Evaluation of tyrosinase inhibitory and antioxidant activities of Angelica dahurica root extracts for four different probiotic bacteria fermentations

Objective: The present study was designed to evaluate the phytochemical screening, antimicrobial, and antioxidant activities from the roots and leaves of Leucas aspera. Methods: The phytochemical screening and Fourier transform infrared (FTIR) analysis of root and leaf extracts were studied using standard methods. The disk diffusion method was performed to analyze the antimicrobial activity of aqueous extract, methanol extract and hexane extract of root and leaf against to selected bacterial and fungal strains. Antibiotics, streptomycin and nystatin were used as standards for bacteria and fungi, respectively. The antioxidant activity of the extracts was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and scavenging of H2O2 free radicals. Results: Preliminary phytochemical screening of extracts exhibited the presence of carbohydrates, proteins, amino acids, steroids flavonoids, terpenoids, saponins, alkaloids, tannins, and phlobatannins. Leaf extracts exhibited effective antibacterial and antifungal activities compared with root extracts against all the tested bacteria and fungi. ME of the leaves exhibited highest antibacterial activity against Staphylococcus aureus (12.8±0.31 mm), followed by Bacillus subtilis (11.4±0.3 mm), Escherichia coli (9.8±0.21 mm), and Pseudomonas aeruginosa (7.3±0.29 mm). Leaf extracts of L. aspera showed effective scavenging activity compared with root extracts. ME of the leaves showed maximum scavenging activities of 38.39 and 36.85%, respectively, against DPPH and H2O2 free radicals with half maximal inhibitory concentration values of 136.17 and 142.42 μg/ml. Conclusion: Phytochemical analysis and FTIR spectrum revealed that different plant secondary metabolites particularly alkaloids, terpenoids, and flavonoids could be responsible for antimicrobial and antioxidant activities of L. aspera leaf extracts.

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Phytochemical and Cytotoxic Screening of Selected Medicinal Plants (Byrsocarpus coccineus, Terminalia avicennioides and Anogeissus leiocarpus) Using Brine Shrimp (Artemia salina) Lethality Assay

European Journal of Nutrition & Food Safety ◽

10.9734/ejnfs/2020/v12i930284 ◽

2020 ◽

pp. 60-71

Author(s):

C. E. Ukwade ◽

O. A. T. Ebuehi ◽

R. A. Adisa

Keyword(s):

Medicinal Plants ◽

Plant Extracts ◽

Brine Shrimp ◽

Antioxidant Activities ◽

Ethanol Extract ◽

Medicinal Uses ◽

Brine Shrimp Lethality ◽

Root Extracts ◽

Anogeissus Leiocarpus ◽

Mineral Analyses

Three medicinal plants, were investigated based on their ethno-medicinal uses. Byrsocarpus coccineus (B.C), Terminalia avicennioides (T.A) and Anogeissus leiocarpus (A.L) are used traditionally in the treatment of various ailments in Nigeria. Proximate and mineral analyses were carried out on the leaf, stem and root of the three plants. Phytochemical composition and antioxidant activities of the aqueous, ethanol and pet ether (leaf, stem and root) extracts, of the three plants were determined and the extracts were subjected to cytotoxic screening using the in vivo brine shrimp lethality tests. The proximate and mineral analyses show appreciable dietary nutrients in the three plants. Phytochemical analyses of B.C, T.A and A.L (leaf, stem and root) extracts, showed the presence of bioactive compounds, such as alkaloids, tannins, saponins, flavonoids, steroid and phenol. Antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide, lipid peroxidation and reducing power), increase in all the plant extracts in a dose dependent manner. The results of brine shrimp lethality tests indicate that plant extracts of B.C, T.A and A.L except A.L stem aqueous extract (130.72 µg/ml), T.A leaf aqueous (130.15 µg/ml) and root aqueous extracts were moderately cytotoxic, while the others were highly cytotoxic. B. coccineus leaf ethanol extract (17.31 µg/ml) was the most cytotoxic. The result shows that B. coccineus leaf ethanol extract has significant antioxidant activity and is cytotoxic to brine shrimp even at low concentration giving credence to its ethno-medicinal uses.

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