Planta Med 2014; 80 - LP83
DOI: 10.1055/s-0034-1395114

Antioxidant, acetylcholinesterase inhibition and antimicrobial activities of the dichloromethane extracts from the aerial parts of Galenia africana L.

KV Phungula 1, A Marston 1, SF van Vuuren 2, PC Zietsman 3, 4, SL Bonnet 1, JH van der Westhuizen 5
  • 1University of the Free State, Department of Chemistry, P.O. Box 339, Bloemfontein 9301, South Africa
  • 2University of the Witwatersrand, Department of Pharmacy and Pharmacology, Faculty of Health Sciences, Parktown 2193, South Africa
  • 3National Museum, Bloemfontein 9300, South Africa
  • 4University of the Free State Centre for Environmental Management, P.O. Box 339, Bloemfontein, 9301, South Africa
  • 5University of the Free State, Directorate Research Development, P.O. Box 339, Bloemfontein, 9300, South Africa

Galenia africana, commonly known as kraalbos, geelbos, and perdebos, belongs to the family Aizoaceae and fresh or dried aerial parts of plants are used. Traditional health practitioners use the aerial parts of G. africana to treat venereal sores, asthma, coughs, wounds, eye infections, TB and skin diseases [1,2]. The present work assesses the antioxidant, acetylcholinesterase inhibition, and antimicrobial activities of the DCM extract of the aerial parts of G. africana. Ground, dry aerial parts (200 g) was extracted sequentially with DCM and MeOH, yielding 200 mg and 500 mg of extract, respectively. Fractionation of the DCM extract via high-performance countercurrent chromatography (HPCCC), followed by purification on Sephadex LH-20, yielded two pure compounds GA2 and GA3 of which the structure elucidation is in progress. The crude DCM extract exhibited antioxidant activity in the TLC 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical scavenging assay, inhibited the formation of acetyl choline in the TLC acetyl cholinesterase inhibitory assay, and showed noteworthy activity against Mycobacterium smegmatis (MIC 0.50 mg/mL), Enterococcus faecalis (0.50 mg/mL), Klebsiella pneumonia (1.0 mg/mL) and Cryptococcus neoformans (0.09 mg/mL). Of the isolated compounds, GA2 showed inhibition of the acetyl cholinesterase enzyme. The antimicrobial testing of the isolated compounds GA2 and GA3 are in progress.

Tab. 1: Summary of antioxidant, acetyl cholinesterase inhibition, antibacterial and antimycobacterial test results.

Test

(TLC)
DPPH

(TLC) Acetyl
cholinesterase

M. smegmatis
ATCC 14468

E. faecalis
ATCC 29212

K. pneumoniae
ATCC 13883

C. neoformans
ATCC 90112

Result

Positive

Positive

Active

Active

Active

Active

MIC

0.50 µg/mL

0.50 mg/mL

1.0 mg/mL

0.09 mg/mL

Acknowledgement: The National Research Foundation, The European Framework 7 project no. 266005 (“MUTHI” project).

Keywords: Galenia africana, antioxidant, acetylcholinesterase, DPPH, antimicrobial, HPCCC

References:

[1] Watt, J. M.; Breyer-Brandwijk, M. G. 1962. The medicinal and poisonous plants of southern and eastern Africa. 2nd ed. Livingstone, London.

[2] De Beer, J. J. J.; van Wyk, B.-E. 2011. An ethnobotanical survey of the Agter-Hantam, Northern Cape Province, South Africa. S. Afr. J. Bot. 77:741 – 754