BIOLOGICAL AND PHYTOCHEMICAL INVESTIGATIONS OF EXTRACTS FROM PTEROCARPUS ERINACEUS POIR (FABACEAE) ROOT BARKS.

BACKGROUND: Pterocarpus erinaceus Poir. belonging to Fabacae familly is used as medicinal plant in Burkina Faso's folk medicine. Roots of P. erinaceus are used to treat ulcer, stomach ache and inflammatory diseases. The objective of the present study was to carry out phytochemical composition of methanol (MeOH) and dichloromethane (DCM) extracts from Pterocarpus erinaceus roots, to isolate pure compounds, and to evaluate their pharmacological activities. METHODS: Chromatographic fractionation led to the isolation of active components of the extracts. The structures were established by NMR analysis and comparison with data from literature. The anti-inflammatory activity was evaluated using croton oil-induced edema of mice ear as well as the effect of extracts against lipoxygenase and lipid peroxidation was evaluated. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Cupric-reducing antioxidant capacity (CUPRAC) methods were used to evaluate the antioxidant activity of the extracts. RESULTS: Friedelin (1), 3a-hydroxyfriedelan-2-one (2), a-sophoradiol (3) and stigmasterol (4) were isolated from DCM extract and maltol-6-O-apiofuranoside-glucopyranoside (5) isolated from MeOH. DCM extract and friedelin, 3a-hydroxyfriedelan-2-one, a-sophoradiol showed a significant anti-inflammatory effect against ear edema. Friedelin (1), α-sophoradiol (3) and maltol-6-O-apiofuranoside-glucopyranoside (5) exhibited lipoxygenase inhibition. MeOH extract (100 µg/mL) inhibited lipoxygenase and lipid peroxidation activities at 45.1 ± 3% and 30.7 ± 0.5% respectively. MeOH extract, ethyl acetate fraction and butanol fraction exhibited antioxidant property with both two methods used. CONCLUSION: The results suggested that the extracts and compounds from roots of Pterocarpus erinaceus possessed local anti-inflammatory effect, antioxidant properties and inhibitor effect against lipoxygenase and lipid peroxidation activities.

Control of Endophytic Frankia Sporulation by Alnus Nodule Metabolites.

A unique case of microbial symbiont capable of dormancy within its living host cells has been reported in actinorhizal symbioses. Some Frankia strains, named Sp+, are able to sporulate inside plant cells, contrarily to Sp- strains. The presence of metabolically slowed-down bacterial structures in host cells alters our understanding of symbiosis based on reciprocal benefits between both partners, and its impact on the symbiotic processes remains unknown. The present work reports a metabolomic study of Sp+ and Sp- nodules (from Alnus glutinosa), in order to highlight variabilities associated with in-planta sporulation. A total of 21 amino acids, 44 sugars and organic acids, and 213 secondary metabolites were detected using UV and mass spectrometric-based profiling. Little change was observed in primary metabolites, suggesting that in-planta sporulation would not strongly affect the primary functionalities of the symbiosis. One secondary metabolite (M27) was detected only in Sp+ nodules. It was identified as gentisic acid 5-O-ß-d-xylopyranoside, previously reported as involved in plant defenses against microbial pathogens. This metabolite significantly increased Frankia in-vitro sporulation, unlike another metabolite significantly more abundant in Sp- nodules [M168 = (5R)-1,7-bis-(3,4-dihydroxyphenyl)-heptane-5-O-ß-d-glucopyranoside]. All these results suggest that the plant could play an important role in the Frankia ability to sporulate in planta and allow us to discuss a possible sanction emitted by the host against less cooperative Sp+ symbionts.