Effect of Piper nigrum on salivary gland of Wistar rat

Abstract

Crushed Piper nigrum fruits are used for seasoning and flavouring of food. Some investigators have reported on its efficacy as an aid to the contraction of the uterus in the diet of post-partum women. This study aims at investigating the effect of P. nigrum fruits on the salivary glands for 3, 5 and 7 days of administration orally. Adult male and female Wistar rats (n = 30) weighing between 150 and 250 g were randomly assigned into experimental (n = 24) and control (n = 6) groups. The rats in the experimental groups received a mixed diet of feed consistency of crushed P. nigrum fruits to rat mash in a ratio of 50:50 (Group A, higher doses) and 25:75 (Group B, minimum doses) and water ad libitum for 3, 5 and 7 days. The rats in the control group received equal amount of rat mash without crushed P. nigrum fruits, for the same number of days. The rats were sacrificed on the 4th, 6th and 8th days. The stomach, small intestine and salivary glands were carefully dissected out and quickly fixed in 10% formol saline for histological and histochemical procedure. The body weights of the rats were recorded before and during treatment. The histological finding after 3 and 5 days administration of crushed P. nigrum fruits showed no significant changes in the histology of the salivary glands. There were vacuolations in the mucosa of the stomach and Brunner’s glands of the duodenum of the experimental animals after 7 days administration of crushed P. nigrum fruits. The histological changes in the salivary glands were marked both in the experimental groups that received the higher doses (of feed consistency in the ratio of 50:50 of crushed P. nigrum fruits to rat mash) for 7 days. There was a slight decrease in the body weight in the experimental groups. This was not significant (P > 0.05). The results show that consumption of crushed P. nigrum fruits for 3 to 5 days may not be harmful, but consumption of it continuously for 7 days even when used with minimum doses may be detrimental to health. Key words: Piper nigrum, salivary glands, detrimental, Wistar rats.