@article {582, title = {An Examination of the Medicinal Potential of Scaevola spinescens: Toxicity, Antibacterial, and Antiviral Activities}, journal = {Pharmacognosy Research}, volume = {3}, year = {2011}, month = {June,2011}, pages = {85-94}, type = {Original Article}, chapter = {85}, abstract = {

Background: Scaevola spinescens is an endemic Australian native plant with a history of use as a medicinal agent by indigenous Australians. Yet the medicinal bioactivities of this plant are poorly studied. Materials and Methods: S. spinescens solvent extracts were tested for antimicrobial activity, antiviral activity and toxicity in vitro. Results: All extracts displayed antibacterial activity in the disc diffusion assay. The methanol extract proved to have the broadest specificity, inhibiting the growth of 7 of the 14 bacteria tested (50\%). The water, ethyl acetate, chloroform, and hexane extracts inhibited the growth of 6 (42.9\%), 5 (35.7\%), 5 (35.7\%), and 4 (28.6\%) of the 14 bacteria tested, respectively. S. spinescens methanolic extracts were equally effective against Gram-positive (50\%) and Gram-negative bacteria (50\%). All other extracts were more effective at inhibiting the growth of Gram-negative bacteria. All extracts also displayed antiviral activity in the MS2 plaque reduction assay with the methanol, water, ethyl acetate, chloroform, and hexane extracts inhibiting 95.2 {\textpm} 1.8\%, 72.3 {\textpm} 6.3\%, 82.6 {\textpm} 4.5\%, 100 {\textpm} 0\% and 47.7 {\textpm} 12.9\% of plaque formation, respectively. All S. spinescens extracts were nontoxic in the Artemia fransiscana bioassay with no significant increase in mortality induced by any extract at 24 and 48 hr. The only increase in mortality was seen for the water extract at 72 hr, although even this extract displayed low toxicity, inducing only 41.7 {\textpm} 23.3\% mortality. Conclusions: The lack of toxicity of the S. spinescens extracts and their inhibitory bioactivity against bacteria and viruses validate the Australian Aboriginal usage of S. spinescens and indicates its medicinal potential.

}, keywords = {Antiviral, Australian medicinal plants, Maroon bush, Medicinal plants, MS2 bacteriophage, Scaevola spinescens}, doi = {10.4103/0974-8490.81955}, author = {Ian E. Cock and Liisa Kukkonen} } @article {858, title = {A Modified MS2 Bacteriophage Plaque Reduction Assay for the Rapid Screening of Antiviral Plant Extracts}, journal = {Pharmacognosy Research}, volume = {2}, year = {2010}, month = {September 2010}, pages = {221-228}, type = {Original Article}, chapter = {221}, abstract = {

Introduction: Traditional methods of screening plant extracts and purified components for antiviral activity require up to a week to perform, prompting the need to develop more rapid quantitative methods to measure the ability of plant based preparations to block viral replication. We describe an adaption of an MS2 plaque reduction assay for use in S. aureus. Results: MS2 bacteriophage was capable of infecting and replicating in B. cereus, S. aureus and F+ E. coli but not F- E. coli. Indeed, both B. cereus and S. aureus were more sensitive to MS2 induced lysis than F+ E. coli. When MS2 bacteriophage was mixed with Camellia sinensis extract (1 mg/ml), Scaevola spinescens extract (1 mg/ml) or Aloe barbadensis juice and the mixtures inoculated into S. aureus, the formation of plaques was reduced to 8.9 {\textpm} 3.8\%, 5.4 {\textpm} 2.4\% and 72.7 {\textpm} 20.9\% of the untreated MS2 control values respectively. Conclusions: The ability of the MS2 plaque reduction assay to detect antiviral activity in these known antiviral plant preparations indicates its suitability as an antiviral screening tool. An advantage of this assay compared with traditionally used cytopathic effect reduction assays and replicon based assays is the more rapid acquisition of results. Antiviral activity was detected within 24 h of the start of testing. The MS2 assay is also inexpensive and non-pathogenic to humans making it ideal for initial screening studies or as a simulant for pathogenic viruses.

}, keywords = {Aloe vera, Antiviral assay, Camellia Sinensis, MS2 bacteriophage, Plaque reduction assay, Scaevola spinescens}, doi = {10.4103/0974-8490.69108}, author = {Ian Cock and FR Kalt} }