Abstract:
The popular edible mushroom Ganoderma lucidum(strain GL-4) has been widely used for the general promotion of health and longevity in Asian countries. The present study was carried out to evaluate the antibacterial and antioxidant activity of the methanolic extract of Ganoderma lucidum. The phytochemicals evaluation reveals the presence of Flavonoids, Steroids, Terpinoids, Alkaloids, Gums carbohydrates, Saponins & Tannins.
The antibacterial and antifungal activity of methanolic extract of Ganoderma lucidum was evaluated with selected twelve bacterial pathogenic such as Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus etc and one fungi was Candida albican. For antimicrobial test, disc diffusion technique was used and the zone of inhibition of microorganisms was measured in mm. The extract of G. lucidum showed moderate antimicrobial activities against the selected strains and maximum inhibition zone 15 mm was recorded from 1500ug/disc of aqueous extract of G. lucidum against Escherichia coli and minimum (8mm) by the Salmonella paratyphi, Betahemolytic streptococcus, Beta megaterinium, and Vibrio mimicus at 1000ug/disc of extract. The methanolic extract showed the maximum antifungal activity 11.5mm inhibition zone was recorded from 1500ug/disc of extract against Candida albican.
These extracts were also checked for their cytotoxicity using a sensitive in vitro Brine shrimp lethality bioassay. The results of brine shrimp lethality bioassay are showed different mortality rate at different concentration. The mortality rate of brine shrimp napulii was found to be increased with the increase with the concentration of the sample.
The antioxidant effect of methanolic extract of G. lucidum was significant in the DPPH method used. Free radical scavenging abilities of the test samples were determined by measuring the change in absorbance of DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) at 517 nm by the UV-Spectrophotometer. Concentration providing 50% inhibition (IC50) was calculated from the graph plotted inhibition percentage versus concentration of the extract. IC50 value of the standard and methanol extract of G. lucidum were 12.6 ug/ml and 581.52 g/ml respectively. So, comparison with the ascorbic acid, it is clear that plant extracts possess moderate antiradical activity. In conclusion, Further investigations are needed to identify the active constituents and the exact mechanism(s) of action responsible for the reported antimicrobial, cytotoxicity and antioxidant properties of G.lucidum.
Description:
This thesis submitted in partial fulfillment of the requirements for the degree of Bachelor of Pharmacy (B.Pharm) of East West University, Dhaka, Bangladesh.