Comparative antioxidant and anti-inflammatory effects of [6]-gingerol, [8]-gingerol, [10]-gingerol and [6]-shogaol.

Zingiber officinale Rosc. (Zingiberaceae) has been traditionally used in Ayurvedic, Chinese and Tibb-Unani herbal medicines for the treatment of various illnesses that involve inflammation and which are caused by oxidative stress. Although gingerols and shogaols are the major bioactive compounds present in Zingiber officinale, their molecular mechanisms of actions and the relationship between their structural features and the activity have not been well studied. The aim of the present study was to examine and compare the antioxidant and anti-inflammatory activities of gingerols and their natural analogues to determine their structure-activity relationship and molecular mechanisms. The in vitro activities of the compounds [6]-gingerol, [8]-gingerol, [10]-gingerol and [6]-shogaol were evaluated for scavenging of 1,1-diphenyl-2-picyrlhydrazyl (DPPH), superoxide and hydroxyl radicals, inhibition of N-formyl-methionyl-leucyl-phenylalanine (f-MLP) induced reactive oxygen species (ROS) production in human polymorphonuclear neutrophils (PMN), inhibition of lipopolysaccharide induced nitrite and prostaglandin E(2) production in RAW 264.7 cells. In the antioxidant activity assay, [6]-gingerol, [8]-gingerol, [10]-gingerol and [6]-shogaol exhibited substantial scavenging activities with IC(50) values of 26.3, 19.47, 10.47 and 8.05 microM against DPPH radical, IC(50) values of 4.05, 2.5, 1.68 and 0.85 microM against superoxide radical and IC(50) values of 4.62, 1.97, 1.35 and 0.72 microM against hydroxyl radical, respectively. The free radical scavenging activity of these compounds also enhanced with increasing concentration (P<0.05). On the other hand, all the compounds at a concentration of 6 microM have significantly inhibited (P<0.05) f-MLP-stimulated oxidative burst in PMN. In addition, production of inflammatory mediators (NO and PGE(2)) has been inhibited significantly (P<0.05) and dose-dependently. 6-Shogaol has exhibited the most potent antioxidant and anti-inflammatory properties which can be attributed to the presence of alpha,beta-unsaturated ketone moiety. The carbon chain length has also played a significant role in making 10-gingerol as the most potent among all the gingerols. This study justifies the use of dry ginger in traditional systems of medicine.

Dugasani S ，Pichika MR ，Nadarajah VD ，Balijepalli MK ，Tandra S ，Korlakunta JN ... -  《-》

Optimization protocol for the extraction of 6-gingerol and 6-shogaol from Zingiber officinale var. rubrum Theilade and improving antioxidant and anticancer activity using response surface methodology.

Ghasemzadeh A ，Jaafar HZ ，Rahmat A 《BMC Complementary and Alternative Medicine》

Cyclooxygenase-2 inhibitors in ginger (Zingiber officinale).

Ginger roots have been used to treat inflammation and have been reported to inhibit cyclooxygenase (COX). Ultrafiltration liquid chromatography mass spectrometry was used to screen a chloroform partition of a methanol extract of ginger roots for COX-2 ligands, and 10-gingerol, 12-gingerol, 8-shogaol, 10-shogaol, 6-gingerdione, 8-gingerdione, 10-gingerdione, 6-dehydro-10-gingerol, 6-paradol, and 8-paradol bound to the enzyme active site. Purified 10-gingerol, 8-shogaol and 10-shogaol inhibited COX-2 with IC(50) values of 32 μM, 17.5 μM and 7.5 μM, respectively. No inhibition of COX-1 was detected. Therefore, 10-gingerol, 8-shogaol and 10-shogaol inhibit COX-2 but not COX-1, which can explain, in part, the anti-inflammatory properties of ginger.

van Breemen RB ，Tao Y ，Li W 《-》

Conversion of gingerols to shogaols in ginger (Zingiber officinale roscoe) by puffing.

Effect of puffing on conversion of gingerols to shogaols, physicochemical properties as well as antioxidant and anti-inflammatory activities of puffed ginger was investigated. Puffing significantly increased extraction yield and the highest value was 12.52% at 980 kPa. The significant decrease in gingerols and increase in shogaols were occurred after puffing, respectively. Especially, 6-shogaol was dramatically increased from 4.84 to 99.10 mg/g dried ginger. Puffed ginger exhibited the higher antioxidant activities (analyzed by DPPH, ABTS, TPC, and TFC) than those of control, and they were significantly increased with increasing puffing pressure. In case of anti-inflammatory activity, puffed ginger did not inhibit NO production, but significantly inhibited TNF-α and IL-6 productions. Among gingerols and shogaols, 6-shogaol showed significantly strong correlations with both antioxidant and anti-inflammatory activities. Consequently, puffed ginger can be applied to functional food industry, which dramatically increased the contents of 6, 8, 10-shogaols, the main bioactive compounds in ginger.

Kim YT ，Shin JS ，Ye SJ ，Kim JH ，Eom SH ，Baik MY ... -  《-》

Anti-neuroinflammatory capacity of fresh ginger is attributed mainly to 10-gingerol.

Despite the anti-neuroinflammatory capacity of ginger, the corresponding active constituents are unclear. This study analyzed the composition of fresh ginger ethanolic extract by using LC-MS. Inhibitory activities of fresh ginger extract and seven gingerol-related compounds on the neuro-inflammation were also evaluated by using a lipopolysaccharide (LPS)-activated BV2 microglia culture model. Except for zingerone and 6-gingerol, other gingerols and shogaols at a concentration of 20 μM inhibited the production of nitric oxide, IL-1β, IL-6 and TNF-α as well as their mRNA levels in LPS-activated BV2 microglia. Blocking NF-κB activation was the underlying mechanism responsible for inhibiting the proinflammatory gene expression. Increasing the alkyl chain length enhanced the anti-neuroinflammatory capacity of gingerols yet, conversely, attenuated those of shogaols. 6-Gingerol was the most abundant compound in the fresh ginger extract, followed by 10-gingerol. Furthermore, fresh ginger extract exhibited a significant anti-neuroinflammatory capacity, which was largely owing to 10-gingerol, but not 6-gingerol.

Ho SC ，Chang KS ，Lin CC 《-》