Evaluation Of Antidepressant Activity of Passiflora Edulis in Laboratory Animals

Passion fruit, Passiflora edulis, is a plant with numerous medicinal properties, including antidiabetic, anxiolytic, antineoplastic, antioxidant, analgesic, and anti-inflammatory properties. The Pass flora genus, the largest of the Passiflora family, has around 500 species. Passionflower is native to Brazil, Paraguay, and Argentina and is widely grown in South America, the Caribbean, South Florida, South Africa, and Asia. The fruit comes in two forms, standard yellow and standard yellow, with an annual production of about 120 tons (1-3). Passiflora comes in two varieties in Bhutan: purple and yellow. The purple type is the most commonly grown type in Bhutan, growing between 900 and 2000 meters above sea level. The temperature of 18-23 ? is conducive to flowering and fruit setting, but higher temperatures are needed for juice production and quality improvement. Passion fruit grows on various soil types, including light to heavy sandy loam of medium texture. It contains various chemical components, such as volatile oils, flavonoids, lipids, triterpenoids, aldehydes, ketones, tridecone, palmitic acid, stearic acid, linoleic acid, quercetin, apigenin, and vitaxin, which can be used for various pharmacological activities (4-6).

Figure 1: Passiflora edulis

The study aims to assess the anti-depressant properties of P. edulis in laboratory animals by conducting a acute oral toxicity of extracts will be determined using OECD guideline 423, and the antidepressant activity will be tested by inducing depression in an animal model.

2. MATERIAL AND METHODS

2.1 Extraction of the Plant Materials

Leaves of Passiflora edulis were shade dried and grind coarsely and extracted using methanol through Cold Maceration technique to obtain Hydro alcoholic extract (HAPE) and the percentage yield was calculated.

2.2Acute Toxicity Study

Total 6 rats of 10-12 weeks age were selected and randomly divided into 2 groups. Group I was vehicle control group which received vehicle (gum acacia 1% w/v in distilled water) while group II was test group that received MEPE. Each group consisted of 3 animals (females). Females were nulliparous and non-pregnant. Dose selected for the present study is limit test dose as mentioned in the guidelines. The starting dose for limit test 2000 mg/kg was selected on the basis of dose suggested in OECD guideline 423(7).

2.3 Evaluation of Antidepressant Activity of Passiflora edulis in Restraint Stress Model in Mice

The study involved five groups of Swiss albino mice for 30 days. The first group was a non-stressed control group without any chemical or treatment. The second group was an acute immobilization stress group given a single immobilization stress episode for 120 minutes daily without any chemical or treatment for five consecutive days. The third group received the standard drug treatment, Sertraline (5 mg/kg, orally). The fourth group was an acute stress + drug group given a single immobilization stress episode with a drug administered 30 minutes before stress exposure. After restraint stress, the mice were returned to their cages for immediate consumption of water and food. During restraint sessions, unstressed control mice were handled for 5 minutes and kept in their cages without food or water (8, 9).

2.4 Parameters for the Evaluation of Antidepressant Activity

The study aimed to assess the effectiveness of a treatment using mice subjected to four behavioral tests for 20 minutes. The study used Elisa-based protein assays for BDNF (ELR-BDNF) and TBARS (TBARS) levels to estimate oxidative stress parameters in brain homogenate. The optical density of samples was measured using a microplate reader at 450nm, and the levels of GSH were estimated using a microplate reader at 412 nm. The study also estimated reduced glutathione levels at 412 nm using fixed concentrations ranging from 10–100 μM. The results were expressed as μM.g-1 of protein (10, 11).

3. RESULT AND DISCUSSION

3.1 Acute Toxicity Study

It was observed that the test drug's (HAPE) LD50 was more than 2000 mg/kg body weight. So, it can be concluded that HAPE were safe up to a dose of 2000 mg/kg body weight based on the observation made during the toxicity studies that an oral dose of 2000 mg/kg body weight did not cause drug-related toxicity and mortality, abnormal clinical signs, remarkable body weight, or gross pathological changes in the animals. According to the Globally Harmonised method, the test substance is classified as "unclassified" or "category - 5" since its LD50 was found to be more than 2000 mg/kg body weight.

3.2 Evaluation of Antidepressant Activity of Passiflora edulis in Restraint Stress Model in Mice

3.2.1 Elevated plus-maze (EPM) test

After drug administration, however these values got considerably reduced compared to that of standard anxiolytic agent Sertraline thereby showing significant antidepressant activity of the test drug (Table 1).

Table 1: Antidepressant Activity of Passiflora edulis using Elevated plus-maze test

Values were expressed in mean±SEM; n=6 ***p<0.001, **p?0.01 and *p? 0.05 when compared to control

3.2.2 Open-Field (OFT) Test

In our present study all the parameters increase in dose dependent pattern showing the antidepressant activity of the test drug. However there is less significant change in number of fecal droppings (Table 2).

Table 2: Antidepressant Activity of Passiflora edulis using Open-Field (OFT) Test

Values were expressed in mean±SEM; n=6 ***p<0.001, **p?0.01 and *p? 0.05 when compared to control

3.2.3 Staircase Exploration (SET) Test

To quickly screen for anxiolytic action in mice, the test was altered. The test drugs at 200 and 400 mg/kg had a noticeable impact on the number of rearing. The common medication Sertraline (5 mg/kg) had a notable antidepressant activity (Table 3).

Table 3: Antidepressant Activity of Passiflora edulis using Stair case Exploration Test

Values were expressed in mean±SEM; n=6 ***p<0.001, **p?0.01 and *p? 0.05 when compared to control

3.2.4 Social Interaction (SIT) Test

When the animals are in a familiar setting, there is more interaction; in a strange arena, there is less. Anxiolytics generally promote social contact as demonstrated by our current investigation, which demonstrates the test drug's antidepressant activity (Table 4).

Table 10: Antidepressant Activity of Passiflora edulis using Social Interaction Test

Values were expressed in mean±SEM; n=6 ***p<0.001, **p?0.01 and *p? 0.05 when compared to control

3.2.5 Estimation of Oxidative Stress Parameters (BDNF, TBARS and GSH) in Brain Homogenate

The study found that hydro alcoholic extract of Passiflora edulis significantly influenced the Oxidative stress parameters levels in mice. The experimental control mice showed significant changes in Oxidative stress parameters compared to normal control mice. Concurrent treatment with hydro alcoholic extract of Passiflora edulis also showed a significant decline in Oxidative stress parameters levels compared to EC group mice (Figure 2-4).

Figure 2: Estimation of BDNF in Brain Homogenate

Values were expressed in mean±SEM; n=6 ***p<0.001, **p?0.01 and *p? 0.05 when compared to control

Figure 3: Estimation of Catalase in Brain Homogenate

Values were expressed in mean±SEM; n=6 ***p<0.001, **p?0.01 and *p? 0.05 when compared to control

Figure 4: Estimation of Reduced Glutathione (GSH) in Brain Homogenate