Assessment and identification of bioactive metabolites from terrestrial Lyngbya spp. responsible for antioxidant, antifungal, and anticancer activities

Lyngbya from fresh and marine water produces an array of pharmaceutically bioactive therapeutic compounds. However, Lyngbya from agricultural soil is still poorly investigated. Hence, in this study, the bioactive potential of different Lyngbya spp. extract was explored. Intracellular petroleum ether extract of L. hieronymusii K81 showed the highest phenolic content (626.22 +/- 0.65 mu g GAEs g(-1) FW), while intracellular ethyl acetate extract of L. aestuarii K97 (74.02 +/- 0.002 mg QEs g(- 1) FW) showed highest flavonoid content. Highest free radical scavenging activity in terms of ABTS(center dot+) was recorded in intracellular methanolic extract of Lyngbya sp. K5 (97.85 +/- 0.068%), followed by L. wollei K80 (97.22 +/- 0.059%) while highest DPPH center dot radical scavenging activity observed by intracellular acetone extract of Lyngbya sp. K5 (54.59 +/- 0.165%). All the extracts also showed variable degrees of antifungal activities against Fusarium udum, F. oxysporum ciceris, Colletotrichum capsici, and Rhizoctonia solani. Further, extract of L. wollei K80 and L. aestuarii K97 showed potential anticancer activities against MCF7 (breast cancer) cell lines. GC-MS analyses of intracellular methanolic extract of L. wollei K80 showed the dominance of PUFAs with 9,12,15-octadecatrienoic acid, methyl ester, (Z,Z,Z) as the most abundant bioactive compound. On the other hand, the extracellular ethyl acetate extract of L. aestuarii K97 was rich in alkanes and alkenes with 1-hexyl2-nitrocyclohexane as the most predominant compound. Extracts of Lyngbya spp. rich in novel secondary metabolites such as PUFAs, alkanes, and alkenes can be further explored as an alternative and low-cost antioxidant and potential apoptogens for cancer therapy.