Validation of Safety and Efficacy of Antitussive Herbal Formulations

Background: Cough is an important defensive pulmonary reflex that removes irritants, fluids or foreign materials from the airways. Frequently, cough is non-productive and requires suppression and opioid receptor agonists such as codeine are commonly used as antitussive agents. However, opioids produce side effects that include sedation, addiction potential and constipation. Novel cough suppressant therapies should maintain or improve upon the antitussive efficacy profile of opioids but with minimum or no side effects. Objective: To evaluate antitussive activity of combination of herbal medicines as formulations in sulphur dioxide - induced cough model in rats. Methodology: Wister rats of either sex, weighing 150 - 200 g, were divided into 7 groups (n = 6). Group 1 served as a control and received normal saline, groups 2 received codeine phosphate, group 3 and 4 received the coded market samples and groups 5, 6 and 7 received the test samples, respectively. Thirty or sixty minutes following administration, the rats were exposed to sulphur dioxide gas for 1 minute and then placed in an open chamber for counting of cough bouts. Results: The formulations exhibited cough inhibitions of between 15 and 27%, and 14 and 38%, with respect to the control group, 30 and 60 minutes after sample administration respectively. Conclusion: The herbal formulations demonstrated significant (p < 0.05) antitussive activity in sulphur dioxide induced cough model. Key words: Antitussive activity; herbal formulations; sulphur dioxide; coug

In vitro anti-viral activity of aqueous extracts of Kenyan Carissa edulis , Prunus africana and Melia azedarach against human cytomegalovirus

The aqueous extracts of three medicinal plants, Carissa edulis (Forssk.) Vahl (Apocynaceae), Prunus africana (Hook.f.) Kalkm (Rosaceae) and Melia azedarach L. (Meliaceae) have shown significant reduction in the replication of human cytomegalovirus (HCMV) in human embryonic lung (HEL) fibroblasts cells in vitro. Using the plaque inhibition assay for the determination of anti-viral activity, the HEL fibroblast cells cultured in 24 well plates were infected with 1 x 102 PFU 91S HCMV and treated with various concentrations of the extracts. The plaques formed were counted after 7 days incubation at 37\ub0C in 5% CO2 and the percent plaques inhibited were calculated against infected untreated control. The effective concentrations inhibiting plaque formation by 50% (EC50) was found between 40 to 80 \u3bcg/ml for all the extracts. The cell cytotoxic concentrations (CC50) for each of the three extracts, by the trypan blue exclusion test, gave a safe therapeutic index. These results have demonstrated the potential anti-viral activities of the extracts of the three medicinal plants at non-cytotoxic concentrations

In vitro anti-viral activity of aqueous extracts of Kenyan Carissa edulis , Prunus africana and Melia azedarach against human cytomegalovirus

The aqueous extracts of three medicinal plants, Carissa edulis (Forssk.) Vahl (Apocynaceae), Prunus africana (Hook.f.) Kalkm (Rosaceae) and Melia azedarach L. (Meliaceae) have shown significant reduction in the replication of human cytomegalovirus (HCMV) in human embryonic lung (HEL) fibroblasts cells in vitro. Using the plaque inhibition assay for the determination of anti-viral activity, the HEL fibroblast cells cultured in 24 well plates were infected with 1 x 102 PFU 91S HCMV and treated with various concentrations of the extracts. The plaques formed were counted after 7 days incubation at 37°C in 5% CO2 and the percent plaques inhibited were calculated against infected untreated control. The effective concentrations inhibiting plaque formation by 50% (EC50) was found between 40 to 80 μg/ml for all the extracts. The cell cytotoxic concentrations (CC50) for each of the three extracts, by the trypan blue exclusion test, gave a safe therapeutic index. These results have demonstrated the potential anti-viral activities of the extracts of the three medicinal plants at non-cytotoxic concentrations

Evaluation of the HIV-1 reverse transcriptase inhibitory properties of extracts from some medicinal plants in Kenya

Extracts from twenty two medicinal plants popularly used in preparing traditional remedies in Kenya were screened for activity against the HIV-1 reverse transcriptase. The screening procedure involved the use of tritium labeled thymidine triphosphate as the enzyme substrate and polyadenylic acid.oligodeoxythymidylic acid [poly(rA).p(dT)12-18] as the template primer dimer. Foscarnet was used as a positive control in these experiments. At a concentration of 100µg/ml, extracts from eight of these plants showed at least 50 per cent reverse transcriptase inhibition. This activity was abitrarily considered as significant. This indicates that there is the probability that some antiretroviral compounds could be identified and isolated from materials from these plants. [Afr. J. Health Sci. 2002; 9:81-90