Dietary and bioactive properties of the berries and leaves from the underutilized Hippophae salicifolia D. Don grown in Northeast India

Scirpusin B isolated from Passiflora edulis Var. flavicarpa attenuates carbohydrate digestive enzymes, pathogenic bacteria and oral squamous cell carcinoma

Passiflora edulis Var. flavicarpa (passion fruit) generates vast waste (60-70%) in the form of peel and seed after the juice extraction. The study aimed to isolate Scirpusin B (SB) from passion fruit (PF) seed waste collected from Northeast India and to analyse its anti-radical, antibacterial, anti-diabetic, and anti-oral cancer activities. Scirpusin B was isolated following hydro-alcoholic extraction, fractionation, and column chromatography. The isolated fraction was further identified through NMR and mass spectroscopy. SB exhibited significant antiradical activity against six standard antioxidant compounds, indicating its commercial application. SB inhibited α-amylase (IC50 Value: 76.38 ± 0.25 µg/mL) and α-glucosidase digestive enzymes (IC50 Value: 2.32 ± 0.04 µg/mL), signifying its antidiabetic properties. In addition, SB showed profound antibacterial activity against eight gram-positive and gram-negative bacteria reported for the first time. Furthermore, SB inhibited SAS and TTN oral cancer cell proliferation up to 95% and 83%, respectively. SB significantly inhibited colonies of SAS and TTn cells in the clonogenic assay, attributing to its anticancer properties. The PI-FACS assay confirmed the ability of SB (75 µM) to kill SAS and TTn cells by 40.26 and 44.3% in 72 h. The mechanism of SB inhibiting oral cancer cell proliferation was understood through western blot analysis, where SB significantly suppressed different cancer hallmark proteins, such as TNF-α, survivin, COX-2, cyclin D1, and VEGF-A. The present study suggests that SB isolated from PF seed can add noteworthy value to the waste biomass for various industrial and medical applications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03876-6.

Optimization of polyphenol extraction from Hippophae salicifolia D. Don leaf using supercritical CO2 by response surface methodology

In this study, an eco-friendly supercritical carbon dioxide (SC-CO2) extraction of polyphenolic compounds from Hippophae salicifolia leaf was optimized to achieve the highest extraction yield with maximum total phenolic content (TPC) and minimum IC50. The central composite design was used to establish an experimental design for RSM. The effect of the pressure, temperature, carbon dioxide flow rate, and co-solvent amount was scrutinized using variance analysis (ANOVA). Under optimized condition (25.13 MPa, 47.53 °C, 14.47 g/min, and 2.43%), the experimental data (yield of extraction: 4.38%, TPC: 84.31 mg GAE/g, and IC50: 41.94 µg/mL) showed good agreement with the predicted values (yield of extraction: 4.53%, TPC: 83.37 mg GAE/g, and IC50: 40.2 µg/mL). Nine polyphenolic compounds: gallic acid, caffeic acid, ferulic acid, vanillic acid, p-coumaric acid, quercetin, myricetin, kaempferol, and rutin were analyzed in SC-CO2 extract using HPLC. SC-CO2 extraction was more selective for ferulic acid, myricetin, and quercetin extraction. The study results revealed that SC-CO2 extract had significant antibacterial activity against eight bacterial strains.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03358-1.