Blechnum Orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent

<p>Abstract</p> <p>Background</p> <p><it>Blechnum orientale </it>Linn. (<it>Blechnaceae</it>) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of <it>Blechnum orientale </it>Linn.</p> <p>Methods</p> <p>Five solvent fractions were obtained from the methanol extract of <it>B. orientale</it> through successive partitioning with petroleum ether, chloroform, ethyl acetate, butanol and water. Total phenolic content was assessed using Folin-Ciocalteu's method. The antioxidant activity was determined by measuring the scavenging activity of DPPH radicals. Cytotoxic activity was tested against four cancer cell lines and a non-malignant cell using MTT assay. Antibacterial activity was assessed using the disc diffusion and broth microdilution assays. Standard phytochemical screening tests for saponins, tannins, terpenoids, flavonoids and alkaloids were also conducted.</p> <p>Results</p> <p>The ethyl acetate, butanol and water fractions possessed strong radical scavenging activity (IC₅₀8.6-13.0 μg/ml) and cytotoxic activity towards human colon cancer cell HT-29 (IC₅₀27.5-42.8 μg/ml). The three extracts were also effective against all Gram-positive bacteria tested: <it>Bacillus cereus, Micrococcus luteus</it>, methicillin-susceptible <it>Staphylococcus aureus </it>(MSSA), methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) and <it>Stapylococcus epidermidis</it>(minimum inhibitory concentration MIC 15.6-250 μg/ml; minimum bactericidal concentration MBC 15.6-250 μg/ml). Phytochemical analysis revealed the presence of flavonoids, terpenoids and tannins. Ethyl acetate and butanol fractions showed highest total phenolic content (675-804 mg gallic acid equivalent/g).</p> <p>Conclusions</p> <p>The results indicate that this fern is a potential candidate to be used as an antioxidant agent, for colon cancer therapy and for treatment of MRSA infections and other MSSA/Gram-positive bacterial infectious diseases.</p

Binding of haptoglobin, inter-alpha-trypsin inhibitor, and alpha 1 proteinase inhibitor to synovial fluid hyaluronate and the influence of these proteins on its degradation by oxygen derived free radicals.

Synovial fluid from 201 normal and pathological knee joints was subjected to gel filtration by Sepharose CL-2B chromatography to separate hyaluronic acid (HA) from unbound proteins, which were retarded on this column. HA from all normal fluids was excluded from the gel and contained 1% or less bound protein. Synovial fluids taken from joints of patients with rheumatoid arthritis (RA) contained considerably more protein bound to HA. In 46% of RA samples the level of protein was greater than 4%, whereas only one fluid examined from osteoarthritic joints contained this amount. The proteins bound to HA from RA joints were identified by sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS-PAGE) and immunodiffusion techniques as the acute phase proteins alpha 1 proteinase inhibitor, inter-alpha-trypsin inhibitor, and haptoglobin. The average relative percentages of these proteins bound to HA were 17.6%, 32.6%, and 29.2% respectively. These HA-protein complexes could be generated in vitro by mixing normal (low protein) HA with any one of the three acute phase proteins. The HA-protein complexes formed in vitro with inter-alpha-trypsin inhibitor or haptoglobin, and those isolated from RA synovial fluids, were more resistant to degradation by oxygen derived free radicals (ODFR) than HA from normal fluids. From these findings we conclude that certain acute phase proteins diffusing into synovial fluid during inflammatory episodes may play an important part in protecting HA from depolymerisation by activated phagocytes