Selected spices and their combination modulate hypercholesterolemia-induced oxidative stress in experimental rats

BACKGROUND: Effect of aqueous extracts of Allium sativum (garlic), Zingiber officinale (ginger), Capsicum fructensces (cayenne pepper) and their mixture on oxidative stress in rats fed high Cholesterol/high fat diet was investigated. Rats were randomly distributed into six groups (n = 6) and given different dietary/spice treatments. Group 1 standard rat chow (control), group 2, hypercholesterolemic diet plus water, and groups 3, 4, 5, 6, hypercholesterolemic diet with 0.5 ml 200 mg · kg-1 aqueous extracts of garlic, ginger, cayenne pepper or their mixture respectively daily for 4 weeks. RESULTS: Pronounced oxidative stress in the hypercholesterolemic rats evidenced by significant (p < 0.05) increase in MDA levels, and suppression of the antioxidant enzymes system in rat's liver, kidney, heart and brain tissues was observed. Extracts of spices singly or combined administered at 200 mg.kg-1 body weight significantly (p < 0.05) reduced MDA levels and restored activities of antioxidant enzymes. CONCLUSIONS: It is concluded that consumption of garlic, ginger, pepper, or their mixture may help to modulate oxidative stress caused by hypercholesterolemia in rats.

Intraspecific strains of Pythium aphanidermatum induced disease resistance in ginger and response of host proteins.

Intraspecific strains of Pythium aphanidermatum induced resistance in ginger against rhizome rot and activated biosynthesis of selected host proteins. Pre-inoculation of plants with IR strain (avirulent) or co-inoculation with SR2 (virulent) caused significant reduction in disease severity. Analysis of protein profiles of ginger leaves of inoculated and non-inoculated plants by SDS-PAGE and Image Master VDS-ID Gel Analysis version : 3.0 revealed that some specific defence proteins/stress proteins increased in inoculated plants. Five such proteins having molecular weight 56, 32, 27, 18 and 14 kDa were detected in leaves of plant treated with IR + SR2 strains. On the contrary, mycelial protein profiles and submerged growth of strains were studied separately and together. Mycelia of IR, SR2 and IR + SR2 exhibited 26, 23 and 25 protein bands, respectively although, 21 bands were common between IR and SR2. Growth of SR2 in synthetic medium was much higher than that of IR, but the growth of two strains together was lower than SR2 alone. To characterise strains, their differential growth response to DL-beta-aminobutyric acid (BABA), a known defence activator of ginger was also tested. Results suggested that at least 5 specific defence proteins/stress proteins were involved in microbially induced resistance in ginger and inducer strains were distinct in their specific protein profiles and sensitivity to BABA.

Kinetic studies on zingiber officinale

The present investigation deals with the isolation, purification and characterization of gingerol, the major pungent constituent of ginger [Zingiber officinale] and its kinetic of extraction using a number of organic solvents. The characterization was carried out through GC and GC-MS. Gingerol has been assayed in the plant material during extraction with various solvents by a HPLC method. In order to develop a relationship between solvent characteristics such as viscosity and dielectric constant and the rates of extraction, the kinetics of extraction of gingerol has been studied by using twelve different solvents in order to evaluate the solvent efficacy in the extraction processes. It has been observed that both solvent viscosity [1/v] and dielectric constant show a linear relationship with the rates of extraction [k]. An increase in solvent viscosity leads to a decrease in the rates of extraction, similarly an increase in dielectric constant also leads to a decrease in the rates of extraction. This appears to be largely due to an unionizable character of gingerol which does not interact with polar solvents. Thus solvent viscosity and dielectric constant both play an important role in the choice of solvents for the extraction of gingerol. Sovlents with relatively low viscosity and dielectric constant are more suitable for the extraction of gingerol from plant material