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Glycyrrhizinate Dipotassium (DPG), Myonecrosis Control and Skeletal Muscle Differentiation: A New Adjuvant Therapy for Snake Envenomation
Author(s) -
Rocha Thalita,
Cavenatti Thais,
Nascimento Lais,
Ziegler Jussara,
Oliveira Thais,
Gracia Marta,
Priolli Denise
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.lb622
Subject(s) - envenomation , myogenin , cardiotoxin , skeletal muscle , myocyte , myogenesis , sarcolemma , snake venom , viper , myod , edema , venom , medicine , pharmacology , chemistry , andrology , anatomy , biochemistry
Considered a public health problem in Brazil, Bothrops snake bites represent 80–90% of ophidian envenomation cases. After the snake bite, skeletal muscle tissue is able to regenerate from satellite cells in myoblasts, which rapidly express myoD and form myotubes, which express myogenin, giving rise to a new muscle fiber. The serum therapy currently used is able to neutralize the systemic effects, but it is not effective in reversing the local damage. Searching for adjuvant therapies that minimize myonecrosis, Glycyrrhizinate Dipotassium (DPG ‐ C 42 H 60 K 2 O 16 ), a derivative of Glycyrrhizic Acid with anti‐inflammatory effect, has been studied. In the present research, the pro‐regenerative properties of DPG on the histoarchitecture of the gastrocnemius muscle was performed in vivo . For this purpose, Swiss mice were divided into 4 groups: group V (with i.m. injection of 100 μL of B. jararacussu venom ‐ 100 μg/mL), DPG group (with i.m. injection of 100 μL of 2% DPG ‐ 100 μL, 1,4 mg/g animal weight), VDPG group (with i.m. injection of venom and 2% DPG, one hour after). The animals were euthanized after 3 and 24h, 3, 7 and 21 days of treatment, and the dissected muscles used for transmission electron microscopy and immunohistochemistry methodologies. Histological analysis showed no myonecrosis for N and DPG groups. However, there was an intense muscular damage in the animals submitted to the venom after 3 and 24 hours, being characterized by hypercontracted fibers, disorganized sarcomeres, cellular, mitochondrial and sarcoplasmic reticulum edema, besides sarcolemma lysis and presence of inflammatory infiltrate. During the regenerative phase, satellite cells, myoblasts and myotubes were observed in V, VDPG and DPG groups, with positive labeling for myoD and myogenin. The action of DPG on myoD expression can be observed as early as 3 hours after its application (p = 0.05). The expression of myoD appeared as a response to the application of DPG in healthy tissue and treated lesion, decreasing over time (r = ‐.494; p = 0.00) while myogenin expression appeared after myoD declines (p = 0.02), with a small increase over time (r = .259, p = 0.03). Such positive reaction was present after 3 hours in DPG group and after 3 and 24 hours in VDPG group. However, myogenin expression was significatively observed after 3 days of DPG injection, with a little increase of expression with time course (r=0.259; p=0.03), remaining until 21 days. The presence of differentiated fibers also in the DPG group, as well as the labeling for myoD and myogenin, suggest the action of DPG in the muscular hyperplasia, an important event for skeletal muscle regeneration. All these findings show that DPG is able to decrease the myotoxic event an has a positive modulating action on regeneration, regardless of whether an inflammatory or myonecrotic process is underway, and can be used as an adjuvant to the current serum therapy. Support or Funding Information FAPESP 2013/10163‐4; CNPq and CAPES scholarshipsDPG effect over myoD expression.