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In Vitro Investigation of the Potential Immunomodulatory and Anti-Cancer Activities of Black Pepper ( Piper nigrum ) and Cardamom ( Elettaria cardamomum )

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In Vitro Investigation of the Potential Immunomodulatory and Anti-Cancer Activities of Black Pepper ( Piper nigrum ) and Cardamom ( Elettaria cardamomum )

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Although the immunomodulatory effects of many herbs have been extensively studied, research related to possible immunomodulatory effects of various spices is relatively scarce. Here, the potential immunomodulatory effects of black pepper and cardamom are investigated. Our data show that black pepper and cardamom aqueous extracts significantly enhance splenocyte proliferation in a dose-dependent, synergistic fashion. Enzyme-linked immunosorbent assay experiments reveal that black pepper and cardamom significantly enhance and suppress, respectively, T helper (Th)1 cytokine release by splenocytes. Conversely, Th2 cytokine release by splenocytes is significantly suppressed and enhanced by black pepper and cardamom, respectively. Experimental evidence suggests that black pepper and cardamom extracts exert pro-inflammatory and anti-inflammatory roles, respectively. Consistently, nitric oxide production by macrophages is significantly augmented and reduced by black pepper and cardamom, respectively. Remarkably, it is evident that black pepper and cardamom extracts significantly enhance the cytotoxic activity of natural killer cells, indicating their potential anti-cancer effects. Our findings strongly suggest that black pepper and cardamom exert immunomodulatory roles and antitumor activities, and hence they manifest themselves as natural agents that can promote the maintenance of a healthy immune system. We anticipate that black pepper and cardamom constituents can be used as potential therapeutic tools to regulate inflammatory responses and prevent/attenuate carcinogenesis.
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In Vitro Investigation of the Potential Immunomodulatory and Anti-Cancer Activities
of Black Pepper (Piper nigrum) and Cardamom (Elettaria cardamomum)
Amin F. Majdalawieh
1
and Ronald I. Carr
2,
*
1
Department of Biology and Chemistry, Faculty of Arts and Sciences, American University of Sharjah, Sharjah,
United Arab Emirates; and
2
Department of Microbiology and Immunology, Faculty of Medicine,
Dalhousie University, Halifax, Nova Scotia, Canada
ABSTRACT Although the immunomodulatory effects of many herbs have been extensively studied, research related to
possible immunomodulatory effects of various spices is relatively scarce. Here, the potential immunomodulatory effects of
black pepper and cardamom are investigated. Our data show that black pepper and cardamom aqueous extracts significantly
enhance splenocyte proliferation in a dose-dependent, synergistic fashion. Enzyme-linked immunosorbent assay experiments
reveal that black pepper and cardamom significantly enhance and suppress, respectively, T helper (Th)1 cytokine release by
splenocytes. Conversely, Th2 cytokine release by splenocytes is significantly suppressed and enhanced by black pepper and
cardamom, respectively. Experimental evidence suggests that black pepper and cardamom extracts exert pro-inflammatory
and anti-inflammatory roles, respectively. Consistently, nitric oxide production by macrophages is significantly augmented
and reduced by black pepper and cardamom, respectively. Remarkably, it is evident that black pepper and cardamom extracts
significantly enhance the cytotoxic activity of natural killer cells, indicating their potential anti-cancer effects. Our findings
strongly suggest that black pepper and cardamom exert immunomodulatory roles and antitumor activities, and hence they
manifest themselves as natural agents that can promote the maintenance of a healthy immune system. We anticipate that black
pepper and cardamom constituents can be used as potential therapeutic tools to regulate inflammatory responses and
prevent=attenuate carcinogenesis.
KEY WORDS: anti-cancer activity black pepper cardamom immunomodulation inflammation
INTRODUCTION
Strong religious and mystical beliefs have been asso-
ciated with the healing properties of many natural
products.
1
The health-promoting properties of many herbs
and spices are numerous and well recognized.
2,3
There is no
doubt that a healthy, functional immune system is highly
correlated with a well-balanced nutritional intake.
4,5
Im-
munonutrition has emerged as a new concept describing
different diets containing certain nutrients, including argi-
nine, glutamine, fish oil, and nucleotides, that have profound
effects on the immune system.
4,5
Immunomodulation is an
induced modification of immune responses by means of in-
troducing natural or synthetic chemical substances that
possess the ability to regulate the immune system.
6–8
Im-
munomodulation is considered to be an invaluable tool for
preventing and treating various infectious and noninfectious
diseases.
6–8
A wide range of natural products isolated from herbs and
spices have been shown to possess immunomodulatory ef-
fects that can be very beneficial in fighting many diseases.
9–12
The great potential that some spices possess in terms of
preventing and treating various diseases, including cancer,
cannot be underestimated.
13–15
However, relatively little is
known about the potential immunomodulatory and anti-
cancer effects of a wide range of commonly used spices, and
the molecular mechanisms underlying such effects are either
poorly understood or largely unidentified. In this study, we
focus on investigating the potential immunomodulatory and
anti-cancer effects of black pepper (Piper nigrum) and
cardamom (Elettaria cardamomum). We also attempt to
shed light on the possible molecular mechanisms by which
black pepper and cardamom extracts exert their immuno-
modulatory and anti-cancer effects.
Many studies have previously demonstrated that black
pepper, its extracts, and its major constituents have diverse
physiological effects in the gastrointestinal tract, kidney,
and liver.
16
Black pepper extracts have also been shown to
exert antimicrobial activities.
17–19
Moreover, some studies
have demonstrated that black pepper extracts and its major
constituents possess anti-cancer properties in vitro and
in vivo.
20–24
Indeed, the ability of black pepper to alter the
Manuscript received 7 May 2009. Revision accepted 26 November 2009.
Address correspondence to: Dr. Amin F. Majdalawieh, Department of Biology and
Chemistry, Faculty of Arts and Sciences, American University of Sharjah, P.O. Box
26666, Sharjah, United Arab Emirates, E-mail: amajdalawieh@aus.edu
*Deceased.
JOURNAL OF MEDICINAL FOOD
J Med Food 13 (2) 2010, 371–381
#Mary Ann Liebert, Inc. and Korean Society of Food Science and Nutrition
DOI: 10.1089=jmf.2009.1131
371
metabolic activity of various enzymes has been proposed as
the mechanism of action by which black pepper inhibits
carcinogenesis.
22,23,25,26
Cardamom was shown to play a wide range of health-
promoting roles against various conditions such as con-
stipation, colic, diarrhea, dyspepsia, vomiting, headache,
epilepsy, and cardiovascular diseases.
27,28
Recently, carda-
mom was reported to exhibit spasmogenic, spasmolytic,
blood pressure-lowering, vasodilator, diuretic, and sedative
activities.
29
Antimicrobial properties of cardamom extracts
have been documented.
30–33
Experimental evidence suggests
that cardamom extracts display anti-cancer activities.
26,34–37
Enzymatic modulation potential
26,34–37
and anti-inflammatory,
antiproliferative, and pro-apoptotic activities
36
have been
proposed as mechanisms underlying the anti-cancer prop-
erties of cardamom.
Our findings suggest that black pepper and cardamom
are potential immunomodulators of splenocyte proliferation
and Th1=Th2 cytokine profiles. Furthermore, our findings
also suggest that the aqueous extracts of black pepper and
cardamom exert pro-inflammatory and anti-inflammatory
roles, respectively. Finally, our study also suggests that the
previously identified anti-cancer activities of black pepper
and cardamom extracts may be mediated via the profound
potential of such extracts to provoke the cytotoxic activity of
natural killer (NK) cells. Hence, our study provides com-
pelling evidence suggesting that black pepper and cardamom
extracts may serve as potential immunoregulators of inflam-
matory responses, Th1=Th2 immune responses, and carci-
nogenesis. We anticipate that black pepper and cardamom
constituents may serve as natural therapeutic agents to pre-
vent=treat diverse inflammatory conditions and various types
of cancer.
MATERIALS AND METHODS
Mice
Age-matched BALB=c and C57=BL6 mice (6–8 weeks
old) were purchased from Jackson Laboratories (Bar Har-
bor, ME, USA) and were kept on a 12-hour light=dark cycle
in the Carleton Animal Care Facility at Dalhousie Uni-
versity, Halifax, NS, Canada. Mice were fed chow diet and
were sacrificed by cervical dislocation for splenocyte or
macrophage isolation.
Preparation of aqueous extracts of the spices studied
Whole-seed black pepper and cardamom were washed,
dried, and ground in liquid nitrogen. After complete evap-
oration of liquid nitrogen, 10 mL of double distilled H
2
O
was added to the 20 g of ground spice and stirred overnight
with magnet stirrer to allow extraction. The crude spice
extracts were centrifuged at 10,000 gfor 15 minutes at room
temperature. Subsequently, the supernatants were harvested
and subjected to rotatory evaporation. After complete
evaporation, a stock concentration of 20 mg=mL of each
extract was prepared, and the extracts were sterilized by
filtration using Nalgene filters (Thermo Fisher Scientific,
Rochester, NY, USA) (pore size, 0.22 mm).
Reagents and materials
Thioglycollate broth medium was purchased from DIFCO
(Detroit, MI, USA). Lipopolysaccharide (LPS) isolated from
Escherichia coli O55:B5 and concanavalin A (ConA) were
purchasedfrom Sigma-Aldrich (St. Louis, MO, USA). RPMI-
1640 medium, fetal bovine serum, penicillin-streptomycin,
and l-glutamine were purchased from Invitrogen (Burlington,
ON, Canada). Interferon-g(IFNg) was purchased from Pepro
Tech (Rocky Hill, NJ, USA). BD OptEIA
TM
enzyme-linked
immunosorbent assay (ELISA) kits were purchased from
BD Pharmingen (Mississauga, ON, Canada). [
3
H]Thymidine
was purchased from Amersham Biosciences (Little Chalfont,
UK). YAC-1 tumor cells (mouse lymphoma cells) were
purchased from the American Type Culture Collection
(Rockville, MD, USA).
Isolation of splenocytes
Splenocyte isolation was performed as previously de-
scribed.
38
In brief, spleens were isolated from BALB=cmice,
cut into several pieces, and gently crushed. Clumps were
further dispersed by passing the suspension through a 19-
gauge needle. Subsequently, cell suspension was filtered
through a 200-mm mesh nylon screen, and cells were collected
by centrifugation. Erythrocytes were lysed using ACK lysis
buffer (0.15 MNH
4
Cl, 1 mMKHCO
3
,and0.1mMdisodium
EDTA), and splenocytes were finally washed and resus-
pended in RPMI-1640 medium supplemented with 10% heat-
inactivated fetal bovine serum, 1% penicillin-streptomycin,
10 mMHEPES, and 50 mMb-mercaptoethanol. By trypan
blue exclusion, cell counting revealed >98% viability.
Peritoneal macrophage isolation and culture
Thioglycollate-elicited peritoneal macrophages were
isolated from BALB=c mice as previously described.
39
In
brief, mice were injected intraperitoneally with 3 mL of
sterile 3% Brewer’s thioglycollate broth solution (Sigma-
Aldrich). Five days later, mice were sacrificed by cervical
dislocation, and peritoneal exudate cells were isolated by
peritoneal lavage. Peritoneal exudate cells were obtained
by centrifugation and resuspended in ACK lysis buffer for
erythrocyte lysis. Subsequently, cells were centrifuged, re-
suspended, and cultured in RPMI-1640 medium supple-
mented with 10% heat-inactivated fetal bovine serum,
1% penicillin-streptomycin, 10 mMHEPES, and 50 mMb-
mercaptoethanol. By trypan blue exclusion, cell counting
revealed >98% viability.
In vitro splenocyte proliferation assay
Splenocyte proliferation was assayed as previously de-
scribed.
40
In brief, 210
5
splenocytes were cultured for
48 and 72 hours in medium supplemented with vehicle,
10 ng=mL LPS, 1 mg=mL ConA, and aqueous extracts of
black pepper and cardamom. Subsequently, cultured sple-
372 MAJDALAWIEH AND CARR
nocytes were pulsed with [
3
H]thymidine (1 mCi per well) for
16 hours before cell harvest. Cells were harvested using a
semiautomated multiwell harvester, and cell lysates were
transferred onto fiberglass filter paper (Skatron Instruments,
Lier, Norway). The dried filter paper was subsequently
transferred to a vial containing 1.5 mL of scintillation fluid
(Beckman, Fullerton, CA, USA). Incorporation of [
3
H]thy-
midine was determined using the 1211 Rackbeta scintilla-
tion counter (LKB Wallac, Turku, Finland).
Measurement of nitric oxide (NO) production
by macrophages (Griess assay)
NO production by macrophages was assessed by the
colorimetric Griess reaction as previously described.
41
In
brief, 210
5
macrophages were cultured in medium sup-
plemented with vehicle, 10 ng=mL LPS, 2 U=mL IFNg,a
combination of LPS and IFNg, or aqueous extracts of black
pepper and cardamom in the presence or absence of IFNg
and=or LPS for 48 hours. Subsequently, 100 mL of super-
natant and serial dilutions of NaNO
2
standard solution were
placed in 96-well microtiter plates and then mixed with
Griess reagent containing 1% sulfanilamide, 0.1% naph-
thylethylenediamide dihydrochloride, and 2.5% H
3
PO
4
. The
optical density was measured at 550 nm using an Emax
Ò
precision microplate reader (Molecular Devices, Sunnyvale,
CA, USA), and the amount of accumulated nitrite in the
samples was quantified according to the standard curve.
NK activity assessment by JAM assay
The cytotoxic activity of NK cells was assessed by JAM
assay as previously described.
42
In brief, YAC-1 tumor cells
were cultured for 4 hours in medium containing 5 mCi=mL
[
3
H]thymidine for labeling. Subsequently, labeled YAC-1
tumor cells were cultured in 96-well V-bottom culture plates
in the presence or absence of splenocytes (containing NK
cells) isolated from C57=BL6 mice at effector:target ratios
(E:T ratios) of 200:1, 100:1, and 50:1. YAC-1 tumor cells
cultured in the presence or absence of splenocytes were
treated with vehicle or aqueous extracts of black pepper and
cardamom. At 4 hours post-incubation, YAC-1 tumor cells
were harvested using a semiautomated multiwell harvester,
and radioactivity was measured using the 1211 Rackbeta
scintillation counter (LKB Wallac). Percentage cytotoxicity
was determined as follows: % cytotoxicity ¼([vehicle-treated
YAC-1 tumor cells targeted-YAC-1 tumor cells]=vehicle-
treated YAC-1 tumor cells)100.
Assessment of cytokine secretion by ELISA
For assessment of interleukin (IL)-4, IL-10, and IFNg
release, 210
5
splenocytes were treated with vehicle,
10 ng=mL LPS, 1 mg=mL ConA, and aqueous extracts of
black pepper and cardamom in the presence or absence of
1mg=mL ConA for 48 hours. For assessment of IL-6 and
tumor necrosis factor-a(TNFa) release, 210
5
macro-
phages were treated with vehicle, 10 ng=mL LPS, 2 U=mL
IFNg, a combination of LPS and IFNg, and aqueous extracts
of black pepper and in the presence and absence of LPS plus
IFNgfor 48 hours and 12 hours (IL-6 and TNFa, respec-
tively). Subsequently, supernatants were harvested, and
cytokine concentration was determined using BD OptEIA
ELISA kits and the Emax precision microplate reader.
Statistical analysis
Data are mean SEM values of the indicated number of
experiments. Statistical significance was determined using
Student’s ttest for unpaired observations; *P<.05, **P<
.01, and ***P<.001 were considered statistically significant.
RESULTS
Assessment of splenocyte proliferation in the presence
of aqueous extracts of black pepper and cardamom
We hypothesized that aqueous extracts of black pepper and
cardamom can potentially enhance splenocyte proliferation. To
test this hypothesis, BALB=c splenocytes were cultured in
medium supplemented with vehicle, ConA (T lymphocyte
mitogen), LPS (B lymphocyte mitogen), or aqueous extracts of
black pepper or cardamom at four doses (1, 10, 50, and
100 mg=mL) for 48 and 72 hours. Subsequently, cultured
splenocytes were subjected to an in vitro proliferation assay
using [
3
H]thymidine incorporation to assess the potential
modulatory effects of the aqueous extracts on splenocyte pro-
liferation. As shown in Figure 1A and B, the proliferation of
splenocytes was enhanced in a dose-dependent manner in the
presence of aqueous extracts of black pepper and cardamom at
72 hours. Notably, all doses (except 1 mg=mL)ofblackpepper
aqueous extract led to significant enhancement of splenocyte
proliferation, but significant enhancement by of splenocyte
proliferation by cardamom was only observed at 100 mg=mL.
Noteworthy is that significant enhancement of splenocyte
proliferation at 48 hours was only observed with black pepper
aqueous extract at 50 and 100 mg=mL (data not shown).
Synergistic stimulatory effect of aqueous
extracts of black pepper and cardamom
on splenocyte proliferation
To determine whether the aqueous extracts of black
pepper and cardamom have any synergistic effect on sple-
nocyte proliferation, BALB=c splenocytes were cultured in
medium supplemented with 100 mg=mL aqueous extract of
black pepper, cardamom, or a combination of both. Vehicle,
LPS, and ConA were used as experimental controls. At 72
hours post-incubation, cultured splenocytes were subjected
to the in vitro splenocyte proliferation assay. As shown in
Figure 1C, splenocyte proliferation was significantly greater
in the presence of aqueous extracts of both black pepper and
cardamom in combination compared to the effect of each
extract separately. Indeed, the enhancement of splenocyte
proliferation in the presence of the aqueous extracts of both
black pepper and cardamom in combination is comparable
to that caused by LPS (P¼.23). A significant synergistic
effect of the aqueous extracts of black pepper and cardamom
on splenocyte proliferation was also observed at lower doses
IMMUNOMODULATION BY BLACK PEPPER AND CARDAMOM 373
(1, 10, and 50 mg=mL) of the extracts (data not shown), in
which the stimulatory action of one extract is enhanced and
magnified in the presence of the other extract. Notably, the
aqueous extract of cardamom displayed a significantly
greater potential to enhance splenocyte proliferation com-
pared to the aqueous extract of black pepper (P¼.004) (Fig.
1C). Together, these data suggest that not only do aqueous
extracts of black pepper and cardamom significantly en-
hance the proliferation of splenocytes, but they also interact
cooperatively to further augment splenocyte proliferation.
Polymyxin B (PB), which is known to potentially inacti-
vate LPS, was used to determine whether the aqueous extracts
of black pepper and cardamom were LPS-contaminated. To
this end, BALB=c splenocytes were cultured in medium
supplemented with aqueous extracts of black pepper and
cardamom at 100 mg=mL in the presence or absence of
1mg=mL PB and subsequently subjected to the in vitro
splenocyte proliferation assay. Clearly, PB significantly re-
duced the ability of LPS to promote splenocyte proliferation,
whereas the ability of aqueous extracts of black pepper or
cardamom to enhance splenocyte proliferation was not altered
in presence of PB (Fig. 1D). Collectively, these results clearly
rule out the possibility that the aqueous extracts of black
pepper and cardamom enhance splenocyte proliferation
because of possible LPS contamination.
Aqueous extracts of black pepper and cardamom
modulate cytokine release by splenocytes
and macrophages
To further evaluate the immunomodulatory effects of the
aqueous extracts of black pepper and cardamom, the pro-
duction of IL-4, IL-10, and IFNgby lymphocytes and the
production of IL-6 and TNFaby macrophages were assessed.
To assess IL-4, IL-10, and IFNgsecretion, BALB=cspleno-
cytes were cultured in medium supplemented with vehicle,
LPS, ConA, and aqueous extracts of black pepper and car-
damom (1, 10, 50, and 100 mg=mL) in the presence or absence
of ConA. As shown in Figure 2A and C, the aqueous extract of
black pepper had no significant effect on IL-4 and IL-10 re-
lease by splenocytes at any of the doses compared to vehicle-
treated splenocytes. However, dose-dependent inhibition of
IL-4 and IL-10 release was observed when splenocytes were
treated with the aqueous extract of black pepper in the pres-
ence of ConA (Fig. 2A and C). With regard to cardamom,
IL-4 and IL-10 release was significantly enhanced when
splenocytes were treated with 50 and 100 mg=mL aqueous
extract of cardamom compared to vehicle-treated splenocytes
(Fig. 2B and D). Likewise, a dose-dependent increase in IL-4
and IL-10 release was observed when splenocytes were
treated with aqueous extract of cardamom in the presence of
ConA compared to ConA-treated splenocytes (Fig. 2B and D).
Noticeably, treatment of splenocytes with the aqueous extract
of black pepper was accompanied by a dose-dependent increase
in IFNgrelease in the presence and absence of ConA compared
to ConA-treated and vehicle-treated splenocytes, respectively
(Fig. 2E). As shown in Figure 2F, the aqueous extract of car-
damom had no significant effect on IFNgrelease by splenocytes
at any of the doses compared to vehicle-treated splenocytes.
However, dose-dependent inhibition of IFNgrelease was ob-
served when splenocytes were treated with the aqueous extract
of cardamom in the presence of ConA (Fig. 2F).
To assess IL-6 and TNFasecretion, BALB=c macro-
phages were cultured in medium supplemented with vehicle,
FIG. 1. Dose-responsive effect of aqueous
extracts of (A) black pepper and (B) carda-
mom on splenocyte proliferation 72 hours
post-treatment. The aqueous extracts of black
pepper and cardamom were used at 1, 10, 50,
and 100 mg=mL. Statistical significance was
determined in comparison to vehicle-treated
splenocytes. (C) Assessment of the synergis-
tic effect of aqueous extracts of black pepper
and cardamom on splenocyte proliferation
72 hours post-treatment. The aqueous extracts
of black pepper and cardamom were used at
100 mg=mL. Statistical significance was de-
termined in comparison to vehicle-treated
splenocytes. (D) Evaluation of the modulatory
effects of aqueous extracts of black pepper
and cardamom on splenocyte proliferation in
the presence of PB 72 hours post-treatment.
For each sample where PB was used, statis-
tical significance was determined in compar-
ison to the relative sample where splenocytes
were left PB-untreated. Count per minutes
(CPM) data are expressed as mean SEM
values. **P<.01, ***P<.001.
374 MAJDALAWIEH AND CARR
LPS, IFNg, combination of LPS and IFNg, and aqueous
extracts of black pepper and cardamom (1, 10, 50, and
100 mg=mL) in the presence or absence of LPS plus IFNg.At
48 and 12 hours post-incubation, supernatants were har-
vested and subjected to ELISA to measure the concentration
of IL-6 and TNFa, respectively. As shown in Figure 3A and
C, IL-6 and TNFarelease by macrophages was significantly
enhanced by the aqueous extract of black pepper in the
presence and absence of LPS and IFNgcompared to mac-
rophages treated with LPS and IFNgand vehicle-treated
macrophages, respectively. Clearly, the aqueous extract of
cardamom alone had no significant effect on IL-6 and TNFa
release by macrophages at any of the doses (Fig. 3B and D).
However, dose-dependent inhibition of IL-6 and TNFare-
lease was observed when macrophages were treated with the
aqueous extract of cardamom in the presence of LPS and
IFNg(Fig. 3B and D). Collectively, these findings suggest
that black pepper and cardamom possess immunomodula-
tory functions with regard to cytokine release profile in
splenocytes and macrophages.
Assessment of NO production by macrophages
in the presence of aqueous extracts of black
pepper and cardamom
To assess the potential ability of aqueous extracts of black
pepper and cardamom to modulate NO production by
macrophages, BALB=c macrophages were cultured in
FIG. 2. Effect of aqueous extracts of (A,C,E)
black pepper and (B,D,F) cardamom on the secretion
of (A,B) IL-4, (C,D) IL-10, and (E,F) IFNgby
splenocytes. The aqueous extracts of black pepper and
cardamom were used at 1, 10, 50, and 100 mg=mL. For
splenocytes that were treated with the aqueous extracts
in the absence of ConA, statistical significance was
determined in comparison to vehicle-treated spleno-
cytes. For splenocytes that were treated with the
aqueous extracts in the presence of ConA, statistical
significance was determined in comparison to ConA-
treated splenocytes. Data are mean SEM values.
*P<.05, **P<.01, ***P<.001.
IMMUNOMODULATION BY BLACK PEPPER AND CARDAMOM 375
medium supplemented with vehicle, IFNg, LPS, or aqueous
extracts of black pepper or cardamom at four different doses
(1, 10, 50, and 100 mg=mL) in the presence or absence of
IFNg. Subsequently, cultured macrophages were subjected
to Griess assay to measure NaNO
2
production. As shown in
Figure 4, LPS, IFNg, and a combination of both caused
macrophages to produce about 9, 40, and 99 mMNaNO
2
,
respectively, compared to 6 mMNaNO
2
in vehicle-treated
peritoneal macrophages. Whereas the aqueous extract of
cardamom had no significant effect on NO production by
macrophages at any of the doses under unstimulatory con-
ditions (Fig. 4B), the aqueous extract of black pepper at
100 mg=mL significantly enhanced NO production by mac-
rophages compared to vehicle-treated macrophages under
unstimulatory conditions (Fig. 4A). In the presence of IFNg,
the aqueous extract of black pepper significantly enhanced
NO production by macrophages at 50 and 100 mg=mL com-
pared to IFNg-treated macrophages (Fig. 4A). Likewise,
treatment of macrophages with 50 or 100 mg=mL black
pepper extract in the presence of LPS and IFNgled to a
significant increase in NO production compared to macro-
phages treated with LPS and IFNg(Fig. 4A). These findings
suggest that the aqueous extract of black pepper mimics the
LPS potential to prime macrophages. Interestingly, however,
the aqueous extract of cardamom significantly suppressed
NO production at 50 and 100 mg=mL doses in the presence of
IFN compared to IFNg-treated macrophages (approximately
twofold suppression) (Fig. 4B). In the presence of both LPS
and IFNg, however, 100 mg=mL cardamom extract was the
only dose capable of causing significant suppression of NO
production by macrophages (Fig. 4B).
The aqueous extract of cardamom is capable of potently
suppressing NO production by IFNg-treated macrophages as
well as IFNg- and LPS-treated macrophages even in presence
of the aqueous extract of black pepper (Fig. 4C). Indeed, the
combined effect of the aqueous extracts of black pepper and
cardamom on NO production is very comparable to the effect
of the aqueous extract of cardamom alone in unstimulated,
IFNg-treated, and IFNg- and LPS-treated macrophages
(P¼.22, P¼.35, and P¼.96, respectively) (Fig. 4C). This
observation indicates that cardamom is a much more potent
modulator of NO production than black pepper.
Evaluation of the cytotoxic activity of NK cells
in the presence of aqueous extracts of black
pepper and cardamom
To further assess the immunostimulatory effects of black
pepper and cardamom, the cytotoxic activity of NK cells
against YAC-1 tumor cells was evaluated in the presence of
FIG. 3. Effect of aqueous extracts of (A,C)
black pepper and (B,D) cardamom on the
secretion of (A,B) IL-6 and (C,D) TNFa
by peritoneal macrophages. The aqueous ex-
tracts of black pepper and cardamom were
used at 1, 10, 50, and 100 mg=mL. For mac-
rophages that were treated with the aqueous
extracts in the absence of LPS and IFNg,
statistical significance was determined in
comparison to vehicle-treated macrophages.
For macrophages that were treated with the
aqueous extracts in the presence of LPS and
IFNg, statistical significance was determined
in comparison to LPS- and IFNg-treated
macrophages. Data are mean SEM values.
*P<.05, **P<.01, ***P<.001.
376 MAJDALAWIEH AND CARR
aqueous extracts of black pepper and cardamom. YAC-1
tumor cells were cultured in medium supplemented with
vehicle, 100 mg=mL aqueous extract of black pepper or
cardamom, and effector cells (NK cells) at E:T ratios of
200:1, 100:1, and 50:1. In addition, YAC-1 tumor cells were
treated with 1, 10, 50, and 100 mg=mL aqueous extracts of
black pepper and cardamom in the presence of effector cells
at the 200:1 E:T ratio. As shown in Figure 5A, the aqueous
extract of black pepper significantly enhances the cytotoxic
activity of NK cells at 50 and 100 mg=mL doses. With regard
to cardamom, significant dose-dependent stimulation of the
cytotoxic activity of NK cells is observed at all doses (1, 10,
50, and 100 mg=mL) (Fig. 5B). Importantly, the aqueous
extracts of black pepper and cardamom possess no direct
cytotoxic activity against YAC-1 tumor cells (Fig. 5A and
B). As expected, the enhanced cytotoxic activity of NK cells
against YAC-1 tumor cells by aqueous extracts of black
pepper and cardamom is proportional to the E:T ratio (data
not shown). Interestingly, the aqueous extracts of black
pepper and cardamom display synergistic stimulatory effect
on the cytotoxic activity of NK cells against YAC-1 tumor
cells (Fig. 5C), in which NK cytotoxic activity is much
greater in the presence of both extracts compared to the
separate action of each extract. Notably, the aqueous extract
of cardamom displays a more potent stimulatory effect on
the cytotoxic activity of NK cells compared to that of black
pepper (Fig. 5C), but this differential ability to enhance
the cytotoxic activity of NK cells did not reach statistical
significance (P¼.13). Taken together, these data strongly
suggest that black pepper and cardamom have the potential
to markedly enhance the anti-cancer activity of NK cells.
DISCUSSION
A search for new drugs designed for promoting optimal
immune function is the main focus of many researchers
worldwide, and natural products used in traditional medi-
cines have been the source of many medically beneficial
drugs.
43,44
In search of such natural products, we investi-
gated the potential immunomodulatory functions of black
pepper and cardamom. In this study, we provide experimen-
tal evidence demonstrating that aqueous extracts of black
pepper and cardamom are potentially capable of modu-
lating the function of various immune cells. Indeed, the
proliferation of splenocytes is significantly enhanced in the
presence of aqueous extracts of black pepper and carda-
mom in a dose-dependent (Fig. 1A and B) and cooperative
(Fig. 1C) fashion. This suggests that the aqueous extracts
of black pepper and cardamom contain constituents that
are capable of promoting the proliferative signaling path-
ways in splenocytes. Consistently, piperine, an active al-
kaloid component of black pepper, was shown to enhance
murine splenocyte proliferation.
45
Similarly, eugenol, an
active component of cardamom, has been reported to
significantly enhance cell-mediated lymphocyte prolifera-
tion in vitro.
46
FIG. 4. Dose-responsive effect of aqueous
extracts of (A) black pepper and (B) cardamom
on NO production by macrophages. The aque-
ous extracts of black pepper and cardamom
were used at 1, 10, 50, and 100 mg=mL. (C)
Assessment of the synergistic effect of aqueous
extracts of black pepper and cardamom on NO
production by macrophages. The aqueous ex-
tracts of black pepper and cardamom were used
at 100 mg=mL. For macrophages that were
treated with the aqueous extracts in the absence
of LPS and IFNg, statistical significance was
determined in comparison to vehicle-treated
macrophages. For macrophages that were trea-
ted with the aqueous extracts in the presence of
IFNg, statistical significance was determined in
comparison to IFNg-treated macrophages. For
macrophages that were treated with the aqueous
extracts in the presence of LPS and IFNg, sta-
tistical significance was determined in compar-
ison to LPS- and IFNg-treated macrophages.
Data are mean SEM values. *P<.05, **P<
.01, ***P<.001.
IMMUNOMODULATION BY BLACK PEPPER AND CARDAMOM 377
The immunomodulatory effects of spices on the release of
major cytokines by splenocytes and macrophages have not
been widely investigated. In our in vitro studies using pri-
mary splenocytes, the release of the Th2 cytokines IL-4 and
IL-10 has been shown to be suppressed by black pepper
extract and enhanced by cardamom extract (Fig. 2). Con-
versely, the release of the Th1 cytokine IFNghas been
shown to be enhanced and suppressed by aqueous extracts of
black pepper and cardamom, respectively (Fig. 2). Con-
sistently, piperine was shown to induce the secretion of Th1
cytokines IL-2 and IFNgfrom splenocytes
45
while inhibit-
ing Th2 cytokine secretion.
47
Moreover, and in agreement
with our findings suggesting that the cardamom extract in-
hibits Th1 cytokine secretion and enhances Th2 cytokine
secretion in splenocytes, eugenol was shown to be a potent
inhibitor of the major Th1 cytokine IL-2.
48
Because Th2
cells are responsible for type-I hypersensitivity responses
(i.e., allergic reactions), it is conceivable that the aqueous
extract of cardamom, but not black pepper, may have the
potential to induce type-I hypersensitivity reactions, devel-
opment of Th2 cells, and establishment of Th2 immune
responses. Interestingly, two studies have suggested that
cardamom powder may be associated with contact and
systemic contact-type dermatitis.
49–51
It is evident that the release of the pro-inflammatory cy-
tokines IL-6 and TNFaby macrophages is enhanced by the
aqueous extract of black pepper (Fig. 3), indicating that black
pepper promotes macrophage pro-inflammatory responsive-
ness. It is noteworthy that our data clearly indicate that the
aqueous extract of black pepper significantly enhances NO
production by macrophages only in the presence of IFNg
(Fig. 4A). This suggests that black pepper extract con-
tains constituents that mimic the ability of LPS to prime
macrophages for enhanced NO production. Conversely, the
aqueous extract of cardamom impedes macrophage pro-
inflammatory responsiveness, as reflected by the suppressive
effects of the cardamom extract on IL-6, TNFa, and NO
release by macrophages (Fig. 3). In agreement with these
results, it was proposed that eugenol leads to inhibited se-
cretion of the proinflammatory mediators IL-1band IL-6,
52
inhibitory NO synthase and NO,
53,54
and cyclooxygenase-
2.
55
Interestingly, oral administration of the aqueous extract
of cardamom is accompanied by a significant reduction in
cyclooxygenase-2 and inhibitory NO synthase expression in
murine models of colon cancer.
36
Moreover, cardamom was
shown to have anti-inflammatory activity against acute
carrageenan-induced plantar edema in albino rats.
56
Taken
together, the aqueous extract of black pepper exhibits pro-
inflammatory activities, whereas the aqueous extract of car-
damom exhibits anti-inflammatory activities in macrophages.
Our study also provides experimental evidence suggest-
ing that the aqueous extracts of black pepper and cardamom
enhance the cytotoxic activity of NK cells (Fig. 5A and B).
Interestingly, the aqueous extracts of black pepper and
cardamom cooperate to robustly augment the cytotoxic ac-
tivity of NK cells to reach about 67% cytotoxicity (Fig. 5C).
It is important to mention that neither the aqueous extract of
black pepper nor that of cardamom had any direct cytotoxic
effect against YAC-1 tumor cells (Fig. 5). These data
strongly suggest that black pepper and cardamom possess
immunostimulatory effects towards NK cytotoxic activity.
Our findings regarding the anticarcinogenic effects of the
black pepper and cardamom extracts are in agreement with
other in vitro and in vivo studies. In one study, oral ad-
FIG. 5. Dose-responsive effect of aqueous
extracts of (A) black pepper and (B) cardamom
on the cytotoxic activity against YAC-1 lym-
phoma cells. The aqueous extracts of black
pepper and cardamom were used at 1, 10, 50, and
100 mg=mL, unless indicated otherwise. An E:T
ratio of 200:1 was used. (C) Assessment of the
synergistic effect of aqueous extracts of black
pepper and cardamom on the cytotoxic activity
against YAC-1 lymphoma cells. The aqueous
extracts of black pepper and cardamom were
used at 100 mg=mL. For samples where cyto-
toxicity was assessed in the presence of the
aqueous extracts at an E:T ratio of 200:1, sta-
tistical significance was determined in compari-
son to vehicle-treated cells at an E:T ratio of
200:1. Data are mean SEM values. *P<.05,
**P<.01, ***P<.001.
378 MAJDALAWIEH AND CARR
ministration of black pepper extract significantly improved
(by *65%) the life span of mice with Ehrlich ascites tu-
mors.
20
In other studies, histopathological analyses have
revealed that the rate of inflammatory cell infiltration into
the submucosa, the incidence of papillae, and changes in
the cytoplasm were decreased when rats with experimen-
tally induced colon carcinogenesis were fed black pep-
per extract.
21,23
A recent study has shown that piperine
has antiproliferative effects on human colon cancer cells.
24
Additionally, piperine was demonstrated to have antitumor
activity in vivo.
57–62
As for the proposed anticarcinogenic
effects of cardamom, several studies have demonstrated that
eugenol inhibits tumor formation in vivo.
63–66
Consistent
with our findings, eugenol has been shown to significantly
enhance the NK cytotoxic activity, suggesting that carda-
mom exerts immunotoxic effects.
67
Although a large body of research has revealed that var-
ious spices and their chemical constituents could potentially
play anticarcinogenic roles, the basis for such anticarcino-
genic effects has been attributed to enzymatic modula-
tion
26,34–37
and anti-inflammatory, antiproliferative, and
pro-apoptotic activities.
36
Indeed, enzymatic modulation
has been deemed a mechanism of action by which black
pepper manifests its anticarcinogenic roles.
22,23,25,26
Like-
wise, enzymatic modulation
26,34–37
and anti-inflammatory,
antiproliferative, and pro-apoptotic activities
36
have been
proposed as mechanisms underlying the anti-cancer prop-
erties of cardamom. Our findings demonstrate that the an-
ticarcinogenic effects of the black pepper and cardamom
extracts may be attributed to the immunostimulatory po-
tential of the spices’ constituents to promote NK cytotoxic
activity against cancer cells.
In conclusion, our study provides experimental evidence
suggesting that black pepper and cardamom have a great
potential to serve as immunomodulatory agents. Black
pepper seems to play pro-proliferative, pro-inflammatory
functions, while cardamom manifests itself as a potent
suppressor of inflammation. In addition, our study demon-
strates that black pepper and cardamom extracts exert anti-
carcinogenic effects via promoting the cytotoxic activity
of NK cells. Although the exact molecular mechanisms
underlying the immunomodulatory effects exerted by the
extracts of black pepper and cardamom on splenocytes,
macrophages, and NK cells are still unknown, elucidation
of the specific signaling pathways involved in this im-
munomodulation is currently underway. Finally, we antici-
pate that the active constituents of black pepper and
cardamom may serve as potential molecular tools for de-
veloping new therapeutic strategies to modulate inflamma-
tory responses and prevent=treat various types of cancer.
ACKNOWLEDGMENTS
We are grateful to Dr. Fredrick Palmer (Dalhousie Uni-
versity, Halifax, NS, Canada) for allowing us to use their
rotatory evaporators in the preparation of the spice extracts.
We thank Hana James, Jillian Tarrant, Wendy Hughes, and
Bruce Musgrave for their invaluable technical assistance.
AUTHOR DISCLOSURE STATEMENT
No competing financial interests exist.
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IMMUNOMODULATION BY BLACK PEPPER AND CARDAMOM 381
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... The aqueous extract of black pepper causes an increment in splenocyte proliferation in a dose-dependent synergistic manner. The rise in Th1 cytokine release by splenocytes and suppression of Th2 cytokine release by splenocytes strongly endorses black pepper for the immunemodulatory effect (Majdalawieh and Carr, 2010). Pepper showed antiviral activity against two viruses "vesicular stomatitis virus and human parainfluenza virus" on HeLa cell lines (Priya and Kumari, 2017). ...
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Ethnopharmacological relevance The coronavirus disease (COVID-19) has relentlessly spread all over the world even after the advent of vaccines. It demands management, treatment, and prevention as well with utmost safety and effectiveness. It is well researched that herbal medicines or natural products have shown promising outcomes to strengthen immunity with antiviral potential against SARS-COV-2. Aim of the review: Our objective is to provide a comprehensive insight into the preventive and therapeutic effects of herbal medicines and products (Ayurvedic) for pre-and post-COVID manifestations. Material and method The database used in the text is collected and compiled from Scopus, PubMed, Nature, Elsevier, Web of Science, bioRxiv, medRxiv, American Chemical Society, and clinicaltrials.gov up to January 2022. Articles from non-academic sources such as websites and news were also retrieved. Exploration of the studies was executed to recognize supplementary publications of research studies and systematic reviews. The keywords, such as “SARS-COV-2, coronavirus, COVID-19, herbal drugs, immunity, herbal immunomodulators, infection, herbal antiviral drugs, and WHO recommendation” were thoroughly searched. Chemical structures were drawn using the software Chemdraw Professional 15.0.0.160 (PerkinElmer Informatics, Inc.). Result A plethora of literature supports that the use of herbal regimens not only strengthen immunity but can also treat SARS-COV-2 infection with minimal side effects. This review summarizes the mechanistic insights into herbal therapy engaging interferons and antibodies to boost the response against SARS-COV-2 infection, several clinical trials, and in silico studies (computational approaches) on selected natural products including, Ashwagandha, Guduchi, Yashtimadhu, Tulsi, etc. as preventive and therapeutic measures against COVID. We have also emphasized the exploitation of herbal medicine-based pharmaceutical products along with perspectives for unseen upcoming alike diseases. Conclusion According to the current state of art and cutting-edge research on herbal medicines have showed a significant promise as modern COVID tools. Since vaccination cannot be purported as a long-term cure for viral infections, herbal/natural medicines can only be considered a viable alternative to current remedies, as conceived from our collected data to unroot recurring viral infections.
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The immune system is a highly developed and complex system. Its optimal functioning is critical to human health, being responsible for safeguarding the human body toward the invading of various pathogens or cancers, and therefore plays a remarkable role in maintaining health. Immunomodulators are agents that change the immunologic function of human, and they include stimulatory and suppressive agents. Diet is one of the main factors that modulate different aspects of the immune functions. The consumption of diets with immunomodulating capacities is known as an efficient tool for preventing the come down of the immune functions and decreasing the risks of infections or cancers, as well as boosting the physiological functions. Recently, an interest has been shifted to the Middle Eastern diet (MED) recognized as one of the healthiest diets, with substantiation of healing and preventing diverse human disorders and increasing longevity. This was attributed to the fact that MED is a wealthy pool of antioxidants, minerals, dietary fibers, essential fatty acids, and vitamins. In this chapter, state-of--the-art knowledge about the effectiveness of the MED on the immune function is reviewed. It is noteworthy that many evidences encourage the consumption of MED aimed at long-term healthy life with improved quality. More future attention should be paid to the consumption of MED with immunomodulatory potential to prohibit the declining of the immune functions and minimize the risk of various disorders such as infections, autoimmune diseases, allergies, or cancer. Moreover, further clinical and mechanistic studies are required to establish the role of MED as immunomodulators.KeywordsImmune systemImmunomodulationMiddle Eastern dietAntioxidantsHuman disorders
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Indian subcontinent, unique for its Unity in Diversity, is made up of 28 provinces and 8 union territories and is known to have amazing diversity of approximately 1402 million people with a wide variety of races and ethnicity staying together harmonically since the ancient time. It is not surprising that India with 15 major languages and about 100 dialects would have a wide variety of cuisines, with each province having its own cooking tradition and taste. Indian ways of food preparation are not the cuisine of a single nationality, but a collective combination of different cuisines from a number of countries with cultural identities that have been heavily influenced by religious and regional particularities. Above the region-specific nature of Indian cuisine, there exists certain common features among the diverse culinary practices. India’s history, rulers, trade partners, and moreover, the religious and cultural traditions have great influence on its cuisines. From the ancient ages, Indian Ayurveda (the medicinal practices for the well-being of humanity) is considered as a method of science of life in a holistic way. Ayurvedic Science signifies the importance of natural medicines using herbals that also includes spices. Spices and herbs are found not only to attribute flavour to bland meals, but also influence human metabolic processes and defence mechanisms. Spices have a diverse array of natural phytochemicals that have complementary and overlapping actions that include antioxidant effects, modulation of detoxifying enzymes, stimulation of immune system, reduction of inflammation, modulation of steroid metabolism, and antibacterial as well as antiviral effects. In this review, efforts have been made to take a cursory glance on the traditional Indian spices and herbs being used since the prehistoric times in the preparation of foods. The medicinal, nutritional, and especially immunostimulant properties of different spices and herbs have been reviewed. The great biodiversity observed in India by virtue of its enormous variety of flora and fauna owe to its wide range of climatic conditions and topographical characteristics. While in the colder northern states, dishes are prepared commonly with the warming aromatic spices, and in contrast, to combat the hot climate in the southern Indian states, the foods prepared are generally lighter to make them easy for the digestive system. Natural anti-inflammatory compounds are abundant in different Indian spices that not only add flavour, but also impart different immuno-boosting effects. Anti-inflammatory compounds are plentifully present in Indian spices and herbs, and their additive or synergistic actions protect the human body against a variety of threats. Some of the important bioactive compounds possessing nutritional/immunostimulant values include piperine from black pepper, curcumin from turmeric, allyl sulphides from garlic, eugenol from cloves, capsaicin from red pepper, etc. Moreover, natural polyphenols found in some common herbs used in different Indian cuisines, i.e. coriander, bay, mint, curry leaves, etc., have been found with immunostimulant properties in combating a multitude of disorders.KeywordsIndian cuisineSpicesHerbsFermented foodBioactiveImmunostimulant propertiesAnti-inflammatory
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Background Food additives act as preventive measures and promote a healthy immune response against pathogenic diseases. There are several functional food additives with antiviral potential that are part of our daily food supplements, which can be exploited to improve the immunity of the human being during the pandemic of Covid-19. Scope and Approach For the development of this literature, an extensive database search using the scientific databases and Google Scholar, as well as commercial search engines such as Google, Google Patent and Patent Scope to search for commercial and patentable applications. Key Finding Food additives such as Phyllanthus emblica, Long pepper, Cinnamon, Turmeric, Cardamom, Ginger, Garlic, Holy basil, and liquorice are used in traditional cultures as preventative treatments. The phytocompounds extracted from these food additives are immune modulators against various pathogenic inflammations. Enhancing the immune response and boosting health are the benefits of these food additives. Conclusion The phytocompounds extracted from food additives such as Phyllanthus emblica, Long pepper, Cinnamon, Turmeric, Cardamom, Ginger, Garlic, Holy basil, and liquorice are immune modulators against various pathogenic inflammations. The research literature and reputable sources online confirm that functional food additives in a regular diet may help cure Covid-19 disease. It is necessary to conduct scientific research to determine the effectiveness of food additives. Proposes the Future Direction The majority of diseases are caused by metabolic disorders. It is clear that the diet plays a major role in controlling the inflammation associated with diseases and metabolic disorders. There are still a lack of phytochemical screenings and their interaction with metabolism. This effort will help the science community to think outside of the box of medicine. Keywords: Covid-19, Functional Food Additives, Immune Response, SARS-CoV-2
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In this study, the immuno-enhancing activity of seed extracts were studied on the macrophage cell lines. We examined the effect of nine seed extracts on nitric oxide (NO) production in RAW 264.7 cells and selected four highly-effective seed candidates (Fagopyrum esculentum, Taraxacum platycarpum, Impatiens balsamina, Helianthus annuus) for further immune-related studies. The effects of the four seed extracts on the production of immune-related cytokines in the RAW 264.7 macrophage cell line and proliferation of Molt-4 as a T cell line were investigated. The secretion of NO from the RAW 264.7 cells was increased up to 39 by adding the seed extracts (25 ) compared to the control. Also, the secretion of tumor necrosis factor-alpha (TNF-) was also increased up to 32 times by adding the seed extracts (25 ). Secretion of cytokines such as interleukin-1 beta (IL-), interleukin-6 (IL-6), and interleukin-10 (IL-10) was also increased and induced the proliferation of T cells compared to the control. In conclusion, these results suggest that four seed extracts provide beneficial immuno-enhancing effects for human health.
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For millennia, spices have been an integral part of human diets and commerce. Recently, the widespread recognition of diet-health linkages bolsters their dietary importance. The bioactive components present in them are of considerable significance owing to their therapeutic potential against various ailments. They provide physiological benefits or prevent chronic ailment in addition to the fundamental nutrition and often included in the category of functional foods. Black pepper (Piper Nigrum L.) is an important healthy food owing to its antioxidant, antimicrobial potential and gastro-protective modules. Black pepper, with piperine as an active ingredient, holds rich phytochemistry that also includes volatile oil, oleoresins, and alkaloids. More recently, cell-culture studies and animal modeling predicted the role of black pepper against number of maladies. The free-radical scavenging activity of black pepper and its active ingredients might be helpful in chemoprevention and controlling progression of tumor growth. Additionally, the key alkaloid components of Piper Nigrum i.e. piperine assist in cognitive brain functioning, boost nutrient's absorption and improve gastrointestinal functionality. In this comprehensive treatise, efforts are made to elucidate the antioxidant, antimicrobial, anti-inflammatory, gastro-protective, and anti-depressant activities of black pepper. Moreover, the synergistic interaction of black pepper with different drugs and nutrients is the limelight of the manuscript. However, the aforementioned health promoting benefits associated with black pepper are proven in animal modeling. Thus, there is a need to conduct controlled randomized trials (CRT's) in human subjects, cohort studies, and meta-analyses. Such future studies would be helpful in recommending its application in diet-based regimens to prevent various ailments.
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Herbs/Botanical plants are considered as God's gift to human beings in the form of natural medicines, like the one well known "Sanjeevani booti" described in Hindu Mythology. The traditional and ethno-veterinary practices have been in use for centuries, transferring the knowledge from generation to generation and they are accessible, easy to prepare and administer, with little or no cost at all. Even though the modern developments in therapeutic field brought about a rapid decline in traditional medicine, the plant-based remedies are still having a crucial role as potential source of therapeutic aids in health systems all over the world for both humans and animals. Among the 21,000 medicinal plants listed by the World Health Organization (WHO), 2500 species are native to India, which stands first in the production of medicinal herbs. This innumerable treasure of medicinal herbs brings India the distinction of 'the botanical garden of the world'. Nowadays immune-based therapies are gaining more importance than monovalent approaches which are having limited benefits. Apart from the actions like treating diseases, control of ecto- and endo-parasites, fertility enhancement, bone setting and poor mothering management, an array of herbal medicines have been reported which are having immunomodulatory effects like modulation of cytokine secretion, histamine release, immunoglobulin secretion, class switching, cellular co-receptor expression, lymphocyte expression, phagocytosis and so on. The present article describes in brief few of these important ones viz., ashwagandha, amla, tulsi, arjuna, aloe vera, garlic, turmeric, ginger, shatavari, neem, guduchi, kiwifruit, tut, kamala, palashlata, kokilaksha etc. being used for human and animal health benefits.
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Objectives: This study aimed to investigate the effect of piperine on airway hyper-responsiveness, pulmonary eosinophilic infiltration, various immune cell phenotypes, Th2 cytokine production, immunoglobulin E and histamine production in a murine model of asthma. Methods: Asthma was induced in Balb/c mice by ovalbumin sensitization and inhalation. Piperine (4.5 and 2.25 mg/kg) was orally administered 5 times a week for 8 weeks. At 1 day after the last ovalbumin exposure, airway hyperresponsiveness was determined and samples of bronchoalveolar lavage fluid, lung cells and serum were collected for further analysis. Key findings: Piperine-treated groups had suppressed eosinophil infiltration, allergic airway inflammation and airway hyperresponsiveness, and these occurred by suppression of the production of interleukin-4, interleukin-5, immunoglobulin E and histamine. Moreover, polymerase chain reaction products for thymus and activation regulated chemokine from lung cell RNA preparations were decreased in the piperine-treated group compared with control groups, although transforming growth factor-β products were increased in the piperine-treated group. Conclusions: The results suggest that the therapeuticmechanism bywhich piperine effectively treats asthma is based on a reduction of Th2 cytokines (interleukin-4, interleukin-5), eosinophil infiltration, and by marked reduction of thymus and activation regulated chemokine, eotaxin-2 and interleukin-13 mRNA expression (especially transcription of nuclear factor-κB dependent genes) in lung tissue, as well as reduced interleukin-4, interleukin-5 and eotaxin levels in bronchoalveolar lavage fluid, and histamine and ovalbumin-specific immunoglobulin E production in serum.
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Isoeugenol is a naturally occurring methoxyphenol found in a variety of foods and essential oils. We investigated the effect of isoeugenol on T-cell function and the regulatory mechanism underlying its effect. Isoeugenol and its structural analog eugenol suppressed the lymphoproliferative response to concanavalin A stimulation in B6C3F1 mouse splenocyte cultures. Isoeugenol inhibited phorbol 12-myristate 13-acetate (PMA) plus ionomycin (Io)-induced IL-2 mRNA expression and protein secretion in B6C3F1 mouse splenocytes, and in EL4.IL-2 mouse T-cells, as determined by real-time RT-PCR and ELISA, respectively. To further characterize the inhibitory mechanism of isoeugenol at the transcriptional level, we examined the DNA binding activity of the transcription factors for IL-2 using an electrophoretic mobility shift assay. Isoeugenol decreased the binding activity of NF-AT and NF-κB in PMA/Io-stimulated EL4.IL-2 cells, but no significant effect was observed for AP-1 or Oct binding activity. Western blot analysis showed that isoeugenol also decreased the nuclear translocation of cytoplasmic NF-AT and NF-κB. These results suggest that isoeugenol suppresses IL-2 production through a decrease of IL-2 mRNA expression and that the inhibition is mediated, at least in part, through the down-regulation of NF-AT and NF-κB.
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Workers in a Swedish spice factory (n= 70). and in the office (n=23) of the same company, were investigated by questionnaire regarding skin symptoms. In a 2nd part of the study, subjects reporting skin symptoms were examined and investigated by patch and prick testing. Skin symptoms were reported by 1/2 the factory workers. Pruritus and skin irritation, particular from cinnamon powder, were common, Patch test reactions to cinnamic aldehyde were found in 11/25 factory workers, but in several cases, the nature of the reactions was difficult to evaluate. Irritant patch test reactions were seen from powders of cardamom, paprika and white pepper. On prick testing, 6/25 workers reacted to cinnamic aldehyde. The results illustrate the difficulties of patch testing with spices and indicate the need for further research and validation of methods.
Chapter
More than 180 spice-derived compounds have been identified and explored for their health benefits (Aggarwal et al. 2008). It is beyond the scope of this chapter to deal with all herbs and spices that may influence the risk of cancer and tumor behavior. Therefore, a decision was made to review those with some of the more impressive biological responses reported in the literature, and a conscious effort was made to provide information about the amount of spices needed to bring about a response and thus their physiological relevance. When possible, recent reviews are included to provide readers with additional insights into the biological response(s) to specific spices and to prevent duplication of the scientific literature. Because there is a separate chapter devoted to curcumin (a bioactive component in turmeric) in this book and there are also several excellent reviews published about curcumin (Patel and Majumdar 2009; Aggarwal 2010; Bar-Sela, Epelbaum, and Schaffer 2010; Epstein, Sanderson, and Macdonald 2010), turmeric is not discussed in this chapter.