In vitro inhibition of cyclooxygenase and 5-lipoxygenase by alkamides from Echinacea and Achillea species.

Polyunsaturated alkamides isolated from Achillea species, Echinacea angustifolia DC., Anacyclus pyrethrum (L.) Link, and Aaronsohnia pubescens (Desf.) Bremer & Humphries, (Compositae) were shown to possess inhibitory activity in in vitro cyclooxygenase (sheep seminal microsomes) and 5-lipoxygenase (porcine leukocytes) assays. Activity appeared to depend on the particular structure of the alkamides.

Anti-inflammatory active polyacetylenes from Bidens campylotheca.

The n-hexane extract of Bidens campylotheca Schultz Bip. ssp campylotheca (Compositae) showed significant in vitro inhibition of cyclooxygenase (CO) and 5-lipoxygenase (5-LO). Five polyacetylenes, heptadeca-2E,8E,10E,16-tetraene-4,6-diyne (1), heptadeca-2E,8Z,10E,16-tetraene-4,6-diyne (2), heptadeca-2E,8E,16-triene-4,6-diyne-10-ol (3), safynol (5) and, as a new compound, safynol-2-O-isobutyrate (4) could be isolated and their structures elucidated mainly by UV, MS, NMR, and COSY-NMR. The isolated compounds exhibited a significant inhibitory effect on cyclooxygenase and 5-lipoxygenase.

[Anti-inflammatory activity of sabal fruit extracts prepared with supercritical carbon dioxide. In vitro antagonists of cyclooxygenase and 5-lipoxygenase metabolism]. / Antiphlogistische Wirkung eines mit hyperkritischem Kohlendioxid gewonnenen Sabalfrucht-Extraktes. In-vitro-Hemmung des Cyclooxygenase- und 5-Lipoxygenase-Metabolismus.

The extract SG 291 (Talso, Talso uno) from the fruits of Sabal serrulata (syn.: Serenoa repens) prepared by supercritical fluid extraction with carbon dioxide is used for the treatment of benign prostatic hyperplasia (BPH) and non bacterial prostatitis. In the present work, the Sabal extract SG 291 was analyzed by gas chromatography and investigated for its inhibitory influence on the biosynthesis of inflammatory arachidonic acid metabolites. The extract SG 291 was found in vitro to be a dual inhibitor of the cyclooxygenase (IC50-value: 28.1 micrograms/ml) and 5-lipoxygenase pathway (IC50-value: 18.0 micrograms/ml). By alkaline hydrolysis, ether extraction and preparative thin layer chromatography the extract SG 291 was separated in three fractions containing acid lipophilic compounds (A), fatty alcohols (B) and sterols (C) as main components. Fraction A inhibited the biosynthesis of cyclooxygenase (CO) and 5-lipoxygenase (5-LO) metabolites in the same intensity as the native extract SG 291, while the fractions B, C and beta-sitosterol showed no inhibitory effect on both enzymes of the arachidonic acid pathways. Therefore, the CO and 5-LO inhibiting principle of Sabal serrulata extract SG 291 must be localized in the acidic lipophilic fraction (SLF). The CO and 5-LO inhibitory effects may give an explanation for the in vivo observed antiphlogistic and antiedematous activity of the lipophilic Sabal serrulata extract SG 291.

Comparative pharmacological investigations of Allium ursinum and Allium sativum.

Extracts of wild garlic (Allium ursinum) and garlic (A. sativum) with defined chemical compositions were investigated for their in vitro inhibitory potential on 5-lipoxygenase (LO), cyclooxygenase (CO), thrombocyte aggregation (TA), and angiotensin I-converting enzyme (ACE). The inhibition rates as IC50 values of both extracts for 5-LO, CO, and TA showed a good correlation with the %-content of the major S-containing compounds (thiosulfinates and ajoenes) of the various extracts. In the 5-LO and CO test the garlic extracts are slightly superior to the wild garlic extracts whereas, in the TA test, no differences could be found. In the ACE test the water extract of the leaves of wild garlic containing glutamyl-peptides showed the highest inhibitory activity followed by that of the garlic leaf and the bulbs of both drugs. The comparative studies underline the usefulness of wild garlic as a substitute of garlic.

Biological activity of novel macrocyclic alkaloids (budmunchiamines) from Albizia amara detected on the basis of interaction with DNA.

Extracts derived from Albizia amara were found to demonstrate activity in a recently developed hplc system designed to detect compounds capable of interacting with DNA. Further investigation led to the procurement of four sets of alkaloid isolates X1-X4 that were found to be macrocyclic pithecolobine alkaloids. All four isolates interacted with calf thymus DNA and were generally cytotoxic with a battery of cultured mammalian cells. As determined with Salmonella typhimurium strain TM677, isolates X1 and X3 were bactericidal, but not mutagenic. Isolate X1 was found to inhibit the catalytic activity of DNA polymerase, RNA polymerase, and HIV-1 reverse transcriptase. With DNA polymerase, the reaction was shown to be inhibited in a manner that was competitive with respect to DNA. In addition, isolate X1 inhibited each of the following: platelet aggregation, human lymphocyte transformation, phorbol-ester-induced chemiluminescence with human granulocytes, and cyclooxygenase activity. Detection of these alkaloids on the basis of their interaction with DNA exemplifies the validity of this approach.