Mitigative Effects of Coconut Oil and Its Water on the Lungs of Male Albino Rats Exposed to Petrol Vapour

This study examined the effects of Petrol or Premium Motor Spirit (PMS) vapour on lungs and the impact of coconut oil and coconut water in ameliorating its degenerative effects. Thirty-five albino rats were grouped into seven groups (n= 5). Groups 1, 2,3,4,5, and 7 were exposed to PMS vapour using an inhalation chamber, 8 hours daily for two weeks. Groups 1 and 2 were treated with 0.4ml/kgb.w coconut oil and coconut water respectively; group 3 was treated with a regular drug (indapamine) at 0.4ml/kgb.w; and groups 4 and 5 were treated with 0.2ml/kgb.w coconut oil and coconut water respectively. Group 6 was negative control and were neither exposed nor treated while group 7 was positive control, exposed to petrol vapour but not treated. Histological analysis showed that the lungs of the experimental test groups indicated degenerative changes in the ultrastructural integrity of interstitium cells. The lungs showed a significant decrease (p < 0.05) in the glutathione (GSH) level on exposure for two weeks when compared with the negative control. It was also observed that the level of malondialdehyde (MDA) increased significantly in all exposed groups compared with the negative control. Treatment with coconut water significantly (p < 0.05) reduced the effects of PMS vapor on the levels of GSH and MDA when compared with the other groups. Hence, treatment with coconut water and oil may provide a useful preventive measure against tissue injury consequent to exposure to PMS vapour experienced in our houses and at petrol filling stations. Abstract

mitigating effects that coconut oil and its water have on the damage caused d by PMS inhalation.

Procurement and Preservation of Coconut Water
The coconuts were bought from Oja market in Ota, Ogun state and the coconut water were obtained freshly from three coconuts daily.

Extraction of Coconut Oil
Cold extraction method was used for extracting coconut oil from the coconut milk by breaking the emulsion without heating.
The edibles part of coconut obtained from a fully developed brown coconut were cut into tiny pieces and blended with a blender. The blended coconut was filtered using cheesecloth into a clean bucket to remove the milk. The milk was left for two days to separate, leaving the oil to rise to the top and the coconut milk to settle at the bottom of the jar. The coconut oil was scooped into plain sample bottles and stored in a dark place away from sunlight.

Experimental Animals
Thirty-five male albino rats were purchased from a farmhouse in Lagos University Teaching Hospital. They were housed in plastic cages with net covers for ventilation and subjected to a standard environmental condition (12:12 hour light: dark cycle). The rats were fed ad-libitum. Wood shavings were used as beddings for the animals. The beddings were changed daily to avoid buildup of toxic ammonia levels. The rats were allowed two weeks acclimatization period prior to exposure. The care of the experimental animals was in accordance to all the necessary rules and regulations in animal research.

Animal Grouping and Exposure
The rats were divided into seven (7) groups, including the positive and negative control group. Each group contained five (5) animals to avoid overcrowding and to allow easy accessibility and identification of the animals in the course of the research. Using an inhalation chamber, all the groups, excluding the negative control group were introduced to PMS by inhalation respectively and proper precautions were taken 8 hours daily for two weeks after which treatment was administered for one week. The weight of each rat was taken before and after treatment. Using a measuring cylinder, 500ml of PMS was measured and distributed among five

Biochemical Analysis
At the end of the experiment, the albino rats were sacrificed by cervical dislocation. The lungs were harvested. Histological preparations were made from these tissues for histological analysis.
The lungs of the rats in each group were used to carry out analysis on oxidative stress and blood samples were taken for lipid profile.

Histopathology Procedure
Histopathology is the microscopic study of diseased tissue.
It is performed by examining a thin tissue section under light microscopes. The tissues were fixed with neutral formalin 10 %, embedded in paraffin, and then manually sectioned with a microtome to obtain 4-5μm thick paraffin sections. Dewaxed sections were then stained with hematoxylin and eosin (H&E) dyes.
After staining, a very thin glass was placed over the tissue sections to protect them and to enhance the optical evaluation of the tissues.

Method for Homogenizing Sample
Harvested organs of the animal were prepared by washing them

Determination of Triacylglycerol (TAG) Concentration:
Triacylglycerol is the main storage form of fatty acids. Triacylglycerol measurement is used in diagnosis and treatment of diseases involving lipid metabolism.

Determination of Catalase (CAT) Activity: Catalase (CAT)
activity was determined according to Sinha [8]. It was assayed

Determination of Reduced Gluthathione (GSH) Level:
The reduced glutathione (GSH) content of liver tissue as non-protein sulphydryl was estimated according to the method described by [9]. To the homogenate 10 % TCA was added, centrifuged. Hoc Test. Difference between groups were considered significant at p < 0.05.

Histology
Histopathology of the lungs of the experimental rats.

Discussion
The toxicity of PMS vapour as well as the mitigating effect of coconut oil and coconut water on the levels of serum lipid profile    showed a significant (p < 0.05) decrease compared to groups 6 and 7. The catalase (CAT) activity of the animals is presented in Figure   7. There is a significant (p < 0.05) decrease in group 1 compared to group 6. Group 2 showed a significant (p < 0.05) increase compared to groups 3 and 4. Group 5 showed a significant (p < 0.05) increase compared to group 7. The superoxide dismutase (SOD) activity of the animals is presented in Figure 8. Group 1 sowed a significant      of all the rats exposed to PMS vapour is represented in Table 2. The average uptake of inhalation exposure was not constant. The total average uptake of inhalation of exposure is 30 ± 6.84mg/kgb.w/ day. Coconut oil and coconut water have been known to have antioxidant and anti-inflammatory properties Cocoinfo International [11]. Coconut has been used to cure many illnesses and diseases and this is due to the biologically active compounds it possesses that act as anti-inflammatory and antioxidants (Table 1).  Note: *The average uptake of inhalation exposure for 14 days is not constant. The total average uptake of inhalation exposure is 30 ± 6.84mg/kg/day.
In this present study, it was observed that the exposure to  In this present study, the level of MDA significantly (p < 0.05) increased in the positive control when compared to the negative control. This is in agreement with previous studies that affirmed that exposure to petroleum products including PMS leads to increased MDA in rats and humans [13][14][15]. A significant (p < 0.05) increase in the MDA level of the positive control, compared with the other groups that were exposed to PMS vapour and treated showed that treatment with coconut oil and water may have reduced the abnormal generation of reactive oxygen species.
Lipid peroxidation results from the release of free radicals that can cause tissue damage by reacting with polyunsaturated fatty acids in cellular membranes to form malondialdehyde (MDA) [15]. Volatile hydrocarbons primarily get absorbed into blood via respiratory tract, leading to toxic effect on the lungs [16]. Several reports have shown that inverse relationship exists between lipid peroxidation and glutathione activities during stress [15]. Reactive   [23,24]. Glutathione protects cells from the free radicals produced through oxidation, while catalase catalyzes the decomposition of hydrogen peroxide to water and oxygen [23,25].
There was a significant (p < 0.05) increase in the levels of TAG and Chol in the groups exposed to PMS vapour. The significant (p < 0.05) increase in TAG and Chol observed is an indication that inhalation on exposure to petrol vapour affects lipid metabolism.
On one hand, lipid metabolism is affected once there is liver damage since the disturbance of cell membrane integrity is likely to cause some membrane lipids to be released into circulation; while on the other hand, it causes the tissue to compromise its effectiveness in regulating lipid metabolism [14]. There was a significant (p < 0.05) increase in the LDL levels of groups 2, 3, and positive control when compared with the negative control and a significant (p < 0.05) decrease in the HDL of groups 1, 3, 4, 5 and the positive control, when compared with the negative control. In the histology study of the lungs, inflammation was observed in the groups exposed to PMS vapour. No significant changes were observed in the lungs of the negative control. The histology study of group 1 which was exposed to PMS vapour and treated with coconut oil at 0.4ml/kgb.w showed alveolar air spaces with mild infiltration of surrounding interstitium by inflammatory cells in the lungs, indicating mild pulmonary inflammation.
[26] investigated the hypothesis that exposure of healthy volunteers to concentrated particles is associated with an influx of inflammatory cells into the lower respiratory tract and concluded that ambient air particles are capable of inducing a mild inflammation in the lower respiratory tract. The increase in the number of inflammatory cells has been reported as alveolitis, which refers to the cell types that are most abundant [26]. Pneumonitis is a general term that refers to the inflammation of lung tissue and is caused by irritants. The histology study of group 2, which was exposed to PMS vapour and treated with coconut water of 0.4ml/kg, showed reduction in alveolar air spaces with moderate infiltration of surrounding interstitium by inflammatory cells in the lungs. The histology study of group 3, which was exposed to PMS vapour and treated with 2ml indapamine showed the lungs alveolar air spaces with mild infiltration of surrounding interstitium by inflammatory cells in the lungs. Thus, indicating mild pulmonary inflammation. This showed that indapamine 2.5mg, a diuretic pill had little significance on the effect of PMS.
The histology study of group 4, which was exposed to PMS vapour and treated with coconut water at 0.2ml/kgb.w showed the lungs alveolar air spaces, with infiltration of surrounding interstitium by aggregates of inflammatory cells forming granulomas. Thus, indicating granulomatous pulmonary inflammation. This showed that coconut water in low concentration had little or no significant effect of PMS vapour on the lungs of male albino rats. The histology study of group 5, which was exposed to PMS vapour and treated with coconut oil at 0.2ml/kgb.w concentration showed a reduction

Conclusion
The results obtained show that exposure to PMS is toxic to the lungs and could cause inflammation. It also shows that exposure to petrol vapour increases oxidative stress and reduces the activities of antioxidant enzymes. Coconut oil and its water have antioxidant and anti-inflammatory properties that may mitigate the effect of PMS vapour in the body.