Phytochemical Screening, Antifungal and Antibacterial Activity of Aqueous and Ethanolic Leaf and Stem Extracts of Gnetum africanum Welw

Abstract

Aqueous and ethanolic leaf and stem extracts of Gnetum africanum were investigated for the presence and composition of these phytochemicals (alkaloid, flavonoid, tannin, phenol, saponin, sterol, terpenoid and cyanogenic glycoside) and their antifungal and antibacterial activities at various concentrations against some selected clinical microbes (fungal strains: Candida albicans and Aspergillus niger and bacterial strains: Staphylococcus aureus, Escherichia coli and Salmonella typhi) using standard methods. Analysis of variance (ANOVA) was employed in data analysis. Qualitative and percent quantitative phytochemical results showed that both the aqueous and ethanolic leaf and stem extracts contained these phytochemicals assayed but at varied quantities except cyanogenic glycoside. Antifungal and antibacterial studies indicated that both the aqueous and ethanolic leaf and stem extracts of Gnetum africanum inhibited the growth of the microbes but at varied levels and the inhibition was extracts concentration dependent. However, both the aqueous and ethanolic leaf and stem extracts showed no inhibition against the bacterial strains at 50 mg mLG 1 of the extracts. The extracts showed higher inhibition against the fungal strains than the bacterial strains. Inhibitory effect of the leaf extract was significantly higher than those of the stem extract. The ethanol extract showed significantly higher inhibition than the aqueous extract. Antibiotics had a better activity when compared to the extracts at the same concentration. Gnetum africanum extracts were biostatic in their action, when purified will give a product with higher activity. The data obtained from the study indicated that the plant possessed antifungal and antibacterial potentials especially antifungal and could be used as natural fungicides.

Antimicrobial and phytochemical evaluation of Datura Stramonium (Jimsonweed) on selected microorganisms

“…And there was no previous work conducted to validate the leaf extracts of this plant using the model employed in this research. Both ethanolic and aqueous extracts showed antibacterial and antifungal activities against test bacteria and fungi which is supported by previous study of Ilodibia et al, [15]. Ethanolic dry extract showed the highest activities against both bacteria and fungi which indicates ethanol is a better solvent than water and dry leaves give better extraction than wet leaves (this could be as a result of reduced water content and more concentrated content in dry leaves).…”

Phytochemical and Antimicrobial Screening of Gnetum Africanum Stem and Root

“…They possess antimicrobial, anticancer, antiinflammatory, and anti-allergy activities [10]. This is in contrast with the findings of Ilodibia et al [11] who worked on the aqueous and ethanolic leaf and stem extracts of G. africanum revealing that alkaloid, tannin, saponin, sterol, flavonoid, and terpenoid were present in both extracts while glycoside was absent. This may be due to the polarity of the solvents employed, which determines their dissolving activity.…”

Chromatographic Analysis and Antibacterial Potential of Extracts of Gnetum Africanum

“…The results have indicated the fact that both extracts had inhibitor effect dependent on the dose on the increase of S. aureus, with maximum inhibition areas of 13.30 and 13.10 mm at 200 mg/mL for the aqueous respectively ethanolic extracts. Although, the extracts didn't present antibacterial activity on the E. coli strain which might suggest the inefficiency against Gram-bacteria [7]. Comparing the results obtained by us with the ones presented in the previous study [7], we ascertain the fact that the determined values at the use of our extracts (methanolic, n-hexane and chloroform) are much lower, the possible explanations being the following: less concentrated extracts, the antibiotic-resistant microorganisms, the type of solvent used for extraction.…”

“…The observed antimicrobial activity can represent a consequence of the rich phytochemistry of leaves, due to the fact that the preliminary phytochemical screening indicated the fact that leaves contain alkaloid, tannin, saponin, sterol, flavonoid, terpenoid, glycoside cyanogen and antraquinone [7]. The antibacterial and antifungal effects of flavonoids and tannins [18], terpenoids (acting on the integrity of cellular membranes and manifesting an inhibitor action on microorganisms) [19], saponins (a special category of glycosides used due to the large range of pharmacology and medicinal features) [20], and of sterols and phenols (which induce a mutagenicity at the level of the cellular DNA) are well known.…”

“…An increased attention was focused on finding new "natural" sources due to the side effects caused by the administration of antibiotics as well as the resistance gained by many microbial strains. Many plant species (spontaneous, cultured, medicinal) showed pharmaceutical and antimicrobial properties [3][4][5][6][7][8][9][10][11][12] therefore testing the possible antimicrobial effects of different parts of plant extracts is recommended. Gnetum africanum is a wide use plant due to its nutritional value, high contents of proteins and minerals, thus it is used in food, animal feed and medical purposes for treating certain diseases.…”