Antifungal Efficacy of Marine Macroalgae against Fungal Isolates from Bronchial Asthmatic Cases

Abstract

Fungal sensitization is very common in bronchial asthmatic cases, and the connection with airway colonization by fungi remains uncertain. Antifungal therapy failure is a significant fraction of the cost and morbidity and mortality in the majority of the asthmatic cases. Hence, the present study aimed to investigate the antifungal activity of five marine macroalgae—Acanthaophora specifera, Cladophoropsis sp., Laurencia paniculata, Tydemania sp., and Ulva prolifera—which were tested on selected fungal pathogens isolated from 15 sputum of 45 bronchial asthmatic patients. The highest antifungal activity was observed in ethanol fractions of L. paniculata followed by U. prolifera, Cladophoropsis sp., A. specifera, and Tydemania sp. The minimum fungicidal concentration and minimum inhibitory concentration values of the ethanolic fractions of algal species were found to be 125–1000 µg/mL and 125–500 µg/mL, respectively. The algal extracts contained terpene alcohol, diterpene, steroids, sesquiterpene, and sesquiterpene alcohol, as determined by GC–MS/MS analyses. The present study shows that the marine macroalgae containing bioactive compounds had excellent inhibitory activity against a variety of fungal pathogens, which may be useful for combating fungal infections and recovering from chronic asthmatic states.

Efficacy and Mechanism of Traditional Medicinal Plants and Bioactive Compounds against Clinically Important Pathogens

“…These metabolites offer clues to manufacture new structural types of antimicrobial and antifungal chemicals that are comparatively safe to humans [62]. The classes of secondary metabolites that have greater antimicrobial properties are flavonoids (flavones, flavonols, flavanols, isoflavones, anthocyanidins), phenolic acids (hydroxybenzoic, hydroxycinnamic acids), stilbenes, lignans, quinones, tannins, coumarins (simple coumarins, furanocoumarins, pyranocoumarins), terpenoids (sesquiterpene lactones, diterpenes, triterpenes, polyterpenes), alkaloids, glycosides, saponins, lectins, steroids, and polypeptides [6,16,56,62,[73][74][75][76][77][78][79][80][81][82][83]. These compounds have copious mechanisms that underlie antimicrobial activity, e.g., disturbing microbial membranes, weakening cellular metabolism, control biofilm formation, inhibiting bacterial capsule production, attenuating bacterial virulence by controlling quorum-sensing, and reducing microbial toxin production [3][4][5][6][73][74][75][76][77][78][79][80][81][82][83][84][85].…”

“…Quercetin 1Rutin 2Naringenin 3sophoraflavanone (4) Tiliroside (5) 2, 4, 6-trihydroxy-30methyl chalcone (6) Acacetin 7Apigenin (8) Morin (9) Rhamnetin (10) Lipophilic 3-arylidene (11) Coumarins (12) Thymol (13) Eugenol (14) Cinnamaldehyde (15) Carvone (16) Carvacrol (17) Galangin (18)…”

“…Hydrophilic flavonoids such as 6-aminoflavone (28), 6-hydroxyflavone (29), apigenin (8), chrysin (24), daidzein (30), genistein (31), auronol (32), and phloretin (25) (Figure 2) have inhibitory effects on E. coli biofilm formation [133,134]. In addition, Phloretin (25) inhibited fimbriae formation in E. coli by reducing the expression of the curli genes (csgA, csgB) and toxin genes (hemolysin E, Shiga toxin 2) [6], eventually inhibiting the formation of biofilm. Hence, phloretin (25) is well known as an antibiotic resistant compound.…”

“…These augmentations of antibiotic resistance and higher recurrence rates of such common infections have a great impact on our society [3][4][5]. Several investigations associated with antimicrobial resistance predict that the mortality toll owing to antimicrobial resistance may exceed 10 million by 2050, theoretically leading to greater mortality in the context of other infectious diseases and malignancies [6]. It is well known that infections are generally difficult to treat due to the development of biofilm in the host, which aids the proliferation of microbes as well as the aggressiveness of the infections [7].…”

A Review on Marine Algae and Its Applications

“…The eminent fungicidal activity was found in marine macroalgae to recover patients from chronic asthmatic states. In particular, L. paniculata was studied to have excellent antifungal activity and so it is recommended as a promising candidate to attain a novel antifungal agent [81].…”