Intracellular ROS Scavenging and Anti-Inflammatory Activities of Oroxylum indicum Kurz (L.) Extract in LPS plus IFN-gamma-Activated RAW264.7 Macrophages

Oroxylum indicum (L.) Kurz has been used as plant-based food and herbal medicine in many Asian countries. The aim of the present study was to examine the antioxidant and anti-inflammatory activities of O. indicum extract (O. indicum) in RAW264.7 cells activated by LPS plus IFN-γ. The phytochemical compounds in O. indicum were identified by GC-MS and LC-MS/MS. Five flavonoids (luteolin, apigenin, baicalein, oroxylin A, and quercetin) and 27 volatile compounds were found in O. indicum. O. indicum presented antioxidant activities, including reducing ability by FRAP assay and free radical scavenging activity by DPPH assay. Moreover, O. indicum also suppressed LPS plus IFN-γ-activated reactive oxygen species generation in RAW264.7 macrophages. It possessed the potent anti-inflammatory action through suppressing nitric oxide (NO) and IL-6 secretion, possibly due to its ability to scavenge intracellular ROS. The synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectroscopy results showed the alteration of signal intensity and integrated areas relating to lipid and protein of the activated RAW264.7 macrophages compared to unactivated cells. This is the first report of an application of the SR-FTIR technique to evaluate biomolecular changes in activated RAW264.7 cells. Our results indicate that O. indicum may be used as a potential source of nutraceutical for the development of health food supplement or a novel anti-inflammatory herbal medicine

Synergism and the mechanism of action of the combination of alpha-mangostin isolated from Garcinia mangostana L. and oxacillin against an oxacillin-resistant Staphylococcus saprophyticus

Globally, staphylococci have developed resistance to many antibiotics. New approaches to chemotherapy are needed and one such approach could be to use plant derived actives with conventional antibiotics in a synergestic way. The purpose of this study was to isolate α-mangostin from the mangosteen (Garcinia mangostana L.; GML) and investigate antibacterial activity and mechanisms of action when used singly and when combined with oxacillin against oxacillin-resistant Staphylococcus saprophyticus (ORSS) strains. The isolated α-mangostin was confirmed by HPLC chromatogram and NMR spectroscopy. The minimum inhibitory concentration (MIC), checkerboard and killing curve were determined. The modes of action of these compounds were also investigated by enzyme assay, transmission electron microscopy (TEM), confocal microscopic images, and cytoplasmic membrane (CM) permeabilization studies. Results The MICs of isolated α-mangostin and oxacillin against these strains were 8 and 128 μg/ml, respectively. Checkerboard assays showed the synergistic activity of isolated α-mangostin (2 μg/ml) plus oxacillin (16 μg/ml) at a fractional inhibitory concentration index (FICI) of 0.37. The kill curve assay confirmed that the viability of oxacillin-resistant Staphylococcus saprophyticus DMST 27055 (ORSS-27055) was dramatically reduced after exposure to isolated α-mangostin (2 μg/ml) plus oxacillin (16 μg/ml). Enzyme assays demonstrated that isolated α-mangostin had an inhibitory activity against β-lactamase in a dose-dependent manner. TEM results clearly showed that these ORSS-27055 cells treated with this combination caused peptidoglycan and cytoplasmic membrane damage, irregular cell shapes and average cell areas were significantly larger than the control. Clearly, confocal microscopic images confirmed that this combination caused considerable peptidoglycan damage and DNA leakage. In addition, the CM permeability of ORSS-27055 was also increased by this combination of actives. Conclusions These findings provide evidence that isolated α-mangostin alone has not only some activity but also shows the synergistic activity with oxacillin against ORSS-27055. The chromone and isoprenyl structures could play a significant role in its action. This synergistic activity may involve three mechanisms of action. Firstly, potential effects of cytoplasmic membrane disruption and increases permeability. Secondly, inhibit β-lactamase activity. Finally, also damage to the peptidoglycan structure. We proposes the potential to develop a novel adjunct phytopharmaceutical to oxacillin for the treatment of ORSS. Future studies require clinical trials to establish if the synergy reported can be translated to animals and humans

Oroxylum indicum (L.) Kurz extract inhibits adipogenesis and lipase activity in vitro

Background: Oroxylum indicum (L.) Kurz (O. indicum) is found in Thailand. It has been used for the treatment of obesity. This study aimed to investigate the effects of an O. indicum extract (OIE) on the adipogenic and biomolecular change in 3T3-L1 adipocytes. Methods: Initial studies examined the chemical components of OIE. The cell line 3T3-L1 was used to establish potential toxic effects of OIE during the differentiation of pre-adipocytes to adipocytes. The inhibitory effect of OIE on lipid accumulation in 3T3-L1 cells was investigated. Moreover, the impact of OIE on pancreatic lipase activity was determined. In further experiments, Fourier Transform Infrared (FTIR) was used to monitor and discriminate biomolecular changes caused by the potential anti-adipogenic effect of OIE on 3T3-L1 cells. Results: Chemical screening methods indicated that OIE was composed of flavonoids, alkaloids, steroids, glycosides, and tannins. The percentage viability of 3T3-L1 cells was not significantly decreased after exposure to either 200 or 150 μg/mL of OIE for 2 and 10 days, respectively compared to control cells. The OIE exhibited a dose-dependent reduction of lipid accumulation compared to the control (p < 0.05). The extract also demonstrated a dosedependent inhibitory effect upon lipase activity compared to the control. The inhibitory effect of the OIE on lipid accumulation in 3T3-L1 cells was also confirmed using FTIR microspectroscopy. The signal intensity and the integrated areas relating to lipids, lipid esters, nucleic acids, glycogen and carbohydrates of the OIE-treated 3T3-L1 adipocytes were significantly lower than the non-treated 3T3-L1 adipocytes (p < 0.05). Principal component analysis (PCA) indicated four distinct clusters for the FTIR spectra of 3T3-L1 adipocytes based on biomolecular changes (lipids, proteins, nucleic acids, and carbohydrates). This observation was confirmed using Unsupervised hierarchical cluster analysis (UHCA). Conclusions: These novel findings provide evidence that the OIE derived from the fruit pods of the plant is capable of inhibiting lipid and carbohydrate accumulation in adipocytes and also has the potential to inhibit an enzyme associated with fat absorption. The initial observations indicate that OIE may have important properties which in the future may be exploited for the management of the overweight or obese