EVALUATION OF A TRADITIONAL DECOCTION FOR ANTIBACTERIAL ACTIVITY AGAINSTSALMONELLA TYPHI AND ITS BIOSAFETY

Abstract

In this study, a traditional decoction made from the leaves of Psidium guavaja (Linn), Azadirachta indica (Linn), Gossypium hirsutum, Mangifera indica, Persea americana, bark of Anacardium occidentale, Swietenia mahagoni and husk of Cocos nucifera (Linn) being used in folklore medicine to treat typhoid fever was investigated for antibacterial activity on Salmonella typhi, the aetiological agent of typhoid fever using agar well diffusion assay. The different components were also individually assayed for growth inhibitory activity on the organism. Moreover, the biosafety of the decoction was also investigated in wistar albino rats by evaluating their haematological parameters and also carry out the histopathological examination of selected vital organs; liver, kidney, heart using standards methods. The decoction exhibited little or no growth inhibitory activity (0.66+0.33 to 1.00+0.00mm) against the S. typhi used. The same trend was also observed with the individual components of the decoction which exhibited growth inhibition with zone diameter ranging from 0.67+0.33 to 5.67+1.21mm on the organism. In vivo administration of the decoction at different volumes which ranged from 0.5 to 2.0 ml for 3 weeks to wistar albino rats caused an appreciable increase in packed cell volume (PCV), red blood cell (RBC), hemoglobin (Hb) and white blood cell (WBC), neutrophils (NEU) and monocytes (MONO) values of the hematological parameters of rats when compared to the control group. Histopathological examination of the liver of rats administered the decoction showed various pathological features ranging from karyolysis, hepatocellular drainage, disappearing of sinusoids and inflammatory cell infiltration, hemorrhage to dot necrosis in addition to other features after one week of administration. However, normal cardiac smooth muscle with well-spaced strata of the heart was observed during the first 2 weeks of administration of the decoction but by the third week, wobbling strata formation was observed. The kidney nephrons showed normal architecture with cell infiltrations and properly formed Bowmans’s capsule by the end of the first week. However, as the administration of the decoction continued, inflammatory cell infiltrations and increase interstitial cells within the Bowman’s capsules was observed and by the third week, there was loss of clear Bowman’s capsules as the volume increased. The ileum of the albino rats fed with decoction after one week of feeding showed normal intestinal villi architecture and cell infiltrations, however, as the experiment progressed the surface of the micro villi of the intestine was washed off. From this investigation, the traditional decoction evaluated has insignificant antibacterial activity against S. typhi used. The acclaimed efficacy by the locals is as a result of its observed immunostimulatory properties.