The Effect of Albumin and Platelet-Poor Plasma Supplemented Botulinum A Toxin on Bioavaliability: An Experimental Rabbit Model

Ethyl Alcohol Versus Botulinum Toxin A: A Comparative Study of the Visual and Histopathological Outcomes in the Rabbit Anterior Auricular Muscle Model

BACKGROUND

Botulinum toxin has long been known for its paralytic effects at the neuromuscular junction. Although it has been widely used for vascular and nervous tissues, there has been no study of the aesthetic effects of the application of ethanol to muscle tissues to date.

OBJECTIVE

The authors aimed to demonstrate the effects of the application of ethanol to muscle tissues after an intramuscular injection and to compare the effects of botulinum toxin A (BTA) and ethanol.

METHODS AND MATERIALS

A total of 28 rabbits were divided into 4 groups (n = 7 each). Botulinum toxin A (5 units) and different concentrations of ethanol (5 cc) were injected into the left and right anterior auricular muscles of all rabbits, respectively. Ear ptosis was assessed, and histopathological examination was performed after all rabbits were euthanized in the eighth week.

RESULTS

Muscle function was affected earlier in ethanol-treated ears than in botulinum-treated ears; however, the ptotic effect lasted for a significantly shorter duration in ethanol-injected ears than in BTA-applied ears.

CONCLUSION

Ethanol can block muscle function reversibly and can serve as an alternative to BTA, particularly when rapid results are desirable.

Bioactivity of abobotulinum toxin is preserved till 2 weeks upon storage at room temperature: Half body comparative study on rabbit model

BACKGROUND

Breakages of the cold chain of botulinum neurotoxin A (BONT-A) preparations is not a rare event and occurs due to several unexpected and unintentional reasons during daily practice and intervention schedules could not be proposed due to the lack of data.

OBJECTIVE

To investigate the heat stability of abobotulinum toxin A (AboBONT-A) in terms of efficacy and duration of action upon storage at room temperature (25°C) for 2, 4, and 8 weeks.

METHODS AND MATERIALS

Twenty rabbits were divided into four groups and received an injection of ideally stored AboBONT-A (Group 1) and stored AboBONT-A for 2 (Group 2), 4 (Group 3), and 8 weeks (Group 4) at room temperature into the anterior auricular muscle. All rabbits were followed up and photographed by weekly for 16 weeks. Grade of paralysis was evaluated by using a modified visual scoring system.

RESULTS

No significant alteration was found in initial potency of stored AboBONT-A at room temperature for up to 4 weeks. Storage at room temperature for 2 weeks did not affect the duration of action (group 2; P = .69), and faster recovery was observed in group 3 and group 4.

CONCLUSION

The bioactivity of AboBONT-A is not altered till 2 weeks upon storage at room temperature.

The role of human serum albumin and neurotoxin associated proteins in the formulation of BoNT/A products

Botulinum neurotoxin (BoNT) is synthesized as a progenitor toxin complex (PTC) by Clostridium botulinum. This PTC comprises, in addition to the neurotoxin itself, neurotoxin associated proteins (NAPs) which are composed of three hemagglutinins and one non-toxic, non-hemagglutinin protein. After oral ingestion, these NAPs protect the neurotoxin from the low pH and proteases in the gastrointestinal tract and play a role in the entry via the intestinal barrier. Two of the three therapeutically used botulinum neurotoxin serotype A (BoNT/A) products (onabotulinumtoxinA and abobotulinumtoxinA) contain different amounts of NAPs, while incobotulinumtoxinA, lacks these proteins. In addition, human serum albumin (HSA) that is supposed to stabilize BoNT/A is added at different concentrations. Up to now, the function of the NAPs and HSA after parenteral therapeutic application is not completely understood. To investigate the influence of NAPs and HSA on potency of BoNT/A, we used the ex vivo mouse phrenic nerve hemidiaphragm assay. Increasing doses of HSA resulted dose-dependently in a more pronounced effect of BoNT/A. Though, a plateau was reached with concentrations of 0.8 mg/ml HSA and higher, the accessory addition of NAPs in a relevant amount (4 ng/ml) did not further enhance the effect of BoNT/A. In conclusion, in our ex vivo assay an adequate concentration of HSA prevented BoNT/A from loss of effect and supplementary NAPs did not alter this effect. A confirmation of these data in an in vivo assay is still lacking. However, it might be supposed that even in clinically applied BoNT/A products an increase of HSA accompanied by the avoidance of NAPs could potentially reduce the injected dose and, thus, the risk of unwanted side effects, the treatment costs as well as the risk of a secondary therapy failure due to BoNT/A neutralizing antibodies.

Botulinum Toxin Type A: Assessing The Effects on The Brain Stem

BACKGROUND

In this study, our aim is to investigate the possible effects of Botulinum toxin type A administrations in the early and late periods on the brain stem.

METHODS

Eighteen white New Zealand rabbits were used in this study with the subjects being divided into three groups. Group I received 0.05 mL sterile saline to the left anterior auricular muscles. Group II and III were injected with Botulinum toxin type A (Botox, Allergan) to the left anterior auricular muscles. Group II was sacrificed 5 days after application and Group III was sacrificed 12 weeks after application; brain stem tissues were then taken. The samples were examined with Caspase 3, 8, and 9 immunohistochemical stainings.

RESULTS

In the control group with Caspase-3 immune staining, moderate-to-strong immune reactivity was seen in a small number of neurons. In the Caspase-8 and 9 immune stainings, the immune reactive neurons were seen in greater numbers when compared with the Caspase-3 immune reactive neurons. In the early and late period, groups with Caspase-8 and 9 immune stainings, the immune reactive neurons were seen in greater numbers and in the wider area when compared with the Caspase-3 immune reactive neurons. No significant differences were recognized in the Caspase immune stainings between the early and late period groups. The results were statistically supported.

CONCLUSION

It was concluded that Botulinum toxin type A application did not trigger apoptosis in stem cell tissues.

NO LEVEL ASSIGNED

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