Polyphenols contents and antioxidant potential of Nauclea latifolia Smith (Rubiaceae) acetonic fractions from Burkina Faso

Scientific information on antioxidant properties and phenolic content of Nauclea latifolia used in ethnoveterinary medicine in Burkina Faso are limited. Therefore, the quantification of the antioxidant activity of different parts of this specie remains an interesting and useful task, particularly for finding new sources for natural antioxidants. The aim of this study was to evaluate the antioxidant activity and total polyphenols of Nauclea latifolia Smith (Rubiaceae) acetonic fractions from Burkina Faso. n-hexane, dichloromethane, ethyl acetate and n-butanol fractions of leaves, barks and root barks were tested for their antioxidant activities using DPPH, ABTS and FRAP methods. Folin-Ciocalteu and AlCl3 reagents were used to quantify the polyphenols. n-butanol fraction of barks (58.16 ± 0.76 mg GAE/100 mg), dichloromethane fraction of barks (51.13 ± 0.99; 26.14 mg GAE/100 mg) have presented the best total phenolic contents while the best total flavonoid contents were found in n-butanol fraction of leaves and n-hexane fraction of leaves with 4.85 ± 0.14 mg EQ/100mg and 2.92 ± 0.13 mg EQ/100mg, respectively. It was observed that n-hexane fraction of leaves was scavenge more DPPH free radicals with a value of 1011.98± 17,01 µmol EAA/g. That of n-butanol fractions of barks was showed the best ferric reduction power (3056.37 ± 96.66 µmol EAA/g) and the highest ABTS cation radicals scavenging capacity (7031.52 ± 254.98 µmol EAA/g). Nevertheless, this work encourages investigations on Burkina Faso plant species used in the ethnoveterinary medicine as sources of antioxidants. Keywords: Fraction; Ouagadougou; Barks, Total Polyphenols Contents; Radicals

Polyphenolic Profile, Anti-Inflammatory and Anti-Nociceptive Activities of Some African Medicinal Plants

The aim of the present study was to investigate the polyphenolic profile and the anti-inflammatory and anti-nociceptive activities of four traditionally used medicinal plants from Burkina Faso: Parkia biglobosa, Detarium microcarpum, Vitellaria paradoxa and Sclerocarya birrea. The analysis of the main phenolic compounds was performed by the HPLC-UV-MS method. The anti-inflammatory effect of the aqueous bark extracts was investigated by the λ-carrageenan-induced rat paw edema test. The anti-nociceptive activity was evaluated by the Randall–Selitto test under inflammatory conditions. Seven phenolic acids (gallic, protocatechuic, gentisic, vanillic, p-coumaric, ferulic, and syringic acids), and three flavonoids (catechin, epicatechin, and quercitrin) were identified in the plant samples. High contents of gallic acid were determined in the D. microcarpum, P. biglobosa and S. birrea extracts (190–300 mg/100 g), and V. paradoxa extract was the richest in epicatechin (173.86 mg/100 g). The λ-carrageenan-induced inflammation was significantly reduced (p P. biglobosa and D. microcarpum extracts (400 mg/kg p.o.). Under the inflammatory conditions, a significant anti-nociceptive activity (p < 0.001) was obtained after 2–3 h from the induction of inflammation. The effects of the tested extracts could be related to the presence of polyphenols and could be useful in the management of certain inflammatory diseases

Exploration of the Antioxidant and Anti-inflammatory Potential of <i>Cassia sieberiana</i> DC and <i>Piliostigma thonningii</i> (Schumach.) Milne-Redh, Traditionally Used in the Treatment of Hepatitis in the Hauts-Bassins Region of Burkina Faso

Inflammation is the supreme biological response to illness. In the Hauts-Bassins region, in traditional medicine, all parts of Cassia sieberiana and Piliostigma thonningii are used to treat hepatitis and inflammation. The aim of this study was to evaluate the in vitro antioxidant and anti-inflammatory activities of their aqueous extracts. High performance liquid chromatography with photodiode array (HPLC-DAD) and ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-MS/MS) analyses highlighted the presence of polyphenols and flavonoids. Antioxidant and anti-inflammatory activities were measured by various methods such as DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), TAC (total antioxidant capacity), anti-protease, anti-lipoxygenase, and membrane stabilization. The best antioxidant activity was observed in the bark (DPPH: IC50 = 13.45 ± 0.10 µg/mL) and roots (TAC = 29.68 ± 1.48 mg AAE/g DW) of Piliostigma thonningii and in the roots (ABTS: IC50 = 1.83 ± 0.34 µg/mL) of Cassia sieberiana. The best anti-inflammatory activity was observed in the bark (anti-lipoxygenase: IC50 = 13.04 ± 1.99 µg/mL) and leaves (anti-proteases: IC50 = 75.74 ± 1.07 µg/mL, membrane stabilization: IC50 = 48.32 ± 6.39 µg/mL) of Cassia sieberiana. Total polyphenols (ABTS: r = −0.679, TAC: r = 0.960) and condensed tannins (ABTS: r = −0.702, TAC: r = 0.701) were strongly correlated with antioxidant activity. Total flavonoids (anti-proteases: r = −0.729), condensed tannins (anti-proteases: r = 0.698), and vitamin C (anti-proteases: r = −0.953) were strongly correlated with anti-inflammatory activity. Total polyphenols, flavonoids, condensed tannins, and vitamin C could contribute to the antioxidant and anti-inflammatory activities of the two studied plants. These results could validate the traditional use of these plants to treat various inflammatory diseases