The complete amino acid sequence of ecarin is deduced from the nucleotide sequence of a cDNA clone isolated by screening a venomous gland cDNA library of Kenyan Echis carinatus. The cDNA sequence with 2379 base pairs encodes an open reading frame of 616 amino acids with a remarkable sequence homology to the putative precursor protein of trigramin from Trimeresurus gramineus venom (61% identity) and a large hemorrhagin, jararhagin, from the pit viper Bothrops jararaca venom (62% identity). Thus, ecarin, as well as jararhagin and trigramin, is translated as a precursor protein, which may be processed posttranslationally. The ecarin proprotein has a "cysteine switch" motif (-Pro-Lys-Met-Cys-Gly-Val-) similar to that involved in the activation of matrix metalloproteinase zymogens. The processed mature protein consists of 426 amino acid residues (residues 191-616), showing the strongest sequence similarity with that of Russell's viper venom factor X activator (RVV-X) heavy chain (64% identity). Like RVV-X heavy chain, ecarin contains metalloproteinase, disintegrin, and cysteine-rich domains. The metalloproteinase domain has a typical zinc-chelating sequence (-His-Glu-Xaa-Xaa-His-Xaa-Xaa-Gly-Xaa-Xaa-His-), as found in crayfish astacin. In the disintegrin domain of ecarin, the Arg-Gly-Asp sequence is replaced by Arg-Asp-Asp, as found in the disintegrin domains of RVV-X heavy chain (Arg-Asp-Glu) and a guinea pig sperm fusion protein, PH-30 beta (Thr-Asp-Glu). These findings show that while there are structural and evolutionary relationships among these proteins, each has a unique functional activity.

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A hemorrhagic protein (60 kDa), HR1B, present in the venom of Trimeresurus flavoviridis is a mosaic protein consisting of an NH2-terminal metalloproteinase-domain, a disintegrin (platelet aggregation inhibitor)-like domain, and a unique COOH-terminal Cys-rich domain. Since the gross structures of HR1B and protein precursors of disintegrins, trigramin, and rhodostomin, all of which contain the metalloproteinase domain, are similar, many disintegrins so far detected in snake venoms are assumed to be autoproteolytic fragments released from precursors. In ongoing related experiments, the newly purified hemorrhagic metalloproteinases, HR1A from T. flavoviridis venom and HT-1 from Crotalus ruber ruber venom, in addition to HR1B, were autoproteolyzed, in the absence of Ca2+, at 37 degrees C for 3-12 h. Under these conditions, HR1A, HR1B, and HT-1 each released a single major fragment of 32, 34, and 31 kDa, respectively. The entire amino acid sequences of the isolated fragments indicated the presence of disintegrin-like and Cys-rich domains in the COOH-terminal regions of HR1A, HR1B, and HT-1, respectively. It seems likely that so-called disintegrins probably originate from various metalloproteinases present in venom. On the bases of peptide sequences close to the autoproteolytic cleavage sites of these metalloproteinases and the sites of fibrinogen cleaved by these enzymes, we synthesized new intramolecularly quenched fluorogenic peptide substrates. Among the 10 peptides tested, 2-aminobenzoyl (Abz)-Ser-Pro-Met-Leu-2,4-dinitroanilinoethylamide (Dna) proved to be the best substrate for venom metalloproteinase, as deduced from kinetic analyses.

This article reviews the effectiveness of Kampo (traditional Japanese herbal medicine) in the treatment of functional gastrointestinal disorders, especially functional dyspepsia (FD) and irritable bowel syndrome (IBS). The results of four randomized, controlled trials (RCTs) suggested the usefulness of rikkunshito in relieving the subjective symptoms of patients with FD. Rikkunshito significantly improved not only gastric symptoms, such as epigastiric discomfort, but also extra-gastric symptoms, such as general fatigue, when compared with control drugs. The therapeutic effects of rikkunshito were more evident when it was prescribed to patients with “kyosho”, i.e., low energy. Two RCTs suggested the efficacy of keishikashakuyakuto for IBS.Basic research studies have demonstrated that these Kampo medicines have multiple sites of action to improve subjective symptoms. For example, rikkunshito improves gastric motility dysfunction, including impaired adaptive relaxation and delayed gastric emptying, gastric hypersensitivity, and anorexia via facilitation of ghrelin secretion. It also exhibits anti-stress effects, i.e., it attenuates stress-induced exacerbation of gastric sensation and anorexia, as well as the hypothalamic-pituitary-adrenocortical axis and sympathetic activation. Keishikashakuyakuto exhibited not only an antispasmodic effect on intestinal smooth muscle, but also antidepressant-like effects. Case series suggest that other Kampo prescriptions are also effective for FD and IBS. However, further studies are necessary to evaluate their efficacy.

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BackgroundIn Japan, a traditional herbal medicine, Tokishigyakukagoshuyushokyoto (TJ-38), is often used for the treatment of peripheral coldness, which is a common complaint among Japanese women. However, the effects of this herbal medicine have yet to be examined in a randomized controlled trial. In the current study, the effect of TJ-38 on the peripheral blood flow in women experiencing peripheral coldness was investigated using a parallel-group randomized controlled trial.MethodsFifty-eight women aged 23 to 79 years with peripheral coldness were randomly divided into the intervention or control group. They were examined using cold bathing tests, physical examinations, and questionnaires in January 2010 for the baseline and in March 2010 for the follow-up, and January 2011 and March 2011, respectively.ResultsAt the baseline, there were no differences in clinical characteristics between the two groups. In the intervention group, peripheral coldness improved after the intervention term; however, it persisted in the control group. Mean values of percentage recovery of the peripheral blood flow after cold bathing tests were 17.2% and −28.2% for the intervention and control groups, respectively (p = 0.007), and the proportions for percentage recovery of >50% were 32% and 0%, respectively (p = 0.0007). Mean values of percent recovery of skin temperature did not differ between the two groups.ConclusionsThe present clinical trial supports that a traditional herbal medicine relieves peripheral coldness in women probably through the improvement of peripheral blood flow.

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