Identified Diallyl Polysulfides from an Aged Garlic Extract which Protects the Membranes from Lipid Peroxidation

Abstract

Garlic exerts various effects on the biological systems: e.g., inhibiting platelet aggregation (1-3), lowering serum and liver cholesterol levels (4, 5), and antibacterial activity (6). We have indicated that the aged garlic extract which was obtained by the ethanol-extraction of cracked garlic bulbs (Allium sativurn L.) protected biological membranes from lipid peroxidation (7). It is essential to clarify the component in garlic extract which has this antioxidant activity.We have tried to identify this component by fractionating the aged garlic extract. The garlic extract was fractionated through ethyl acetate-extraction and silica gel column chromatography with n-hexane as the eluent. The sulfide fractions thus obtained were further separated by high performance liquid chromatography [(HPLC; TSK gel ODS 8OTM (TOSOI-I), eluent: 90% ethanol]. All fractions obtained from these separation processes were subjected to the assay for antioxidant activity, using rat liver microsomes in the same way as described previously (7). Lipid peroxidation in rat liver microsomes was induced by ascorbic acid and Fe2 and was evaluated by the formation of thiobarbituric acid reactive substances (TBA-RS). As a result, five components were found to have high activities to inhibit lipid peroxidation. 'Fl-NMR, C-NMR, and the high resolution mass spectroscopy revealed these components to be the diallyl polysulfides [CH2 = CH -CH2 -(S) -CH2CH=CH2I (n = 3-7), i.e., diallyl trisulfide, diallyl tetrasulfide, diallyl pentasulfide, diallyl hexasulfide, and diallyl heptasulfide. Their inhibiting effects against lipid peroxidation were dose-dependent. A representative example is shown in Fig. 1. A remarkable inhibition against lipid peroxidation was observed at the concentration of 25g/ml diallyl heptasulfide. The inhibiting effects of all the diallyl polysulfides against lipid peroxidation were compared at a concentration of 25.tg/ml (Fig.2). Among them, in particular, four diallyl polysulfides, the diallyl tetra-, penta-, hexa-, and heptasulfides, exhibited much more potent antioxidant activities than diallyl trisulf'ide. The crude aged garlic extract showed an almost perfect protection against lipid peroxidation in rat liver microsomes at 40 mg/mI of garlic extract, as shown in the previous paper (7). In the same reaction systems, these four Downloaded by: University of Pennsylvania Libraries. Copyrighted material.

The effect of antioxidant properties of aqueous garlic extract and Nigella sativa as anti-schistosomiasis agents in mice

“…AGE treatment prevented the increase in MDA, probably in part by scavenging the very reactive hydroxyl and peroxyl radicals. Aged garlic extract and diallyl polysulfides inhibit the formation of thiobarbituric acid-reactive and fluorescent substances induced by iron-ascorbic acid in isolated liver microsomal membranes 17 , indicating the protective effect of garlic against lipid peroxidation. It has been reported that chronic garlic intake significantly decreased lipid peroxidation and increased endogenous antioxidants, such as catalase and GSH 5 .…”

Garlic Extract Ameliorates Renal and Cardiopulmonary Injury in the Rats with Chronic Renal Failure

“…The members of the Allium family, including garlic, contain very high levels of biochemically active organic sulfur compounds, and their extracts have been known to protect organs from various injuries. [36][37][38] Since ROS have been implicated in mediating various pathological processes (e.g., ischemic heart disease, peripheral arterial occlusive disease, hypertension, hyperlipidemia, and toxicities), it can be suggested that the beneficial effects of garlic in these conditions may be due to its antioxidant activity. [39][40][41][42][43][44][45][46] The compounds in garlic (S-allylcysteine, S-allyl-mercapto cysteine, S-allyl-cysteine sulfoxide, and allicin), through their radical scavenging abilities, have been suggested to be responsible for its preventive effects against oxidative injury.…”

“…16,26,52 In the present study, AGE treatment significantly decreased MDA levels in the kidney, heart, and lung of CRF rats, probably in part, by scavenging the very reactive hydroxyl and peroxyl radicals. Horie et al 38 suggested that AGE and diallyl polysulfides inhibit the formation of TBA-reactive and fluorescent substances induced by iron-ascorbic acid in isolated liver microsomal membranes, indicating the protective effect of garlic against lipid peroxidation. Similarly, it was previously shown in several nephrotoxicity models that oxidative damage in the kidney tissue was prevented Garlic Extract Ameliorates Renal and Cardiopulmonary Injury 723 by AGE, which was demonstrated by reduced MDA levels and restored renal functions.…”

Determination of Dimethyl Disulfide, Diallyl Disulfide, and Diallyl Trisulfide in Biopesticides Containing Allium Sativum Extract by Gas Chromatography

“…These components are recognized as antioxidant, antithrombotic, anticancer, antibacterial, antimicrobial, nematicidal, and insecticidal activity material (Al-Delaimy and Ali, 1970;Kamanna and Chandrasekhara, 1983;Horie et al, 1992;Kyung, 2006;Nuttakaan et al, 2006;Anwar et al, 2009). …”