Phytochemical profile and insecticidal activity of Agave americana leaf extract towards Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

Objective: The present study was carried out to investigate antimicrobial, antiradical and insecticidal potential of leaf and fruit of Gardenia gummifera L. f. (Rubiaceae).Methods: The leaf and fruits were shade dried, powdered and extracted by maceration process using methanol. Antibacterial activity was evaluated against Gram positive and Gram negative bacteria by Agar well diffusion assay. Antifungal activity was determined against six seed-borne fungi by Poisoned food technique. Antiradical activity of leaf and fruit extracts was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis 3-ethylbenzothiazoline 6-sulfonate (ABTS) radical scavenging assays. Insecticidal activity of leaf and fruit extracts, in terms of larvicidal and pupicidal activity, was assessed against larvae and pupae of Aedes aegypti.Results: Both the extracts inhibited all test bacteria. Marked antibacterial activity was displayed by fruit extract when compared to leaf extract. S. epidermidis and E. coli were inhibited to highest and least extent by both extracts respectively. Fruit extract was found to exhibit higher antifungal effect when compared to leaf extract. Leaf extract and fruit extract exhibited highest inhibitory activity against A. niger and A. flavus respectively. Leaf and fruit extracts scavenged DPPH radical’s dose dependently with an IC50 value of 49.01µg/ml and 2.53µg/ml respectively. The scavenging of ABTS by leaf and fruit extracts was dose dependent and the IC50 value for leaf and fruit extract was 2.58µg/ml and 2.31µg/ml respectively. Fruit extract was shown to exhibit marked antiradical activity when compared to leaf extract. Leaf and fruit extracts exhibited dose dependent insecticidal activity in terms of larvicidal and pupicidal activity and the susceptibility of larvae and pupae to extracts was in the order II instar larvae>IV instar larvae>pupae. Fruit extract displayed marked insecticidal potential when compared to leaf extract.Conclusion: Overall, fruit extract of G. gummifera exhibited marked antimicrobial, antiradical and insecticidal activity when compared to leaf extract. The plant can be used for developing agents/formulations effective against infectious microorganisms, oxidative stress and insect vectors that transmit dreadful diseases. The observed bioactivities could be ascribed to the presence of active principles which are to be isolated and characterized.

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Impact of a Pitanga Leaf Extract to Prevent Lipid Oxidation Processes during Shelf Life of Packaged Pork Burgers: An Untargeted Metabolomic Approach

Foods ◽

10.3390/foods9111668 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1668

Author(s):

Gabriele Rocchetti ◽

Letizia Bernardo ◽

Mirian Pateiro ◽

Francisco J. Barba ◽

Paulo E. S. Munekata ◽

...

Keyword(s):

Lipid Oxidation ◽

Leaf Extract ◽

Thiobarbituric Acid ◽

Butylated Hydroxytoluene ◽

Antioxidant Compounds ◽

Oxidation Processes ◽

Phytochemical Profile ◽

Plant Leaf Extract ◽

The Impact ◽

Metabolomic Approach

In this work, the comprehensive metabolomic changes in pork burgers treated with different antioxidants, namely, (a) a control without antioxidants, (b) 200 mg/kg butylated hydroxytoluene (BHT), and (c) 250 mg/kg pitanga leaf extract (PLE, from Eugenia uniflora L.), each one packaged under modified atmosphere (80% O2 and 20% CO2) for 18 days storage at 2 ± 1 °C, were deeply studied. In particular, untargeted metabolomics was used to evaluate the impact of the antioxidant extracts on meat quality. The PLE phytochemical profile revealed a wide variety of antioxidant compounds, such as polyphenols, alkaloids, and terpenoids. Multivariate statistics (both unsupervised and supervised) allowed to observe marked differences in BHT and PLE burgers metabolomic profiles during storage. Most of the differences could be attributed to hexanoylcarnitine, 4-hydroxy-2-nonenal, 6-hydroxypentadecanedioic acid, 9S,11S,15S,20-tetrahydroxy-5Z,13E-prostadienoic acid (20-hydroxy-PGF2a), sativic acid, followed by glycerophospholipids. In addition, significant correlations (p < 0.01) were observed between thiobarbituric acid reactive substances and metabolites related to lipid oxidation processes. Therefore, the approach used showed a clear modulation of lipid oxidation, likely promoted by the plant leaf extract, thus confirming the ability of PLE to delay lipid oxidative phenomena during storage.

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