Abstract
Background: Solanum dasyphyllum is a plant with several ethno-medicinal uses as food and medicine in treatment of fever, skin diseases, inflammation, stomach ache and some systemic infections. To date there is little scientific validation of the folkloric claims of S. dasyphyllum compared to other species of the Solanaceae family. This study determined the antimicrobial and antioxidant potential of methanol extract and fractions of the leaves of S. dasyphyllum and analysed the phyto-constituents using GC-MS technique.Methods: The dried leaves of S. dasyphyllum were extracted by Soxhlet apparatus with 80% methanol and the crude extract subjected to Phytochemical screening and liquid-liquid fractionation. Crude extract and fractions were subjected to antimicrobial screening, minimum inhibitory concentrations (MICs) and minimum bactericidal/fungicidal concentrations (MBC/MFC) determination and time-kill kinetics study. Crude extract was assayed for antioxidant activity and analysed by GC-MS.Results: Percentage yield of S. dasyphyllum was 12.5% and tested positive for flavonoids, alkaloids, saponins, cyanogenic glycosides, tannins and reducing sugars. The crude extract and fractions were active on all the isolates at concentrations >0.5 mg/mL. MICs of the crude extract and fractions ranged between 0.25 and >4 mg/mL, MBC ranged between 1 and >4 mg/mL and MFC ranged between 0.5 and >4 mg/mL. The MBC/MIC ratio was >4 for dichloromethane fractions against S. aureus (ratio 8) and MFC/MIC ratio ethylacetate fraction against the fungi isolates (ratio 8). The time-kill kinetics study showed dichloromethane and ethylacetate fractions to be bactericidal with zero viable count at 4 - 6hours against the isolates. The crude extract displayed moderate antioxidant with weak DPPH radical scavenging activity. The GC-MS analysis showed 29 metabolites including the phenols and polyphenols derivatives, eucalyptol, levomenthol, benzofuranone derivative, diethyl phthalate, neophytadiene, 1-Docosene, 17-Pentatriacontene, Phytol, Thunbergol and esters of decanoic acid derivatives all of which are known to have anti-infective and anti-oxidant properties.Conclusion: This study therefore confirmed the ethno-medicinal claim of S. dasyphyllum and thus elucidates the potentials of the plant as a good source of bioactive compounds including those with strong anti-infective and antioxidant properties.
Saturated Ceramides from the Sponge Dysidea Robusta
