Antioxidant activities of sulfated polysaccharides from brown and red seaweeds

The in vitro antioxidant activities of the following six sulfated polysaccharides were investigated: iota, kappa and lambda carrageenans, which are widely used in the food industry, fucoidan (homofucan) from the edible seaweed Fucus vesiculosus and fucans (heterofucans) F0.5 and F1.1 from the seaweed Padina gymnospora. With respect to the inhibition of superoxide radical formation, fucoidan had an IC50 (the half maximal inhibitory concentration) of 0.058 mg·mL−1, while the IC50 for the kappa, iota and lambda carrageenans were 0.112, 0.332 and 0.046 mg·mL−1, respectively. All of the samples had an inhibitory effect on the formation of hydroxyl radicals. The results of peroxidation tests showed that fucoidan had an IC50 of 1.250 mg·mL−1 and that the kappa, iota and lambda carrageenans had an IC50 of 2.753 and 2.338 and 0.323 mg·mL−1, respectively. Fucan fractions showed low antioxidant activity relative to fucoidan. These results clearly indicate the beneficial effect of algal polysaccharides as antioxidants

Expressão gênica do colágeno em ferida cutânea de equinos tratada com plasma rico em plaquetas

O plasma rico em plaquetas (PRP) é um produto derivado da centrifugação do sangue total, cuja utilização concentra-se em melhorar a reparação de diferentes tecidos, tendo em vista os fatores de crescimento nele contido. Entretanto, os benefícios da terapia no contexto clínico ainda não estão totalmente esclarecidos. Objetivou-se avaliar a expressão dos genes dos colágenos tipos I e III durante diferentes fases do processo de cicatrização da pele tratada com PRP. Foram utilizados oito equinos machos castrados, mestiços, hígidos, com idade entre 16 e 17 (16,37±0,52) anos. Três feridas em formato quadrangular (6,25cm²) foram confeccionadas nas regiões glúteas direita e esquerda de todos os animais. Doze horas após indução das lesões, 0,5mL do PRP foi administrado em cada uma das quatro extremidades das feridas (T=grupo tratado), de uma das regiões glúteas, escolhida aleatoriamente. A região contralateral foi utilizada como controle (NT=grupo não tratado). As feridas foram submetidas à limpeza diária com água Milli Q, e amostras foram obtidas com biópsias utilizando-se Punch de 6mm de diâmetro. Seis biópsias de pele foram obtidas a primeira no dia de indução das lesões (T0), e as demais com 1 (T1) 2 (T2) 7 (T3) e 14 (T4) dias após a realização das feridas. A sexta biópsia (T5) foi realizada após o completo fechamento da pele. A avaliação da expressão dos genes dos colágenos tipos I e III foi realizada pela técnica qRT-PCR e os dados analisados pelo teste de Bonferroni, t de Student, t pareado e análise de regressão (p<0,05). Diferenças (p<0,05), entre grupos, foram observadas para a expressão de ambos os colágenos nos T1 a T4, sendo maior nos animais do grupo T. O pico de expressão dos colágenos tipos I e III ocorreu no T5 para ambos os grupos, mas a maior expressão foi diferente (p<0,05) do tempo zero a partir do T3. Nos animais do grupo tratado a expressão dos colágenos começou a estabilizar no T5, enquanto que nos equinos do NT os valores permaneceram elevados. A administração local de uma única dose do PRP em ferida cutânea na região glútea de equinos, resulta em maior expressão gênica local dos colágenos tipos I e III. Entretanto, essa expressão não altera o tempo máximo de fechamento macroscópico da ferida

Histomorphometric analysis of the Achilles tendon of Wistar rats treated with laser therapy and eccentric exercise

Abstract: Low-level laser therapy is recommended for the treatment of tendinopathies despite the contradictory results related to the ideal dose of energy, wavelength and time of application. This study aimed to assess the effects of laser therapy and eccentric exercise on tendinopathy of the Achilles tendon of Wistar rats. Forty-eight adult male rats were randomly distributed into four groups (L= laser; E= eccentric exercise; LE = laser and eccentric exercise; and R= rest). Laser therapy (904nm/3J/cm2) and/or eccentric exercise (downhill walking; 15o incline treadmill; 12m/min; 50min/day) was started 24h after induction of unilateral tendinopathy and remained for 20 days. At 3, 7, 14 and 21 days after lesion induction, three rats from each group were euthanized and the tendons were collected for histological and morphometric analyses. There was no difference among groups or among times for the characteristics hemorrhage (p=0.4154), fibrinous adhesion formation (p=0.0712), and organization of collagen fibers (p=0.2583) and of the connective tissue (p=0.1046). For these groups, regardless of the time, eccentric exercise led to epitenon thickening (p=0.0204), which was lower in the group treated with laser therapy. Histological analysis revealed differences (p=0.0032) in the number of inflammatory cells over time. They were more numerous in the group that only exercised. This result was confirmed by morphometric analysis, which showed a significant interaction (groups x time) for this characteristic. Eccentric exercise increased (p=0.0014) the inflammatory infiltrate over time (3 and 21 days). However, association with laser therapy reduced inflammatory reaction. On the other hand, the combination of the treatments increased angiogenesis in morphometric (p=0.0000) and histological (p=0.0006) analyses compared with the other groups, while the isolated application of low-level laser reduced this characteristic over time. Animals maintained at rest presented the lowest amount (p=0.0000) of fibroblasts, according to the morphometric analysis. However, histological evaluation showed a significant group x time interaction (p=0.0024). Greater amounts of fibroblasts were observed in groups E, L and LE on the 7th, 14th and 21st days, respectively. The animals that received laser therapy and were exercised showed a greater (p=0.0000) amount of collagen fibers over time. Laser therapy at a dose of 3J and at a wavelength of 904nm, starting 24h after surgical induction of tendinopathy in Wistar rats, is suitable for angiogenesis and prevention of tendon thickening, which can be associated with the intensity of inflammatory process. When associated with eccentric exercise, the therapy has the advantage of increasing the amount of collagen fibers, reducing fibrinous adhesions and inflammatory infiltrate, despite prolonging angiogenesis. Therefore, eccentric exercise performed concomitantly with laser therapy improves the histological properties of the injured tendon