14.3.1.6 Antiallergic and Antitussive Effects
Shang et al. evaluated antitussive, anti-asthmatic, and expectorant activities of
various fractions/phytochemicals (20, 24, and 30) from A. scholaris leaves (Shang
et al. 2010). The antitussive activity was evaluated in various animal models
(Ammonia or sulfur dioxide-induced mice coughing and citric acid-induced guinea
pigs coughing) while histamine-induced bronchoconstriction in guinea pig was
used for the evaluation of the anti-asthmatic activity. Codeine phosphate was used
as a positive control in the antitussive screening, while aminophylline is in bronchoconstriction and ammonium chloride is used in case of expectorant activity. In
ammonia liquor-induced cough in mice, among the various fractions evaluated, the
alkaloid rich fraction exhibited a significant reduction in the coughing frequency
(30.7 and 39.3% for 50 and 100 mg/kg of alkaloid rich fraction), while these
activities were comparatively lesser than the codeine phosphate (55.4% at 30 mg/
kg). In sulfur dioxide-induced cough in mice, alkaloid rich fraction (100 mg/kg)
exhibited a 62.2% increment in the cough latent period, whereas codeine phosphate
(30 mg/kg) resulted in 83.2%. A similar kind of results was obtained in citric
acid-induced cough in guinea pigs wherein a 153.8 and 419.0% increment in the
latent period of cough with the alkaloidal fraction (100 mg/kg), and codeine
phosphate (30 mg/kg) groups, with a cough inhibition frequency of 62.4, and
91.9%, respectively. In the anti-asthmatic effects in guinea pigs, alkaloid rich
fraction (79.9% at 200 mg/kg) exhibited an increased tumble and delitescence of
convulsion with that of aminophylline group (90.1% at 100 mg/kg). In expectorant
effect analysis, ammonium chloride (1500 mg/kg) and the alkaloids fraction (at 60
and 120 mg/kg) could markedly enhance tracheal phenol red output (112.7 and
152.1, 138.6% increase, respectively).
The preliminary screening highlighted the potential role of alkaloid rich fraction
in exhibiting antitussive and anti-asthmatic effects. Hence, the study was further
proceeded with the alkaloids fraction and main alkaloids (20, 24, and 30). In
ammonia-induced cough, i.g. administration of 20 (10 mg/kg) and 24 (5 mg/kg)
resulted in 38.9 and 34.1% increment in the latent period of cough in mice, and
these are comparable with the codeine phosphate (30 mg/kg, i.g., resulted in 47.6%
increment). The same trend was observed within the case of anti-asthmatic effect
screening. At a dose of 10 mg/kg, the 20 group increased the tumble and delitescence of convulsion of guinea pigs by 63.0% while aminophylline group resulted in
96.3% of the parameters.
Qin et al. evaluated the antitussive effects of 43–48 (Qin et al. 2015b). In
ammonia-induced cough (mice), the total alkaloids from the inadequately dried
leaves exhibited a lesser % inhibition (38.0 and 27.2% at 20 and 10 mg/kg) than the
dried leaves (58.0 and 45.6% at 20 and 10 mg/kg). Codeine phosphate (30 mg/kg)
was used as a positive control that resulted in 77.6% inhibition.
Zhao et al. identified various alkaloids (20, 24, 75, and 30) from the ethanolic
extract of A. scholaris leaves and evaluated the effects in airways allergic conditions
(Zhao et al. 2017). Ovalbumin-induced airways allergic inflammatory models in SD
rats were used in the study, and dexamethasone (2 mg/kg, once daily) was used as a
484
A. T. Paul et al.
Shang et al. evaluated antitussive, anti-asthmatic, and expectorant activities of
various fractions/phytochemicals (20, 24, and 30) from A. scholaris leaves (Shang
et al. 2010). The antitussive activity was evaluated in various animal models
(Ammonia or sulfur dioxide-induced mice coughing and citric acid-induced guinea
pigs coughing) while histamine-induced bronchoconstriction in guinea pig was
used for the evaluation of the anti-asthmatic activity. Codeine phosphate was used
as a positive control in the antitussive screening, while aminophylline is in bronchoconstriction and ammonium chloride is used in case of expectorant activity. In
ammonia liquor-induced cough in mice, among the various fractions evaluated, the
alkaloid rich fraction exhibited a significant reduction in the coughing frequency
(30.7 and 39.3% for 50 and 100 mg/kg of alkaloid rich fraction), while these
activities were comparatively lesser than the codeine phosphate (55.4% at 30 mg/
kg). In sulfur dioxide-induced cough in mice, alkaloid rich fraction (100 mg/kg)
exhibited a 62.2% increment in the cough latent period, whereas codeine phosphate
(30 mg/kg) resulted in 83.2%. A similar kind of results was obtained in citric
acid-induced cough in guinea pigs wherein a 153.8 and 419.0% increment in the
latent period of cough with the alkaloidal fraction (100 mg/kg), and codeine
phosphate (30 mg/kg) groups, with a cough inhibition frequency of 62.4, and
91.9%, respectively. In the anti-asthmatic effects in guinea pigs, alkaloid rich
fraction (79.9% at 200 mg/kg) exhibited an increased tumble and delitescence of
convulsion with that of aminophylline group (90.1% at 100 mg/kg). In expectorant
effect analysis, ammonium chloride (1500 mg/kg) and the alkaloids fraction (at 60
and 120 mg/kg) could markedly enhance tracheal phenol red output (112.7 and
152.1, 138.6% increase, respectively).
The preliminary screening highlighted the potential role of alkaloid rich fraction
in exhibiting antitussive and anti-asthmatic effects. Hence, the study was further
proceeded with the alkaloids fraction and main alkaloids (20, 24, and 30). In
ammonia-induced cough, i.g. administration of 20 (10 mg/kg) and 24 (5 mg/kg)
resulted in 38.9 and 34.1% increment in the latent period of cough in mice, and
these are comparable with the codeine phosphate (30 mg/kg, i.g., resulted in 47.6%
increment). The same trend was observed within the case of anti-asthmatic effect
screening. At a dose of 10 mg/kg, the 20 group increased the tumble and delitescence of convulsion of guinea pigs by 63.0% while aminophylline group resulted in
96.3% of the parameters.
Qin et al. evaluated the antitussive effects of 43–48 (Qin et al. 2015b). In
ammonia-induced cough (mice), the total alkaloids from the inadequately dried
leaves exhibited a lesser % inhibition (38.0 and 27.2% at 20 and 10 mg/kg) than the
dried leaves (58.0 and 45.6% at 20 and 10 mg/kg). Codeine phosphate (30 mg/kg)
was used as a positive control that resulted in 77.6% inhibition.
Zhao et al. identified various alkaloids (20, 24, 75, and 30) from the ethanolic
extract of A. scholaris leaves and evaluated the effects in airways allergic conditions
(Zhao et al. 2017). Ovalbumin-induced airways allergic inflammatory models in SD
rats were used in the study, and dexamethasone (2 mg/kg, once daily) was used as a
484
A. T. Paul et al.