Enzyme Activity

Photomed Laser Surg. 2009 Oct 26. [Epub ahead of print]

Effect of GaAlAs Laser Irradiation on Enzyme Activity.

Da Silva NS, Potrich JW.

1 Laboratório de Biologia Celular & Tecidual, Instituto de Pesquisa & Desenvolvimento, UNIVAP , São José dos Campos, Brazil .

Abstract Objective: The aim of this study was to determine the influence of laser irradiation on enzyme activity. Background Data: Enzymes are catalysts of extraordinary efficiency, able to accelerate reactions by manifold. Enzyme laser light activation is currently a fast-growing field and a large number of studies have been produced. Materials and Methods: Liquid CNPG amylase and control serum (Qualitrol 1H) were used in the experiments. Laboratory analysis of alpha-amylase was performed on two sample groups: (i) E + S and (ii) E + S + L, in six repetitions per irradiation dose. Group 2 was irradiated with gallium-aluminum-arsenide (GaAlAs) 904 nm at doses of 0.01, 0.1, 0.5, and 1 J/cm(2). Enzyme activity was read using a spectrophotometer equipped with a thermostatic chamber capable of precise absorbance measurement at 405 nm. Results: The results were analyzed with the Student’s t-test, and the percentage of enzyme activity was determined. Photomodulation of alpha-amylase activity by GaAlAs laser was analyzed following irradiation with different doses. Irradiation doses from 0.01 to 1 J/cm(2) led to differences in enzyme activity: 0.01 J/cm(2) (0.10%), 0.1 J/cm(2) (13.44%), 0.5 J/cm(2) (12.57%), and 1 J/cm(2) (-6.10%). Conclusion: Irradiation doses of 0.1 J/cm(2) and 0.5 J/cm(2) led to statistically significant increases in enzyme activity in comparison to the control. The similar curves of the effects of temperature and pH on enzymatic activity observed in this study suggest that laser irradiation also possess an optimum dose to modulate the enzymatic activity. That is, enzymes have an optimum laser dose (or range) at which their activity is maximal, whereas at higher or lower doses activity decreases.

J Photochem Photobiol B. 2009 Dec 2;97(3):145-51. Epub 2009 Sep 11.

Effect of phototherapy with low intensity laser on local and systemic immunomodulation following focal brain damage in rat.

Moreira MS, Velasco IT, Ferreira LS, Ariga SK, Barbeiro DF, Meneguzzo DT, Abatepaulo F, Marques MM.

LIM-51, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.


Brain injury is responsible for significant morbidity and mortality in trauma patients, but controversy still exists over therapeutic management for these patients. The objective of this study was to analyze the effect of phototherapy with low intensity lasers on local and systemic immunomodulation following cryogenic brain injury. Laser phototherapy was applied (or not-controls) immediately after cryogenic brain injury performed in 51 adult male Wistar rats. The animals were irradiated twice (3 h interval), with continuous diode laser (gallium-aluminum-arsenide (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP), 660 nm) in two points and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). The experimental groups were: Control (non-irradiated), RL3 (visible red laser/ 3 J/cm(2)), RL5 (visible red laser/5 J/cm(2)), IRL3 (infrared laser/3 J/cm(2)), IRL5 (infrared laser/5 J/cm(2)). The production of interleukin-1IL-1beta (IL-1beta), interleukin6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha) was analyzed by enzyme immunoassay technique (ELISA) test in brain and blood samples. The IL-1beta concentration in brain of the control group was significantly reduced in 24 h (p<0.01). This reduction was also observed in the RL5 and IRL3 groups. The TNF-alpha and IL-6 concentrations increased significantly (p<0.01 and p<0.05, respectively) in the blood of all groups, except by the IRL3 group. The IL-6 levels in RL3 group were significantly smaller than in control group in both experimental times. IL-10 concentration was maintained stable in all groups in brain and blood. Under the conditions of this study, it is possible to conclude that the laser phototherapy can affect TNF-alpha, IL-1beta and IL-6 levels in the brain and in circulation in the first 24 h following cryogenic brain injury.