Effects of aqueous and ethanolic extracts of costus (Saussurea lappa) against Pneumococcal TIGR4 growth

ABSTRACT

A long historical reputation for folk plant therapy has gained the trust of people. The World Health Organisation (WHO) states that 80% of the world's population relies on traditional medicinal plants. The roots of Saussurea lappa (S. lappa) were extracted by both aqueous and ethanol solutions before being investigated against Streptococcus pneumoniae ( S. pneumoniae) TIGR4. Inhibition zones were also measured. Statistical analysis demonstrated that the aqueous extract of S. lappa had an obvious bacteriostatic effect, whereas the ethanolic extract suppressed the bacterial cell densities at all experimental times. The bacterial viable counts showed that all pneumococci died at 5 hr post-inoculation when using 1% of 4 mg/ml S. lappa. On the other hand, live bacterial cells were detected until 11 hr in the absence of the plant extract. Moreover, disc diffusion methods illustrated a clear biological effect against S. pneumoniae. This highlights strong promise for S. lappa against this aggressive bacterium and might offer an alternative natural preventative candidate that possibly facilitates complications following respiratory viral infection (RVIs), such as coronaviruses.