Variation in antibacterial and anti-inflammatory activity of different growth forms of Malva parviflora and evidence for synergism of the anti-inflammatory compounds

Malva parviflora leaves and roots were collected from five sites within the Qacha's Nek District in Lesotho. These plants had two distinct growth forms - upright and prostrate. Hexane, methanol and water extracts were made from the plant material and tested for antibacterial and anti-inflammatory activity using the disc diffusion and cyclooxygenase-1 (Cox-1) bioassays, respectively. Hexane, methanol and water extracts made from Malva parviflora with a prostrate growth form inhibited the growth of Gram-positive and Gram-negative bacteria, while extracts made from plants with an upright growth form inhibited the growth of Gram-positive bacteria only. Cox-1 anti-inflammatory activity of hexane, methanol and water extracts did not show any variation between the two growth forms. The hexane extracts of both the leaves and roots were the most inhibitory. The water extracts had the least inhibitory activity. Bioassay-guided fractionation of the root dichloromethane extract showed that Cox-1 anti-inflammatory activity was caused by at least two compounds that acted synergistically to produce the biological effect. (C) 2004 Elsevier Ireland Ltd. All rights reserved.