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Ocimum basilicum L. (Lamiaceae) is a wellknown perennial herb in Indian medicine used to treat various disorders like upper respiratory tract infections and wound healing. Primarily we investigated the anti-inflammatory activity of crude extracts of Ocimum basilicum using peripheral blood mononuclear cells (PBMC) of healthy individuals. Ocimum basilicum crude methanolic extract showed a good inhibitory effect on the proliferative response of PBMC in mitogenic lymphocyte proliferation assays. Furthermore, gene expression studies on lipopolysaccharide (LPS) induced production of proinflammatory cytokines like Tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β) and IL-2 showed down regulation of the markers. It also suppressed the induction of inducible nitric oxide synthase (iNOS) and the subsequent production of nitric oxide (NO) in LPS-stimulated RAW 264.7 macrophages in a timedependent manner. Our results showed that Ocimum basilicum crude methanolic extract inhibits the key proinflammatory cytokines and mediators, which accounts for its anti-inflammatory effect.

Young leaf explants of Ocimum sanctum L. incubated on solidified Murashige and Skoog (MS) medium supplemented with 2 mg l -1 1-naphthaleneacetic acid (NAA) and 0.2 mg l -1 kinetin (Kn) developed rhizogenic callus. When these were subcultured onto MS medium supplemented with 1.5 mg l -1 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 0.5 mg l -1 NAA, friable rhizogenic callus was observed. Upon transfer of this friable callus onto liquid MS medium containing 4 mg l -1 NAA and 1.3 mg l -1 6-benzyladnine (BA) under continuous agitation at 90 rpm and 16 h photoperiod, roots with an optimum dry weight of 1,460 mg l -1 were obtained. An ethyl acetate extract of these roots exhibited 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity.

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Molecules with bi-functional activities are preferred targets in drug discovery research today. In this study, a possible dual role (anti-inflammatory and anti-bacterial activity) of a plant extract has been discussed. As an initiative, the extract is found to suppress inflammation caused by endotoxin release from an enteric pathogen. Enteropathogenic Escherichia coli (E. coli) (EPEC O127:H6) causes persistent diarrhea and continues to be a major health problem among infants in developing countries. Host inflammatory response during EPEC infection is weak when compared to infections caused by other enteric pathogens. This is due to the suppression of intestinal inflammatory response by type III secreted proteins of EPEC during infection process. The weak inflammatory response is thus possibly due to disruption of tight junctions, which in turn facilitate recruitment of macrophages from the underlying lamina propria or shedding of bacterial products like lipopolysaccharide (LPS) during antibiotic mediated bacterial lysis. Since intestinal cells are non-responsive to LPS, the inflammatory response would be elicited by the intestinal macrophages present at the site of infection. Apart from commercial LPS from E. coli O111: B4, LPS was isolated from EPEC and used for inducing inflammatory markers like TNFα, IL-1β, IL-8 and TLR4 in J774 A.1 murine macrophage like cells to make this study clinically relevant. Alpinia officinarum is a traditional, perennial herb used widely in China and India for treating arthritis and gastrointestinal disorders. The ethyl acetate extract of Alpinia officinarum effectively suppressed EPEC LPS * To whom correspondence should be addressed: Center for Biotechnology, Anna University, Chennai-600025, Tamil Nadu, India. Tel.: +91-44-22350772; Fax: +91-44-22350299; E-mail: lakshmibs@annauniv.edu # These authors contributed equally to this work.induced inflammatory response thereby exhibiting potential in a clinical scenario, wherein diarrhea induced by EPEC or products of its lysis is either a consequence of macrophage induced inflammation or antibiotic treatment or due to a potential, yet to be analyzed, anti-bacterial activity of Alpinia officinarum extract against EPEC.