Modulation of human complement activation and the human neutrophil oxidative burst by different root extracts ofPicrorhiza kurroa

In vitro immunomodulatory activity of plants used by the Tacana ethnic group in Bolivia

One hundred and seventy-eight ethanolic plant extracts from the pharmacopoeia of the Tacana, an ethnic group from Bolivia, were screened for immunomodulatory activity using complement cascade inhibition and ADP-induced platelet aggregation inhibition assays. Six impaired both complement pathways (classical and alternative): stem bark from Astronium urundeuvea (Anacardiaceae), Cochlospermum vitifolium (Cochlospermaceae), Terminalia amazonica (Combretaceae), Triplaris americana (Polygonaceae), Uncaria tomentosa (Rubiaceae) and Euterpe precatoria (Arecaceae) roots. Inhibition of complement cascade was independent of essential ion complexation, and was not due to direct hemolytic activity on target red blood cells. For A. urundeuvea, C. vitifolium, and T. amazonica, anti-inflammatory activity relied on cyclo-oxygenase inhibition. Four of these species (A. urundeuva, T. americana, U. tomentosa and E. precatoria) are used traditionally to treat inflammatory processes.

Complement modulating activity of Rwandan medicinal plants

Forty-two ethanolic extracts of thirty-six Rwandan medicinal plants were investigated for their influence on complement-mediated hemolysis. The plants were selected on the base of their ethnomedicinal use in infections and autoimmune diseases. Eight plant extracts showed an inhibitory activity against the classical pathway of the complement system and ten plant extracts against the alternative pathway. Three plant extracts exhibited an interesting activity against both pathways, i.e. Aspilia pluriseta, Coleus kilimandschari, and Macaranga kilimandscharica (leaves and stem). Further study indicated that the complement inhibitory activity was not caused by chelation of bivalent cations or by direct action on the target erythrocytes.

Immunomodulatory and anti-inflammatory activity of Picrorhiza scrophulariiflora

Extracts of the rhizomes of Picrorhiza scrophulariiflora Pennell (Scrophulariaceae) were investigated for their in vitro and in vivo immunomodulatory properties. Diethyl ether extracts showed potent inhibitory activity towards the classical pathway of the complement system, the respiratory burst of activated polymorphonuclear leukocytes, and mitogen-induced proliferation of T-lymphocytes. Furthermore, such extracts showed anti-inflammatory activity towards carrageenan-induced paw edema. No effects were observed in experimentally induced arthritis in mice.

An ethnopharmacological study on common privet (Ligustrum vulgare) and phillyrea (Phillyrea latifolia)

Ligustrum vulgare and Phillyrea latifolia leaves were well known in the Mediterranean historical medicine for their oropharyngeal anti-inflammatory effects. At the present time a popular phytotheraputical use of these species remains only in a few isolated southern European areas. Phytochemical and phytopharmacological studies of the methanolic extractives of their leaves were carried out. Flavonoidic fractions as well as different isolates, apigenin and luteolin derivatives showed significant in vitro complement inhibiting effects on the classical pathway of the complement system. A possible phytoceutical utilisation of the aerial parts of these species could represent (especially regarding the genus Phillyrea) an interesting perspective for many semi-arid Mediterranean regions.

Studies on anti-complementary activity of extracts and isolated flavones from Ligustrum vulgare and Phillyrea latifolia leaves (Oleaceae)

Polar fractions and flavones isolated from methanolic extracts of the leaves of Ligustrum vulgare and Phillyrea latifolia (Oleaceae), whose popular use as an anti-inflammatory is well-known in Mediterranean historical medicine and ethnobotany, showed significant in vitro complement inhibiting effect on the classical pathway of the complement system. Among the isolated flavonoidic structures, apigenin-7-O-glucoside, apigenin-7-O-rutinoside, luteolin-4'-O-glucoside, luteolin-7-O-glucoside and ligustroflavone presented remarkable activity.

In vitro and in vivo inhibition of microsomal lipid peroxidation by MA-631

Excess free radicals are linked to many diseases, including aging, atherosclerosis, and cancer. Previously, we have shown that MA-631 (a complex herbal mixture) inhibits human low-density lipoprotein (LDL) oxidation and may play a role in prevention of atherosclerosis. In this study we further evaluated the in vivo and in vitro antioxidant activity of MA-631. Both the alcoholic and aqueous extracts of MA-631 inhibited enzymatic- and nonenzymatic-induced rat liver microsomal lipid peroxidation in a concentration-dependent manner. The thiobarbituric acid-reactive substances (TBARS) values (nmol malondialdehyde (MDA)/mg microsomal protein) were 1.43 +/- 0.18 for microsomes alone (baseline for enzymatic system), 19.63 +/- 2.50 for microsomes + reduced nicotinamide adenine dinucleotide phosphate (NADPH) (oxidation without inhibitor), 9.89 +/- 1.41 for heated microsomes (baseline for nonenzymatic system), and 27.15 +/- 0.08 for microsomes + ascorbate (oxidation without inhibitor). The concentrations (micrograms/2 ml) of MA-631 which produced 50% inhibition (IC50) of enzymatic- and non-enzymatic-induced lipid peroxidation were 15.2 +/- 2.0 and 17.0 +/- 2.6, respectively, for the aqueous extract, and 4.3 +/- 0.8 and 6.4 +/- 1.2, respectively, for the alcoholic extract. A 2% MA-631 (w:w) supplemented diet fed to rats for three weeks inhibited in vivo, toluene-induced microsomal lipid peroxidation in the brain, kidney, liver, and heart. These results imply that MA-631 may be useful in the prevention of free radical-linked diseases.

Immunostimulatory activity of Picrorhiza kurroa leaf extract

A 50% ethanolic extract of Picrorhiza kurroa Royle ex Benth. (Scrophulariaceae) leaves (PKLE) was found to stimulate the cell-mediated and humoral components of the immune system as well as phagocytosis in experimental animals. PKLE elicited a dose-related increase in SRBC, induced 4 h (early) and 24 h (delayed) hypersensitivity reactions in mice and rats, and horse serum induced Arthus reaction in guinea pigs. It also enhanced the humoral immune responses in mice and rats and phagocytic function of the cells of the reticuloendothelial system in mice. PKLE exhibited no mitogenic activity but augmented the responsiveness of murine splenocytes to T cell mitogens phytohaemagglutinin (PHA) and concanavalin A (Con A) and B cell mitogen lipopolysaccharide (LPS E. coli).

Inhibition of human low-density lipoprotein oxidation in vitro by Maharishi Ayur-Veda herbal mixtures

In this study, we examined the effect of the Maharishi Ayur-Veda herbal mixtures (MAHMs) Maharishi Amrit Kalash-4 and -5 (M-4 and M-5), MA-631, and Maharishi Coffee Substitute (MCS) on low-density lipoprotein (LDL) oxidation and compared the potency of these mixtures to ascorbic acid, alpha-tocopherol, and probucol. LDL was incubated in 95% air and 5% CO2, with or without 3 microM Cu(+2), in the presence or absence of MAHMs, for 6 or 24 h. In a separate experiment, LDL was incubated as above except MAHMs were added at 0, 1.5, and 3.5 h after incubation started to assess their effect on initiation and propagation of LDL oxidation. Our results demonstrate that MAHMs caused concentration-dependent inhibition of LDL oxidation as assessed by thiobarbituric acid-reactive substances and electrophoretic mobility. The MAHM showed more antioxidant potency in preventing LDL oxidation than ascorbic acid, alpha-tocopherol, or probucol. Also, MAHMs inhibited both initiation and propagation of cupric ion-catalyzed LDL oxidation. These results suggest the importance of further research on these herbal mixtures in the investigation of atherosclerosis and free radical-induced injury.