Phytochemical analysis and antioxidant potential of Ocimum gratissimum Linn (Lamiaceae) commonly consumed in the Republic of Benin

Abstract

In the Benin pharmacopoeia, the use of Ocimum gratissimum Linn (Lamiaceae) based on the empirical knowledge is widespread. The objective of this work is the matching of the virtues attributed to this plant in folk medicine with the biomolecules present through a thorough phytochemical exploration. Standard screening is based on the differential reactions of precipitation and staining. Phenolic compounds, total flavonoids, and condensed tannins were quantified by colorimetric Folin-Ciocalteu, AlCl3, and acid vanillin methods, respectively. Phenolic acids were investigated by the HPLC Ultimate 3000 chain and the antioxidant capacity evaluated by the ferric reducing antioxidant power method coupled with that of 2,2-diphenyl-1-picrylhydrazyl. Standard screening revealed the presence of flavonoids, alkaloids, tannins, anthracene derivatives, steroids, and terpenoids. The total contents of phenolics, flavonoids, and tannins were 56.59 mg gallic acid equivalent /100 mg, 13.71 mgEQ/100 mg, and 8.6 mgEC/100 mg, respectively. For specific assays, three flavonoids (chrysin, isorhamnetin, and quercetin) and six phenolic acids (tannic, ellargic, ferrulic, syringic, chlorogenic, and caffeic) have been identified. The antioxidant activity ranges from 78.92 to 106.25 mmol. Ascorbic acid equivalent /g extract with free radical inhibition ranging from 5.24% to 76.59%. The 50% inhibitory concentration giving a value of 6.175 mg ml −1 is greater than that of the pure molecule. The presence of these phytocompounds endowed with antiradical power testifies to the medicinal potentialities of O. gratissimum. These results confirm the empirical use of O. gratissimum in this study area.

Phytochemical Screening, Antioxidant Activity and Cytotoxicity of four Medicinal Plants for Antidiabetic Purposes Used in the Ivorian Pharmacopoeia

“…Also, the presence of polyphenols, tannins and saponosides in aqueous extracts of V. colorata leaves was confirmed by the work of Sawadogo et al [18] with the exception of alkaloids. The presence of polyphenols, flavonoids, tannins, alkaloids, saponins as well as sterols and terpenes in O. gratissimum extracts is confirmed by the results of Kpètèhoto et al [19] with the exception of leucoanthocyanins, as well as those obtained by N'Guessan et al [20] with the absence of saponins. Also, the results of the phytochemical composition of the T. tetraptera aqueous extract are similar to those found by Mbieleu et al [21] ; Larbie et al [22] and Obeng et al [23].…”