Pharmacological Basis For Antianaphylactic, Antihistaminic And Mast Cell Stabilization Activity Of Ocimum Sanctum
G Sridevi, P Gopkumar, S Ashok, C Shastry
allergy., antihistaminic, hypersensitivity, ige, mast cell degranulation
G Sridevi, P Gopkumar, S Ashok, C Shastry. Pharmacological Basis For Antianaphylactic, Antihistaminic And Mast Cell Stabilization Activity Of Ocimum Sanctum. The Internet Journal of Pharmacology. 2008 Volume 7 Number 1.
Purpose: The present paper reports the antianaphylactic, antihistaminic and mast cell stabilization activity of Ocimum
Allergy is one of the common diseases that affect mankind with diverse manifestations. The prevalence of allergy and asthma has risen in the recent years despite an improvement in the general health of the population 1 . Allergic diseases are responsible for significant morbidity and have severe economic impact 2 . Various epidemiological studies have identified the causes for an increase in the prevalence of upper and lower respiratory tract allergic diseases. Some of the postulated reasons are increasing environmental pollution 3 and increased predisposition of individuals producing excessive IgE through a major change in the gene pool, changing lifestyles, and an increasing awareness of the disorders 4 .Intensive research during the last several decades has highlighted the role of lymphocytes, immunoglobulins, mast cells, and various autacoids in the etiopathogenesis of allergic conditions. Inspite of the voluminous literature on the subject, the treatment of allergic diseases continues to be far from satisfactory. The available treatment options for upper and lower respiratory tract allergic diseases have major limitations owing to low efficacy, associated adverse events, and compliance issues 5 .
A review of the literature mentions the use of plant in allergic conditions. However, there is no scientific data available to authenticate the folklore claim as well there is no scientific evaluation regarding its activity profile. Hence the present study was undertaken to evaluate the antianaphylactic, antihistaminic and mast cell stabilization activity of alcoholic extract of Ocimum
Materials And Methods
Plant leaves were collected localy. The leaves were authenticated by Dr. Gopalakrishna Bhat, Department of Botany, Poorna Prajna College, Udupi, Karnataka, India. A voucher specimen (O.S 5/99) was deposited in the herbarium of our institute.
Wistar rats (175-200 g) and guinea pigs (400-600 g) of either sex are procured from Indian Institute of Sciences. They are maintained under standard conditions (temperature 22 ± 2 ° C, relative humidity 60±5% and 12 h light/dark cycle)0.The animals were housed in sanitized polypropylene cages containing sterile paddy husk as bedding. They had free access to standard pellet diet and water
Histamine and horse serum were procured from Sigma Chemicals and toluidine blue from Loba-Chemie, Mumbai. Elisa kit for IgE was supplied by Orion diagnostics, Espoc, Finland. All other chemicals and reagents were procured from Hi-Media Laboratories limited, Mumbai.
Twenty-eight rats were sensitized by injecting subcutaneously 0.5 ml of horse serum along with 0.5 ml of triple antigen containing 20,000 million
Serum total IgE was quantified with an ELISA protocol according to the manufacturer's instructions. Briefly, the plates were coated with affinity-purified rabbit anti IgE overnight at 4 °C and then blocked with 1% bovine serum albumin (BSA) in phosphate buffered saline (PBS) for 1 h at 37°C. The serum samples and appropriate dilutions of a standard IgE preparation were placed in the wells, and the plates were incubated for 3 h at 4 °C. Sample blank wells were treated similarly but without serum. The bound IgE was detected with polyclonal goat anti IgE antibodies (incubation for 1 h at 37 °C), followed by HRP-conjugated rabbit anti-goat antibodies (incubation for 1 h at 37 °C). The plates were developed by the addition of O-phenylene diamine and read in an ELISA (Anthos HT-II, USA) plate reader at 490 nm 910 .
Mast cell stabilizing activity
Thirty-two rats were divided into four groups of eight animals in each group. Group I served as control and received vehicle (water). Group II (sensitized control group, received only water), Groups III (test extract) and IV (prednisolone) were sensitized by injecting 0.5 ml of horse serum subcutaneously along with 0.5 ml of triple antigen containing 20,000 million
Histamine-induced bronchospasm in guinea pigs
Bronchospasm was induced in guinea pigs by exposing them to 1% histamine aerosol under constant pressure (1 kg/cm 2 ) in an aerosol chamber (24 × 14 × 24 cm) made of perplex glass. Of the two groups of six animals each, Group I served as control and Group II received test ethanolic extract 400 mg/kg, p.o.,once a day for 5 days. The animals were exposed to 1% histamine aerosol under constant pressure (1 kg/cm 2 ) in an aerosol chamber on day 0 without any treatment. The end point, preconvulsive dyspnea (PCD) was determined from the time of aerosol exposure to the onset of dyspnea leading to the appearance of convulsions 141516 . As soon as PCD commenced, the animals were removed from the chamber and exposed to fresh air. This PCD was taken as day 0 value. On days 1 and 5, 2 h after the administration of the drug, the time for the onset of PCD was recorded as on day 0.
The results of various studies were expressed as mean ± SEM and analyzed statistically using one-way ANOVA, followed by Bonferroni's multiple comparison post-hoc test or Chi- square test or unpaired Student's '
Effect of extract on anaphylactic shock-induced bronchospasm in sensitized rats
Test extract protected the sensitized rats against anaphylactic shock in a dose-dependent manner. In control rats, intravenous antigen challenge (horse serum) caused shock in 100% of the animals, while in treated rats (400 mg/kg of etanolic extract), the onset of symptoms of shock was delayed (P
Values are mean ± SEM except for mortality, which is expressed as percentage, n=7 in each group; Total score: F=50508, df =27, P=0.0050; Onset of symptoms: F=20.51, df = 27, P=0.0001. *P<0.05, # P<0.001 as compared to control. (ANOVA followed by Bonferroni’s multiple comparison post hoc tests for total score and onset of symptoms. Chi-square test for mortality).
Mast cell stabilizing potential of O. leaf extract
Antigen challenge resulted in significant degranulation of the mesentric mast cells (approximately 88%, P
Values are mean ± SEM, n=8 in each group. * Significantly different from sensitized control (P<0.0001).
Effect on histamine-induced bronchospasm
Values are mean ± SEM, n=6 in each group. * (P<0.008) as compared to control on day 5 (unpaired Students‘t’ test)
Discussion And Conclusion
Experimental animal model of asthma is characterized by allergen-induced immediate airway constriction and late airway reactivity to a pharmacological vasoconstrictor such as histamine and leukotrienes. Histamine is a central mediator in the pathogenesis of allergic and inflammatory disorders. In the present study, O.
Basophils, mast cells, and their preformed
Experimental results indicated the potent benefits of O.
Authors are greatfull to Chemical Engg, department, National Institute of technology Surathkal, Karnataka for help in initial quantification of Phytoconstituents.