Analgesic and anti-inflammatory potential of four varieties of bell pepper (Capsicum annum L.) in rodents

Abstract

The aim of the study was to evaluate the analgesic and anti-inflammatory activity of four different colored (green, yellow, orange and red) sweet bell peppers (Capsicum annuum L.) available in the local market of Karachi Pakistan. Their 95% ethanol extracts at 200 and 400 mg/kg were prepared and compared with commonly used analgesic (aspirin) and anti-inflammatory agents supporting its traditional use. The analgesic effects of 95% ethanol extracts of Capsicum annum L. were investigated by acetic acid-induced writhing, tail immersion and hot plate test. The anti-inflammatory activities were observed using carrageenan-induced edema of the hind paw in rats. Animals were divided into 10 groups (n=7): (1) Control (2) CAG 200 (3) CAG 400 (4) CAR 200 (5) CAR 400 (6) CAO 200 (7) CAO 400 (8) CAY 200 (9) CAY 400 and (10) Standard. All the extracts were given orally. Acute toxicity was also determined by increasing the dose till 3000 mg/kg, which showed no evidence of mortality. All extracts of Capsicum significantly increased the hot plate pain threshold, moreover remarkably reduced the carrageenan-induced rat paw edema. Results obtained were compared with the corresponding control group revealed that the fresh fruits extract of all four kinds of bell pepper (200 mg/kg and 400mg/kg) possess anti-inflammatory and pain suppressing activities possibly mediated via PG synthesis inhibition.

Full text

doi.org/10.36721/PJPS.2021.34.4.REG.1369-1376.1
Pak. J. Pharm. Sci., Vol.34, No.4, July 2021, pp.1369-1376 1369
Analgesic and anti-inflammatory potential of four varieties of bell
pepper (Capsicum annum L.) in rodents
Nimra Mazhar1,3, Sadia Ghousia Baig2, Salman Ahmed1,
Mohammad Mohtasheem ul Hasan1, Amber Palla3 and Ghazala Ishrat3
1Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, University of Karachi, Karachi, Pakistan
2Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, University of Karachi, Karachi, Pakistan
3Faculty of Pharmacy, Salim Habib University, Karachi, Pakistan
Abstract: The aim of study was to evaluate the analgesic and anti-inflammatory activity of four different colored (green,
yellow, orange and red) sweet bell peppers (Capsicum annuum L.) available in the local market of Karachi Pakistan.
Their 95% ethanol extracts at 200 and 400 mg/kg were prepared and compared with commonly used analgesic (aspirin)
and anti-inflammatory agents supporting its traditional use. The analgesic effects of 95% ethanol extracts of Capsicum
annum L. were investigated by acetic acid induced writhing, tail immersion and hot plate test. The anti-inflammatory
activities were observed using carrageenan-induced edema of hind paw in rats. Animals were divided into 10 groups
(n=7): (1) Control (2) CAG 200 (3) CAG 400 (4) CAR 200 (5) CAR 400 (6) CAO 200 (7) CAO 400 (8) CAY 200 (9)
CAY 400 and (10) Standard. All the extracts were given orally. Acute toxicity was also determined by increasing the
dose till 3000 mg/kg, which showed no evidence of mortality. All extracts of Capsicum significantly increased the hot
plate pain threshold, moreover remarkably reduced the carrageenan-induced rat paw edema. Results obtained were
compared with corresponding control group revealed that the fresh fruits extract of all four kinds of bell pepper (200
mg/kg and 400mg/kg) possess anti-inflammatory and pain suppressing activities possibly mediated via PG synthesis
inhibition.
Keywords: Capsicum annum, Capsaicin, di-hydrocapsaicin, Phenolic compounds, anti-nociceptive.
INTRODUCTION
Epidemiologic evidences show that by increasing
consumption of vegetables there are constructive effects
on health. Plants contains multiple varieties of
phytochemical constituents which have valuable
therapeutic properties that can be utilized for the therapy
of human ailments (Atolani et al., 2020, Akinpelu et al.,
2008). Studies conducted in-vivo and in vitro with
animals show role of food in maintenance of health and
on the reducing risk of diseases (Bastos et al.,
2009).Native from the America, sweet bell pepper is
regarded as Capsicum annuum L. species belonging to the
Solanaceae family which is widely consumed worldwide
with increasing popularity. Another factor of attraction is
it availability in an extensive multiplicity of colors (green,
yellow, orange, red, and purple), shapes, sizes and its
characteristic flavor (Castro et al., 2008).
Notwithstanding, there are roughly 20 wild species that
have been archived (Heiser Jr, 1973). The color of each
Capsicum assortment within the full-ripe stage is
dependent on its capacity for synthesizing carotenoids and
for holding chlorophyll pigments (Collera-Zúñiga et al.,
2005). Significance of Capsicum prevails since the 7500
BC (Nadeem et al., 2011). Non-sharp sweet chilies are
named as 'Capsicums' which are local to Mexico. In
American English, it is by and large known as the Chili
Pepper or Bell Pepper. Whereas, Bell pepper is regarded
as pepper in British English, although in Australian and
Indian English, there is no utilized name and the name
Capsicum is being usually utilized for peppers solely.
Capsicum is locally regarded as Shimla Mirch in Pakistan
(Grubben and Denton, 2004). Pepper is one of many
crops that is sensitive to high temperature and grown in
the mid-latitudes and said to have sensitivity to high
temperatures. (Erickson and Markhart, 2002).
Capsicum is a vital agricultural crop due of its economic
significance, as well as for its generally high antioxidant
content, they are extraordinary source of ascorbic acid,
natural colors and other antioxidant compounds
(Ghasemnezhad et al., 2011). Carotenoids, phenolic
compounds and other phytochemicals have been
identified from many species of Capsicum (Asnin and
Park, 2015). Some of the new metabolites have recently
been reported from pepper such as tetrahydropentoxyline,
acid colnelenic, blumenol C glucoside and
gingerglycolipid (Guevara et al., 2021). Carotenoid
pigments produced during ripening are responsible for
producing yellow, orange, and red coloration of bell
peppers. More than 30 different plant pigments have been
isolated and identified in pepper until date.
(Ghasemnezhad et al., 2011). Chemical analysis of fruits
also indicates the presence cinnamic acid and flavonoids
derivatives(Materska and Perucka, 2005). Peppers are a
good source of vitamins E and vitamin A and one pod of
*Corresponding author: e-mail: nimra.mazhar@shu.edu.pk

Analgesic and anti-inflammatory potential of four varieties of bell pepper
Pak. J. Pharm. Sci., Vol.34, No.4, July 2021, pp.1369-1376
1370
chili can provide 5% of vitamin E whose RDA is around
8-10 mg and contributes to antioxidant activities (Do
Rêgo et al., 2012, Krinsky, 2001). Since decades
Capsicum pain-killing properties have been identified and
as a result, they are utilized for compounding of different
ointments (Perucka and Materska, 2001). Capsaicin is
additionally the dynamic compound that is liable of
therapeutic potential of Capsicum. It has been utilized as a
pain relieving agent for joint inflammation and for
analgesia (Sora et al., 2015). Chili is supposed to have
higher antioxidative capacity than other vegetables like
ginger and garlic(Shobana and Naidu, 2000,
Mňahončáková et al., 2021) and has a beneficial effect on
metabolic processes in the human organism and can
decrease the risk of cardiovascular diseases (Sanati et al.,
2018) Besides the use of bell pepper as culinary
ingredient, it is also used in traditional system especially
for treating symptoms such as stomach ache, diarrhea and
dysentery (Tchiegang et al., 1999). Postpartum abdominal
and back pain is found to be resolved by using of
decoction of fruits (Coe, 2008). In Indian central
Himalaya, Oil of Capsicum annum L. is used in dog bite
(Samal and Dhyani, 2006). Fruits of Capsicum have
evidence of use as anti-hypertensive (Pieroni et al., 2004).
Smoke bath/steam bath of leaves are found to be
effective against headache, epilepsy, blood vomit and
breathing difficulties (Valadeau et al., 2010). Stem is
used for dental and oral health care (Kayode and
Omotoyinbo, 2008).
The current experimental study was conducted to
determine the analgesic and anti-inflammatory potential
of four varieties of bell pepper to authenticate their
traditional use.
MATERIALS AND METHODS
Plant materials
Four varieties of fruit of Capsicum annum L. were
procured in Karachi by local market. Multiple varieties
were distinguished by a taxonomist and stored with
voucher numbers Capsicum annum variety [Green bell
pepper (CAG)CAGG/(G) 04-15, red bell pepper (CAR)
CAGR/(R) 05-15, Orange bell pepper (CAO) CAGO/(O)
06-15, Canary belt (CAY) CAGC/(Y) 07-15. All four
fruits 1 kg each were soaked in 98% EtOH for 3 days,
Filtration of the EtOH extract was done to obtain
concentrated crude extract, Percentage yield 5-7% of each
extract.
Animals
The guidelines and regulation were observed during the
conduction of all experiments in accordance with the
Ethical Committee of University of Karachi. Either sex
male or female Swiss albino mice of (20-25g) and Wistar
albino rats (150-180g) were used. These animals were
obtained from animal house maintained at the Department
of Pharmacology, University of Karachi. All animals
were acclimatized for 7 days in cages. They were
provided food and water at 25±1oC with a 12-hour light-
dark cycle. Institutional guidelines were followed for the
use of animals. The animals were assigned to different
groups to be treated in experiments.
Ethical approval
Ethical approval number: IBC KU-210 / 2021.
Chemicals
The following substances were used: Carrageenan, Acetic
acid (Merck & Sigma Chemical Co.), Aspirin (Reckitt
Benkiser Pakistan), Diclofenac Sodium (Glaxo Smith
Kline)
Preparation of extracts
All four varieties (1Kg) were individually washed
thoroughly and sliced into small pieces followed by
soaking in 2L98% ethanol solvent separately for three
days. The resultant mixtures were filtered with
Whatman’s filter paper. The filtrates were dried at 40oC
under vacuum using rotary evaporator. All ethanol
extracts were stored at 8°C and warm at room temperature
for performing pharmacological activities on animals.
(Walum, 1998)
Acute toxicity test
Acute toxicity of the extracts was performed in mice as
described earlier (Walum, 1998). Seven mice were
selected randomly and were fasted for overnight. Mice in
each group were treated with doses 1000, 2000 and 3000
mg/kg of the ethanol extracts orally. Control group of
mice was treated with normal saline (10ml/kg) PO.
Toxicity was observed for 6h and the mortality was
observed for 24 h.
Analgesic activity
Tail immersion test
Mice were divided into ten groups of seven animals in
each group. Before experiment, hot water was maintained
at 56oC in which 3cm of mice tail was immersed (Bannon
and Malmberg, 2007). The time measured for tail with-
drawl from hot water was measured in seconds was
considered as the reaction time and was noted 1h before
and after the oral administration of the extracts CAG,
CAO, CAR, CAY (200 and 400mg/kg). Acetyl salicylic
acid (100mg/kg) was given orally 30min before the test to
the positive control group and physiological saline (10
ml/kg) to the control group.
Hot plate test
A hot plate test was performed according to a previously
reported method (Li et al., 2011). Mice were grouped into
10 groups (n=7 per group), Control group received saline
(10ml/kg) and the positive control group received 100
mg/kg, of the acetyl salicylic acid. Other groups were
given 200 and 400mg/kg of CAG, CAO, CAR, CAY

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Pak. J. Pharm. Sci., Vol.34, No.4, July 2021, pp.1369-1376 1371
extracts. Mice were observed individually on the hot plate
which was maintained at the temperature of 55±0.05oC.
The time in seconds for which mice remained on hot plate
without licking or flicking of hind limb and jumping was
considered as latency time. Time was noted at 0 and after
30, 60, 90, 120, 150 and 180 seconds of administration.
Anti-inflammatory activity
Inflammatory paw edema in rats
Carrageenan-induced rat paw edema method was
employed to determine the anti-inflammatory potential of
the extracts (Morris, 2003). Wistar albino rats (150-180g)
were divided into ten groups with seven rats in each
group. Each rat was treated orally with CAG, CAO, CAR
and CAY (200mg/kg and 400mg/kg) extract, 1h before
carrageen an injection. Carrageenan (0.1ml of a 1%
suspension prepared in 0.9% NaCl) was injected into the
sub-plantar region of right hind paw of rats. Positive
control group of rats was treated orally with 50mg/kg of
diclofenac sodium as a standard medicine. Vehicle control
group received saline (10ml/kg). The paw volume was
measured by Plethysomometer after carrageen injection at
0-300 min.
The difference between the initial and subsequent paw
volume reading gave the actual oedema volume.
The percent inhibition of inflammation was calculated
using the formula:









c
t
V
V
1 100inhibition %
Where Vc represents oedema volume in control and Vt the
oedema volume in the group treated with the tested
flavone or diclofenac.
STATISTICAL ANALYSIS
Data were reported as mean ± standard error of mean
(SEM). Statistical analysis was conducted using
Statistical Package for the social sciences (SPSS), version
20 (SPSS Inc Chicago, IL, USA). Data were analyzed by
one-way analysis of variance (ANOVA) along with
Tukey HSD. Values were considered significantly
different when *=p<0.05 (significant), **=p<0.01 (more
significant), *** = p<0.001 (highly significant)
RESULTS
Acute toxicity results
The acute toxicity assay determined that Capsicum annum
extracts are non-toxic because no mortality was observed
till the end at a dose up to 3000mg/kg. So, both the
extracts were found to be safe and 200 and 400mg/kg
body weight has been used for the comparative
pharmacological activities.
Analgesic activity
Tail immersions method
Ethanolic extracts of Capsicum showed positive results in
all the varieties of bell pepper extracts at the doses of 200
and 400 mg/kg (table 1).
As compared with the control, the most significant
analgesic effect of CAG 200 mg/kg was found to be at
150 min (P<0.01). the results were also significant at 60-
and 90-min P<0.01 (tables 1 and 2).
By increasing the dose up to 400 mg/kg the significant
value exhibited from 30 min and remain significant at 150
min (P<0.01), with the maximum effect at 120 seconds,
which is closely related to the significance of aspirin at 60
seconds (P<0.01).
CAR 200 mg/kg, exhibited significant effect only at 90
min (P<0.01), at the doses of 400mg/kg, the value become
significant from 30 min and remain significant till 120
min, with the maximum significance at 90 min (P<0.01).
Fig. 1: show different types of Bell pepper (1. CAG, 2.
CAR, 3. CAO, 4. CAY)
CAO 200 mg/kg, the extract showed significant result
from 30 min to 150 min, with the maximum significance
at 90 min (P<0.01). By inclining the dose up to 400
mg/kg the significance was observed at 60 min which
remains till 150 min.
CAY 200 mg/kg showed positive results at 60 min and
maximum significance at 90 seconds. Rest all values were
non-significant as compare to the control. CAY 400
mg/kg, exhibited significant value from 30 to 90 min with
the maximum significance at 30 min.
Hot plate test
Hot plate method determined that 95% ethanolic extracts
of the varieties of Capsicum annum 200 and 400 mg/kg
(bw) showed positive analgesic effect, except CAO which
does not showed any effects (table 2).
For CAG 200 mg/kg, the value remains significant from
60 to 180 min, with the maximum effect at 150 min,
which is high as compared to the standard p<0.01. In
comparison with the control, the doses of 400 mg/kg
showed dose dependent decrease in reaction time and the
value remains significant from 30 min to 180 min, with
the maximum significance at 30 min (18.33±3.23), which
is higher as compare to positive control (8.66±0.33).

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Pak. J. Pharm. Sci., Vol.34, No.4, July 2021, pp.1369-1376 1373
CAR 200 exhibit significant activity at 60 min and
remains significant till 120 min with P<0.05, by
increasing the dose to 400mg/kg, the value remains
significant from 30 till 150 min.
CAO showed no significant analgesic effect at both 200
and 400mg/kg. CAY 200mg/kg, showed highly
significant values from 30-90 min (P<0.01) and remain
significant till 150 min with p<0.05 and by increasing the
dose up to 400mg/kg, the significant value exhibited at 30
min to 90 min after that the values show no significant.
Anti-Inflammatory activity
Carrageenan-induced paw edema test
Control and the treatment with the extracts of bell pepper
altogether diminishes paw edema at both the doses 200
and 400mg/kg (table 3). The ethanolic extracts of CAG,
CAR, CAO, CAY at 200mg/kg, exhibit significant values
at 180 min and remains significant till 300 min, with the
maximum significance of CAY at 240 min with P<0.01.
By increasing the doses up to 400mg/kg, all the extracts
of Capsicum i.e., CAG, CAR, CAO, CAY showed
positive results from 180 to 300min with P<0.05, with
exception of CAG and CAY, which also exhibit
significance at 120 min. the maximum effect exhibited by
CAY 400mg/kg at 180 min (3.43±0.05), that is highly
significant as compared to positive control at 60 min
(1.84±0.01).
Percentage inhibition is relatively high at high doses as
compared to low doses of each test sample which indicate
dose dependent response.
DISCUSSION
Capsicum annum L. (Bell pepper) has traditionally been
used for the treatment of dysmenorrhea (Valadeau et al.,
2010) indicating that it may exhibit analgesic, as well as,
anti-inflammatory activity. However, scientific validation
for the same is missing. The current study was planned to
assess the anti-inflammatory and analgesic potential of
the four varieties of bell pepper using in vivo assays. For
this purpose, we prepared ethanolic extracts of various
species of Capsicum annum (bell pepper) including green
(CAG), red (CAR), orange (CAO) and yellow (CAY) and
investigated their analgesic and anti-inflammatory effect
with possible mechanisms. Tail flick and hot plate
methods were used to assess the analgesic effect, whereas,
carrageenan-induced rat paw edema model was used to
explore the anti-inflammatory potential.
Hot plate test as well as, tail flick (in-vivo) assays have
become the standard methods for investigating the
antinociceptive properties of compounds/extracts (Bianchi
Table 3: Anti-inflammatory potential of Capsicum annum in the carrageenin-induced rats paw oedema model
Percentage of inflammation at time (minutes)
Group Dose
mg/kg 0 60 120 180 240 300
Control 1.51± 0.04 2.90±0.03 3.75±0.06 4.55±0.05 5.43±0.07 5.70±0.07
CAG 200 1.94±0.02 3.10±0.06 3.52±0.04 3.72±0.03** 3.82±0.03** 3.71±0.42**
CAG 400 1.73±0.05 2.70±0.07 2.90±0.04** 2.94±0.04** 2.48±0.04** 2.12±0.03**
CAR 200 1.91±0.11 3.04±0.02 3.34±0.04 3.55±0.05** 3.63±0.04** 3.39±0.04**
CAR 400 1.92±0.05 2.99±0.13 3.30±0.18 3.12±0.08** 2.90±0.03** 2.62±0.03**
CAO 200 1.98±0.03 3.10±0.03 3.68±0.03 3.66±0.06** 3.64±0.05** 3.44±0.04**
CAO 400 1.71±0.07 3.13±0.13 3.35±0.11 3.33±0.13** 3.29±0.17** 2.62±0.09**
CAY 200 1.99±0.02 3.17±0.07 3.47±0.05 3.75±0.03** 3.93±0.01** 3.68±0.06**
CAY 400 1.65±0.04 2.92±0.05 3.27±0.03* 3.43±0.05** 2.70±0.02** 2.28±0.12**
Diclofenac 50 1.64±0.02 1.84±0.01 1.8±0.03** 1.76±0.02** 1.75±0.02** 1.73±0.02**
Observations were taken at 0, 60, 120, 180,240, 300 minutes, Values are mean ± SEM, N=7, *=p<0.05, **=p<0.01, *** = p<0.001
Values were considered significantly different when *=p<0.05 (significant), **=p<0.01 (more significant), *** = p<0.001 (highly significant)
Table 4: Anti-inflammatory potential of Capsicum annum in the carrageenin-induced rats paw oedema model
expressed as: Percent of inhibition of oedema formation at time (minutes).
Percentage of inhibition at time (minutes)
Group Dose
mg/kg 60 120 180 240 300
CAG 200 -6.8 6.2 18.7 29.7 35
CAG 400 6.8 23 35.4 54.4 63
CAR 200 -4 11 22 34 41
CAR 400 -3 12 31 47 55
CAO 200 -6.8 2 19.6 33 40
CAO 400 -7 14 27 39.5 54
CAY 200 -9.31 8 18 27.7 36
CAY 400 -0.6 12.8 25 50.3 60
Diclofenac 50 57.6 52 62 67.8 70

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Pak. J. Pharm. Sci., Vol.34, No.4, July 2021, pp.1369-1376
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and Franceschini, 1954, Ben-Bassat et al., 1959, Abdala
et al., 2014). Numerous plants pigment’s extracts have
been reported to possess analgesic effect (Sengupta et al.,
2012)
The oral administration of all the varieties of bell pepper
extract exhibited significant analgesic effect as compared
to the negative control when tested in tail flick assay. The
onset of analgesic effect in all the bell peppers’ species
was 30 seconds and 60 seconds at 200 and 400mg/kg
doses respectively, except CAR which exhibited a
delayed onset of 90 seconds at the tested dose of 200
mg/kg. Amongst the 4 varieties studied, i.e., CAG, CAR,
CAO and CAY, the analgesic activity was superior in
CAG and CAO as the latency at 400mg/kg tested dose
was maintained up till 150 seconds, as compared to CAR
and CAY whose duration at the same dose was
maintained up till 120 and 90 seconds respectively (CAG
400mg/kg = CAO 400mg/kg > CAR 400mg/kg > CAY
400mg/kg). This difference in effect could be attributed to
the difference in phenolic contents in different species of
bell pepper which are known to exhibit analgesic activity.
Since HPLC analysis of green pepper showed higher
amounts of phenolics as compared to red and yellow
peppers (Zhang and Hamauzu, 2003), therefore we
suggest that the predominant difference in analgesic
activity in bell pepper varieties may be the reflection of
different phenolic compounds present in each variety of
bell pepper.
The current findings suggest that Bell pepper may be
mediating its effect via spinal mediated anti-nociceptive
effect, as this test determines animals’ latencies in
nociceptive response to thermal stimulus, a response
characteristic of narcotic drugs such as morphine
(YAKSH et al., 1977, Smith et al., 1982, Smith et al.,
1985)
To further get an insight into possible mechanism of
action we studied the different varieties of bell pepper
extracts by using hot plate test. Oral administration of
CAG, CAR, CAY and CAO reduced thermal sensation at
the tested doses of 200mg/kg and 400 mg/kg, with
maximal effect observed for CAG and minimal effect for
CAO. CAG retained its analgesic activity till 180 seconds
at both the tested doses. However, both the tested doses
differed in onset of action, with CAG 200 mg/kg onset at
60 seconds, whereas CAG 400 dose exhibited its
analgesic effect at 30 seconds. The least effective in terms
of duration of action was CAO, whose effect only
retained till 30 and 60 seconds at 200 and 400 mg/kg
doses respectively. (CAG 400>CAG200>CAR400>
CAR200>CAY400>CAY 200 >CAO 400> CAO 200) so,
we can conclude that extracts of bell pepper can also
exhibit centrally acting analgesic activity,
This analgesic activity via hot plate test depicts the
possibility for bell pepper to be used as centrally acting
analgesic agent and in this test animal nociceptive
response latencies are measured by thermal stimulus
which predominantly involves supraspinal pathway and is
used to differentiate between central and peripheral
analgesic effects. Thus, bell peppers mediate their
analgesic activity by both the central and peripheral
pathways (Bannon and Malmberg, 2007).
The analgesic effect produced by Capsicum annum may
be attributed to the presence of Capsaicin (Alkaloid).
Capsaicin and di-hydrocapsaicin constitute 90% of these
compounds in pepper (Hamed et al., 2019), a known
active compound of this plant, which has been employed
as a topical analgesic against arthritis pain and
inflammation since many decades(Sanatombi and
Sharma, 2008). Powerful analgesic activity is observed by
systemic capsaicin in animal models of chronic
neuropathic pain. Capsaicin is known to mediate its
antinociceptive effect via central pathways by
desensitizing the primary sensory neurons mediated by
inhibition of “substance P”. (Szallasi et al., 2007, Liu and
Nair, 2010)
Further to this we demonstrate for the first time the anti-
inflammatory effects of four varieties of bell pepper by
using paw edema method. The carrageenan- induced paw
edema test is suitable for evaluation of anti-inflammatory
drugs and assessment of the effect of natural products as
anti-edematous (Hernández-Ortega et al., 2012).
Development of edema induced by carrageenan has been
described biphasic (Vinegar et al., 1969). After
administration of carrageenan in the plantar tissues of
rat’s right-hand paw, there was sudden elevation of paw
volume compared to histamine and serotonin injection(Lo
et al., 1982). The anti-inflammatory effect of carrageenan
induced paw edema is shown in table 3 and the
percentage inhibition of inflammation is demonstrated in
table 4. Both the positive control group (given diclofenac
sodium) and treatment groups (administered different
varieties of bell pepper, i.e., CAG, CAR, CAO and CAY)
decrease in paw volume indicates the reduction of
carrageenan induced inflammation and percentage
inhibition is found to significantly high at 400mg/kg for
all varieties as compared to control indicating the anti-
inflammatory activity of all the varieties of bell pepper.
There are two phases in these edema models, with first
phase which is regarded as early phase (1-2h) is
characterized by release of histamine, serotonin and
increase of PG synthesis, while the late phase (2-5h) is
initiated by bradykinin, leukotrienes, polymorphonuclear
cell and Prostaglandins produced by tissue macrophages
and also the induction of COX II. The pretreatment of rats
with four varieties of bell pepper extracts produced no
significant effect in early phase, but exhibited
predominant effects in phase II. Thus, it is probable that
all the varieties CAG, CAR, CAO and CAY mediated
anti-inflammatory effect by inhibiting the neutrophil

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Pak. J. Pharm. Sci., Vol.34, No.4, July 2021, pp.1369-1376 1375
migration and reducing the levels of pro-inflammatory
cytokines.
The anti-inflammatory potential of bell pepper may be
credited to the presence of Capsaicin, a major ingredient
of pepper, which is known to exhibit an anti-
inflammatory mechanism by the inhibition of PGE2 and
NO production and also may be a consequence of
antioxidants compounds present in bell peppers(Kim et
al., 2003). The study on leaves of capsicum also confirms
the immunosuppressive activity against T-cell activation
in vitro responsible for anti-inflammatory activity
(Hazekawa et al., 2017).
However, our study justifies the anti-inflammatory
property of bell pepper fruits which were not studied
before. There are no epidemiologic studies showing
whether bell pepper intake may be beneficial in human
inflammatory diseases despite these data showing the
anti-inflammatory effects of bell pepper and capsaicin
intake may be beneficial in human inflammatory diseases
CONCLUSION
The present experimental study demonstrates for the very
first time the potential analgesic and anti-inflammatory
activities of native Pakistani bell pepper extracts.
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