Antityphoid and Antioxidant Activities of Leaf Extracts of Dracaena deisteliana Eng. (Dracaenaceae)

Abstract

Salmonellosis is a major public health problem in developing countries where it is endemic. The genus Salmonella express the oxyR gene that codes for several proteins that allow them to resist free radicals. To investigate the antioxidant activity in vitro (aqueous and hydroethanolic extracts in vivo (of the 55% hydroethanolic extract)) of Dracaena deisteliana leaves in albino’s rats of Wistar strain previously infected with the Salmonella Typhi ATCC 6539 strain. The in vitro antioxidant activity of these extracts was determined by studying their anti-radical power with DPPH●, then their iron-reducing power and determining their flavonoids and total phenols content. The in vivo antioxidant activity was determined in plasma and tissues of albino’s rats of wistar strain aged between 8 and 10 weeks previously infected with Salmonella typhi ATCC 6539. These infected rats concurrently received daily doses of Dracaena deisteliana extract (10, 20 and 51.84 mg/kg) and ciprofloxacin (14 mg/kg) as positive control, for 15 days. At the end of the treatment period, the animals were sacrificed and blood, liver, kidney, heart, lung, spleen testis and ovaris were collected for evaluation of antioxidants parameters, which included malondialdehyde, nitric oxide, catalase and peroxidase, as well as biological responses. Regarding the in vitro antioxidant tests, the 55% hydroethanolic extract had the best IC50 (11.99 μg/ml). The iron reducing power of this extract was higher than the other extracts at 200 μg/ml. The highest levels of flavonoids and total phenols were obtained respectively with this extract. This extract (10, 20 and 51.84 mg/kg) cured the infected rats between the 8th and 12th day of treatment. The extract also significantly reduced blood malondialdehyde and nitric oxide levels, and significantly increased the activity of catalase and peroxidase in the infected rats. The results suggest that leaves extract of Dracaena deisteliana contains antisalmonella and antioxidant substances, which could be used for the treatment of typhoid fever and reduces the state of oxidative stress caused by Salmonella. Typhi during rat’s infection.