4-epi-Pimaric acid: a phytomolecule as a potent antibacterial and anti-biofilm agent for oral cavity pathogens.

The present study focused on the antibacterial and biofilm inhibitory potential of 4-epi-pimaric acid isolated from aerial parts (stem and leaves) of Aralia cachemirica L. (Araliaceae) against oral cavity pathogens. 4-epi-Pimaric acid exhibited minimum inhibitory concentration (MIC) in the range of 4-16 µg/ml and minimum bactericidal concentration (MBC) two- to four-folds higher than MIC. There was significant inhibition in the biofilm formation by Streptococcus mutans on the saliva coated surface (P < 0.05), and confocal microscopy revealed that 4-epi-pimaric acid inhibited the clumping and attachment of S. mutans. At 8 × MIC concentration, it significantly prevented the pH drop and reduced S. mutans biofilms (P < 0.05). Increased propidium iodide staining and leakage of 260- and 280-nm absorbing material by 4-epi-pimaric acid treated cells of S. mutans suggested that it probably causes disruption of the cytoplasmic membrane structure. It also exhibited significant suppression of TNF-α expression in human neutrophils, suggestive of its anti-inflammatory activity. Furthermore, the compound was found to be significantly safe (IC(50) >100 µg/ml) in the MTT assay on AML-12 cell lines. In conclusion, 4-epi-pimaric acid showed promising antibacterial, anti-biofilm and anti-inflammatory potency and this compound can be exploited for therapeutic application in oral microbial infections.

Sub-acute toxicity evaluation of an aqueous extract of Labisia pumila, a Malaysian herb.

Labisia pumila (Myrsinaceae), is a popular herb among the women in Malaysia known locally as "Kacip Fatimah". Recently many nutraceutical products containing the powdered or extracted parts of the plant have become available for women's health care. However no evaluation of the effect of the repeated dosing of any herbal product of this plant had been undertaken prior to a 28-day sub-acute study presented in this report. The results showed that a dose of 50mg/kg of an aqueous extract of L. pumila corresponded to no-adverse-effect-level (NOAEL), whereas higher doses were associated with some toxicity concerns.

In vitro cytotoxic elemanolides from Vernonia lasiopus.

Two new elemanolides, epivernodalol and lasiopulide, were isolated after chromatographic separation of the alcoholic extract of the dried aerial parts of the Vernonia lasiopus. These elemanolides are new C-10 epimers of the sesquiterpene lactones vernodalol and demethylacroylated vernodalol isolated from other species of Vernonia. Both elemanolides showed in vitro cytotoxicity against human cancer cell lines in culture. This is the first report of isolation and cytotoxic activity of the two elemanolides from V. lasiopus.

Benzophenanthridine alkaloids from Corydalis flabellata.

Four new alkaloids, characterized as 6-(2-hydroxyethyl)-5,6-dihydrosanguinarine (1), 6-acetonyl-5,6-dihydrosanguinarine (2), N-methyl-2,3,7,8-tetramethoxy-5,6-dihydrobenzophenanthridine-6-ethanoic acid (3), N-methyl-2,3,7,8-tetramethoxy-6-oxo-5,6-dihydrobenzophenanthridine (4), together with oxosanguinarine (5), spallidamine (6), 6-acetonyl-5,6-dihydrochelerythrine (7), 6-oxochelerythrine (8) and sanguidimerine (9) were isolated from the roots of Corydalis flabellata.

Growth and alkaloid production in suspension cultures of Hyoscyamus muticus as influenced by various cultural parameters.

Suspension cultures of Hyoscyamus muticus L. were raised in RT medium supplemented with NAA 10 (-5)M. Effects of pH, vitamins, sucrose, sodium and potassium succinate, chemical precursors and phytohormones on growth, morphogenesis and total tropane alkaloid production have been examined. Of these, low pH, sodium succinate, precursors and IAA enhanced alkaloid production. Alkaloid synthesis was higher during stationary phase and was found to be independent of morphogenesis.