The laxative effect of fresh pulp aqueous extracts of Thai Tamarind cultivars
Tamarindus indica Linn (Caesalpiniaceae), is widespread cultivated in Thailand. People consume it both raw and ripe as fresh fruit and favor its sour and sweet taste. The pulp, leaves, seeds and bark are used in traditional medicine for several applications e.g. anti-helminthic (seeds), treatment of constipation (ripened fruit) . Fresh pulp aqueous extracts of five Thai tamarind cultivars (one sour tamarind: Preaw-yak, four sweet tamarinds: Sri chom poo, Kanti, Sri tong boa, Sri tong nak) are examined for the laxative effect on small intestinal transit in rats . The results showed that oral administration of fresh pulp aqueous extracts of a sour tamarind and one sweet tamarind (Kanti) at the dose ranged from 1.6 to 1.8g/kg significantly increased the small intestinal transit in rats when compared with that of the control group (p<0.05). In addition, fresh pulp aqueous extracts from all cultivars elevated peristalsis in isolated rat ileum . However, both effects did not relate to the dose used. Major acids in fresh pulp aqueous extracts are tartaric acid, malic acid and citric acid. The combinations of three acids at the concentration present in fresh pulp aqueous extracts of Preaw-yak and Kanti significantly increased the small intestinal transit in rats when compared with that of the control group (p<0.05). Each acid at the dose of 100mg/kg also caused the increase of small intestinal transit in rats. Our results support the use of fresh pulp of tamarind as laxative in the primary health care suggested by Thai ministry of public health.
Acknowledgements: National Research Council of Thailand, Faculty of Pharmacy Chulalongkorn University, Faculty of Medicine, Chiang Mai University.
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