Bioévaluation du champignon sauvage Ganoderma lucidum d’Algérie

Abstract

aimed to valorize the biological and the pharmacological virtues of an Algerian medicinal mushroom, named Reishi “Ganoderma lucidum”, by the investigation of its nutritional profile and phytochemical characterization, as well as the evaluation of its fruiting bodies biological activities. The nutritional composition analysis revealed that the fruiting bodies were rich in proteins (11.26±0.39g/100g), in carbohydrates (85.25 ± 0.38g/100g), in minerals (1.9±0.00g/100g), while it contained little amounts of fats (1.58 ± 0.01g/100g), and as a result; calories were found (407.9 ± 0.05 Kcal/100g). In fact, HPLC analysis showed the presence of a high content of α-tocopherol (2510 ± 3.35µg/100g). Besides, the phytochemical study made it possible to highlight the main secondary metabolites; in particular, the phenolic compounds (flavonoids, tannins) and triterpenes in major. Whereby, the polyphenols and the flavonoids quantification stated that Ext-AcEt demonstrated the highest level of the two bioactive substances (171.1 ± 1.06 μg GAE/mg extract and 102.5 ± 0.69 μg PE/mg extract) and (25.48 ± 0.13 μg QE/mg and 40.45 ± 0.83 μg RE/mg of extract), respectively; followed by the aqueous, the butanol and then the chloroform fractions. Moreover, the results of the in vitro antioxidant potential of the extracts using several colorimetric methods showed that all the studied extracts presented a strong antioxidant activity, while the highest activity was proved by Ext-AcEt [DPPH• (IC50 =28.51 ± 0.24 μg/mL), ABTS•+ (IC50 =10.06 ± 0.13 μg/mL), GOR (IC50 =15.46 ± 0.48 μg/mL), FRAP (A0.5 =22.74 ± 0.30 μg/mL), CUPRAC (A0.5 =21.36 ± 0.04 μg/mL), phenanthroline (A0.5 =12.87 ± 0.26 μg/mL) and SPF (32.04 ± 0.29)]. The enzymes inhibitory ability of the same extracts was also examined. In which an excellent inhibitory effect against tyrosinase enzyme was exhibited, especially by Ext-Chl (IC50= 4.03 ± 0.23 μg/mL). The two fractions; Ext-AcEt and Ext-But, also exerted a potential effect against urease (IC50 = 78.97 ± 1.46 and 152.14±1.48 μg/mL, consecutively) and a mild capacity against lipase (IC50 = 370. 33 ± 1.13 and IC50 = 566.01 ± 8.99 μg/mL, consecutively). Additionally, a moderate inhibitory effect was marked for all the extracts against acetylcholine esterase and butyrylcholine esterase. Furthermore, the obtained extracts showed a noticeable antibacterial effect against all the examined bacterial strains. In this research, an in vitro anti-inflammatory activity of mushroom aqueous extract was also evaluated, in which a significant effect in protein denaturation inhibition was observed. This latest finding ; in vitro anti-inflammatory activity, was confirmed by an in vivo test where the aqueous fraction also revealed a potential anti-inflammatory effect by reducing significantly the paw rats edema induced by carrageenan. Thus, this study confirmed the preventive and the therapeutic efficacy of the studied mushroom; Reishi, and provided measurable biological evidence of its antioxidant, enzyme inhibitory, antibacterial and antiinflammatory properties.