribosome inactivating protein (rML) analogous to nML revealed a short half-life of about 13 min in cancer patients. This open-label, phase I, monocenter clinical trial was performed in order to describe the pharmacokinetics of nML.
Methods:
In 15 healthy male volunteers aged 18-42 years, nML were detected with a modified sandwich immuno-polymerase chain reaction (PCR) technique (Imperacer, Chimera Biotec) after single subcutaneous injection of a mistletoe extract (abnobaVISCUM(R) Fraxini 20 mg) with marketing authorization containing about 20 microg nML/ml. Secondary objectives were safety and the number of activated natural killer cells (CD54(+)/CD94(+)).
Results:
In none of the volunteers were nML detectable before the injection, and in all volunteers, nML were detected in serum samples after injection. Individual variability, however, was large. Mean and median peak concentrations were reached 1 and 2 h after injection, respectively. In some volunteers, nML were still detectable at the final investigation 2 weeks after injection. The injection resulted in fever and flu-like symptoms in all volunteers, but no serious adverse events occurred. All symptoms and local reactions at the injection site completely disappeared within a range of 4-95 days. The number of activated natural killer (NK) cells did not change.
Conclusions:
Natural ML from abnobaVISCUM Fraxini 20 mg are detectable in serum after a single subcutaneous injection. Detectability is considerably longer compared with intravenously administered rML. The subcutaneous injection of this preparation without usual pretreatment with lower doses results in short-lasting fever and other flu-like symptoms.
Insights
Natural mistletoe lectins (nML) are detectable in serum for longer than recombinant forms after subcutaneous injection. This study characterized nML pharmacokinetics and safety in healthy volunteers.
Area of Science:
- Pharmacology and Toxicology
- Immunology
- Complementary and Alternative Medicine
Background:
- Understanding the pharmacokinetics of natural mistletoe lectins (nML) is crucial for optimizing mistletoe-based therapies.
- Previous studies with intravenous recombinant mistletoe lectins (rML) indicated a short half-life (approx. 13 min).
Purpose of the Study:
- To determine the pharmacokinetics of natural mistletoe lectins (nML) following subcutaneous administration.
- To evaluate the safety profile and impact on natural killer (NK) cell activation after nML injection.
Main Methods:
- A single subcutaneous injection of abnobaVISCUM® Fraxini (20 mg) containing approximately 20 microg nML/ml was administered to 15 healthy male volunteers (aged 18-42).
- nML levels in serum were quantified using a modified sandwich immuno-polymerase chain reaction (PCR) technique (Imperacer, Chimera Biotec).
- Secondary endpoints included monitoring for adverse events and changes in activated NK cell counts (CD54+/CD94+).
Main Results:
- nML were detected in all volunteers post-injection, with significant individual variability.
- Peak nML concentrations were observed at 1-2 hours, with detectability extending up to 2 weeks in some participants.
- All volunteers experienced transient fever and flu-like symptoms; no serious adverse events were reported. NK cell activation did not change.
Conclusions:
- Natural mistletoe lectins (nML) from abnobaVISCUM® Fraxini are detectable in serum for a considerably longer duration after subcutaneous injection compared to intravenously administered rML.
- Subcutaneous administration of this mistletoe preparation, without prior dose escalation, induced short-term, self-limiting flu-like symptoms.
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