Anti-angiotensin converting enzyme (ACE) proteins from mycelia of Ganoderma lucidum (Curtis) P. Karst

Background: Ganoderma lucidum has been purported as a potent remedy in the treatment and prevention of several ailments, including hypertension. This study aimed to explore the anti-ACE potential of protein fractions from the mycelia of G. lucidum. Methods: Ganoderma lucidum mycelia were cultivated by submerged fermentation in a liquid medium containing brown sugar and spent brewer's yeast. Intracellular proteins were fractionated from mycelia crude water extract by ammonium sulphate precipitation, and their angiotensin converting enzyme inhibitory activity was evaluated. The potential anti-ACE protein fractions were further separated by RP-HPLC and characterised using proteomics platforms. Results: Preliminary result demonstrated that the mycelia crude water extract inhibited ACE at IC50 value of 1.134 +/- 0.036 mg/mL. Following protein fractionation and HPLC purification, the presence of highly potential anti-ACE proteins with the IC50 values less than 200 mu g/mL was detected. Characterisation of these proteins demonstrated the presence of four different antihypertensive-related proteins involved in the regulation of blood pressure through different mechanisms. Conclusions: This study suggests that the mycelia of G. lucidum has high potential in lowering blood pressure level due to the presence of several antihypertensive-related proteins such as cystathionine beta synthase-like protein, DEAD/DEAH box helicase-like protein, paxillin-like protein, and alpha/beta hydrolase-like protein.