Aloe Polysaccharides Mediated Radioprotective Effect through the Inhibition of Apoptosis

Abstract

Polysaccharides from aloe are always considered an effective radioprotector on irradiation-induced skin damage. The aim of this study was to determine if aloe polysaccharides (AP) have radioprotective effects on normal human cells in vitro and mouse survival in vivo and to explore the mechanism. Pretreatment with 50 microg/ml AP could improve the surviving fraction at 2 Gy (SF2) of three normal cell lines 293, ECV304, and C. liver from 41.5%, 46.5%, and 40.9% to 49.4%, 72.1%, and 89.1%, respectively. AP could also reduce the apoptotic rate of C. liver cells from 9.5% and 43.0% to 2.2% and 10.9% 48 h and 72 h after 2 Gy irradiation, respectively. Western blot analysis showed that pretreatment with AP could block the upregulation of pro-apoptotic p53, Bax, and Bad and the downregulation of Bcl-2 by irradiation. AP could lower thymocyte apoptosis of mice in vivo after 6 Gy irradiation and abrogate the cell cycle perturbation. Fifty mg/kg of AP treatment for 30 min before 7.5 Gy irradiation provided the best radioprotective effect and improved the 30-day survival rate of mice to 86.0%, from 10.0%. AP exerted radioprotective effects in vitro and in vivo through an inhibition of apoptosis.

Protective role ofAloe veraagainst X-ray induced testicular dysfunction

“…Gpx, GR, GST and SOD activities were significantly increased in the X‐ray‐irradiated group when compared to the control group, which could be due to excessive generation of free radicals, and in an attempt to scavenge these, A. vera ‐pre‐treated X‐ray‐irradiated group exhibited significant decrease when compared to the X‐ray‐irradiated mice. It has been previously reported that A. vera conferred protection against X‐ray‐induced damage in animals (Rowe, ; Wang et al., ).…”

“…Aloe first gained popularity with report of its success in treating X‐ray burns in United States in 1930s (Rowe, ). Polysaccharides from Aloe conferred protection against X‐ray‐induced skin damage in mice (Wang et al., ). Aloe vera extract had exhibited radioprotective ability against gamma radiation‐induced testicular damage in experimental animals (Gehlot et al., ; Purohit et al, ).…”

Comparative Study of the Possible Hepatoprotective Effect of Each of N-acetylcysteine, Coenzyme Q10 and Aloe Vera Gel in Acute Acetaminophen Induced Hepatotoxicity in Albino Rats. (Histological and Biochemical Study)

“…It exerts its protective effect through suppression of oxidative stress and free radicals, acceleration of lipolysis and inhibition of inflammatory response Parmar et al 2010). A study conducted by Wang et al, (2004) demonstrated that Aloe vera polysaccharides exert its protective effect through the inhibition of apoptosis which is mediated by inhibition of pro-apoptotic protein expression and over expression of anti-apoptotic proteins with a subsequent inhibition of apoptosis and cell cycle disruption.…”

The synergistic effects of traditional Chinese herbs and radiotherapy for cancer treatment

“…Moreover, the Chinese herbal preparation, Yangyin Humo Decoction (YHD), was able to alleviate the oral mucomembranous reaction to radiation applied to patients with head-neck tumors (26). In addition, aloe polysaccharides (AP) have demonstrated radioprotective effects by blocking the upregulation of pro-apoptotic p53, Bax and Bad, and the downregulation of Bcl-2, in normal human cells in vitro and in mice in vivo (27). …”