Abstract:
Piperine (1-piperonyl-piperidine) is the active ingredient of black pepper (P.-
nigrum) and long pepper (P. longum), which has been used in traditional medicine. It
is known as a bioenhancer, which increases the bioavailability of drugs and nutrient
supplements. It has been noted for its analeptic drug, anti-epilepsy, anti-fertility, and
anti-inflammation properties but its immunotoxicity has been rarely reported. The
objective of this study is to investigate the general effects of piperine and indicate
levels of safe consumption. Rats immunized with rabbit serum proteins were fed
piperine at the doses of 5, 10, 25, 50, 100 and 250 mg/kg BW for 7, 14, 30 and 90
days, respectively. The results showed that there were no remarkable effects of
piperine at all treated doses on thymus, spleen, liver, adrenal gland and small intestine.
Cell proliferation assay by 5’-bromo-2’-deoxy-uridine (BrdU) showed no proliferative
change in any cell population of the thymus, spleen and Payer’s patches. There was
no detectable antibodies response observed by immunoelectrophoresis. However, the
rats treated with piperine at the doses of 100 and 250 mg/kg BW showed decreasing in
body weight gain and food consumption. Rats treated with piperine at the dose of 100
mg/kg BW were nervous, hyperactive, jumping and running around the cage, in
contrast, those treated with piperine at the dose of 250 mg/kg BW showed depressive
effects. The pathological findings of the rat’s testis fed with piperine at the dose of
250 mg/kgBW showed deformity of the seminiferous tubules with a decrease of
spermatozoa while the stomach showed some congestion