Inhibition of the formation of amyloid-like fibrils with spices, especially cloves.

During the study of inhibition of amyloid fibril formation, α-chymotrypsin protein was developed in 55% ethanol at pH 7.0. We investigated the inhibitory effect of different spices on amyloid fibril formation using turbidity measurements and Congo red binding assays. We found that all spices except the black pepper and caraway seed prevented fibril formation. The highest inhibition was measured with the clove, which reduced the amount of aggregates by 90%. We studied the inhibitory effect of the cloves at different concentrations on aggregation, it was found that the inhibitory activity of clove is dependent on concentration. We have measured the total phenolic content of the spice extracts too. Based on all these findings we have come to the following conclusion: Our results indicate that spices can contain other compounds too - not only phenolic compounds - which influence the formation of amyloid fibrils, and the effectiveness of various phenolic compounds are different.

Inhibition of the formation of amyloid-like fibrils using herbal extracts.

We tested the amyloid fibril formation inhibitory effect of seven teas diluted in 55% ethanol at pH 7.0 at a protein concentration of 0.15 mg/ml α-chymotrypsin. In the experiments we investigated the formation and inhibition of amyloid fibrils by turbidity measurements, aggregation kinetics experiments and Congo red binding assay. The results suggest that the different teas effectively inhibit the formation of amyloidlike fibrils. The two most potent inhibitors were peppermint and melilot, extracts which almost completely inhibited the formation of aggregates in 5-fold dilution. The inhibitory effect on the aggregation formation of melilot and peppermint extracts was concentration dependant. The extent of inhibition was found to be proportional with the total concentration of phenolic compounds.

H2S confers colonoprotection against TNBS-induced colitis by HO-1 upregulation in rats.

Hydrogen sulfide (H2S) is an endogenous mediator that contributes to many important physiological processes including vasodilation and vascular smooth muscle relaxation; in turn, preventing tissue damage and reducing inflammation. Heme oxygenase (HO) enzymes, of which HO-1 is inducible by harmful stimuli, were found to regulate intestinal inflammation in experimental animal models of colitis. We aimed to investigate the protective effects of H2S against 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats, and whether HO enzyme system is involved in the H2S-induced colonic cytoprotection. Male Wistar rats were treated with TNBS to induce colitis, and H2S donor (Lawesson's reagent) was prepared two times/day at different concentrations, and delivered per os (from day 1 to day 3). Our results suggest that daily treatment (2 times/day) with H2S donor, could significantly decrease the extent of colonic inflammation compared to vehicle treatment, and the most effective daily dose of H2S donor against inflammation was 18.75 µM/kg/day. Per os administration of H2S donor increased the colonic HO enzyme activity; on the contrary, the protective effect of H2S was abolished by the co-treatment with HO inhibitor. Our findings suggest that H2S confers colonoprotection, probably by modulation of anti-inflammatory parameters and HO enzyme activity.

Giant Mitochondria as Possible Bioindicators of Environmental Injuries in Fish Liver.

The effect of hypoxia (80 pHg) and simultaneously applied paraquat (1,1'-dimethyl-4,4-bipyridynum dichloride) was investigated on carp liver using electron microscopic methods. The appearance of giant mitochondria was the most conspicuous alteration in the liver cells. Most of the giant mitochondria were elongated and rod-shaped, often arranged side by side forming clusters beside the nucleus. Crook-like and irregular forms also occured among giant mitochondria. The lenght of the giant mitochondria often was greater than the diameter of nucleus: namely 5-10 µm. The outer membrane of the giant mitochondria was well preserved, but inner membranes (cristae) were usually absent, and a high density matrix filled in the inner space of mitochondria. High power magnification often revealed a regular, filamentous paracristal arrangement in the dense material of the matrix. Swollen giant mitochondria with light matrix and tubular elements also occured in low number. Although fine structural characteristics of carp liver giant mitochondria are not specific for inducing agents (hypoxia + paraquat treatment) the appearance of altered giant mitochondria may be a useful signal for monitoring cell damaging enviromental xenobiotics.