Studien Studie Momordica

Grazyna Sobal, Wolfgang Lehner*, Gerald Stübinger#, Helmut Sinzinger.
Department of Nuclear Medicine, * TTM GmbH, # Center of Biomocular Medicine and Phamacology, Medical University of Vienna

·         Momodica charantia (MM), (bitter gourd) is an herbal tropical plant (Thailand)

·         Exerts a very broaden action in-vivo
- hypoglycaernic
- antioxidant
- hypocholesterolemic
- anticancer

·         We investigated ist antioxidant properties by quantitation of lipid peroxidation end-products malon-di-aldehyde (MDA) in native (n), and glycated (g,gox) LDL.

·         Modified LDL accumulates in blood vessels and promote the formation of atherosclerotic plagues.

·         Influence on LDL phospholipids (PC) oxidative degradation and lyso-phosphatidylcholine (Ly-PC) formation by mass spectrometry (MALDI) was investigated too.

·         Native LDL (nLDL) was isolated from plasma of healthy individuals (non smokers, no medication) by sequential ultracentrifugation followed by in-vitro oxidation by (50µM) copper to obtain oxidized LDL (oxLDL).

·         Glycation of LDL was performed by incubation of nLDL with 500mM glucose in the presence of 1 mM EDTA and 20 µM BHT (gLDL) or without (goxLDL).

·         Lipid peroxydation end products were estimated by tiobarbituric acid reactive substances (TBARS)-assay and lipids were extracted from modified LDL (delipidation) and analysed by MALDI-TOF-MS.

·         MM inhibited oxidation of nLDL and gLDL in a dose-dependent manner. At a concentration of 0.3mg/mL the inhibition of nLDL oxidation was express by 99.5-80% from 2-24h, respectively. This plasma concentration corresponds to max. daily dose of MM (Fig.1).

·         At a lower concentration of 0.1mg/mL, according to posible drug metabolism in –vivo, the inhibition was only slightly lower amounting to 95-79% up to 6h (Fig.1).

·         At a very low concentrations of 0.03mg/mL and 0.01mg/mL, the inhibition was still pronouced by 13.7-7.1%, respectively up to 2h.

·         For gLDL oxidation, producing much higher oxidative stress the inhibitory effect was slightly lower than by nLDL, but stoll amounting to 38.8% at 0.3mg/mL for 4h (oxidation max.) and persisting up to 24h amounting to 23.6% (Fig.2).

·         At 0.3mg/mL – 0.01mg/mL the inhibition was still expressed amounting to 21-11.7%, respectively, persisting up to 2h (Fig.2).

·         Modification of nLDL by glycation (gLDL/goxLDL) changes the PC profile by decreasing PL- and SL-PC (both 18:2) about 40%, PA- and SA-PC (both 20:4) in the range of 40-77% and PD-PC (22:6) about 90%, respectively. Lyso-PC (16:0 and 18:0) was increased 2-14 fold as compared ton LDL (Fig.3).

·         A strong inhibitory effect of MM was observed in case of nLDL. PA-PC (20:4) degradation was inhibited by 35-fold, PD-PC (22:6) 10-fold, and PL-PC by 145% at a concentration of 0.3 mg/mL MM. Lyso-PC formation was inhibited by about 95% (Fig.4)

·         At a concentration of 0.1 mg/mL MM PD-PC (22:6) was protected by 120% relative to the level of gLDL, PA- and SA-PC (both 20:4) were protected between 10-34% and PL-PC (18:2) by 13%, respectively. Lyso-PC formation was inhibited by 37%. At a concentration of 0.3mg/mL MM showed a lesser protective effect on all PC species. In case of SL-and PA-PC breakdown was even increased up to 30% in glDL (Fig.5).

·         In goxLDL PD-PC was protected by 230% at a concentration of 0.1mg/mL MM. Degradation of PL- and SL-PC was inhibited by 28-37%. 3% was observed in case of PA-PC. Lyso-PC formation was inhibited by 20-40%. In contrast 0.3mg/mL MM increased lyso-PC formation in the range of 12-75% (Fig.6).

·         Momordica charantia exerts very strong antioxidative properties against nLDL and gLDL oxidation.

·         High protective effects were also found against phospholipids degradation expecially of those, which contain polyusaturated fatty acids PUFA, arachidonic acid PA-PC (20:4) and docosahaexaenoic acid (22:6). These PUFA are responsible for increased lipids peroxidation cascade, generation of free radicals and finally fragmentation of their chains.

·         Protective effects were also found by Lyso-P formation as a consequence of inhibition of phospholipids degradation.

·         The application of MM in vivo might have beneficial effects for patients suffering from hypercholestero-lemia and diabetes