Antioxidant, Anti-Diabetic and Anti-Inflammatory Activities of Passifloara foetida grown in Sri Lanka

Passiflora foetida (Padagedi) is identified as an underutilized fruit in Sri Lanka, used in traditional medicine for several diseases. The objective of this study was to determine the antioxidant, anti-diabetic, and anti-inflammatory properties of the leaves and fruits of P. foetida. Methanol (100 %) was used to prepare the plant extracts. The antioxidant activity was determined using total phenolic content (TPC), total flavonoid content (TFC), total alkaloid content (TAC), 2,2-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging, ferric reducing antioxidant power (FRAP), and oxygen radical absorption capacity (ORAC) assays. The anti-diabetic effects of plant extracts were determined by using anti-glycation and anti-amylase inhibitory assays. Cell viability was analyzed by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. Based on the findings, the leaf extract of P. foetida showed a higher TPC (21.46±1.56 mg GAE/g of extract), TFC (4.25±0.23 mg QE/g of extract), TAC (4.37±6.50 mg/g of extract), DPPH (10.91±1.29 mg TE/g of extract), ABTS+ (105.80±18.62 mg TE/g of extract), FRAP (11.85±1.45 mg TE/g of extract), and ORAC (46.23±3.58 mg TE/g of extract) compared to its fruit extract. The anti-amylase and anti-glycation activities were high in the leaf extract of P. foetida (30.7% and 77.65 % respectively). The fruit extract of P. foetida had the highest cell viability and nitric oxide (NO) production-inhibition in RAW macrophage (264.7 cells) compared to the fruit extract. It can be concluded that P. foetida has good therapeutic properties, and could be a potential source for pharmaceuticals and nutraceuticals industries.