Black Pepper and its Pungent Principle-Piperine: A Review of Diverse Physiological Effects

Abstract

Black pepper (Piper nigrum) is one of the most widely used among spices. It is valued for its distinct biting quality attributed to the alkaloid, piperine. Black pepper is used not only in human dietaries but also for a variety of other purposes such as medicinal, as a preservative, and in perfumery. Many physiological effects of black pepper, its extracts, or its major active principle, piperine, have been reported in recent decades. Dietary piperine, by favorably stimulating the digestive enzymes of pancreas, enhances the digestive capacity and significantly reduces the gastrointestinal food transit time. Piperine has been demonstrated in in vitro studies to protect against oxidative damage by inhibiting or quenching free radicals and reactive oxygen species. Black pepper or piperine treatment has also been evidenced to lower lipid peroxidation in vivo and beneficially influence cellular thiol status, antioxidant molecules and antioxidant enzymes in a number of experimental situations of oxidative stress. The most far-reaching attribute of piperine has been its inhibitory influence on enzymatic drug biotransforming reactions in the liver. It strongly inhibits hepatic and intestinal aryl hydrocarbon hydroxylase and UDP-glucuronyl transferase. Piperine has been documented to enhance the bioavailability of a number of therapeutic drugs as well as phytochemicals by this very property. Piperine's bioavailability enhancing property is also partly attributed to increased absorption as a result of its effect on the ultrastructure of intestinal brush border. Although initially there were a few controversial reports regarding its safety as a food additive, such evidence has been questionable, and later studies have established the safety of black pepper or its active principle, piperine, in several animal studies. Piperine, while it is non-genotoxic, has in fact been found to possess anti-mutagenic and anti-tumor influences.

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Black Pepper and its Pungent Principle-Piperine: A
Review of Diverse Physiological Effects
K. Srinivasan
a
a
Department of Biochemistry and Nutrition, Central Food Technological Research
Institute, Mysore, India
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Principle-Piperine: A Review of Diverse Physiological Effects', Critical Reviews in
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Critical Reviews in Food Science and Nutrition, 47:735–748 (2007)
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ISSN: 1040-8398
DOI: 10.1080/10408390601062054
Black Pepper and its Pungent
Principle-Piperine: A Review
of Diverse Physiological Effects
K. SRINIVASAN
Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore - 570020, India
Black pepper (Piper nigrum) is one of the most widely used among spices. It is valued for its distinct biting quality attributed
to the alkaloid, piperine. Black pepper is used not only in human dietaries but also for a variety of other purposes such as
medicinal, as a preservative, and in perfumery. Many physiological effects of black pepper, its extracts, or its major active
principle, piperine, have been reported in recent decades. Dietary piperine, by favorably stimulating the digestive enzymes
of pancreas, enhances the digestive capacity and significantly reduces the gastrointestinal food transit time. Piperine has
been demonstrated in in vitro studies to protect against oxidative damage by inhibiting or quenching free radicals and
reactive oxygen species. Black pepper or piperine treatment has also been evidenced to lower lipid peroxidation in vivo
and beneficially influence cellular thiol status, antioxidant molecules and antioxidant enzymes in a number of experimental
situations of oxidative stress. The most far-reaching attribute of piperine has been its inhibitory influence on enzymatic
drug biotransforming reactions in the liver. It strongly inhibits hepatic and intestinal aryl hydrocarbon hydroxylase and
UDP-glucuronyl transferase. Piperine has been documented to enhance the bioavailability of a number of therapeutic drugs
as well as phytochemicals by this very property. Piperine’s bioavailability enhancing property is also partly attributed to
increased absorption as a result of its effect on the ultrastructure of intestinal brush border. Although initially there were
afew controversial reports regarding its safety as a food additive, such evidence has been questionable, and later studies
have established the safety of black pepper or its active principle, piperine, in several animal studies. Piperine, while it is
non-genotoxic, has in fact been found to possess anti-mutagenic and anti-tumor influences.
Keywords black pepper, piperine, antioxidant effect, bioavailability enhancing effect, anti-mutagenic, anti-cancer influence
INTRODUCTION
Black pepper (Piper nigrum) is one of the most widely used
among spices. It is valued for its distinct biting quality attributed
to piperine and its isomers (Govindarajan, 1977). Black pepper
is used not only in human dietaries but also for other purposes
such as medicinal, as a preservative, in perfumery, and even as
an insecticide. Black pepper is considered as the king of spices,
as it fetches the highest return as judged from the volume of
international trade. The solvent extracted pepper oleoresin, con-
taining the essential oil contributing to the aroma of pepper and
piperine, the alkaloid contributing to the pungency, has many ad-
vantages such as convenience of commercial handling and free
from microbial contamination and biodeterioration, and hence
sometimes preferred to pepper in processed foods. Many phys-
Address correspondence: Tel: +91-0821-2514876; Fax: +91-0821-
2517233; E-mail: ksri.cftri@gmail.com
iological effects of black pepper, its extracts or its major active
principle, piperine, have been reported in recent decades.
SAFETY OF BLACK PEPPER CONSUMPTION
Though pepper has been in use for a long time as a food
additive, there are controversial reports regarding its safety as
a food additive (Buchanan, 1978; Concon, et al., 1979). These
reports point to the possible carcinogenicity of an ethanolic ex-
tract containing piperine among several other constituents hav-
ing methylenedioxy benzene as part of the molecule. Concon
et al. (1979) observed the incidence of malignant and multiple
tumors in mice cutaneously administered with pepper. Piperine
(Fig. 1), the major active principle of black pepper, is closely
related in structure to the known natural carcinogens—safrole,
estragole, and methyleugenol which are also widely distributed
in spices and plant oils (Ames, 1983). Namiki et al. (1984) have
735

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736 K. SRINIVASAN
Figure 1 Structure of piperine.
reported that among several spices treated with sodium nitrite,
pepper exhibited the strongest mutagenic activity as indicated
by the Ames test. Epstein and Swartz (1984) consider that ev-
idence for the carcinogenicity of pepper is inadequate as it is
based on the results of single questionable study of Concon et al.
(1979).
In acute toxicity studies, LD
50
values for a single i.v., i.p.,
s.c., i.g., and i.m. administration of piperine to adult male mice
were 15.1, 43, 200, 330, and 400 mg/kg body wt, respectively
(Piyachaturawat et al.,1983). The i.p. LD
50
value was higher
viz., 60 mg/kg body weight in adult females and 132 mg/kg
body weight in weanling male mice. In adult female rats, the i.p.
LD
50
value was 33.5 mg/kg body weight whereas the i.g. LD
50
value was 514 mg/kg body weight. Most animals given a lethal
dose died of respiratory paralysis within 3–17 min. In subacute
toxicity studies, the rats died within 1–3 days after treatment.
Histopathologic changes included severe hemorrhagic necrosis
and edema in the gastrointestinal tract, the urinary bladder, and
the adrenal glands. Death of these animals may be attributable
to multiple dysfunctions in their organs.
Earlier studies in our laboratory indicated that no adverse
effect was caused by feeding black pepper or piperine at lev-
els equivalent to normal human intake or as much as 250 times
as indicated by growth, organ weights, and blood constituents
(Srinivasan and Satyanarayana, 1981). Black pepper, its oleo-
resin, or its active principle piperine, fed to rats at doses 5–20
times normal human intake did not cause any adverse effect
on growth, food efficiency ratio and organ weights, blood cell
counts, and the levels of blood constituents like hemoglobin, to-
tal serum proteins, albumin, globulin, glucose and cholesterol,
activities of serum aminotransferases and phosphatases, fat, and
nitrogen balance (Bhat and Chandrasekhara, 1986).
The non-genotoxic nature of piperine was evidenced in lat-
ter studies using four different test systems, namely, Ames test
using Salmonella typhimurium, micronucleus test, sperm shape
abnormality test and dominant lethal test using Swiss albino
mice (Karekar et al., 1996). In the Ames test, six different doses
of piperine, in the range of 0.005–10 µmol/plate, did not induce
his+ revertants, with or without metabolic activation, indicat-
ing its non-mutagenic nature. In the bone narrow micronucleus
test using two doses (10 and 20 mg/kg body weight), piperine
itself was non-mutagenic. Like in somatic cells, piperine (10
and 50 mg/kg body weight) failed to induce mutations in male
germ cells of mice as assessed by using the sperm shape abnor-
mality and dominant lethal tests. Piperine thus appears to be a
non-genotoxic chemical. The immuno-toxicological effects of
piperine were investigated in Swiss mice, gavaged at a dose of
1.12, 2.25, or 4.5 mg/kg body weight for five consecutive days
(Dogra et al., 2004). All these dose levels had no overt toxic
effect, while the lowest dose had no immunotoxic effect.
INFLUENCE OF BLACK PEPPER OR PIPERINE
ON DIGESTION
Spices, by virtue of their pungent principles and by impart-
ing flavor to foodstuffs, enhance salivary and gastric secretions.
Glatzel, studying the effect of spices on the secretion and com-
position of saliva in human subjects, observed that black pepper
and other spices enhance the secretion of saliva and the activ-
ity of salivary amylase (Glatzel, 1968). The digestive stimu-
lant action of spices is probably exerted through a beneficial
stimulation of the liver to produce and secrete bile rich in bile
acids, which play a very important role in fat digestion and ab-
sorption. Several commonly used spices including black pepper
and its active principle, piperine, have been examined for their
effect on bile secretion in our laboratory using experimental
rats (Bhat and Chandrasekhara, 1987). In these animal mod-
els, bile has been systematically collected by cannulating the
common biliary-pancreatic duct following the spice treatment.
Spices have been examined for their influence on bile as a re-
sult of both a continued intake through the diet for a period
of time and as a one-time exposure orally. The results of these
studies revealed that dietary black pepper or piperine which have
no hypocholesterolemic influence, had no beneficial stimulatory
influence on bile acid production by the liver and its secretion
into bile (Bhat and Chandrasekhara, 1987). On the other hand,
the oral administration of piperine as a single dose significantly
increases bile acid secretion. Stimulation in bile acid secretion
(µmol/h) was to an extent of about 30% over the control.
Exhaustive animal studies have been carried out in our lab-
oratory to examine the influence of spices on the activities of
enzymes that participate in digestion. The influence of dietary
intake and single dose administration of several commonly used
spices or their active principles including piperine on the pan-
creatic digestive enzymes and the terminal digestive enzymes of
the small intestinal mucosa has been reported by us (Platel and
Srinivasan, 1996, 2000). In these studies, piperine was fed to
animals at levels corresponding to about five times the average
human dietary intake of black pepper. The levels were based
on calculated dietary intake of spices in the form of curry pow-
der and on a dietary survey conducted in India (Thimmayamma
et al., 1983). Dietary intake of piperine significantly increased
pancreatic lipase activity and piperine stimulated lipase activity
up to 30% of control. In contrast to the beneficial stimulation
of pancreatic lipase by piperine as a result of continued intake,
a single, oral dose consumption of the same failed to exert a
stimulatory effect. The pancreatic amylase activity is observed
to be elevated by dietary piperine (to an extent of 87%). These
studies also reveal that piperine when incorporated in the diet,
stimulates trypsin activity by as much as 150%. Chymotrypsin
was also significantly higher in animals fed piperine. Such a ben-
eficial influence of this spice on the activity of proteases was not

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PHYSIOLOGICAL EFFECTS OF BLACK PEPPER AND PIPERINE 737
Table 1 Antioxidant influence of black pepper and piperine
Animal model Effect demonstrated Author
Rat liver microsomes Marginal inhibitory effect of piperine on ascorbate-Fe
++
-induced lipid peroxidation Reddy and Lokesh (1992)
Rats Piperine treatment protected against oxi-dative stress induced in intestinal lumen by
carcinogens
Khajuria et al. (1998)
Streptozotocin-Diabetic rats Intraperitoneal administration of piperine for 2 week partially protected against diabetes
induced oxidative stress
Rauscher et al. (2000)
In vitro Inhibition / quenching of super oxides and hydroxyl radicals by piperine; Inhibition of lipid
peroxidation
Mittal and Gupta (2000)
Human LDL Piperine protects Cu
++
-induced lipid per-oxidation of human LDL Naidu and Thippeswamy (2002)
Mice Piperine treatment decreased mitochondrial lipid peroxidation and augmented antioxidant
defense system during benzo(α)pyrene – induced lung carcinogenesis
Selvendiran et al. (2004)
Rats fed high fat diet Dietary black pepper/piperine reduces high fat diet induced oxidative stress by lowering lipid
peroxidation, restoring act-vities of antioxidant enzymes and GSH
Vijayakumar et al. (2004)
In vitro Black pepper aqueous extract & piperine inhibit human PMNL 5-lipoxygenase Prasad et al. (2004)
evident when administered as a single oral dose. Piperine promi-
nently enhanced the activity of intestinal lipase. The stimulation
of this enzyme activity was more than 100% of the control in
spice principle-treated groups. An appreciable increase in in-
testinal lipase activity was observed in animals given single oral
doses of piperine and so also the activity of intestinal amylase
(Platel and Srinivasan, 1996).
ANTIOXIDANT EFFECT OF PIPERINE
Oxygen radical injury and lipid peroxidation have been sug-
gested as major causes of atherosclerosis, cancer, and the ag-
ing process. Reactive oxygen species and reactive metabolic
intermediates generated from various chemical carcinogens are
known to play an important role in cell damage and in the ini-
tiation and progression of carcinogenesis. Many radical scav-
engers, interestingly naturally occurring antioxidants, have been
found to be effective in inhibiting the induction of carcinogene-
sis by a wide variety of chemical carcinogens. Studies have also
indicated that various spice principles form an important group
as antioxidants. Piperine has been demonstrated in in vitro ex-
periments to protect against oxidative damage by inhibiting or
quenching free radicals and reactive oxygen species and inhibit
lipid peroxidation (Mittal and Gupta, 2000). Piperine was found
to act as a hydroxyl radical scavenger at low concentrations, but
at higher concentrations, it activated the Fenton reaction result-
ing in increased generation of hydroxyl radicals. Whereas it acts
as a powerful superoxide scavenger with an IC
50
of 1.82 mM,
a 52% inhibition of lipid peroxidation was observed at a dose
of 1.4 mM with an IC
50
of 1.23 mM. However, Krishnakantha
and Lokesh (1993) have observed that piperine failed to scav-
enge superoxide anions while investigating the effect of various
spice principles on scavenging of superoxide anion as measured
by nitroblue-tetrazolium reduction in xanthine-xanthine oxidase
system. Reddy and Lokesh (1992) have reported that piperine
had only marginal inhibitory effects on ascorbate/Fe
2+
-induced
lipid peroxidation in rat liver microsomes even at high concen-
trations (600 µM) when compared to the beneficial inhibition of
lipid peroxidation by antioxidants—vitamin E, t-butylhydroxy
toluene, and t-butylhydroxy anisole (Table 1).
Piperine is shown to be an effective antioxidant and offers pro-
tection against the oxidation of human low density lipoprotein
(LDL) as evaluated by copper ion-induced lipid peroxidation of
human LDL by measuring the formation of thiobarbituric acid
reactive substance and relative electrophoretic mobility of LDL
on agarose gel (Naidu and Thippeswamy, 2002). The aqueous
extract of black pepper as well as piperine have been examined
for their effect on human PMNL 5-lipoxygenase (5-LO), the key
enzyme involved in biosynthesis of leukotrienes (Prasad et al.,
2004). The formation of 5-LO product 5-HETE was significantly
inhibited in a concentration-dependent manner with IC
50
values
of 0.13 mg for aqueous extracts of pepper and 60 µM for piper-
ine. Thus, piperine of black pepper might exert an antioxidant
physiological role by modulating 5-LO pathway.
Using diabetes mellitus as a model of oxidative damage,
Rauscher et al. (2000) investigated whether piperine treat-
ment (10 mg/kg/day, i.p. for 14 days) would protect against
diabetes-induced oxidative stress in streptozotocin-induced di-
abetic Sprague-Dawley rats. All tissues from diabetic animals
exhibited disturbances in antioxidant defense when compared
with normal controls. Treatment with piperine reversed the di-
abetic effects on glutathione concentration in brain, on renal
glutathione peroxidase and superoxide dismutase activities, and
on cardiac glutathione reductase activity and lipid peroxidation.
Piperine treatment did not reverse the effects of diabetes on
hepatic antioxidant status. Thus, subacute treatment with piper-
ine for 14 days is only partially effective as an antioxidant in
diabetes.
Khajuria et al. (1998) have investigated whether piperine
is able to inhibit or reduce the oxidative changes induced by
chemical carcinogens in a rat intestinal model. Carcinogenesis
was initiated in intestinal lumen of rats with 7,12-dimethyl ben-
zanthracene, dimethyl aminomethyl azobenzene, and 3-methyl
cholanthrene. Oxidative alterations were assessed by determin-
ing thiobarbituric acid reactive substances (TBARS) as a mea-
sure of lipid peroxidation, thiol status and expression of γ -
glutamyl transpeptidase (γ -GT), and Na
+
,K
+
-ATPase activity
in intestinal mucosa. Data indicated that carcinogen induced

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738 K. SRINIVASAN
glutathione depletion with substantial increase in TBARS and
enzyme activities. A protective role of piperine against the oxida-
tive alterations by the carcinogen was indicated by the observed
inhibition of TBARS, a significant increase in the glutathione
levels and restoration in γ -GT and Na
+
,K
+
-ATPase activity.
Selvendiran et al. (2004) have recently investigated the im-
pact of piperine on alterations of mitochondrial antioxidant
system and lipid peroxidation in benzo(α)pyrene (B(α)p) in-
duced experimental lung carcinogenesis. Oral supplementation
of piperine (50 mg/kg body weight) effectively suppressed lung
carcinogenesis by B(α)p in mice as revealed by a decrease in
the extent of mitochondrial lipid peroxidation and concomitant
increase in the activities of enzymatic antioxidants (superox-
ide dismutase, catalase, and glutathione peroxidase) and non-
enzymatic antioxidant (reduced glutathione, vitamin E, and vi-
tamin C) levels when compared to lung carcinogenesis bearing
animals. This suggests that piperine may extend its chemopre-
ventive effect by modulating lipid peroxidation and augmenting
antioxidant defense system.
Vijayakumar et al. (2004) have recently examined the effect
of supplementation of black pepper or piperine on tissue lipid
peroxidation, enzymic, and non-enzymic antioxidants in rats fed
a high-fat diet and observed that these spices can reduce high-fat
diet induced oxidative stress. Groups of Wistar rats were fed a
high-fat diet (20% coconut oil, 2% cholesterol and 0.125% bile
salts), a high-fat diet plus black pepper (0.25 g or 0.5 g/kg body
weight), a high-fat diet plus piperine (0.02 g/kg body weight) for
a period of 10 weeks. Significantly elevated levels of TBARS,
conjugated dienes (CD) and significantly lowered activities of
super oxide dismutase (SOD), catalase (CAT), glutathione per-
oxidase (GPx), glutathione-S-transferase (GST), and reduced
glutathione (GSH) in the liver, heart, kidney, intestine, and aorta
were observed in rats fed the high fat diet as compared to the
control rats. Simultaneous supplementation with black pepper or
piperine lowered TBARS and CD levels and maintained SOD,
CAT, GPx, GST, and GSH levels near to those of control rats.
INFLUENCE OF BLACK PEPPER ON LIPID
METABOLISM
There were no significant changes in serum free and total
cholesterol and liver total cholesterol in rats fed a normal diet
supplemented with 0.02, 0.15, 0.5, 2.0, and 5% black pepper or
Table 2 Influence of piperine on drug metabolizing enzyme system
Effects demonstrated Investigators
a) Inhibition of aryl hydroxylation, N-demethylation, O-deethylation and glucuronidation in vitro by piperine Atal et al. (1985)
b) Lower aryl hydroxylase and UDP-glucuronyl transferase activities, prolonged hexobarbital sleeping time in piperine treated rats Atal et al. (1985)
c) Decreased UDP-glucuronic acid concentration and rate of glucuronidation in isolated epithelial cells of Guineapig small intestine by
piperine
Singh et al. (1986)
d) Inhibition of aryl hydroxylase and O-deethylase activities by piperine in vitro and in vivo in pulmonary microsomes Reen and Singh (1991)
e) Decreased activities of hepatic microsomal cytochrome P
450
, N-demethylase, aryl hydroxylase by intragastric/intra-peritoneal
piperine in Sprague-Dawley rats
Dalvi and Dalvi (1991)
f) Inhibition of UDP-glucose dehydrogenase and UDP- glucuronyl transferase in rat and guinea pig liver and intestine by piperine Reen et al. (1993)
g) Suppression of aryl hydroxylation in cell culture is mediated by direct interaction of piperine with cytochrome P
450
and not by down
regulation of its gene expression
Reen et al. (1996)
0.05% piperine (Srinivasan and Satyanarayana, 1981) or pep-
per oleoresin at 11, 22, and 44 mg% levels in the diet for 8
weeks (Bhat and Chandrasekhara, 1986). In contrast, Cho and
Lee (1983) reported that the feeding of pepper at a 5% level in
the diet to rats for 8 weeks led to a significant increase in serum
cholesterol. Dietary black pepper, which did not affect the serum
and the liver cholesterol concentration, also did not affect the
activity of hepatic cholesterol-7α-hydroxylase, the rate limiting
enzyme in the conversion of cholesterol to bile acids (Srinivasan
and Sambaiah, 1991).
INFLUENCE OF PIPERINE ON DRUG METABOLIZING
ENZYME SYSTEM
In the context of piperine having been reported to enhance
drug bioavailability, Atal et al. (1985) studied the interaction of
piperine with drug biotransforming reactions in hepatic tissue in
vitro and in vivo. Piperine inhibited aryl hydrocarbon hydroxy-
lation, ethylmorphine-N-demethylation, 7-ethoxy-coumarin-O-
deethylation, and 3-hydroxybenzo(α)pyrene (3-OH-BP) glu-
curonidation in rat liver post-mitochondrial supernatant in
vitro in a dose-dependent manner. Piperine’s inhibition of
these reactions in liver post-mitochondrial supernatant from 3-
methylcholanthrene- and phenobarbital-treated rats was similar
to the controls. Inhibition by piperine of arylhydrocarbon hy-
droxylase (AHH) from 3-methylcholanthrene-treated rats was
comparable to that observed with 7,8-benzoflavone. Piperine
caused noncompetitive inhibition of hepatic microsomal AHH
from the untreated and 3-methylcholanthrene-treated rats with
aK
i
of 30 µM which was close to the apparent K
m
of AHH
observed in the controls. Similarly, the kinetics of inhibition
of ethylmorphine-N-demethylase from control rat liver micro-
somes exhibited noncompetitive inhibition with a K
m
of 0.8 mM
and K
i
of 35 µM. These studies demonstrated that piperine is
a nonspecific inhibitor of drug metabolism which shows little
discrimination between different cytochrome P
450
forms. Oral
administration of piperine in rats strongly inhibited the hepatic
AHH and UDP-glucuronyl transferase activities. The maximal
inhibition of AHH observed within1hrestored to a normal
value in 6 h. Pretreatment with piperine prolonged hexobarbital
sleeping time and zoxazolamine paralysis time in mice at half
the dose of SKF-525A. These results demonstrate that piperine
is a potent inhibitor of drug metabolism (Table 2).

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PHYSIOLOGICAL EFFECTS OF BLACK PEPPER AND PIPERINE 739
Singh et al. (1986) further explored the basis of inhibition
of glucuronidation by piperine by examining the rate of glu-
curonidation of 3-OH-BP and UDP-glucuronic acid (UDPGA)
content in the intact isolated epithelial cells of the guinea-pig
small intestine. Glucuronidation of 3-OH-BP was dependent
on the duration of incubation, cellular protein, and endogenous
UDPGA concentration. Piperine caused a concentration-related
decrease in the UDPGA content and the rate of glucuronidation
in the cells. It required much lower concentrations of piper-
ine than D-galactosamine to diminish the endogeneous level
of UDPGA. At 50 µM piperine, the rate of glucuronida-
tion was reduced to about 50% of the basal rate. Piperine
caused noncompetitive inhibition of hepatic microsomal UDP-
glucuronyltransferase with Ki of 70 µM. The study demon-
strated that piperine modifies the rate of glucuronidation by low-
ering the endogeneous UDPGA content and also by inhibiting
the transferase activity.
Dalvi and Dalvi (1991) have examined the influence of in-
tragastrically administered piperine (100 mg/kg) on hepatic
mixed function oxygenase system in adult Sprague-Dawley rats.
An increase in hepatic microsomal cytochrome P
450
and cy-
tochrome b
5
,NADPH-cytochrome-C reductase, benzphetamine
N-demethylase, aminopyrine N-demethylase, and aniline hy-
droxylase was observed 24 h following treatment. On the
other hand, a 10 mg/kg dose given i.p. exhibited no effect on
the activities of the aforementioned parameters of the hep-
atic drug-metabolizing enzyme system. However, when the
intragastric and intraperitoneal doses were increased to 800
mg/kg and 100 mg/kg, respectively, piperine produced a signif-
icant decrease in the levels of cytochrome P
450
, benzphetamine
N-demethylase, aminopyrine N-demethylase, and aniline hy-
droxylase 24 h after treatment. An i.p. administration of rats
with piperine (100 mg/kg) produced a significant decrease
in hepatic cytochrome P
450
and activities of benzphetamine
N-demethylase, aminopyrine N-demethylase, and aniline hy-
droxylase 1 h after the treatment (Dalvi and Dalvi, 1991a).
Twenty-four h later, these parameters along with cytochrome
b
5
and NADPH-cytochrome-C reductase remained depressed in
piperine-treated rats. This suggested that the effect of piperine
on hepatic mixed-function oxidases is monophasic.
In vitro and in vivo modulation of drug metabolizing en-
zymes by piperine has been investigated in pulmonary micro-
somes of rats and guinea pigs (Reen and Singh, 1991). Piper-
ine caused concentration related non-competitive inhibition in
vitro (50% at 100 µM) of AHH and 7-ethoxycourmarin deethy-
lase (7ECDE) activities, which were comparable in control and
3-methylcholanthrene (3MC) treated rats. In guinea pig micro-
somes however, piperine caused strong inhibition at lower con-
centrations (35% at 10 µM) and relatively much lesser inhibition
with further increase in concentrations. In vivo, piperine given
at a dose of 25 mg/kg body weight to rats caused a maximal
inhibition at1hofboth the enzymes, while only AHH returned
to normal value within 4 h. Similarly, upon daily treatment of
piperine (15 mg/kg body wt) to rats for 7 days, 7ECDE was con-
sistently inhibited, while AHH showed faster recovery. Piperine
thus appeared to cause a differential inhibition of two forms of
cytochrome P
450
and thus would accordingly affect the steady-
state level of those drugs metabolized by these pulmonary forms
of cytochrome P
450
.
The modifying potential of black pepper on the hepatic bio-
transformation system has been assessed in mice fed on a diet
containing 0.5, 1, and 2 % black pepper (w/w) for 10 and 20 days
(Singh and Rao, 1993). Data revealed a significant and dose-
dependent increase in glutathione S-transferase and sulfhydryl
content in the experimental groups except the one maintained
on 0.5% black pepper diet for 10 days. Elevated levels of cy-
tochrome b
5
and cytochrome P
450
were also significant and dose-
dependent. The level of melondialdehyde (MDA) was lowered
in the group fed on a 2% black pepper diet for 20 days. Be-
ing a potential inducer of the detoxication system, the possible
chemopreventive role of black pepper in chemical carcinogene-
sis is suggested.
The effects of piperine on UDP-glucose dehydrogenase
(UDP-GDH) and glucuronidation potentials of rat and guinea
pig liver and intestine were studied by Reen et al. (1993). Piper-
ine caused a concentration-related strong non-competitive in-
hibition of UDP-GDH (50% at 10 µM) reversibly and equipo-
tently, in both tissues. Data from structure-activity comparisons
of piperine analogs indicated that the presence of conjugated
double bonds in the side chain of the molecule is a factor in piper-
ine inhibition. However, the UDPGA contents were decreased
less effectively by piperine in isolated rat hepatocytes compared
with enterocytes of guinea pig small intestine. Piperine at 50 µM
caused a marginal decrease of UDPGA in hepatocytes when the
rate of glucuronidation of 3-OH-BP decreased by about 40%.
UDP-glucuronyltransferase (UGT) activities towards 3-OH-BP
and 4-OH-biphenyl were also determined. Piperine did not af-
fect the rate of glucuronidation of 4-OH-biphenyl in rat liver,
whereas that of 3-OH-BP was impaired significantly. In a guinea
pig small intestine, both these activities were inhibited signifi-
cantly requiring less than 25 µM piperine to produce a more than
50% inhibition of UGT(s). The results suggested that piperine is
a potent inhibitor of UDP-GDH, by virtue of conjugated double
bonds in the molecule, and it exerts stronger effects on intestinal
glucuronidation than in rat liver.
By studying the modulation of B(α)p metabolism and regu-
lation of cytochrome CYP1A1 gene expression by piperine in
5L cells in culture, it is observed that piperine mediated the in-
hibition of the AHH activity and the consequent suppression of
the procarcinogen activation is the result of direct interaction of
piperine with cytochrome P4501A1-protein and not because of
down regulation of its gene expression (Reen et al., 1996).
INFLUENCE OF PIPERINE ON BIOAVAILABILITY
OF DRUGS
Piperine, the alkaloidal constituent of black and long peppers,
is now established as a bioavailability enhancer of various struc-
turally and therapeutically diverse drugs and other substances.
Potential of piperine to increase the bioavailability of drugs in

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740 K. SRINIVASAN
Table 3 Modulation of bioavailability of drugs, phytochemicals, carcinogens by black pepper and piperine
System Effect demonstrated Investigator
Humans Increased bioavailability of vasicine and sparteine as a result of Piper longum/piperine treatment Atal et al. (1981)
Humans Enhanced systemic availability of propranolol and theo-phylline as a result of piperine treatment Bano et al. (1991)
Rats Decreased metabolic activation of fungal toxin aflatoxin B
1
and hence its increased accumulation in plasma Allamesh et al. (1992)
Humans Increased serum concentration of curcumin by concomitant administration of piperine Shobha et al. (1998)
Humans Increased plasma levels of coenzyme Q
10
by coadministration of piperine Badmaev et al. (2000)
Mice Delayed elimination of anti-epileptic drug – phenytoin by treatment of piperine Velpandian et al. (2001)
Rats Enhanced bioavailability of β-lactam antibiotics – Amoxi-cillin trihydrate and Cefotaxime by coadministration of piperine Hiwale et al. (2002)
Mice Increased plasma levels and delayed excretion of epigallo-catechin-3-gallate from green tea as a result of intragastric
cotreatment with piperine
Lambert et al. (2004)
humans is of great clinical significance. A concise mechanism
responsible for its bioavailability enhancing action is poorly un-
derstood. Atal et al. (1981) have evaluated the scientific basis of
the use of the trikatu group of acrids (long pepper, black pepper,
and ginger) in the large number of prescriptions in the indige-
nous Ayurvedic system of medicine. Piper longum (long pepper)
increased the blood levels of the test drug, vasicine, by nearly
233%. Under the influence of piperine, blood levels of the test
drug, sparteine, increased more than 100%. The results suggest
that these acrids have the capacity to increase the bioavailability
of certain drugs. The authors concluded that the trikatu group of
drugs increases the bioavailability of drugs either by promoting
rapid absorption from the gastrointestinal tract, or by protect-
ing the drug from being metabolized in its first passage through
the liver after being absorbed, or by a combination of these two
mechanisms (Table 3).
Piperine has been reported by several researchers to have
an effect on the activation and deactivation of exogenous sub-
stances. (-)-Epigallocatechin-3-gallate (EGCG) from green tea
(Camellia sinensis) has demonstrated chemopreventive activity
in animal models of carcinogenesis. Lambert et al. (2004) have
observed that cotreatment with dietary piperine enhances the
bioavailability of EGCG in mice. Intragastric coadministration
of 163.8 µmol/kg EGCG and 70.2 µmol/kg piperine to male
CF-1 mice increased the plasma C(max) and area under the
curve (AUC) by 1.3-fold compared to mice treated with EGCG
only. Piperine appeared to increase EGCG bioavailability by
inhibiting glucuronidation and gastrointestinal transit. Piperine
(100 µM) inhibited EGCG glucuronidation in mice small in-
testine (by 40%). EGCG appearance in the colon and the feces
of piperine-cotreated mice was slower than in mice treated with
EGCG alone. The effect of piperine on the bioavailability and
pharmacokinetics of propranolol and theophylline has been ex-
amined in a crossover study, wherein subjects received a single
oral dose of propranolol (40 mg) or theophylline (150 mg) alone
or in combination with piperine (20 mg/day for 7 days) (Bano
et al., 1991). An enhanced systemic availability of oral propra-
nolol and theophylline was evidenced as a result of piperine
treatment.
Velpandian et al. (2001) have reported from a study on
mice a similar effect of piperine in altering the pharmacoki-
netics of phenytoin, an anti-epileptic drug. Pretreatment of
piperine significantly delayed the elimination of phenytoin.
Co-administration of piperine enhanced the bioavailability of
β-lactam antibiotics, amoxycillin trihydrate, and cefotaxime
significantly in rats (Hiwale et al., 2002). The improved
bioavailability is reflected in various pharmacokinetic pa-
rameters viz. the tmax, the Cmax, the half-life, and AUC, of
these antibiotics and was attributed to the effect of piperine on
microsomal metabolizing enzymes.
Black pepper extract consisting of 98% piperine has been
evidenced to increase plasma levels of orally supplemented
coenzyme Q
10
in a clinical study using a double-blind design
(Badmaev et al., 2000). The relative bioavailability of 90 mg
and 120 mg of coenzyme Q
10
administered in a single-dose ex-
periment or in separate experiments for 14 and 21 days with
placebo or with 5 mg of piperine was determined by comparing
measured changes in plasma concentration. Supplementation of
120 mg coenzyme Q
10
with piperine for 21 days produced a sig-
nificant, approx. 30% greater, AUC, than was observed during
supplementation with coenzyme Q
10
plus placebo. It is inferred
that the bioenhancing mechanism of piperine to increase the
plasma levels of supplemental coenzyme Q
10
is nonspecific.
The effect of piperine, a known inhibitor of hepatic and in-
testinal glucuronidation on the bioavailability of curcumin was
evaluated in rats and healthy human volunteers (Shoba et al.,
1998). When curcumin was given alone at 2 g/kg to rats, mod-
erate serum concentrations were achieved over a period of 4 h.
Concomitant administration of piperine 20 mg/kg increased the
serum concentration of curcumin for a short period of 1–2 h
post drug. Time to maximum was significantly increased while
plasma half-life and clearance significantly decreased, and the
bioavailability was increased by 154%. On the other hand, in hu-
mans, after a dose of2gcurcumin alone, serum levels were either
undetectable or very low. Concomitant administration of piper-
ine 20 mg produced much higher concentrations from 0.25 to 1 h
post-drug, the increase in bioavailability was 2000%. The study
shows that in the dosages used, piperine enhances the serum
concentration, the extent of absorption and the bioavailability
of curcumin in both rats and humans. This assumes importance
in the context of diverse medicinal properties of curcumin of
Curcuma longa.
The effect of piperine on the metabolic activation and dis-
tribution of [3H]-aflatoxin B
1
(AFB
1
)inrats has been stud-
ied by Allamesh et al. (1992). Piperine markedly inhibited
liver microsome-catalysed AFB
1
binding to calf thymus DNA

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PHYSIOLOGICAL EFFECTS OF BLACK PEPPER AND PIPERINE 741
Table 4 Influence of black pepper and piperine on gastrointestinal system
Effects demonstrated Investigators
Digestive stimulant action:
a) Stimulation of digestive enzymes of Pancreas by dietary piperine Platel and Srinivasan (2000)
b) Stimulation of digestive enzymes of Intestine by dietary piperine Platel and Srinivasan (1996)
c) Oral administration of piperine increases biliary bile acid secretion Bhat and Chandrasekhara (1987)
Influence on intestinal motility and food transit time:
a) Gastrointestinal food transit time shortened by prolonged dietary piperine in rats Platel and Srinivasan (2001)
b) Increased orocecal transit time after black pepper consumption in humans Vazquez-Olivencia et al. (1992)
c) Piperine inhibited gastric emptying of solids/liquids in rats; inhibited gastrointestinal transit in mice Bajad et al. (2001)
d) Piperine dose-dependedly delayed gastrointestinal motility in mice Izzo et al. (2001)
Effect on gastric mucosa:
a) Black pepper caused increases in gastric parietal and pepsin secretion and increased gastric cell exfoliation in humans Myers et al. (1987)
b) Black pepper increased gastric acid secretion in anesthetized rats Vasudevan et al. (2000)
c) Piperine increased gastric acid secretion in albino rats Ononiwu et al. (2002)
d) Piperine showed protective action against gastric ulcer in rats and mice induced by stress, indometacin, HCl Bai and Xu (2000)
Anti-diarrhoral property:
a) Piperine inhibited diarrhea produced by castor oil, MgSO
4
, arachidonic acid in mice Bajad et al. (2001)
b) Piperine reduced castor oil induced intestinal fluid accumu-lation in mouse intestine. Capasso et al. (2002)
Influence on absorptive function:
a) Piperine stimulated γ -glutamyl transpeptidase activity and enhanced uptake of amino acids in isolated epithelial cells Johri et al. (1992)
of rat jejunum
b) Piperine modulated the membrane dynamics and permea-tion characteristics, increasing the absorptive surface Khajuria et al. (2002)
and induction of synthesis of proteins associated with cyto-skeletal function
in vitro, in a dose-dependent manner. Rats pretreated with piper-
ine accumulated considerable AFB
1
radioactivity in plasma and
in the tissues examined as compared to the controls. However,
piperine had no influence on hepatic AFB
1
-DNA binding in vivo,
which could possibly be due to the null effect of piperine on
liver cytosolic glutathione transferase activity. Piperine-treated
rat liver microsomes demonstrated a tendency to enhance AFB
1
binding to calf thymus DNA in vivo.
INFLUENCE ON THE GASTROINTESTINAL SYSTEM
(TABLE 4)
Effect on Gastric Mucosa
While pungent spices have long been implicated as a cause of
gastric mucosal injury, very few studies have been reported on
their long-term effect on the gastric mucosa. Myers et al. (1987)
assessed the effects of black pepper on the gastric mucosa us-
ing double-blind intragastric administration of the spice (1.5 g)
to healthy human volunteers, with aspirin (655 mg) as positive
control. Serial gastric washes were performed after the admin-
istration and gastric contents were analyzed for DNA, pepsin,
blood, sodium, potassium, parietal cell secretion, and nonpari-
etal cell secretion. Black pepper caused significant increases in
parietal secretion, pepsin secretion, and potassium loss. Gastric
cell exfoliation (as reflected in DNA loss in gastric contents)
was increased after black pepper administration. Mucosal mi-
crobleeding was seen after spice administration. The effect of
black pepper was similar to aspirin in any parameter studied.
The long-term result of daily pepper ingestion is unknown.
Vasudevan et al. (2000) have studied the effect of various
spices on gastric acid secretion in anesthetized rats, and report
that black pepper significantly increased gastric acid secretion.
Piperine was studied for its effect on gastric acid secretion in
white albino rats (Ononiwu et al., 2002). Increasing the dose
from 20 mg/kg to 142 mg/kg produced dose dependent signifi-
cant increase in gastric acid secretion. The effect of piperine was
significantly antagonized by cimetidine (1 mg/kg) but not by at-
ropine (1 mg/kg). Any involvement of cholinergic receptors in
the observed piperine-induced increase in gastric acid secretion
is thus excluded. There is however an indication that stimulation
of histamine H2 receptors by piperine is likely to be involved in
the increased acidity induced by piperine.
On the other hand, Bai and Xu (2000) have evidenced protec-
tive action of piperine against experimental gastric ulcer in rats
and mice. The gastric mucosa damage was induced by stress,
indometacin, HCl, and pyloric ligation in rats or mice. The num-
ber of gastric ulcers, the volume and acidity of gastric juices,
and pepsin activity were monitored. Piperine at 25, 50, and 100
mg/kg i.g. protected animals from gastric ulceration in a dose-
dependent manner. The inhibitory rates were 16.9, 36.0, and
48.3% in stress ulcers; 4.4, 51.1, and 64.4% in indometacin ul-
cers; 19.2, 41.5, and 59.6% in HCl ulcers; 4.8, 11.9, and 26.2%
in pyloric ligation ulcers, respectively; Piperine inhibited the
volume of gastric juice, gastric acidity, and pepsin activity.
Antidiarrhoeal Property
Peppers are added in traditional antidiarrhoeal formulations
of different herbs. A study has been made in experimental mice to
determine the rationale, if any, for its use in traditional antidiar-
rhoeal formulations (Bajad et al., 2001), where the antidiarrhoeal
activity of piperine against castor oil, MgSO
4
and arachidonic
acid was examined. It significantly inhibited diarrhoea produced

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742 K. SRINIVASAN
by these cathartics at 8 and 32 mg/kg p.o. dose. Inhibition of
castor oil induced the enteropooling by piperine suggests its
inhibitory effect on prostaglandins. Capasso et al. (2002) inves-
tigated the effect of piperine on castor oil-stimulated fluid accu-
mulation in the small intestine of mice. Piperine (2.5–20 mg/kg,
i.p.) dose-dependently reduced castor oil-induced intestinal fluid
accumulation. It was further understood that piperine reduces
castor oil-induced fluid secretion with a mechanism involving
capsaicin-sensitive neurons, but not capsazepine-sensitive vanil-
loid receptors.
Influence on Absorptive Function
The effect of piperine on the absorptive function of the in-
testine has been studied in in vitro experiments which showed
that piperine (25–100 µM) significantly stimulated γ -glutamyl
transpeptidase (γ -GT) activity, enhanced the uptake of radiola-
belled amino acids and increased the lipid peroxidation in freshly
isolated epithelial cells of rat jejunum (Johri et al., 1992). The
kinetic behavior of γ -GT towards substrate and acceptor altered
in the presence of piperine.This suggested that piperine may
interact with the lipid environment to produce effects leading
to increased permeability of the intestinal cells. It is hypothe-
sized that piperine’s bioavailability-enhancing property may be
attributed to increased absorption, which may be due to alter-
ation in membrane lipid dynamics and change in the confor-
mation of enzymes in the intestine (Khajuria et al., 2002). The
results of membrane fluidity studies using an apolar fluorescent
probe, pyrene (which measures the fluid properties of hydrocar-
bon core), showed an increase in intestinal brush border mem-
brane fluidity. Piperine also stimulated Leucine amino peptidase
and Glycyl-glycine dipeptidase activity, due to the alteration in
enzyme kinetics. This suggests that piperine could modulate the
membrane dynamics due to its apolar nature by interacting with
surrounding lipids and hydrophobic portions in the protein vicin-
ity, which may decrease the tendency of membrane lipids to act
as stearic constrains to enzyme proteins and thus modify enzyme
conformation. Ultra-structural studies with piperine showed an
increase in microvilli length with a prominent increase in free
ribosomes and ribosomes on the endoplasmic reticulum in en-
terocytes, suggesting that synthesis or turnover of cytoskeletal
components or membrane proteins may be involved in the ob-
served effect. Thus, it is suggested that piperine may induce al-
terations in membrane dynamics and permeation characteristics,
along with the induction of the synthesis of proteins associated
with cytoskeletal function, resulting in an increase in the small
intestine absorptive surface, thus assisting efficient permeation
through the epithelial barrier.
Influence on Gastrointestinal Motility and Food Transit Time
Vazquez-Olivencia et al. (1992) have evaluated the effects of
black pepper on small intestinal peristalsis measuring orocecal
transit time utilizing the lactulose hydrogen breathe test. The lac-
tulose hydrogen breath test was done on healthy subjects on dif-
ferent days with or without black pepper (1.5 g) given in gelatin
capsules. An increase in orocecal transit time was observed after
black pepper consumption (90 ± 51 min to 122 ± 88 min). Bajad
et al. (2001) report that piperine inhibits gastric emptying (GE) of
solids/liquids in rats and gastrointestinal transit (GT) in mice in a
dose and time dependent manner. It significantly inhibited GE of
solids and GT at the doses extrapolated from humans (1 mg/kg
and 1.3 mg/kg p.o. in rats and mice, respectively). However,
at the same dose the effect was insignificant for GE of liquids.
One week oral treatment of 1 mg/kg and 1.3 mg/kg in rats and
mice, respectively, did not produce a significant change in ac-
tivity as compared to single dose administration. GE inhibitory
activity of piperine is independent of gastric acid and pepsin
secretion. Izzo et al. (2001) have studied the effect of piperine,
which activates vanilloid receptors, on upper gastrointestinal
motility in mice. Piperine (0.5–20 mg/kg i.p.) dose-dependently
delayed gastrointestinal motility. The inhibitory effect of piper-
ine (10 mg/kg) was strongly attenuated in capsaicin (75 mg/kg
in total, s.c.)-treated mice. The study indicated that the vanilloid
ligand piperine can reduce upper gastrointestinal motility. The
effect of piperine involves capsaicin-sensitive neurones, but not
vanilloid receptors.
The gastrointestinal food transit time was significantly short-
ened by dietary piperine (Platel and Srinivasan, 2001). The re-
duction in food transit time produced by dietary piperine roughly
correlates with its beneficial influence either on digestive en-
zymes or on bile secretion (Platel and Srinivasan, 2001). Thus,
the dietary piperine, which has enhanced the activity of digestive
enzymes, also has markedly reduced the food transit time at the
same level of consumption. This reduction in food transit time
could probably be attributed to acceleration in the overall di-
gestive process as a result of increased availability of digestive,
enzymes.
ANTIMUTAGENIC AND TUMOR INHIBITORY
EFFECTS
El Hamss et al. (2003) have shown that black pepper is
effective in reducing the mutational events induced by the
promutagen-ethyl carbamate in Drosophila melanogaster using
the wing Somatic Mutation and Recombination Test. Suppres-
sion of metabolic activation or interaction with the active groups
of mutagens could be mechanism by which the spice exerts its
antimutagenic action. Black pepper extracts have been demon-
strated to possess tumor inhibitory activity (Loder et al., 1969).
The tumor reducing activity of orally administered extracts of
black pepper was studied in mice transplanted i.p. with Ehrlich
ascites tumor (Unnikrishnan and Kuttan, 1990). The life span
was increased in these mice by 65% indicating the potential
use of the spice as anti-cancer agents as well as anti-tumor
promoters.
The alcoholic extract of Piper longum fruits and its compo-
nent piperine was studied for their immunomodulatory and anti-
tumor activity (Sunila and Kuttan, 2004). The alcoholic extract
of the fruits was 100% toxic at 500 µg/ml to Dalton’s lymphoma

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PHYSIOLOGICAL EFFECTS OF BLACK PEPPER AND PIPERINE 743
ascites (DLA) cells and 250 µg/ml to Ehrlich ascites carcinoma
(EAC) cells. Piperine was found to be cytotoxic towards DLA
and EAC cells at 250 µg/ml. The alcoholic extract and piperine
was also found to produce cytotoxicity towards L929 cells in
culture at a concentration of 100 and 50 µg/ml, respectively.
The administration of alcoholic extract of Piper longum (10
mg/animal) as well as piperine (1.14 mg/animal) could inhibit
the solid tumor development in mice induced with DLA cells and
increase the life span of mice bearing Ehrlich ascites carcinoma
tumor to 37 and 59%.
Pradeep and Kuttan (2002) have recently demonstrated the
antimetastatic activity of piperine by studying the effect of piper-
ine on the inhibition of lung metastasis induced by B16F-10
melanoma cells in C57BL/6 mice. A simultaneous administra-
tion of the compound with tumor induction produced a signifi-
cant reduction (95%) in tumor nodule formation. The elevated
levels of serum sialic acid and serum γ -GT activity in the un-
treated animals was significantly reduced in the animals treated
with piperine. Piperine-treated animals survived the 90 days ex-
periment. Histopathology of the lung tissue also correlated with
the lifespan of the drug-treated animals.
The cytoprotective effect of piperine on B(α)p-induced ex-
perimental lung cancer has been investigated in mice and ob-
served that piperine may extend its chemopreventive effect by
modulating lipid peroxidation and augmenting antioxidant de-
fense system (Selvendiran et al., 2003). Oral administration of
piperine (100 mg/kg body weight) effectively suppressed lung
cancer initiated with B(α)p as revealed by the decrease in the
extent of lipid peroxidation with concomitant increase in the ac-
tivities of enzymatic antioxidants (superoxide dismutase, cata-
lase, and glutathione peroxidase) and non-enzymatic antioxi-
dants (reduced glutathione, vitamin E, and vitamin C) levels
when compared to lung cancer bearing animals.
Piperine has been evidenced to show chemopreventive ef-
fects when administered orally on lung cancer bearing animals
(Selvendiran and Sakthisekaran, 2004). The beneficial effect
of piperine is primarily exerted during the initiation phase and
the post-initiation stage of B(α)p induced lung carcinogenesis,
via beneficial modulation of lipid peroxidation and membrane
bound ATPase enzymes. Selvendiran et al. (2004a) studied the
ability of piperine to prevent lung carcinogenesis induced by
B(α)p in mice and its effects on cell proliferation. Administration
of piperine significantly decreased the levels of lipid peroxida-
tion, protein carbonyls, the nucleic acid content, and polyamine
synthesis that were found to be increased in lung cancer bear-
ing animals. Piperine could effectively inhibit B(α)p-induced
lung carcinogenesis in albino mice by offering protection from
protein damage and also by suppressing cell proliferation.
DELETERIOUS EFFECT OF PIPERINE
ON THE REPRODUCTIVE SYSTEM
The effect of piperine on the fertilizing ability of hamster
sperm was investigated in vitro (Piyachaturawat et al., 1991).
Sperm were incubated in a capacitation medium for3hprior to
co-incubation with hamster eggs in a fertilization medium for
another 3 h. Addition of 0.18–1.05 mM piperine reduced both
the percentage of eggs fertilized and the degree of polyspermia
in a dose-dependent manner. When piperine was administered to
mature male albino rats at doses of 5 and 10 mg/kg body weight,
p.o., respectively, for 30 days, only the higher dose caused a
significant reduction in the weights of testis and accessory sex
organs (Malini et al., 1999). Histological studies revealed that
piperine at a 10 mg dose, caused severe damage to the semi-
niferous tubule, caused a decrease in seminiferous tubular and
Leydig cell nuclear diameter, and desquamation of spermato-
cytes and spermatids. Correlated to the structural changes, a fall
in caput and cauda epididymal sperm concentrations was also
evident. A 10 mg dose of piperine also caused a marked in-
crease in serum gonadotropins and a decrease in intratesticular
testosterone concentration, despite normal serum testosterone
titres.
The reproductive toxicity of piperine was studied in Swiss
albino mice (Daware et al., 2000) with respect to the effect on
the estrous cycle, their mating behavior, the toxicity to male
germ cells, fertilization, and the implantation and growth of
pups. Piperine (10 and 20 mg/kg body weight) increased the
period of the diestrous phase resulting in decreased mating per-
formance and fertility. Post-partum litter growth was not af-
fected by the piperine treatment and sperm shape abnormalities
were not induced at doses up to 75 mg/kg. Considerable anti-
implantation activity was recorded after five days post-mating
oral treatment with piperine. These results show that piperine in-
terferes with several crucial reproductive events in a mammalian
model. The effect of piperine on the fertilization of eggs with
sperm has been investigated in female hamsters intragastrically
treated with piperine at doses of 50 or 100 mg/kg body weight
from day 1 through day 4 of the oestrous cycle (Piyachaturawat
and Pholpramool, 1997). During piperine treatment, these fe-
males were superovulated and artificially inseminated (AI) with
spermatozoa from untreated male hamsters at 12 h after hCG in-
jection. Administration of piperine to the superovulated animals
markedly enhanced the percent fertilization at9hafter AI.
OTHER PHYSIOLOGICAL EFFECTS
The anti-inflammatory activity of piperine has been re-
ported in rats employing different experimental models like
carrageenan-induced rat paw edema, cotton pellet granuloma,
and croton oil-induced granuloma pouch (Mujumdar et al.,
1990). Piperine acted significantly on early acute changes in
inflammatory processes and chronic granulative changes. Pun-
gent principles of dietary spices including piperine have been
reported to induce a warming action via adrenal catecholamine
secretion (Kawada et al., 1988). Black pepper extract was found
to possess growth-stimulatory activity in cultured melanocytes
(Lin et al., 1999). Its aqueous extract at 0.1 mg/ml was observed
to cause nearly 300% stimulation of the growth of a cultured
mouse melanocyte line, melan-a, in 8 days, hence it is inferred

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744 K. SRINIVASAN
Table 5 Other physiological effects of black pepper and piperine
Effects demonstrated Investigators
Antimutagenic and tumor inhibitory effects:
a) Black pepper is effective in reducing mutational events induced by procarcinogen—ethylcarbamate in Drosophila El Hamss et al. (2003)
b) Tumour inhibitory activity of black pepper in mice implanted with Ehrlich ascites tumour Unnikrishnan and Kuttan (1990)
c) Piperine inhibited tumor development in mice induced with Dalton’s lymphoma cells and increased the life span Sunila and Kuttan (2004)
of mice bearing Ehrlich ascites carcinoma
d) Anti-metastatic activity of piperine on lung metastasis induced by melanoma cells in mice Pradeep and Kuttan (2002)
e) Chemopreventive effect of piperine on benzo(α)pyrene induced experimental lung cancer in mice Selvendiran et al. (2003) Selvendiran
and Sakthisekaran, (2004);
Selvendiran et al. (2004a)
Effect on reproductive system:
a) Piperine decreased fertilizing ability of hamster sperms and degree of polyspermia in vitro Piyachaturawat et al. (1991)
b) Continued oral intake of piperine produced reduction in weights of testis, fall sperm concentration, decrease in Malini et al. (1999)
intra-testicular testosterone concentration in mature male rats
c) Oral intake of piperine decreased fertility due to interference with crucial reproductive events in albino mice. Daware et al. (2000)
Other effects:
a) Thermogenic action of piperine via adrenal catecholamine secretion in rats Kawada et al. (1988)
b) Anti-inflammatory activity of piperine in experimental models: carrageenan-induced rat paw edema, cotton pellet Mujumdar et al. (1990)
granuloma, croton oil induced granuloma pouch
c) Growth stimulatory activity of black pepper extract in cultured melanocytes Lin et al. (1999)
d) Anti-thyroid activity of piperine and hence decreased glucose concentration in mice Panda and Kar (2003)
e) Piperine inhibited mitochondrial oxidative phosphorylation and diminished calcium uptake in vitro Reanmongkol et al. (1988)
f) Piperine exerted protection against t-butyl hydroperoxide and carbon tetrachloride in hepatotoxicity by reducing Koul and Kapil (1993)
lipid peroxidation
g) Piperine exerted chemopreventive effect by retarding the acti-vation of procarcinogen aflatoxin B
1
and hence Singh et al. (1994)
protecting from its cytotoxicity and genotoxicity
h) Piperine promoted cytotoxicity induced by benzo(α)pyrene in cultured lung fibroblast cells Chu et al. (1994)
i) Piperine pretreatment potentiated hepatotoxicity of carbon tetrachloride in rats Piyachaturawat et al. (1995)
that piperine is a potential repigmenting agent for the treatment
of vitiligo (Table 5).
Piperine was evaluated for its thyroid hormone and glucose
regulatory efficacy in adult Swiss albino mice (Panda and Kar,
2003). Its daily oral administration (2.5 mg/kg) for 15 days low-
ered the serum levels of both the thyroid hormones, thyroxin
(T
4
) and triiodothyronine (T
3
)aswell as glucose concentra-
tions with a concomitant decrease in hepatic 5

D enzyme and
glucose-6-phospatase (G-6-Pase) activity. The decrease in T
4
,
T
3
concentrations and in G-6-Pase were comparable to that of a
standard antithyroid drug, Proylthiouracil. It is suggested that a
higher dose of piperine may inhibit thyroid function and serum
glucose concentration in euthyroid individuals.
The in vitro effects of piperine on three bioenergetic reac-
tions namely, oxidative phosphorylation, ATPase activity and
calcium transport by isolated rat liver mitochondria have been
investigated (Reanmongkol et al., 1988). The study suggested
that piperine inhibits mitochondrial oxidative phosphorylation
at the level of respiratory chain. Piperine did not inhibit the mito-
chondrial ATPase activity induced by dinitrophenol, but by itself
stimulated activity of this enzyme. Piperine was also found to
diminish calcium uptake and to facilitate the release of accumu-
lated calcium by the mitochondria incubated with succinate or
ATP. The effect of piperine on calcium transport is likely to be
consequential to the effects of this compound on the mitochon-
drial respiratory chain and ATPase activity. The influence of
piperine on the enzymes and bioenergetic functions in isolated
rat liver mitochondria and hepatocytes has been studied, and it
was observed that piperine produces concentration related site-
specific effects on mitochondrial bioenergetics and enzymes of
energy metabolism (Jamwal and Singh, 1993).
Piperine was evaluated for its antihepatotoxic potential in
order to validate its use in traditional therapeutic formulations
(Koul and Kapil, 1993). It exerted a significant protection against
t-butyl hydroperoxide and carbon tetrachloride hepatotoxicity
by reducing both in vitro and in vivo lipid peroxidation, leak-
age of enzymes—alanine aminotransferase (AlAT) and alkaline
phosphatase and by preventing the depletion of glutathione and
total thiols in the intoxicated mice.
Piperine pretreatment potentiated the hepatotoxicity of CCl
4
in a dose-dependent manner in rats (Piyachaturawat et al., 1995).
The maximum potentiation occurred at a dose of 100 mg/kg
BW was intragastrically administered 4 h prior to an intraperi-
toneal injection of CCl
4
,atwhich time the activities of plasma
AlAT and aspartate aminotransferase (AsAT) were elevated by
70–80%. Concurrent with the rise in AlAT and AsAT activi-
ties, the accumulation of hepatic triglyceride increased whereas
the plasma level of triglyceride decreased. Piperine pretreat-
ment also potentiated CCl
4
-induced lipid peroxidation in the
liver. In the in vitro system in which the tissue was prein-
cubated with piperine and CCl
4
was added into the incuba-
tion medium, piperine also exhibited a concentration depen-
dent potentiation on CCl
4
-induced lipid peroxidation and on
the activity of NADPH-cytochrome C-reductase. The results
indicated that piperine potentiated CCl
4
-induced hepatotoxic-
ity by interacting with liver cells and increased the activity of

Downloaded By: [Srinivasan, K.] At: 01:14 8 November 2007
PHYSIOLOGICAL EFFECTS OF BLACK PEPPER AND PIPERINE 745
NADPH-cytochrome C reductase. The increase in activity of
this enzyme accelerated the biotransformation of CCl
4
, thereby
increasing lipid peroxidation and enhancing hepatotoxicity.
Piperine was found to promote DNA damage and cytotox-
icity induced by B(α)p in cultured V-79 lung fibroblast cells
(Chu et al., 1994). The V-79 cells were treated with a non-toxic
dose of piperine (1–20 µM) plus 10 µMB(α)p, or pretreated
with piperine for 30 min or 2 h prior to the administration of
10 µMB(α)p. B(α)p cytotoxicity was potentiated significantly
by piperine under each experimental condition. The study also
suggested that the promotion by piperine of B(α)p-induced cy-
totoxicity in V-79 lung fibroblast cells is due to mechanisms that
decrease the activities of GST and UDP-GTase and increase the
formation of a B(α)p-DNA adduct.
Singh et al. (1994) studied the effect of piperine on the cyto-
toxicity and genotoxicity of aflatoxin B
1
(AFB
1
)inrat hepatoma
cells H4IIEC3/G-(H4IIE) using cellular growth and the forma-
tion of micronuclei as endpoints. AFB
1
inhibited the growth
of H4IIE cells with an ED
50
of 15 nM. Piperine markedly re-
duced the toxicity of the mycotoxin. Thus, at 100 µM piperine
largely restored the rate of growth of the cells. Likewise, piper-
ine reduced the AFB
1
-induced formation of micronuclei in a
concentration-dependent manner. Piperine itself was not toxic
to the cells up to a concentration of almost 100 µM. The re-
sults suggest, that piperine is capable of counteracting AFB
1
toxicity by suppressing cytochromes P
450
mediated bioactiva-
tion of the mycotoxin. Reen et al. (1997) have investigated the
potential of piperine for inhibiting the activity of cytochrome
P4502B1 and protecting against AFB
1
in V79MZr2B1 (r2B1)
cells (Chinese hamster cells) engineered for the expression of rat
CYP4502B1. Piperine inhibited 7-methoxycoumarin demethy-
lase in preparations of r2B1 cells with an IC
50
of approximately
10 µM. Piperine at 60 µM completely counteracted the cytotox-
icity and formation of micronuclei by 10 µM AFB
1
and reduced
the toxic effects of 20 µM AFB
1
by >50%. The results suggest
that: (i) Piperine is a potent inhibitor of rat CYP4502B1 activity;
(ii) AFB
1
is activated by r2B1 cells to cytotoxic and genotoxic
metabolites; and (iii) piperine counteracts CYP4502B1 medi-
ated toxicity of AFB
1
in the cells and might, therefore, offer a
potent chemopreventive effect against procarcinogens activated
by CYP4502B1.
ABSORPTION AND METABOLISM OF PIPERINE
Upon administration of piperine to male albino rats at a dose
of 170 mg/kg by gavage or 85 mg/kg intraperitoneally, about
97% was absorbed irrespective of the mode of dosing (Bhat and
Chandrasekhara, 1986). 3% of the administered dose was ex-
creted as piperine in the feces, while it was not detectable in the
urine. When everted sacs of rat intestines were incubated with
200–1000 µgofpiperine, about 47–64% of the added piperine
disappeared from the mucosal side (Bhat and Chandrasekhara,
1986). Only piperine was present in the serosal fluid and also
the intestinal tissue, indicating that piperine did not undergo any
metabolic change during absorption. The examination of the
passage of piperine through the gut indicated that the highest
concentration in the stomach and small intestine was attained
at about 6 h. Only traces (less than 0.15%) of piperine were
detected in the serum, the kidney, and the spleen from 30 min
to 24 h. About 1–2.5% of the intraperitoneally administered
piperine was detected in the liver during 0.5–6 h after admin-
istration as contrasted with 0.1–0.25% of the orally adminis-
tered dose. The increased excretion of conjugated uronic acids,
conjugated sulphates, and phenols indicated that scission of the
methylenedioxy group of piperine, glucuronidation and sulpha-
tion appear to be the major steps in the disposition of piperine
in the rat. After oral administration of piperine (170 mg/kg)
to rats, the metabolites in urine (0–96 h) were identified to be
piperonylic acid, piperonyl alcohol, piperonal, and vanillic acid
in the free form, whereas only piperic acid was detected in 0–6
h bile (Bhat and Chandrasekhara, 1987). The kidney appears
to be the major excretion route for piperine metabolites in rats
as no metabolite could be detected in feces. Based on these re-
sults, a pathway for the biotransformation of piperine in rats has
been proposed (Fig. 2). In a recent investigation (Bajad et al.,
2003), to further study the reported differences in its metabolism
in rats and humans, a new major urinary metabolite was de-
tected in rat urine and plasma using HPLC and characterized
as 5-(3,4-methylenedioxy phenyl)-2,4-pentadienoic acid-N-(3-
yl propionic acid)-amide. This metabolite has a unique structure
in that it retains the methylenedioxy ring and conjugated double
bonds while the piperidine ring is modified to form propionic
acid group.
Khajuria et al. (1998) have made an effort to understand the
absorption dynamics of piperine in the intestine on oral absorp-
tion. Using intestinal everted sacs and cycloheximide treatment
and exclusion of Na
+
the salts from the incubating medium as
the variables used, the absorption half-life, the absorption rate,
the absorption clearance, and apparent permeability co-efficient
were computed. Data suggested that piperine is absorbed very
fast across the intestinal barrier. It may act as an apolar molecule
and form apolar complex with drugs and solutes. It may modu-
late membrane dynamics due to its easy partitioning, thus help-
ing in efficient permeability across the barriers.
CONCLUSIONS
Black pepper or its active principle piperine has been exper-
imentally demonstrated by a number of independent investiga-
tors to possess diverse physiological effects (Fig. 3). Piperine has
been evidenced to protect against oxidative damage by inhibit-
ing or quenching free radicals and lower lipid peroxidation and
beneficially influence cellular thiols, antioxidant molecules and
antioxidant enzymes in different situations of oxidative stress.
The most far-reaching attribute of piperine has been its inhibitory
influence on hepatic, pulmonary, and intestinal drug metabo-
lizing system. It strongly inhibits a particular cytochrome P
450
and hence phase-I reactions mediated by the same, especially
aromatic hydroxylation. It also strongly retards glucuronidation
reactions of phase-II. As a result of interference with crucial

Downloaded By: [Srinivasan, K.] At: 01:14 8 November 2007
746 K. SRINIVASAN
Figure 2 Biotransformation of piperine.
Figure 3 Summary of diverse physiological effects of black pepper and piperine.

Downloaded By: [Srinivasan, K.] At: 01:14 8 November 2007
PHYSIOLOGICAL EFFECTS OF BLACK PEPPER AND PIPERINE 747
drug metabolizing reactions in the liver, piperine enhances the
bioavailability of therapeutic drugs, i.e., increases their plasma
half-life, and delays their excretion. Piperine also possesses a cy-
toprotective effect by retarding the activation of certain procar-
cinogens by the drug metabolizing system. The gastro-intestinal
system is affected by black pepper and piperine in many ways.
Both black pepper and piperine have been evidenced to have
a definite effect on intestinal motility, the antidiarrhoral prop-
erty, and on the ultrastructure of intestinal microvilli improving
the absorbability of nutrients. Among other physiological ef-
fects piperine exerts, its potential antifertililty influence on the
reproductive system has been clearly established in in vitro
and animal systems. Antimutagenic and anti-tumor properties
of piperine have been evidenced by a number of animal and cell
line studies. Although initially there were a few controversial
reports regarding the safety of black pepper or piperine as a
food additive, the latter studies have established the safety of
this spice in several animal studies.
REFERENCES
Allameh, A. et al. (1992). Piperine, a plant alkaloid of the piper species, enhances
the bioavailability of aflatoxin B1 in rat tissues, Cancer Lett., 61:195–199.
Ames, B. N. (1983). Dietary carcinogens and anticarcinogens: Oxygen radials
and degenerative diseases, Science, 221:1256–1264.
Atal, C. K. et al. (1981). Scientific evidence on the role of Ayurvedic herbals on
bioavailability of drugs, J. Ethnopharmacol., 4:229–232.
Atal, C. K. et al. (1985). Biochemical basis of enhanced drug bioavailability
of piperine: Evidence that piperine is a potent inhibitor of drug metabolism,
J. Pharmacol. Exp. Ther., 232:258–262.
Badmaev, V. V. et al. (2000). Piperine derived from black pepper increases
the plasma levels of coenzyme Q10 following oral supplementation, J. Nutr.
Biochem., 11:109–113.
Bai, Y. F., and Xu, H. (2000). Protective action of piperine against experimental
gastric ulcer, Acta Pharmacol. Sin., 21:357–359.
Bajad, S. et al. (2001). Antidiarrhoeal activity of piperine in mice, Planta Med.,
67:284–287.
Bajad, S. et al. (2001). Piperine inhibits gastric emptying and gastrointestinal
transit in rats and mice, Planta Med., 67:176–179.
Bajad, S. et al. (2003). Characterization of a new rat urinary metabolite of
piperine by LC/NMR/MS studies, Eur. J. Pharm. Sci., 19:413–421.
Bano, G. et al. (1991). Effect of piperine on bioavailability and pharmacoki-
netics of propranolol and theophylline in healthy volunteers, Eur. J. Clin.
Pharmacol., 41:615–617.
Bhat, G. B., and Chandrasekhara, N. (1986). Lack of adverse influence of black
pepper, its oleoresin and piperine in the weanling rat, J. Food Safety, 7:215–
223.
Bhat, B. G., and Chandrasekhara, N. (1986). Studies on the metabolism of
piperine: absorption, tissue distribution and excretion of urinary conjugates
in rats, Toxicology, 40:83–92.
Bhat, B. G., and Chandrasekhara, N. (1987). Metabolic disposition of piperine
in the rat, Toxicology, 44:99–106.
Bhat, G. B., and Chandrasekhara, N. (1987a). Effect of black pepper and piperine
on bile secretion and composition in rats, Nahrung, 31:913–916.
Buchanan, R. L. (1980). Toxicity of spices containing methylene dioxy benzene
derivatives: A review, J. Food Safety, 1:275–293.
Capasso, R. et al. (2002). Effect of piperine, the active ingredient of black pepper,
on intestinal secretion in mice, Life Sci., 71:2311–2317.
Cho, S. Y., and Lee, S. H. (1983). Effect of black pepper on the composition of
serum and liver in rat, Hanguk Yongyang Siklyong Hakhoechi, 12:219–224.
Chu, C. Y. et al. (1994). Modulatory effect of piperine on benzo[α]pyrene cyto-
toxicity and DNA adduct formation in V-79 lung fibroblast cells, Food Chem.
Toxicol., 32:373–377.
Concon, J. M. et al. (1979). Black pepper (Piper nigrum): Evidence of carcino-
genicity, Nutr. Cancer, 1:22–26.
Dalvi, R. R., and Dalvi, P. S. (1991). Comparison of the effects of piperine ad-
ministered intra gastrically and intraperitoneally on the liver and liver mixed
function oxidases in rats, Drug Metab. Drug Interact., 9:23–30.
Dalvi, R. R., and Dalvi, P. S. (1991a). Differences in the effects of piperine
and piperonyl butoxide on hepatic drug-metabolizing enzyme system in rats,
Drug Chem. Toxicol., 14:219–229.
Daware, M. B. et al. (2000). Reproductive toxicity of piperine in Swiss albino
mice, Planta Med., 66:231–236.
Dogra, R. K. et al. (2004). Immunotoxicological effects of piperine in mice,
Toxicology, 196:229–236.
El Hamss, R. et al. (2003). Antimutagenic properties of bell and black peppers,
Food Chem. Toxicol., 41:41–47.
Epstein, S. S., and Swartz, J.B. (1984). Cancer and diet, Science, 224:660–666.
Glatzel, H. (1968). Physiological aspects of flavour compounds. Indian Spices,
5: 13–21.
Govindarajan, V. S. (1977). Pepper - Chemistry, technology and quality evalu-
ation, CRC Crit. Rev. Food Sci. Nutr., 9:115–225.
Hiwale, A. R. et al. (2002). Effect of co-administration of piperine on pharma-
cokinetics of β-lactam antibiotics in rats, Indian J. Exp. Biol., 40:277–281.
Ioannidesn C. et al. (1981). Safrole: Its metabolism, carcinogenicity and inter-
actions with cytochrome p-450. Food Cosmet. Toxicol., 19:657–666.
Izzo, A. A. et al. (2001). Effect of vanilloid drugs on gastrointestinal transit in
mice, Br. J. Pharmacol., 132:1411–1416.
Jamwal, D. S., and Singh, J. (1993). Effects of piperine on enzyme activities
and bioenergetic functions in isolated rat liver mitochondria and hepatocytes,
J. Biochem. Toxicol., 8:167–174.
Johri, R. K. et al. (1992). Piperine-mediated changes in the permeability of rat
intestinal epithelial cells: Status of γ -glutamyl transpeptidase activity, uptake
of amino acids and lipid peroxidation, Biochem. Pharmacol., 43:1401–1407.
Karekar, V. R. et al. (1996). Assessment of genotoxic effect of piperine using
Salmonella typhimurium and somatic and somatic and germ cells of Swiss
albino mice, Arzneimittel Forschung, 46:972–975.
Kawada, T. et al. (1988). Some pungent principles of spices cause the adrenal
medulla to secrete catecholamine in anesthetized rats. Proc. Soc. Exp. Biol.
Med., 188:229–233.
Khajuria, A. et al. (1998). Permeability characteristics of piperine on oral ab-
sorption - an active alkaloid from peppers&abioavailability enhancer, Indian
J. Exp. Biol., 36:46–50.
Khajuria, A. et al. (1998). Piperine modulation of carcinogen induced oxidative
stress in intestinal mucosa, Mol. Cell. Biochem., 189:113–118.
Khajuria, A. et al. (2002). Piperine modulates permeability characteristics of
intestine by inducing alterations in membrane dynamics: influence on brush
border membrane fluidity, ultrastructure & enzyme kinetics, Phytomedicine,
9:224–231
Kim, H. Y. et al. (1975). Effect of spices on salivary amylase. Iha Uihak Hoechi
(Korean), 7:78–82.
Koul, I. B., and Kapil, A. (1993). Evaluation of the liver protective potential of
piperine, an active principle of black and long peppers. Planta Med., 59:413–
417.
Krishnakantha, T. P., and Lokesh, B. R. (1993). Scavenging of superoxide anions
by spice principles, Indian J. Biochem. Biophys., 30:133–134.
Lambert, J. D. et al. (2004). Piperine enhances the bioavailability of the tea
polyphenol (-)-epigallocatechin-3-gallate in mice, J. Nutr., 134:1948–1952.
Lin, Z. et al. (1999). Stimulation of mouse melanocyte proliferation by Piper
nigrum fruit extract and its main alkaloid - piperine, Planta Med., 65:600–603.
Loder, J. W. et al. (1984). Tumor inhibitory plants: amides of pepper novaehol-
landiae, Aust. J. Chem., 22:1531–1538.
Malini, T. et al., (1999). Effects of piperine on testis of albino rats, J. Ethnophar-
macol., 64:219–225.
Mittal, R., and Gupta, R. L. (2000). In vitro antioxidant activity of piperine, Exp.
Clin. Pharmacol., 22:271–274.

Downloaded By: [Srinivasan, K.] At: 01:14 8 November 2007
748 K. SRINIVASAN
Mujumdar, A. M. et al. (1990). Anti-inflammatory activity of piperine. Jpn. J.
Med. Sci. Biol., 43:95–100.
Myers, B. M. et al. (1987). Effect of red pepper and black pepper on the stomach,
Am. J. Gastroenterol., 82:211–214.
Naidu, K. A., and Thippeswamy, N. B. (2002). Inhibition of human low density
lipoprotein oxidation by active principles from spices, Mol. Cell. Biochem.,
229:19–23.
Namiki, K. et al. (1984). Mutagen formation by nitrite-spice reactions, J. Agric.
Food Chem., 32:948–952.
Ononiwu, I. M. et al. (2002) Effects of piperine on gastric acid secretion in
albino rats, Afr. J. Med. Sci., 31:293–295.
Panda, S. and Kar, A. (2003). Piperine lowers the serum concentrations of thyroid
hormones, glucose and hepatic 5

D activity in adult male mice, Horm. Metab.
Res., 35:523–526.
Piyachaturawat, P. et al. (1983). Acute and subacute toxicity of piperine in mice,
rats and hamsters, Toxicol. Lett., 16:351–359.
Piyachaturawat, P. et al. (1991). Effects of piperine on hamster sperm capacita-
tion and fertilization in vitro, Int. J. Androl., 14:283–290.
Piyachaturawat, P. et al. (1995). Potentiation of carbon tetrachloride hepatotox-
icity by piperine, Drug Chem. Toxicol., 18:333–344.
Piyachaturawat, P., and Pholpramool, C. (1997). Enhancement of fertilization
by piperine in hamsters. Cell Biol. Int., 21:405–409.
Platel, K., and Srinivasan, K. (1996). Influence of dietary spices or their active
principles on digestive enzymes of small intestinal mucosa in rats, Int. J. Food
Sci. Nutr., 47:55–59.
Platel, K., and Srinivasan, K. (2000). Influence of dietary spices and their active
principles on pancreatic digestive enzymes in albino rats, Nahrung, 44:42–
46.
Platel, K., and Srinivasan, K. (2001). Studies on the influence of dietary spices
on food transit time in experimental rats, Nutr. Res., 21:1309–14.
Pradeep, C. R., and Kuttan, G. (2002). Effect of piperine on the inhibition of lung
metastasis induced B16F-10 melanoma cells in mice, Clin. Exp. Metastasis,
19:703–708.
Prasad, N. S. et al. (2004). Spice phenolics inhibit human PMNL 5-lipoxygenase,
Prostaglandins Leukot. Essent. Fatty Acids, 70:521–528.
Rauscher, F. M. et al. (2000). Effects of piperine on antioxidant pathways in
tissues from normal and streptozotocin-induced diabetic rats, J. Biochem.
Mol. Toxicol., 14:329–334.
Reanmongkol, W. et al. (1988). Effects of piperine on bioenergetic functions of
isolated rat liver mitochondria, Biochem. Pharmacol., 37: 753–757.
Reddy, A. C., and Lokesh, B. R. (1992). Studies on spice principles as antioxi-
dants in the inhibition of lipid peroxidation of rat liver microsomes, Mol. Cell.
Biochem., 111:117–124.
Reen, R. K., and Singh, J. (1991). In vitro and in vivo inhibition of pulmonary
cytochrome P450 activities by piperine, a major ingredient of piper species,
Indian J. Exp. Biol., 29:568–573.
Reen, R. K. et al. (1993). Impairment of UDP-glucose dehydrogenase and glu-
curonidation activities in liver and small intestine of rat and guinea pig in vitro
by piperine, Biochem. Pharmacol., 46:229–238.
Reen, R. K. et al. (1996). Piperine impairs cytochrome P4501A1 activity by di-
rect interaction with the enzyme and not by down regulation of CYP1A1 gene
expression in rat hepatoma 5L cell line, Biochem. Biophys. Res. Commun.,
218:562–569.
Reen, R. K. et al. (1997). Piperine inhibits aflatoxin B
1
-induced cytotoxicity and
genotoxicity in V79 Chinese hamster cells genetically engineered to express
rat cytochrome P4502B1, J. Ethnopharmacol., 58:165–73.
Selvendiran, K. et al. (2003). Cytoprotective effect of piperine against
benzo[a]pyrene induced lung cancer with reference to lipid peroxidation and
antioxidant system in Swiss albino mice, Fitoterapia, 74:109–115.
Selvendiran, K. et al. (2004). Modulatory effect of Piperine on mitochondrial
antioxidant system in benzo(α)pyrene-induced experimental lung carcino-
genesis, Phytomedicine, 11:85–89.
Selvendiran, K. et al. (2004a). Protective effect of piperine on benzo(α)pyrene-
induced lung carcinogenesis in Swiss albino mice, Clin. Chim. Acta, 350:73–
78.
Selvendiran, K., and Sakthisekaran, D. (2004). Chemopreventive effect of
piperine on modulating lipid peroxidation and membrane bound enzymes
in benzo(α)pyrene induced lung carcinogenesis, Biomed. Pharmacother.,
58:264–267.
Shoba, G. et al. (1998). Influence of piperine on the pharmacokinetics of cur-
cumin in animals and human volunteers, Planta Med., 64:353–356.
Singh, J. et al. (1986). Piperine-mediated inhibition of glucuronidation activity
in isolated epithelial cells of the guinea-pig small intestine: evidence that
piperine lowers the endogeneous UDP-glucuronic acid content. J. Pharmacol.
Exp. Ther., 236:488–493.
Singh, J. et al. (1994). Piperine, a major ingredient of black and long peppers,
protects against AFB1-induced cytotoxicity and micronuclei formation in
H4IIEC3 rat hepatoma cells, Cancer Lett., 86:195–200.
Singh, A., and Rao, A. R. (1993). Evaluation of the modulatory influence of
black pepper (Piper nigrum L.) on the hepatic detoxication system, Cancer
Lett., 72:5–9.
Srinivasan, K., and Sambaiah, K. (1991). Effect of spices on cholesterol-7α-
hydroxylase activity and on serum & hepatic cholesterol levels in the rat, Int.
J. Vitam. Nutr. Res., 61:364–369.
Srinivasan, M. R., and Satyanarayana, M. N. (1981). Effect of black pepper
(Piper nigrum Linn.) and piperine on growth, blood constituents and organ
weights in rats, Nutr. Rep. Int., 23:871–876.
Sunila, E. S., and Kuttan, G. (2004). Immunomodulatory and antitumor ac-
tivity of Piper longum Linn. and piperine, J. Ethnopharmacol., 90:339–
346.
Unnikrishnan, M.C., and Kuttan, R. (1990). Tumour reducing and anticarcino-
genic activity of selected spices, Cancer Lett., 51:85–89.
Vasudevan, K. et al. (2000). Influence of intra-gastric perfusion of aqueous spice
extracts on acid secretion in anesthetized albino rats, Indian J. Gastroenterol.,
19:53–56.
Vazquez-Olivencia, W. et al. (1992). The effect of red and black pepper on
orocecal transit time. J. Am. Coll. Nutr., 11:228–231.
Velpandian, T. et al. (2001). Piperine in food: interference in the pharmacoki-
netics of phenytoin, Eur. J. Drug Metab. Pharmacokinet., 26:241–247.
Vijayakumar, R. S. et al. (2004). Antioxidant efficacy of black pepper (Piper
nigrum L.) and piperine in rats with high fat diet induced oxidative stress,
Redox Rep., 9:105–110.