TITLE:
Modulation of the in vitro Oxidative Stress and Erythrocyte Cell Membrane Integrity Using Aqueous, Hydroethanolic and Ethanolic Stem-Barks Extracts of Greenwayodendron suaveolens (Engl. & Diels) Verdc
AUTHORS:
Patrick Hervé Diboue Betote, Moustapha Gambo Abdoulaye, Francis Ngolsou, Esther Del Florence Ndedi Moni, Adeline Sabine Fanta Yadang, Fidel Castro Lah Weyepe, Gabriel A. Agbor, Nga Nnanga, Maximilienne Ascension Nyegue
KEYWORDS:
Greenwayodendron suaveolens, Secondary Metabolites, Oxidative Stress, Antioxidant Activity, Anti-Inflammatory Properties and Oral Acute Toxicity
JOURNAL NAME:
Pharmacology & Pharmacy,
Vol.15 No.3,
March
21,
2024
ABSTRACT: Pneumonia, a respiratory infection induces acute or
chronic inflammation, characterized by increased activity of lymphocytes and
neutrophils, thus generating oxygen-free radicals that decrease the endogenous
antioxidants defence system. The aim of this experimental study focused on the
capacity of nontoxic aqueous, hydroethanolic and ethanolic extracts of Greenwayodendron
suaveolens (Engl. & Diels) Verdc. subsp. suaveolens to regulate
free reactive species and protein inflammation generated by infectious disease.
The phytochemical screenings of G. suaveolens extracts were carried out
according to precipitation and colorimetric methods. The total antioxidant and
flavonoid contents were determined by the Folin-Ciocalteu and Aluminium
Chloride ethanolic methods. The efficiency of G. suaveolens extracts on
free radicals was evaluated using DPPH•, ABTS+•, and FRAP
methods. The anti-inflammatory properties of extracts were evaluated according
to in vitro protein (BSA) denaturation, Proteinase Inhibitory Action,
and Red Blood Cell Membrane stabilization assays. The G. suaveolens aqueous, hydroethanolic and ethanolic extracts were used for the acute toxicity
assessment according to the OECD protocol. The obtained results showed the
presence of flavonoids, phenols, polyphenols, tannins, anthocyanins, alkaloids,
terpenoids, and sterols as secondary metabolites families in G. suaveolens extracts. The highest contents of total antioxidants and flavonoids were
highlighted in the hydroethanolic extract. However, it’s the G. suaveolens aqueous extract that showed the best free
radical DPPH• and ABTS+• scavenging activities (SC50)
of 11.06 μg/mL and 15.16 μg/mL respectively. The highest ferric-reducing
activity was found in G. suaveolens ethanolic extract
with 866.23 μg EGA/mg of dry weight. The hydroethanolic extract has shown a
high anti-inflammatory activity through BSA denaturation and erythrocyte membrane
haemolysis with inhibitory concentrations 50 (IC50) of 48.63 and
59.22 μg/mL respectively. In contrast, proteinase inhibitory activity revealed
a better potential of IC50 (34.19 μg/mL) for the ethanolic extract.
In oral acute toxicity, all treated groups revealed neither mortality nor any
significant alteration in behaviour and
locomotion. The lethal dose 50 (LD50) of G. suaveolens extracts was >5000 mg/kg. These results suggest that G. suaveolens stem-barks extracts may serve as therapeutic sources to prevent
inflammation induced by oxidative stress, an important feature of infectious
diseases.