Isolation of the antidiarrhoeal tiliroside and its derivative from Waltheria indica leaf extract

The antidiarrhoeal effect of Waltheria indica methanol extract and fractions have been reported earlier but, the present work examined the intestinal relaxant effects of two flavonoid-phenyl propanoids isolated from the methanol extract. The active aqueous fraction was subjected to vacuum liquid chromatography using dichloromethane with increasing concentration of ethyl acetate, and that of methanol and water successively. The ten (10) fractions obtained were combined to give seven (7). The fraction 2 (C, D) was subjected to preparative thin layer chromatography on silica gel GF254 (10-40μm) using CHCl3-CH3OH (8:2) to obtain compound coded F2. Fraction 4 (F) was subjected to column chromatography using silica gel (60-120μm mesh) and eluted with dichloromethane with increasing concentrations of methanol. Fractions 9-28 were combined and subjected to column chromatography using chloroform with increasing concentration of methanol. The fractions 1-16 of these were purified on Sephadex LH-20 to obtain compound BAA. The identities of the two compounds were established using spectroscopic methods. The antidiarrheal effect of compound F2 was evaluated on mice using charcoal transit (100,200, 400mg/kg), castor oil (40, 60 mg/kg) while the two compounds were examined for their inhibitory effects on Ach-induced ileum contraction. The effects of the compounds were compared with loperamide (3mg/kg) and atropine (80μg). Compounds F2 and BAA were identified as tiliroside and 3’’’, 5’’’-dimethoxy tiliroside respectively. Tiliroside inhibited the charcoal transition in the animals in a dose dependent pattern with 400mg/ mL eliciting 63.41% inhibition compared to 59.23% produced by loperamide. The compound also elicited significantly (P<0.05) prolonged onset of stooling and reduced the number and weight of stools produced lower than the control. The two compounds drastically inhibited the Ach-induced contractions of the ileum. The compound, tiliroside at 10mg, completely abolished the contraction by Ach unlike 3’’’, 5’’’-dimethoxy tiliroside which reduced the contraction to 1.92% at 20mg. The identified compounds seem to be responsible for the ethnomedicinal use of the plant in treating diarrhea.

Isolation of 1-(3′,4′-Dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)-propan-2-ol from Grape Seed Extract and Evaluation of its Antioxidant and Antispasmodic Potential

HPLC profiling of phenolics in grape seed extracts revealed a prominent peak of an unknown substance with concentrations up to 5.3%. Spectroscopic data allowed the identification of the compound 1 as 1-(3′,4′-dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)-propan-2-ol. 1 is known to be produced from catechin and epicatechin through anaerobic bacteria from human, as well as the rat, intestines. It was hypothesized that the marc remaining after expression of juice from grapes became infested during storage, resulting in the production of 1. Because compound 1 is infrequently found in nature and has never been found in grape seeds, its presence may be considered a marker of an unwanted anaerobic bacterial process occurring during production. The antioxidant potential of 1 was determined by DPPH, ABTS, and FRAP (ferric reducing antioxidant power) assays and compared to the potential of the following compounds: phloroglucine, pyrogallol, gallic acid, catechin, and epicatechin. Furthermore, it was established that 1 significantly reduced guinea pig ileum contraction induced by histamine.

RELAXATION EFFECT OF ETHANOLIC EXTRACT OF AVERRHOA BILIMBI L. LEAVES ON ILEUM SMOOTH MUSCLE CONTRACTION OF IN VITRO ISOLATED RAT (RATTUS NORVEGICUS)

Objective: The study was aimed to investigate the relaxation effect of ethanolic extract of Averrhoa bilimbi L. leaves (EEABL) and ondansetron against 5-HT-induced contraction of the 5-HT3 receptor.Methods: The study of the relaxation effect of the cumulative concentration EEABL leaves (0.5–4 mg/mL) and ondansetron (10−5–3×10−2) after the contracted with 5-HT (EC80: 1.158×10−6 M) was conducted in vitro using isolated rat’s ileum organ in the Tyrode solution.Results: The EEABL and ondansetron decreased ileum contraction after induced by 5- HT. EEABL has no difference in terms of ability as ondansetron in reducing the ileum smooth muscle contraction induced by 5-HT (p>0.05).Conclusion: The EEABL has relaxation effect on smooth muscle of rat’s isolated ileum which has induced by 5-HT.