The in vitro antibacterial activities and time kill regimes of crude methanol extract of Helichrysum pedunculatum was assessed using standard microbiological procedures. The experiment was conducted against a panel of bacterial species made up of clinical, environmental and reference strains. The extract was active against eleven of the twenty-one bacteria tested at a concentration of 10 mg/ml. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.1 -5.0 mg/ml. The average log reduction in viable cell count in time kill assay ranged between 0.17 Log 10 to 6.37 Log 10 cfu/ml after 6 h of interaction, and between 0.14 Log 10 and 6.99 Log 10 cfu/ml after 12 h interaction in 1×MIC and 2×MIC of the extract. The extract was bactericidal against 8 of the test bacteria at 1×MIC and against 9 of the test bacteria at 2×MIC from 12 h interaction period. At both MIC levels, the extract was bactericidal to all the reference strains and four of the six environmental strains at both MIC levels after 12 h of interaction. Also the extract was bactericidal to four of the six environmental strains at both MIC levels after 12 h of interaction and bacteriostatic during the first 6 h of interaction. Inhibitory levels of crude methanol extract of H. pedunculatum could be bacteriostatic or bactericidal independent of Gram's characteristic.

Sansevieria aethiopica (Thunb) has been reported to be used for the treatment of oral infections in Eastern Cape of South Africa. Based on ethnobotanical survey, the plant was selected for the possible synergistic effects of its acetone, ethanol and methanolic extracts with gentamicin on the planktonic and sessile cells of Enterococcus faecalis ATCC 29212 and Enterococcus faecalis KZN. In vitro interactions between the plant extracts and gentamicin were studied using checkerboard macrodilution method and anti-biofilm activity of the iso-effective combinations was determined by semi-quantitative adherence assay. Acetone extract of S. aethiopica has the highest inhibitory activity. The minimum concentration of gentamicin that inhibited the two isolates was the same (0.016 mg/ml). Different isoeffective points were observed with fractional inhibitory concentration indexes ranged between 0.375 and 1.9313. Out of the iso-effective points observed only four were synergistic while one was addictive. The maximum biofilm reduction was observed when the two antibacterial agents were combined. We therefore suggest that the extracts of the plant at the test concentrations can be used in combination with gentamicin for oral hygiene.