Free Radical Scavenging, Antimicrobial and Immunomodulatory Activities of Orthosiphon stamineus

Abstract

Received : 12 March 2012; in revised form: 10 April 2012 / Accepted: 17 April 2012 / Published: 8 May 2012 Abstract: Orthosiphon stamineus is considered an important traditional folk medicine. In this study ethanol and aqueous extracts of O. stamineus were evaluated in vitro for their antioxidant, antimicrobial as well as for their immunomodulatory properties on human peripheral blood mononuclear cells (PBMCs). The DPPH radical scavenging method was used for the determination of antioxidant activity, while the antibacterial efficacy was investigated by both disc diffusion method and Minimum Inhibitory Concentration (MIC) against four bacterial strains (Gram-positive and Gram-negative). Furthermore, the immunomodulatory potential of the extracts was investigated through the MTT assay. Aqueous extract of O. stamineus exhibited significant free radical scavenging activity with IC 50 9.6 µg/mL, whereas the IC 50 for the ethanol extract was 21.4 µg/mL. The best antimicrobial activity was shown by the aqueous extract of O. stamineus against Staphylococcus aureus, with inhibition zone of 10.5 mm and MIC value 1.56 mg/mL. OPEN ACCESSMolecules 2012, 17 5386 Moreover, the results observed from the MTT assay showed that both plant extracts stimulated the PBMCs proliferation in vitro in a concentration-dependent manner, but the aqueous extract has remarkable activity against PBMCs. These findings indicate that O. stamineus showed high antioxidant activity and may be considered as an immunomodulatory agent.

Antibacterial activity of Orthosiphon stamineus towards Staphylococcus aureus and methicilin resistant Stahpylococcus aureus (MRSA)

“…The lowest MIC value was seen for S. aureus (12.5 mg/mL for methanol extract and 6.25 mg/mL for aqueous extract). Alshawsh (2012), showed that the lowest MIC value of O. stamineus leaf extract at 1.56 mg/mL while in this present study, the aqueous extract from the whole plant showed the lowest MIC value of 6.25 mg/mL. The antibacterial activity in their study is higher compared to this study because different part of the plant was used.…”

In vitro Antibacterial Activity of Zingiber officinale and Orthosiphon stamineus on Enterococcus faecalis

“…The O. stamineus extract used in this study was more in a crude form, which may explain its low antibacterial activity. Previous studies which reported the protective effects of O. stamineus employed methanolic (Chun-Hoong et al, 2010;Malahubban et al, 2013) and ethanolic extracts (Alshawsh et al, 2012;Mohamed et al, 2012).…”

“…Studies on the antimicrobial activity of O. stamineus have been reported against Staphylococcus aureus, Streptococcus agalactiae and Vibrio parahemolyticus (Ho et al, 2010;Mohammed et al, 2012).…”

Prospecting for Bioactive Constituents from Traditional Medicinal Plants through Ethnobotanical Approaches

“…5) was isolated from the roots of C. robustum, which is used as a traditional Chinese medicine to treat external injuries and irregular menses, and showed good scavenging effects against DPPH radicals with an IC 50 value of 39 µM. 58) Furthermore, numerous extracts from TMPs showed marked antioxidant activity, such as Kleinhovia hospita, 59) Orthosiphon stamineus, 60) Anogeissus acuminata, 61) etc.…”