Development and Comparative Study of Phytosomes of Ethanol Extracts of Bridelia Ferruginea and Bryophyllum Pinnatum Leaves for Enhanced Antimicrobial and Ulcer Protective Properties

Abstract

Herbal products have been found to show less activity in in vivo studies when compared to their activity in in vitro studies. Most of the phytochemicals in plants such as flavonoids, terpenoids and polyphenols are highly polar in nature and are unable to cross the highly lipid-rich biological membranes which lead to poor bioavailability. Phytosome is a natural product obtained by reaction of a stoichiometric amount of plant extract and phospholipids using a suitable solvent. Bridelia ferruginea (Euphorbiaceae) and Bryophyllum pinnatum Lam. (Crassulacea) are locally used in the treatment of various diseases. This study was based on the development of phytosomes from ethanol extracts of Bridelia ferruginea and Bryophyllum pinnatum leaves for enhanced antimicrobial and ulcer protective properties. The phytochemical screening of both plant extracts revealed the presence of tannins, carbohydrates, hydrogen cyanide, phenols, flavonoids, reducing sugar, alkaloids, steroids, terpenoid, saponin and glycosides. Higher concentration of phenols (1911.01 ± 2.308 mg/100g) was found in Bridelia ferruginea extract than that of (66.67 ± 12.73 mg/100g) found in Bryophyllum pinnatum extract. Both extracts (B. pinnatum and B. ferruginea) showed free radical-scavenging activity against 2, 2, diphenyl-1- picryl hydrazyl (DPPH), total antioxidant capacity (TAC) and ferric reducing antioxidant power (FRAP) in all tested concentrations (15.63 ¬¬¬¬– 1000 µg/ml). B. ferruginea and B. pinnatum showed their highest ferric reducing antioxidant power of 174.29 ± 22.42 µMfe2+ /g and 672.46 ± 23.05 µMfe2+ /g respectively at the concentration of 1000 µg/ml. Scanning electron microscopy revealed that Bridelia ferruginea phytosome complexes have rougher surface morphology when compared to surface morphology of Bryophyllum pinnatum phytosome complexes at x1000 magnification. The Fourier Transform Infrared Spectroscopy spectrum peaks revealed interaction between individual extracts and phospholipid in the formulation of phytosomes. The presence of functional groups was detected which include alcohols (O-H) at 3324.8 cm-1 – 3358 cm-1, aliphatic compound (C-H) at 2922.2 cm-1, 2918.5 cm-1, carbonyl compounds (aldehydes and ketones; C=O) at 1710.8 cm-1 - 1736.9 cm-1. The entrapment efficiency showed that all the complexes have more than 90% entrapment. The highest entrapment of 97.42% was found in 1:5 phytosome complex of Bryophyllum pinnatum and the least entrapment of 94.14% was found in 1:5 phytosome complex of Bridelia ferruginea. In vitro drug release was higher in Bridelia ferruginea phytosome complexes than in the Bryophyllum pinnatum phytosome complexes within 3 h of investigation. It was observed that 1:1 Bridelia ferruginea phytosomes released 65.87% of its extract within 3 h of investigation while 1:1 Bryophyllum pinnatum phytosome released 13.47% within the same time interval. Bryophyllum pinnatum and Bridelia ferruginea showed no zone of inhibition with the selected bacterial isolates. The acute toxicity study on both extracts was greater than 5000 mg/kg. Both plants and their phytosome complexes exhibited ulcer protective property. The highest percentage protection was found among groups pretreated with 400 mg/kg of 1:3 phytosome complexes of Bridelia ferruginea which gave 78.14% mucosa protection and Bryophyllum pinnatum that produced 77.86% protection. There was a significant increase (p < 0.05) in pH, HDL, SOD, CAT and GPx among groups pretreated with extracts and phytosomes when compared to the pH, HDL, SOD. CAT and GPx activity of the untreated group (control). However, significant decrease (p < 0.05) in gastric volume, total acidity, urea, creatinine, ALT, AST, ALP and MDA was observed among the pretreated groups when compared to the ulcer untreated group (control). Histological examination of the stomach tissues of rats revealed various degrees of necrosis on the mucosa tips of indomethacin-induced ulcerated rats.