Phytochemical, Antimirobial Screening and Human Health Risk Assessment of Heavy Metals of Stem-Bark and Root Extracts of Newbouldia Laevis (Boundary Tree)

Abstract

Increasing awareness of multi-drug resistant strains of microorganisms and the hazards associated with the use of synthetic / orthodox drugs has increased investigations on plant extracts as possible alternative drugs. Extracts of Newbouldia laevis stem-bark and root were subjected to phytochemical and antimicrobial screening as well as heavy metal concentration content. The aim was to investigate the potentiality of using the extracts as alternative to synthetic / orthodox drugs and conduct ecological, and human health risk assessment of heavy metals in the extracts. Phytochemical screening of the extracts was carried out using standard methods. Antimicrobial activities of the aqueous, methanol and n-hexane extracts were carried out using agar well diffusion method. The test organisms were laboratory isolates of Salmolella tyhpi, Staphylococcus aureus, Escherichia coli, Pseudomanas aeruginosa, Aspergellus flavus, Aspergillus niger, and Candida albican. Metal concentration of the extracts was carried out using Atomic Absorption Spectrometry (AAS). Phytochemical screening showed the presence of the following phytochemicals in the stem-back and root extracts: alkaloid (1.00%, 4.00%), flavonoids (7.00%, 0.60%), saponins (10.00%, 11.00%), cardiac glycosides (2.24%, 3.06%), steroids (2.50%,4.87%), terpenoids (1.80%, 1.26%), and tannins (6.00%,10.00%) respectively. The survey of heavy metal concentration was Zn (12.10 mg/kg), Mn (3.45 mg/kg), Cr (4.55) and Zn (10.80 mg/kg), Mn (2.88 mg/kg) and Cr (4.99 mg/kg) in stem bark and root extracts respectively. Cd, Cu and Pb were not detected in both extracts. This showed that the levels of concentrations of the metals determined were generally below the maximum permissible limits established by International regulatory bodies. All the extracts inhibited growth of the test organisms. The aqueous and ethanol extracts proved more potent than the positive control (tetracycline). The results of ecological risk assessment showed PERI, Cdeg, mCdeg and PLI values of 0.8097, 0.1423, 0.0474 and 0.1222 respectively for the stem bark extract and 0.7015, 0.1332, 0.0444 and 0.1139 respectively for the root extract. Human health risk assessment of the heavy metals gave a total hazard index of 0.0764 and 0.0667 for stem bark and root extracts respectively. These ecological and human health risk assessment results indicated no risk in taking the extracts as alternative medicine. This study therefore has justified ethno-medical use of the plant for the treatment of diseases caused by these pathogens

Assessment of Heavy Metals on African Catfish (Clarias gariepinus) from Some Fish Ponds in Emene, Enugu State, South-East Nigeria

“…Each digested sample was filtered using Whatman filter paper (0.45μm) and then transferred into a 50 mL Erlenmeyer flask and diluted to mark with distilled water. Heavy metals (Pb, Cd, Cu, Cr, Zn and Fe) were determined in the solution using Atomic Absorption Spectrophotometry as adopted from a study by Orakwue et al [42] with little modifications. Procedural blanks were run alongside samples as the analysis was processed in triplicates to ensure the quality of the results obtained.…”

EVALUATION OF ANTIOXIDANT ACTIVITY OF ETHANOL EXTRACT OF SHADE-DRIED LEAF OF M. oleifera GROWN IN UTU IKPE, IKOT EKPENE LOCAL GOVERNMENT AREA, NIGERIA

“…The table further revealed an inverse relationship between reducing power of an antioxidant percentage inhibition of an antioxidant of test substances [31][32]. processes and prevent damage to cellular membrane and resist oxidative stress [35]. The activity of antioxidant is due to its ability to donate proton and trap free radicals.…”