1Department of Pharmacology & Therapeutics, King George’s Medical University, India
1Department of Centre for Advanced Research (CFAR), King George’s Medical University, India
Submission: March 08, 2021; Published: April 14, 2021
*Corresponding author: Rajendra Nath, Professor, Department of Pharmacology &Therapeutics, King George’s Medical University, Lucknow, India
How to cite this article: Shivangi S, Aaliya B, Rishi P, Satyendra K S, Amod K S. Evaluation of the Effect of Rosuvastatin and Fenofibrate Alone and in
Combination on Chronic Unpredictable Mild Stress Induced Depression in Wistar Rats. Open Access J Neurol Neurosurg 2021; 15(1): 555904.
Introduction: Depression is ranked by WHO as the single largest contributor to global disability (7.5% of all years lived with disability in 2015). Despite current anti-depressants, depression is constantly on the rise. Efficacy and safety are a concern with the long-term use of antidepressants. The need of the time is to explore further options with better patient compliance, more potent and efficacious, and with fewer side effects. Rosuvastatin and Fenofibrate have shown antidepressant effects in past studies, which requires further exploration, therefore this research is designed to evaluate the antidepressant effect of these drugs on chronic unpredictable mild stress induced depression in Wistar rats.
Methods: Experimental study was conducted using a total of 30 Wistar rats divided into 5 groups randomly. Depression was induced in all 5 groups by chronic unpredictable mild stress applied for a period of 4 weeks. Group I have given 1ml saline, Group II Rosuvastatin 20mg/kg body weight, Group III Fenofibrate 200mg/kg body weight, Group IV was given a combination of Rosuvastatin 20mg/kg and Fenofibrate 200mg/kg, Group V has given standard drug Imipramine 20mg/kg body weight. All drugs were given orally and started one week before subjecting rats to a daily stressor and continued till the stress was given for the next 4weeks. After 4weeks of stress, a Forced swimming test and Sucrose preference test were performed to assess the effect of drugs on depression.
Result: Both Rosuvastatin and Fenofibrate showed a significant antidepressant effect in behavioural tests for depression. Results were statistically significant (p<0.05).
Conclusion: Both Rosuvastatin and Fenofibrate showed promising antidepressant effects, though furthermore extensive research required to establish these findings
Globally, depression is the top cause of illness and disability among young and middle-aged populations . People with depression are 1.52 times more likely to die than the general population, probably due to their untreated mental or physical health problems , as nearly half of all cases of depression remain undetected for years, and approximately 15 percent of depressive patients particularly young and elderly men die of suicide. Poor mental health can be a precursor to or a consequence of Chronic Non-Communicable Diseases (NCDs) (cardiovascular diseases, mental health disorders, diabetes, and cancer) [3,4]. The etiology
of depression is not clear and various factors have been suggested in relation to its pathophysiology like
i. genetic factors,
ii. biogenic amines-serotonin, nor-epinephrine, and dopamine,
iii. alteration in hormonal regulation,
iv. alteration in sleep,
v. alteration in neurophysiology and
vi.psychosocial factors .
Serotonin is a major amine involved in the pathophysiology
of depression. Selective serotonin reuptake inhibitors as main
antidepressant drugs further support the role of serotonin .
There are several disadvantages with available antidepressant- [i]
Onset of action of antidepressant effect takes around 4–6 weeks
[6,7], [ii] Majority of patients do not respond at all to currently
available antidepressant , [iii] several side effects decrease
the patient’s compliance to therapy [9–11]. Hence, research is
required for exploring new drugs with better efficacy and safety
and fewer side-effects. Rosuvastatin [12-17] and Fenofibrates 
have shown antidepressant effects in past studies and require
further exploration, therefore this research is designed to evaluate
the antidepressant effect of these drugs on chronic unpredictable
mild stress-induced depression in Wistar rats.
Thirty adult Wistar rats of either sex weighing 160-200 grams
were procured from CSIR-IITR, Gheru Campus, Lucknow, India.
The animals were housed in an Institutional animal house under
standard conditions of housing- room temperature of 24-27°C
and humidity of 60-65% with 12-hour light and dark cycle. The
food was given in the form of dry pellets and water ad libitum.
The study protocol has been approved by the Institutional Animal
Ethical Committee (Reference no. 121/IAEC/2019), of King
George’s Medical University Lucknow, India, till approval the rats
were acclimatized to a new environment. The maintenance of the
animals and the experimental procedures were in the accordance
with the guiding principles of the committee for the purpose of
control and supervision of experimentation on animals (CPCSEA),
Govt. of India.
The Wistar rats were given two-four weeks to acclimatize
to the environment of the animal house. A total of thirty Wistar
rats were used in the study and they were distributed randomly
into five groups with six rats (n = 6) in each group. All rats were
subjected to Four weeks of unpredictable mild stressors. The
vehicle and drugs were given to all respective Groups one week
prior to subjecting daily stressors and continued till the stress
was given i.e., for the next 4weeks, (including Group I)
Group I: (non-treated stress group) given 1ml saline orally
Group II: Rosuvastatin 20mg/kg body weight (b.w) per oral
Group III: Fenofibrate 200mg/kg b.w p.o.
Group IV: Combination of Rosuvastatin 20mg/kg b.w and
Fenofibrate 200mg/kg b.w p.o.
Group V: standard drug Imipramine 20mg/kg b.w p.o.
After 4weeks of CUMS (Table 1) and drug administration is
over, the rats are then subjected to Behavioral Tests for assessing
drug effect on depressed state- Forced Swimming Test (FST) and
Sucrose Preference Test (SPT)
FST- The duration of immobility was recorded during the last
5 min of the 6min swimming session.
SPT- Sucrose preference ratio (SPR) is calculated for each rat.
FST is done after exposing rats of all groups to 4weeks of
CUMS along with drug administration. Apparatus- Transparent
cylindrical jar of dimensions (50 cm high × 20 cm diameter). It
is filled with water at Room temperature. The height of water in
the jar is kept such that the hind limbs of a rat can just touch the
base of the jar. A pre-test session is carried out for making rats
familiar with the process. It is conducted 24hr before the main
test. In pre-test each rat of each group is allowed to swim for 15
mins, no measurements are taken. After the swim, each rat is
dried with towels and heated for 15 min before being returned
to their home cages. The next day FST is performed- Each rat is
made to float in the jar for 6 minutes. The duration of immobility
was recorded during the last 5 min of the 6min swimming session.
Rat is considered Immobile when rat floats in an upright position,
making only small movements to keep its head above water. After
each swim rats dried with towels & heated for 15 min before being
returned to their home cages. Principle- Initially the rat makes
effort to escape and makes movements for the same. The more
depressed is rat the earlier it quits making escape efforts and
lies immobile. So, by calculating the duration of immobility the
antidepressant effect of drugs can be compared [26,27].
SPT is done after exposing rats of all groups to 4weeks of
CUMS along with drug administration.
Sucrose solution (1% w/v) is prepared. Each rat is placed in
a separate cage and marked appropriately according to the Group
Training- Rats are trained for 2days to adapt to sucrose
solution (1% w/v)-
Day1- 2 bottles of sucrose solution placed in each cage for
Day2- 1 sucrose solution bottle, 1 water bottle placed in each
cage for next 24hrs.
On SPT Day- Rats are deprived of food & water for 5hrs and
after 5hrs rat in each cage is provided with 1 sucrose solution
bottle, 1 water bottle for next 24hrs.
Principle- Depressed rats lose interest in sweet sucrose
solution which they otherwise relished [Anhedonia]. More is
depression lesser is sucrose consumption. So, by calculating SPR
the antidepressant effect of drugs can be assessed.
After 24hrs consumption of sucrose & water for each rat noted
Sucrose preference ratio is calculated for each rat.
All data were expressed as Mean±SEM for six rats in each group.
One-way analysis of variance (ANOVA) followed by Dunnett’s
multiple comparison test was used for statistical analysis. It was
carried out using the SPSS software package, version 21.0. P-value
< 0.05 was considered as significant.
The results were depicted as Mean ± SEM in Table2 and
graphically represented in Figure 1. From the Table 2 for FST,
the mean and standard error of the mean (SEM) for Group
I to Group V for Immobility in Rats in FST test, using One Way
ANOVA the p-value is <0.05 at 95% confidence interval, showing
a statistically significant relationship among variables. Applying
the Post hoc Dunnett Multiple Comparison Test, Group I to Group
IV were compared with Group V the p-value is <0.001 showing a
statistically significant relationship.
When each group was compared with Group III, the p-value
is <0.001 with the control group (Group I) and imipramine group
(Group V). Comparing the Group III group with Group II the p-value
is <0.05. Comparing Group III with Group IV the p-value is >0.05
(Table 2, Figure 1). Results are expressed as Mean ± SEM (n-6).
One-way ANOVA followed by Dunnett’s multiple comparison test.
Applying One Way ANOVA the p-value is <0.05 at 95% confidence
interval (the statistically significant relationship between the
SPT was conducted on rats from Group I to Group V and
sucrose preference ratio (SPR) was calculated, and the result
depicted as Mean ± SEM in Table3 and graphically represented
in Figure 2. From the Table 3, the mean and standard error of the
mean (SEM) for Group I to Group V, using One Way ANOVA the
p-value is <0.05 at 95% confidence interval, showing a statistically
significant relationship. Applying the Post hoc Dunnett Multiple
Comparison Test, Group I to Group IV were compared with Group
V, the p-value is <0.001 when compared with Group I and Group
II, the p-value is <0.01 with Group III and compared with Group IV
p-value is <0.05. When each group was compared with Group III,
the p-value is <0.001 when compared with Group I, the p-value is
<0.05 with Group II, Group IV, and Group V, showing a statistically
significant relationship with Group III (Table 3, Figure 2).
Results are expressed as Mean ± SEM (n-6). One-way ANOVA
followed by Dunnett’s multiple comparison test. Applying One
Way ANOVA the p-value is <0.05 at 95% confidence interval (the
statistically significant relationship between the variables).
a; p<0.001 compared to Group V
Almost every individual must have gone through some
depressive phase in his/her life. Some are able to cope with
it on their own, some resort to counselling and alternative
treatment modalities, some end up being on long-term/lifetime
of antidepressants, and some unlucky ones are not even able to
address it and silently succumb to it. Under the current scenario
with increased globalization, rapid socio-demographic transition,
with stressful busy lives, the cases of depression are continuously
increasing . Despite the drugs available, globally depression
is on the rise, resulting in increased disability and mortality. This
indicates there is a justifiable requirement for further exploration
and understanding of the neuropath physiology of depression
with efforts at discovering novel effective drugs. The present
study is an attempt in the same direction to further explore the
pathophysiology of depression as well as to explore the pleiotropic
effects of Rosuvastatin and the beneficial effect of Rosuvastatin and
Fenofibrate in managing depression. This study was conducted to
assess the anti-depressant effect of test drugs Rosuvastatin and
Fenofibrate alone and in combination using approved behavioral
models for depression assessment. In studies conducted in the
past, Rosuvastatin and Fenofibrate have shown positive results
when used for depression [12-18,20,30-32].
In this study 30, Adult Wistar rats were used. Rats were
randomly divided into 5 groups with 6 rats in each group. Rats
were allowed to acclimatize to the new environment for a period
of 1 to 2 weeks.
The behavioral tests used for assessment of depression arearei.
Forced Swim Test [26-28]
ii. Sucrose Preference Test [24,28]
Group I was a non-treated CUMS subjected group i.e. was
given no drug but only stressors for 4weeks along with 1ml of
saline daily for 5weeks (starting 1 week prior to start of CUMS and
continued till 4 weeks of CUMS), Group II was given Rosuvastatin
daily for 5weeks (starting 1 week prior to start of CUMS and
continued till 4 weeks of CUMS) with 4week CUMS, Group III
Fenofibrate daily for 5weeks (starting 1 week prior to start of
CUMS and continued till 4 weeks of CUMS) with 4 weeks of stress,
Group IV was combination group with both Rosuvastatin and
Fenofibrate given daily for 5weeks (starting 1 week prior to start
of CUMS and continued till 4 weeks of CUMS) along with CUMS,
Group V was standard drug group and was given Imipramine daily
for 5weeks (starting 1 week prior to start of CUMS and continued
till 4 weeks of CUMS) with 4 weeks of stress and results of test
drug group were compared with standard drug group.
Control (most depressed) 112.39±2.25 > Rosuvastatin
93.23±0.90 > Fenofibrate 84.35±1.47 > Combination of R and F
79.48±1.94 > Imipramine 68.82±0.98 (Table 2, Figure 1).
A rat that is most depressed shows maximum immobility
and shows the least despair to escape. From the above results,
the Control Group (I) which is given no drug but only CUMS for
4weeks shows maximum immobility (depression). Imipramine
is used as a standard drug. It is a tricyclic antidepressant (TCA).
Imipramine acts by inhibiting the reuptake of both serotonin and
norepinephrine. This is carried out by inhibiting Norepinephrine
transporter (NET) and serotonin transporter (SERT) located
at neuronal/platelet membrane at low and therapeutically
attained concentrations. Reuptake inhibition results in increased
concentration of the amines in the synaptic cleft in both CNS
and periphery . Imipramine Group (V) rats are hence
least depressed and so show the least immobility, followed by
Combination drug Group (IV) (R+F) which shows an additive
effect for antidepressant activity in FST. Fenofibrate Group (III)
shows a better result than Rosuvastatin Group (II), which can
be attributed to the ability of Fenofibrate to cross BBB while
Rosuvastatin doesn’t show such activity.
Control 45.96±4.45 (least) (most depressed) < Rosuvastatin
51.57±6.30 < Fenofibrate 63.21±2.43 < Combination of R and F
75.28±1.88 < Imipramine 84.76±2.27 (Table 3, Figure 2). The
rat that is depressed shows the least interest in drinking sucrose
solution, so drinks the least amount of sucrose [Anhedonia]. From
the above results Control Group (Group I) which was subjected to
CUMS and was given no drug, drinks the least amount of sucrose
solution, hence showing maximum depressive activity. Imipramine
being an antidepressant, hence Group V shows maximum SPR
and least depressive activity. Fenofibrate is PPAR (Peroxisome
Proliferator Activated Receptor) α agonist. It is also a fibric acid
analog. Fibrates bind to PPARα and reduce triglycerides and
increase HDL-C through PPARα-mediated action . Recently,
more and more Fenofibrate-induced pharmacological effects
on the CNS are being reported [20,31,32]. In previous studies,
Fenofibrate has shown anti-depressant activity. Fenofibrate is
a selective agonist of PPAR-α, it has been previously reported
that WY14643, another selective agonist of PPAR-α, produced
antidepressant-like effects in mice by activating the BDNF
signalling pathway .
Rosuvastatin is an HMG-CoA reductase inhibitor. This is
commonly used and is a potent statin. In a patient with severe
hypercholesterolemia, it causes a greater reduction in Low-
Density Lipoprotein-C partly due to its longer persistence in the
plasma, and in patients with raised Triglyceride levels, it raises
High-Density Lipoprotein-Cholesterol by 15–20% (greater rise
than other statins) . Statins in addition to their cholesterollowering
action are known to possess many cholesterol
independent actions including a favorable effect on vascular
endothelium . Moreover, there is emerging data indicating
that statins exert neuroprotective and antioxidant actions .
Past studies investigating the effects of statins specifically on
mood have reported mixed findings with some studies showing
that statins in fact may protect against the risk of depression [12-
Keeping in view the result obtained in the present study,
the following conclusions may be drawn regarding the potential
effectiveness of test drugs against Depression: Both Rosuvastatin
& Fenofibrate have shown antidepressant effect. Fenofibrate was
found to be more effective than Rosuvastatin. The combination
of both test drugs showed slightly favorable results over their
individual use. These results are encouraging in showing the
additional anti-depressant effect of Statins & Fibrates apart from
their cholesterol lowering effect, but details of the complete
mechanism have yet not been explored. Therefore, further
experiments are required to elucidate the exact mechanism of
action. Also, more specific and longer duration animal and human
studies are required to further substantiate the finding of the
Authors are grateful to Dr. SC Sharma, Technical Assistant,
Institutional Animal House of our University. Authors are also
grateful to Mr. Ashok Kumar, senior lab technician and Mr. Shyam,
lab attendant of our Department.