Carbohydrate fraction of Aloe vera ameliorates inflammation through suppression of pro-inflammatory mediators and oxidative stress in vitro and rats with Freund’s adjuvant induced paw edema

Abstract

Aloe vera (L.) Burm. F (Asphodelaceae) is a traditional medicinal plant having multiple biological activities such as wound healing, anticancer and antidiabetic activity, etc. These properties have been attributed to the constituents present in Aloe vera. One of the major constituents is carbohydrate, which has not been explored much for its antioxidant and anti-inflammatory activity. Here, we evaluated the antioxidant and anti-inflammatory potential of carbohydrate fraction (CF) of Aloe vera extract using in vitro and in vivo model for its therapeutic application in the treatment of inflammation. CF extract was prepared using hot water extraction followed by ethanolic precipitation. The CF extract was tested for free radical scavenging assays, lipopolysaccharide-stimulated RAW264.7 cells in vitro and in vivo by Freund’s adjuvant induced rat paw edema model. The free radical scavenging activity of CF extract significantly increased in a concentration-dependent manner with maximum inhibition observed at the concentration of 2 mg/mL. CF extract (20 and 60 µg/mL) showed their maximum cell viability in RAW264.7 cells by MTT assay. CF extract shows a considerable decrease of inflammatory mediators in both in vitro and as well as in vivo studies. The increase of superoxide dismutase and catalase levels in CF treated adjuvant induced rats decreases ROS/RNS levels and inflammatory mediators. It may be primarily activated by
NF-κB and AP-1 indicating its potent antioxidant activity that promotes modulation in cellular redox state. The results suggest that carbohydrate fraction of Aloe vera could be useful for the management of oxidative stress and inflammatory diseases.