Boswellic acids, derived from the Boswellia serrata plant, have been demonstrated to have anti-inflammatory properties in experimental animal models. The present study was aimed to evaluate the uro-protective effect of boswellic acids in rats with cyclophosphamide-induced cystitis. Interstitial cystitis was induced by cyclophosphamide (CYP). In order to analyze the reduction of the urothelial damage, the bladder weight, the nociception response, and the Evans blue dye extravasation from the bladder were evaluated. To investigate the involvement of lipid peroxidation and enzymatic antioxidants CAT, SOD, and GPX and MPO and NO were evaluated. IL-6 and TNF-α were measured by the ELISA immunoassay technique. The results showed that pretreatment with boswellic acids significantly reduced urothelial damage which was accompanied by a decrease in the activity of MDA, CPO, and NO levels and prevention of the depletion of CAT, SOD, and GPX. The levels of IL-6 and TNF-α were dramatically reduced by boswellic acids. Histopathological findings revealed a considerable reduction in cellular infiltration, edema, epithelial denudation, and bleeding. Our findings showed that boswellic acids, by their antioxidant and anti-inflammatory properties, negate the detrimental effects of cyclophosphamide on the bladder, suggesting boswellic acids as promising therapeutic alternatives for cystitis.
Boswellic acids, derived from the Boswellia serrata plant, have been demonstrated to have anti-inflammatory properties in experimental animal models. The present study was aimed to evaluate the uro-protective effect of boswellic acids in rats with cyclophosphamide-induced cystitis. Interstitial cystitis was induced by cyclophosphamide (CYP). In order to analyze the reduction of the urothelial damage, the bladder weight, the nociception response, and the Evans blue dye extravasation from the bladder were evaluated. To investigate the involvement of lipid peroxidation and enzymatic antioxidants CAT, SOD, and GPX and MPO and NO were evaluated. IL-6 and TNF-α were measured by the ELISA immunoassay technique. The results showed that pretreatment with boswellic acids significantly reduced urothelial damage which was accompanied by a decrease in the activity of MDA, CPO, and NO levels and prevention of the depletion of CAT, SOD, and GPX. The levels of IL-6 and TNF-α were dramatically reduced by boswellic acids. Histopathological findings revealed a considerable reduction in cellular infiltration, edema, epithelial denudation, and bleeding. Our findings showed that boswellic acids, by their antioxidant and anti-inflammatory properties, negate the detrimental effects of cyclophosphamide on the bladder, suggesting boswellic acids as promising therapeutic alternatives for cystitis.
Cyclophosphamide (CYP)
is the first line drug in treating large
granular lymphocyte leukemia and breast cancer. Patients who have
received conventional chemotherapy treatments which contain oxazaphosphorine
alkylating drugs such as CYP have experienced interstitial cystitis
(IC).[1] The direct interaction of the uroepithelium
with acrolein, the urotoxic byproduct of CYP, is the mechanistic explanation
of CYP-induced IC. Some mediators, such as tumor necrosis factor-α
(TNF-α), interleukin-6 (IL-6), and nitric oxide (NO), have been
found to have a significant role in the pathophysiology of IC.[2] IC has also been related to ailments like fibromyalgia,
chronic fatigue syndrome, irritable bowel syndrome, and lupus, so
it might be a symptom of a widespread problem. The treatment goal
should be to alleviate the discomfort of interstitial cystitis, which
is often generic and empiric.[3]Initiatives
have been devoted to mitigate the adverse effects of
CYP on the bladder mucosa using various medications.[4] Despite the fact that mesna (2-mercaptoethanesulfonate
Na) is the most regularly utilized agent to prevent CYP-induced IC,[5] nonsteroidal anti-inflammatory drugs, corticosteroids,
and nitric oxide synthase inhibitors have been proven to protect rats
from CYP-induced cystitis across many investigations.[5,6] The preference of natural remedies to treat IC is becoming more
popular, and several studies have demonstrated that extracts of medicinal
plants or isolated components can alleviate cystitis in rodents caused
by cyclophosphamide.[7]Boswellic acids,
a group of pentacyclic triterpene compounds, are
isolated from Boswellia serrata Roxb. ex Colebr.
and Boswellia carteri Birdw. (Buraceace). Boswellia serrata L., (Indian frankincense) is a vital Indian
medicinal plant that has historically been used to treat inflammatory
conditions.[8,9] In current medicine and pharmacology, antiarthritic,
anti-inflammatory, antihyperlipidemic, antiatherosclerotic, analgesic,
and hepatoprotective activities of B. serrata are
well documented.[10,11] It has the characteristic properties
of an antiseptic, analgesic, nephroprotective, tranquilizer, and expectorant.
Numerous studies have been shown that it has a potential effect in
managing inflammatory disorders like edema, arthritis, asthma, bowel
disease, cancer, and carcinomas.[12] Boswellic
acids have shown anti-inflammatory potential in various inflammatory
conditions (Ammon, 2016).The basic reason for this exploratory
study was to investigate
the uroprotective potential of boswellic acids and to illustrate their
mechanism(s) underlying against cyclophosphamide induced interstitial
cystitis rat model.
Materials and Methods
Chemicals Used
All the chemicals
used were of analytical grade. Both cyclophosphamide and mesna (Sigma-Aldrich)
were obtained from the Oncology Department, Doctors Hospital Lahore,
Lahore, and CYP was reconstituted with 0.9% normal saline to make
an injectable solution. Boswellic acids (97%) was obtained from Yuantai
Biological Technology (China).
Animals
Used
This study concluded
30 female rats (Sprague–Dawley, 250 ± 10 g). These animals
were purchased from the “animal house” at the University
of Veterinary and Animal Sciences, Lahore, and then kept for 12 h
in a light/dark cycle along with free approach to food and water with
sustained temperature (21 ± 3 °C). The study was conducted
with the approval from Institutional Research Ethics Committee of
Faculty of Pharmacy (IREC-2020-30), The University of Lahore, Lahore,
Pakistan.
Cyclophosphamide-Induced Interstitial Cystitis
The rats were injected CYP (150 mg/kg solution prepared in 0.9%
normal saline) once a day intraperitoneal on days 1, 4, and 7 for
the induction of interstitial cystitis. On the eighth day, rats were
sacrificed and utilized for study purposes.[13]
Study Design
Female rats were divided
into five groups (n = 5) after a 10-day habituation
period. Group I, control; received 0.9% normal saline on first, fourth,
and seventh day intraperitoneal. Group II, diseased control; received
CYP (150 mg/kg) by intraperitoneal injection on first, fourth and
seventh day. Group III, mesna (standard drug treatment): they had
been administered mesna (40 mg/kg) orally 1 h before CYP. Groups IV
and V, Boswellic acids (100 and 200 mg/kg) treated: administered boswellic
acids in 100 and 200 mg/kg doses orally 1 h before CYP intraperitoneal
injection on first, fourth, and seventh day.
Collection
of Blood Samples and Urinary Bladder
On the eighth day, all
experimental rats were sacrificed, and blood
samples were collected and allowed to coagulate for half an hour at
37 °C in sterile centrifuge tubes. After centrifugation, the
serum was extracted and stored at −20 °C and used in determining
oxidative stress biomarkers malondialdehyde (MDA), protein carbonyl
content (CPO), nitric oxide (NO), glutathione peroxide (GPX), superoxide
dismutase (SOD), catalase, TNF-α, and IL-6 levels (51). The
urinary bladders or tissues were excised abruptly and immersed in
physiological formalin solution for histopathological examinations.
Assessment of Nociception
Prior to
behavioral testing, the rats were placed individually in observation
boxes and acclimatized for 30 min. The following behavioral changes
were assessed: (1) activity (walking, climbing, and grooming); (2)
immobilization; and (3) visceral pain-related behaviors (“crises”).
Additionally, the behavioral changes were graded on the following
scale: 0 indicates normal; 1 indicates a piloerection; 2 indicates
a vigorous piloerection; 3 indicates difficult breathing; 4 indicates
abdominal licking; and 5 indicates abdominal stretching and contraction.[14] After CYP injection, the rats were examined
for 2 min, every 30 min for a total of 4 h, to score the nociceptive
responses. An open-field test was conducted at the conclusion of 4-h
observation session. The rats were placed in a box divided into nine
squares for 10 min, and the number of squares crossed with the four
paws used as a locomotor activity index.[15]
Macroscopic Analyses
Following the
rats having been euthanized, an explorative laparotomy was performed,
and the animal’s bladder was removed, drained, and weighed.
Bladder edema was reported as an increase in bladder wet weight, expressed
in milligrams.[16] Gray’s criteria
was followed for the gross examination of hemorrhage and edema of
urinary bladders. All bladders were excised and transacted at the
bladder neck. The following categories showed the acuteness of edema
as (3+) severe, (2+) moderate, (1+) mild, or (0) absent edema, which
were all considered. When fluid was visible both externally and internally
in the bladder walls, the edema was considered severe. When the edema
was restricted to the inner mucosa, it was classed as moderate; when
there were only minimal edematogenic signals then mild edema was considered.
The bladders were also examined for hemorrhage and classified into
four categories based on the presence of (3+) intravesical clots,
(2+) mucosal hematomas, (1+) bladder vessel dilatation, and (0) for
the normal aspect.[14]
Evaluation of Vascular Protein Leakage by
the Evans Blue Dye Technique
The rats were given an intraperitoneal
injection of CYP along with intravenous infusion of Evans blue dye
(25 mg/kg), 30 min before execution.[17] After
execution, the bladders were excised, dissected, and cultured for
dye extraction in incubator at 56 °C for 6 h (overnight) in vials
containing formamide solution (1 mL/bladder). By measuring the absorbance
at 600 nm and comparing it to the standard curve of Evans blue dye
μg/bladder, the concentration of extracted dye was determined.[16]
Biochemical Parameters
Malondialdehyde Assay
The reaction
mixture contained 100 μL of serum and 1 mL of 0.67% thiobarbituric
acid (TBA), and a clear solution was formed. Then 500 μL 20%
trichloroacetic acid (TCA) was added, making the solution milky, and
then the solution was incubated for 20 min at 100 °C and centrifuged
at 3000 rpm for 20 min. Supernatant absorbance value was determined
at 532 nm. MDA levels were assessed by molar extinction coefficient
1.56 × 105 M–1 cm–1 and the values were indicated as unit of μmol/mL.[34]
Protein Carbonyl Content
Assay
First, 200 μL of sample was taken into the Eppendorf,
and then
we added 300 μL of 10 mM solution of dinitrophenylhydrazine
(DNPH) (dissolved into 2 M HCl). After that the sample with DNPH was
incubated at room temperature for 30 min. A yellow or orange color
appeared in the Eppendorf. Then 300 μL of 20% (w/v) trichloroacetic
acid was added into the Eppendorf. Then solution was centrifuged at
3000 rpm for 20 min. Supernatant was discarded and washed the pellet
with 1 mL ethanol. After washing with 1.5 mL of 6 M guanidine hydrochloride
was added and mixed it well. The Eppendorf tube was incubated at 90
°C for 15 min; centrifugation was done for 5 min. The supernatant
absorbance was read at 370 nm. Serum plus HCl was used as the blank.[35]
Catalase Analysis
Catalase activity
was assessed by taking a 50 μL sample and 500 μL of 20
mM hydrogen peroxide in the test tube, which was mixed thoroughly
with the help of vortex. Bubbles formed in the test tube. Then sample
solution incubated for 3 min at 37 °C, and after incubation 2000
μL of 32.4 mmol/L ammonium molybdate was added ito the test
tube which stopped the reaction, as seen by the yellow color appearance
in the test tube. The test tube that contained 550 μL of distilled
water and 2000 μL of ammonium molybdate was used as the blank.
The absorbance was taken at 374 nm and measured as KU.[18]
Superoxide Dismutase,
GPX, NO, IL-6 and
TNF-α Assays
For determination of superoxide dismutase,
GPX, NO, IL-6, and TNF-α levels, commercially available kits
(SolarBio Kits, China) were used. The procedure was followed as per
the manufacturer’s protocols.
Histopathological
Studies
After
being weighing and microtomized, bladders were preserved in formalin
solution (10%), diaphanized, and embedded in paraffin; these were
stained with haematoxylin and eosin (H&E) and assessed in an optical
microscope by two trained clinical analysts through blind inspection,
each specimen was examined by a pathologist who was unaware of the
treatment and took into consideration the existence and severity of
edema, tissue damage, and hemorrhage.[16]
Statistical Analysis
The data were
expressed as mean ± SEM. The data acquired from various groups
were statistically analyzed by one-way analysis of variance (ANOVA)
followed by Tukey’s multiple comparison tests using Graph Pad
Prism version 8.4.2. P ≤ 0.05 was considered
as significant statistically.
Results
Effect of Boswellic Acids on Nociception
After seventh
day trial, 9 square boxes were made and rats were
put in one by one to check the number of squares crossed by each rat.
The assessment of nociception was observed for 10 min by counting
the no. of squares crossed. The number of boxes crossed by rats treated
with CYP was less (10.75 ± 1.5) in relation to the control group
(60.5 ± 1.84), and this number was noticeably increased in mesna
(40 mg/kg) and boswellic acids (100 mg/kg and 200 mg/kg) treated groups
(36 ± 1.95, 48.5 ± 1.55) respectively (Figure a).
Figure 1
Effect of boswellic acid
on number of squares crossed by rats (a),
vascular permeability of Evans blue dye in urinary bladder (b) and
serum levels of MDA, CPO (c) and catalase (d) in control, diseased
control (CYP 150 mg/kg), standard drug (mesna 40 mg/kg) and boswellic
acids (100 mg/kg and 200 mg/kg) treated groups (P < 0.01 compared to
the control group, P < 0.05 compared to diseased control group, P < 0.01 compared
to diseased control group; n = 5) in cyclophosphamide
induced cystitis (EBD; Evans blue dye, CYP; cyclophosphamide, MDA;
malondialdehyde, CPO; carbonyl protein content).
Effect of boswellic acid
on number of squares crossed by rats (a),
vascular permeability of Evans blue dye in urinary bladder (b) and
serum levels of MDA, CPO (c) and catalase (d) in control, diseased
control (CYP 150 mg/kg), standard drug (mesna 40 mg/kg) and boswellic
acids (100 mg/kg and 200 mg/kg) treated groups (P < 0.01 compared to
the control group, P < 0.05 compared to diseased control group, P < 0.01 compared
to diseased control group; n = 5) in cyclophosphamide
induced cystitis (EBD; Evans blue dye, CYP; cyclophosphamide, MDA;
malondialdehyde, CPO; carbonyl protein content).
Macroscopic Analysis
Effect
of Boswellic Acids on Bladder Weight
The administration of
CYP, induced hemorrhage and edema of urinary
bladder which could be verified by increase in bladder weight. It
was observed that rats treated with CYP (150 mg/kg) had an increased
(97%) bladder weight than the control group. However, groups pretreated
with mesna (40 mg/kg) and boswellic acids (100 and 200 mg/kg) presented
inhibition of increase in bladder weight, respectively (Table ).
Table 1
Effect
of Bowellic Acids on Weight,
Edema, and Hemorrhage of Urinary Bladdera
groups
bladder
weight (mg) (mean ± SEM)
edema
hemorrhage
control
8.00 ± 0.05
0
0
diseased control (CYP 150 mg/kg)
16.62 ± 0.52b
3+
3+
mesna treated (40 mg/kg)
11.56 ± 0.19c
2+
1+
boswellic acids treated (250 mg/kg)
10.98 ± 0.46c
1+
2+
boswellic acids treated (500 mg/kg)
9.39 ± 0.24c
1+
1+
Control, diseased control (CYP 150
mg/kg), standard drug (mesna 40 mg/kg), and boswellic acids (100 mg/kg
and 200 mg/kg) treated groups.
P < 0.01 compared
to the control group, and P < 0.05 compared to
the diseased control group.
P < 0.01 compared
to the diseased control group; n = 5 in cyclophosphamide-induced
cystitis.
Control, diseased control (CYP 150
mg/kg), standard drug (mesna 40 mg/kg), and boswellic acids (100 mg/kg
and 200 mg/kg) treated groups.P < 0.01 compared
to the control group, and P < 0.05 compared to
the diseased control group.P < 0.01 compared
to the diseased control group; n = 5 in cyclophosphamide-induced
cystitis.
Effect of Boswellic Acids on Edema and Hemorrhage
The
rats treated with CYP (150 mg/kg) presented edema and hemorrhage
of urinary bladder prominently when compared with the control group.
However, these morphological changes were markedly reduced in mesna
(40 mg/kg) and boswellic acids (100 and 200 mg/kg) treated rats, respectively
(Table ).
Effect of Boswellic Acids on Vascular Permeability
Vascular protein leakage was evaluated by Evan blue dye extravasation
permeability. The optical density of extracted dye was measured on
spectrophotometer at 600 nm. It was observed that Evans blue dye concentration
(vascular permeability) has been significantly elevated (0.68 ±
0.004) in diseased control group contrasted to control group (0.17
± 0.002) and decreased (0.45 ± 0.015, 0.32 ± 0.013)
remarkably in boswellic acids (100 and 200 mg/kg) treated group of
rats respectively (Figure ).
Effect of Boswellic Acids on Malondialdehyde
The administration
of cyclophosphamide significantly increased
the levels of MDA. Pretreatment with boswellic acids was able to prevent
this increase presenting that boswellic acids were capable to reduce
oxidative stress (Figure c).
Effect of Boswellic Acids
on Carbonyl Protein
Content
An enhanced (0.008) carbonyl protein content was
detected in diseased control group (CYP 150 mg/kg) balanced to control
group. In mesna (40 mg/kg) and boswellic acid (100 mg/kg and 200 mg/kg)
treated group of rats, carbonyl protein content levels were gradually
dropped (0.006 ± 0.0002, 0.006 ± 0.0002, 0.004 ± 0.0001)
as shown in Figure c.
Effect of Boswellic Acids on Catalase Activity
There was a sharp drop off (29.09 ± 1.67) noticed in the levels
of catalase enzyme in diseased control group in relation to control
group (78.00 ± 3.33), while in mesna (40 mg/kg) and boswellic
acids (100 and 200 mg/kg) treated group catalase levels were increased
(46.90 ± 2.21, 53.68 ± 2.45, 65.27 ± 2.88) significantly
(Figure d).
Effect of Boswellic Acids on Superoxide
Dismutase (SOD)
A decrease (5.51 ± 0.19) in superoxide
dismutase activity by cyclophosphamide induced oxidative stress was
significant as compared with control group (11.6 ± 0.008). CYP-treated
rats showed a remarkable improvement (10.81 ± 0.06) in SOD activity
when boswellic acids were preadministered (Figure a).
Figure 2
Analysis of SOD (a), GPX (b), NO (c), IL-6 (d)
and TNF-α
(e) levels in Control, Diseased control (CYP 150 mg/kg), Standard
drug (mesna 40 mg/kg) and boswellic acid (100 mg/kg and 200 mg/kg)
treated groups (P < 0.01 compared to the control group, P < 0.05 compared to diseased
control group, P < 0.01 compared to diseased control group; n = 5) in cyclophosphamide induced cystitis (SOD; superoxide dismutase,
CYP; cyclophosphamide, GPX; glutathione peroxide, NO; nitric oxide,
IL-6; interleukin 6,TNF-α; tumor necrosis factor-α).
Analysis of SOD (a), GPX (b), NO (c), IL-6 (d)
and TNF-α
(e) levels in Control, Diseased control (CYP 150 mg/kg), Standard
drug (mesna 40 mg/kg) and boswellic acid (100 mg/kg and 200 mg/kg)
treated groups (P < 0.01 compared to the control group, P < 0.05 compared to diseased
control group, P < 0.01 compared to diseased control group; n = 5) in cyclophosphamide induced cystitis (SOD; superoxide dismutase,
CYP; cyclophosphamide, GPX; glutathione peroxide, NO; nitric oxide,
IL-6; interleukin 6,TNF-α; tumor necrosis factor-α).
Effect of Boswellic Acids
on Glutathione
Peroxide
Glutathione peroxide level dropped (379.94 ±
9.86) in diseased control group when compared to control group (810.90
± 12.00), while in mesna (40 mg/kg) and boswellic acids (100
and 200 mg/kg) treated group, there was a significant increase (712.79
± 10.34, 1046.85 ± 10.79, 1113.72 ± 8.81) in GPX levels
(Figure b).
Effect of Boswellic Acids on Nitric Oxide
The administration
of cyclophosphamide induced a significant increase
(65.54 ± 1.38) in nitric oxide level when compared with control
group (20.00 ± 0.71). Pretreatment with boswellic acids was able
to significantly attenuate (29.99 ± 1.66) this increase in the
diseased group (Figure c).
Effect of Boswellic Acids on Interleukin-6
and Tumor Necrosis Factor-α
It was observed that IL-6
and TNF-α levels in the diseased control group rose (88.92 ±
1.38, 28 ± 2.35) in comparison with the control group (23.15
± 1.07, 12 ± 0.82), and these were notably reduced (62.44
± 1.68, 51.70 ± 1.23, 38 ± 1.20, 22 ± 0.4, 20.25
± 0.25, 18.5 ± 0.28) in mesna (40 mg/kg) and boswellic acids
(100 and 200 mg/kg) treated groups (Figure d and 2e).
Histopathological Studies
Urinary
bladder tissues were assessed for histopathological studies. The isolated
bladder was stained with H&E to observe morphological changes.
Bladders from the control group represented normal intact cells with
no inflammation while in the diseased control group inflammation and
severe edema were found. Pretreatment with boswellic acids at both
doses restores the intact normal architecture of bladder by reducing
the inflammation as shown in Figure .
Figure 3
Histopathological studies (H and E staining) of control
group (a),
diseased control (b), mesna treated (c), boswellic acids (100 mg/kg)
treated (d), and Boswellic acids (200 mg/kg) treated (e). (a) Urinary
bladder from control group showing intact mucosa, normal cells and
transitional epithelium with no tissue degeneration. No granuloma
or malignancy was seen. (b) Treatment with CYP caused ulceration of
mucosal lining and a part of transitional epithelium has been sloughed
off. The interstitial tissue and cleaves of muscle coats carried a
dispersed mix of inflammatory cells. There was an evidence of urinary
bladder necrosis leading to interstitial cystitis, (c) Standard drug
treated (mesna 40 mg/kg) group represented normal contracted transitional
epithelium with intact urothelium, (d) with less congestion in submucosa
and an intact transitional epithelial lining in rats treated with
a low dose of boswellic acids (100 mg/kg). (e) Histopathological evaluation
of boswellic acids treated (200 mg/kg) rat urinary bladder detected
a mild congestion in submucosa and an undamaged transitional epithelium.
There was no evidence of any disorder, granuloma or malignancy (black
arrow shows intact transitional epithelium; red arrow shows sloughed
off transitional epithelium).
Histopathological studies (H and E staining) of control
group (a),
diseased control (b), mesna treated (c), boswellic acids (100 mg/kg)
treated (d), and Boswellic acids (200 mg/kg) treated (e). (a) Urinary
bladder from control group showing intact mucosa, normal cells and
transitional epithelium with no tissue degeneration. No granuloma
or malignancy was seen. (b) Treatment with CYP caused ulceration of
mucosal lining and a part of transitional epithelium has been sloughed
off. The interstitial tissue and cleaves of muscle coats carried a
dispersed mix of inflammatory cells. There was an evidence of urinary
bladder necrosis leading to interstitial cystitis, (c) Standard drug
treated (mesna 40 mg/kg) group represented normal contracted transitional
epithelium with intact urothelium, (d) with less congestion in submucosa
and an intact transitional epithelial lining in rats treated with
a low dose of boswellic acids (100 mg/kg). (e) Histopathological evaluation
of boswellic acids treated (200 mg/kg) rat urinary bladder detected
a mild congestion in submucosa and an undamaged transitional epithelium.
There was no evidence of any disorder, granuloma or malignancy (black
arrow shows intact transitional epithelium; red arrow shows sloughed
off transitional epithelium).
Discussion
Cyclophosphamide-induced interstitial
cystitis is well characterized,
and the etiology of this adverse effect is related to its toxic metabolite
(acrolein), which promotes a rupture of the intraluminal membrane,
enabling contact with the deeper epithelial layers, which in turn
induces displacement of the urothelial cells to develop a typical
robust inflammatory process, resulting histologically in subepithelial
edema, neutrophil infiltration, hemorrhage, and endothelial tissue
destruction.[19] In the pathogenesis of IC,
three factors stand out: oxidative stress generated by acrolein, the
inflammatory process (with an emphasis on edema), and bleeding, which
emphasizes the overall clinical aspect of this illness.[20] In this regard, the protocols designed in the
present study aimed to determine the role of boswellic acids in cyclophosphamide-induced
cystitis. Boswellic acids are natural substances with pharmacological
effects which include antioxidant and anti-inflammatory activities.Several investigations in experimental animals have demonstrated
that various medicinal herbs or isolated substances can protect against
interstitial cystitis caused by CYP. Curcumin, ternatin, spirulina, Phyllanthus niruri, alpha phellandrene, Ipomoea
obscura, and the inner bark of Caesalpinia pyramidalis have all been proven to be effective antioxidants in the treatment
of CYP-induced IC.[7,15,16,21]The current investigation found that
pretreatment with boswellic
acid reduced CYP-induced severe urinary bladder toxicity (represented
by nociception, increased bladder weight, and vascular permeability).
Assessment of nociception exhibited an increase in behavioral changes
including activity like walking and climbing, immobility, and behaviors
symptomatic of visceral pain (“crises”).[15] For this locomotor activity, the rats were put
in a container with portions of 9 squares, the number of squares crossed
was counted for 10 min. Pain crisis induced by cyclophosphamide injection
was averted significantly by an oral pretreatment with boswellic acids
(100 mg/kg and 200 mg/kg). Previous studies exhibited an analgesic
effect in some models.[16]The development
of edema, which is typical with IC, was detected.
The presence of edema was determined indirectly by calculating the
mean bladder wet weight, and it was discovered that boswellic acids
were capable of preventing edema. In this case, doses of 100 and 200
mg/kg of boswellic acids produced significant results. In this line,
investigations have demonstrated that extracts or chemicals extracted
from herbal medicines can attenuate cystitis in rodents caused by
oxazophorines.[21]Evans blue dye was
applied to describe the degree of bladder tissue
edema because this fluorescent material adheres to serum albumin with
a greater affinity, and this complex has commonly been used to experimentally
explore the degree of capillary leakage that accompanies inflammatory
reaction, consisting of a relatively inexpensive, reliable, and convenient
method, and which can be adapted to appraise leakage in a variety
of experimental pathological conditions.[22] The outcomes of the Evans blue dye assessment of the growth of IC
showed that boswellic acids at doses of 100 and 200 mg/kg were able
to reduce vascular protein leakage, confirming that boswellic acids
have defensive prospects against the development of CYP-induced IC.Cyclophosphamide administration induced oxidative stress; caused
renal damage in rats by glomerular inflammation, epithelial cytosolic
vacuolization in cortical tubules, hemorrhagic alterations and interstitial
edema in the renal cortex and oxidative damage, as increased kidney
malondialdehyde (MDA) levels in serum.[7] MDA level was measured to determine lipid peroxidation.[33] Pretreatment with boswellic acids (100 and 200
mg/kg) showed their capability in reducing oxidative injury including
MDA lipid peroxidation in CYP-induced interstitial cystitis by dropping
the levels of MDA. These findings were aligned with a previous study.[23]Protein carbonylation, the most frequent
type of ROS-induced protein
modification, is considered irreversible and aims to induce protein
degradation. The toxicity of cyclophosphamide is mediated by its binding
to cellular antioxidants, which led to the depletion of cellular defense
mechanisms and perhaps an elevation in protein carbonyl content.[24] The CPO levels in the cyclophosphamide administered
rats increased compared to control group rats. Pretreatment with boswellic
acids (100 and 200 mg/kg) showed these were capable of reducing oxidative
stress in CYP-induced interstitial cystitis by decreasing the levels
of carbonyl protein content in cystitis.GPX and CAT activity
were markedly smaller in the CYP group than
in the normal group, which is consistent with prior investigations.[25] It has been shown that CYP therapy causes the
generation of reactive oxygen species (ROS), which causes oxidative
stress harm to the bladder urothelium. Furthermore, acrolein can reduce
the concentration of GPX.[26] When compared
to the CYP group, boswellic acids dramatically raised the levels of
GPX and CAT in the bladder. The activities of glutathione reductase
and catalase enzymes were boosted by boswellic acids.[27] Because CYP has a pro-oxidant character, it causes oxidative
stress by lowering antioxidant enzyme activity. It enhances lipid
peroxidation in the body. The pro-inflammatory aspect of CYP intoxication
may potentially play a role in the disruption of total redox cycling
in bladder tissues.The importance of NO in HC pathophysiology
was underlined.[28] In our investigation,
CYP injection resulted
in increased levels of NO in bladder tissue than the control. In addition
to increased production of inducible nitric oxide synthase, these
augmented NO levels could be explained by physiological adaptation
processes of the bladder in reaction to acrolein. As a result, overproduction
of reactive oxygen and nitrogen species (ROS and RNS) occurs, causing
damage to the bladder wall. NO levels were dramatically reduced after
boswellic acid treatment, which is consistent with prior research
showing that boswellic acid reduces nitrogen species formation.[29] Because of its potential to scavenge NO, boswellic
acid was found to reduce NO synthesis and iNOS overexpression. Furthermore,
multiple experimental studies have shown that inhibiting iNOS is useful
in the treatment of CYP-induced cystitis.[30,31]In this work, boswellic acid decreased the release of inflammatory
cytokines like IL-6 and TNF-α in a dose-dependent manner. It
has been reported previouly that TNF-α participates actively
in IC induced by CYP.[31] Boswellic acid’s
cytokine inhibitory impact may have helped to bladder architectural
protection and reduced inflammatory infiltration. As a result, the
organ protection activity in CYP-induced cystitis could be attributed
to suppression of pro-inflammatory cytokines.CYP caused bladder
inflammation in the mucosa and submucosa which
resulted in vascular injury and subsequent hemorrhage, as well as
mucosal perforation, according to our findings. Multiple investigations
in rats revealed similar bladder alterations after CYP treatment.[14,32] As with other plant extracts, boswellic acid treatment dramatically
reversed these histological alterations in the bladder.[32] This impact could be attributed by boswellic
acid’s potential to lower oxidative stress and inflammation
while also speeding up healing.
Conclusion
It is concluded that boswellic acids possessed a powerful uroprotective
effect by lowering urinary bladder weight, Evans blue dye concentration,
MDA, CPO, NO, IL-6, and TNF-α, and increasing CAT, GPX, and
SOD activities. It is suggested that boswellic acids have indeed been
proposed as a potential uroprotective agent versus cyclophosphamide-induced
interstitial cystitis. More clinical research is intended to explain
the benefits and potential mechanism of uroprotection of boswellic
acids.
Authors: R L Levine; D Garland; C N Oliver; A Amici; I Climent; A G Lenz; B W Ahn; S Shaltiel; E R Stadtman Journal: Methods Enzymol Date: 1990 Impact factor: 1.600
Authors: H Avci; E T Epikmen; E Ipek; R Tunca; S S Birincioglu; H Akşit; S Sekkin; A N Akkoç; M Boyacioglu Journal: Exp Toxicol Pathol Date: 2017-02-21
Authors: Jose M Mota; Gerly A Brito; Raphael T Loiola; Fernando Q Cunha; Ronaldo de A Ribeiro Journal: Int Braz J Urol Date: 2007 Sep-Oct Impact factor: 1.541