Effects of ultrasonic treatment on the molecular weight and anti-inflammatory activity of oxidized konjac glucomannan

Abstract

The ultrasound-degraded oxidized konjac glucomannan (U-OKGM) was manufactured and its immune activity in RAW264.7 macrophages was examined. Results showed that ultrasound treatment, which was an effective method to obtain low molecular weight OKGM, did not change the main structure of polysaccharides under the test conditions. Molecular weights (M W) of OKGM and U-OKGM are about 1.58 × 10 6 g/mol and 5.64 × 10 5 g/mol, respectively. We showed that U-OKGM could inhibit NO secretion and augment phagocytotic activity of RAW264.7 cell, and 0.8 mg/mL U-OKGM reached significant level (p < 0.05). Meanwhile, TNF-α and IL-1β secretion levels were significantly (p < 0.05) decreased by U-OKGM treatments in LPS-stimulated RAW264.7 cells. Moreover, the mRNA transcription of IL-1β, TNF-α, IL-6 and iNOS were significantly (p < 0.05) inhibited by U-OKGM in LPS-activated RAW264.7 macrophages. The results suggest that ultrasonic treatment provides a viable modification to obtain low-molecular-weight polysaccharide, and U-OKGM has strong anti-inflammatory effects on LPS-stimulated RAW264.7 macrophages. Efectos del tratamiento por ultrasonidos en el peso molecular y la actividad antiinflamatoria del glucomanano de konjac oxidado RESUMEN Para este estudio, se elaboró glucomanano de konjac oxidado y degradado por ultrasonidos (U-OKGM), sometiéndose a examen la actividad inmune que proporciona a los macrófagos RAW264.7. Los resultados dan cuenta de que el tratamiento por ultrasonidos demostró ser un método efectivo para obtener un bajo peso molecular de la OKGM; por otra parte, dicho tratamiento no modificó la estructura principal de los polisacáridos sometidos a las condiciones de prueba. Los pesos moleculares (M W) del OKGM y el U-OKGM obtenidos fueron de alrededor de 1.58 × 10 6 g/mol y 5.64 × 10 5 g/mol, respectivamente. Se constató que el U-OKGM puede inhibir la secreción de NO y aumentar la actividad fagocítica de las células RAW264.7, además de que la cantidad de U-OKGM lograda, 0.8 mg/mL, fue significativa (p < 0.05). Asimismo, como resultado de los tratamientos de células RAW264.7 estimuladas con LPS con U-OKGM, disminuyeron significativamente (p < 0.05) los niveles de secreción de TNF-α y IL-1β. Aunado a ello, las transcripciones de ARNm de IL-1β, TNF-α, IL-6, y iNOS en macrófagos RAW264.7 activados por LPS fueron inhibidas de manera significativa (p < 0.05) por la U-OKGM. Los resultados sugieren que el tratamiento por ultrasonidos proporciona una modificación viable para obtener un polisacárido de bajo peso molecular, mientras que la U-OKGM proporciona fuertes efectos antiinflamatorios a los macrófagos RAW264.7 estimulados por LPS.

Effect of Ultrasound-Treated Arabinoxylans on the Oxidative Stability of Soybean Oil

“…However, the ultrasonic treatment did not show a significative effect on the amount of total phenolic compounds of AX ( Table 2), suggesting that the amount of total phenolic compounds did not influence the antioxidant activity of the polysaccharide. Several studies have reported that a decrease in the Mw could improve the antioxidant activity of polysaccharides [20,32,34]. However, based on these findings, the Mw appears not to be the main factor influencing the antioxidant activity of AX under the conditions tested.…”

“…Several studies have documented that low-Mw polysaccharides exert better biological properties than un-degraded or high-Mw polysaccharides [23,31,32]. Molecules with low Mw have better water-solubility, lower viscosity and simple structure [33].…”

“…Molecules with low Mw have better water-solubility, lower viscosity and simple structure [33]. The ultrasonic treatment has been widely used for the degradation of polysaccharides in order to reduce their Mw and improve their biological activities [20,32,34]. Therefore, in this study, AX were exposed to ultrasonic treatment at 25% power (AX-1) and 50% power (AX-2) for 15 min and the effect of such treatments on their macromolecular features are presented in Table 1.…”

Ultrasound-assisted depolymerization of kappa-carrageenan and characterization of degradation product

“…Cellular and molecular analyses indicate that the ultrasonicated ulvan elicits a jasmonic acid signaling pathway that pro vided tobacco plant resistance to necrotrophic pathogens. Zheng et al [25] demonstrated that ultrasonic treatment of polysaccharide konjac glucomannan afforded degradation product having AMW of 5.64 × 10 5 Da. The degraded polysaccharide has been shown to increase the immune-suppression capability of konjac glucomannan towards RAW264.7 macrophages.…”

Study on the Application of GE-E10 Ultrasound Equipment to Estimate Fetus Weight and Compare Its Accuracy With Birth Weight

“…Subsequently, multiple parameters were usually used to estimate fetal weight in clinical practice, such as fetal biparietal diameter, abdominal circumference, head circumference, femoral lengthand etc., which improved the accuracy of fetal weight prediction to some extent [7]. With the continuous improvement of modern medical technologies, the application of four-dimensional color ultrasound in obstetric examination has been gradually popularized, maintaining the advantages of higher image de nition and more accurate diagnosis of fetal malformation, and more accurate results can also be obtained from measurement of the above indicators.…”