Endophytic fungi from Cissus quadrangularis plant a promising source of bioactive compounds.

Cissus quadrangularis is a succulent, perennial plant belonging to the family Vitaceae typically found in Asia and Africa's tropical and subtropical forest zones. It is an ancient medicinal plant, containing phytosterols, polyphenols, flavonoids, carbohydrates, and ascorbic acid. Due to the presence of phytosterols it plays a crucial role in bone fracture healing. However, due to the limited resources of these medicinal plants there is a need to search for a reservoir of biologically active metabolites. This medicinal property of the plants therefore may be attributed to the endophytic fungi within the plant. This study includes isolation of endophytic fungi from C. quadrangularis and the characterization of fungal extracts. Three endophytes were isolated namely Colletotrichum gloeosporioides, Colletotrichum siamense and Phoma sp. The qualitative analysis of targeted metabolites from Cissus quadrangularis stem and fungal extracts of all the three endophytes showed the presence of phytosterols. Methanol extracts of endophytes and C. quadrangularis plant exhibit significant antioxidant and the radical scavenging activity because of the presence of β-carotene. The Ic50 value for stem and isolated endophytes was 5.748, 19.937, 7.00, and 6.493 respectively. This study will give further scope for studying the bone healing ability of phytosterol from the endophytic isolates of C. quadrangularis plant.