Gymnema inodorum (Lour.) Decne. Extract Alleviates Oxidative Stress and Inflammatory Mediators Produced by RAW264.7 Macrophages

Abstract

Gymnema inodorum (Lour.) Decne. (G. inodorum) is widely used in Northern Thai cuisine as local vegetables and commercial herb tea products. In the present study, G. inodorum extract (GIE) was evaluated for its antioxidant and anti-inflammatory effects in LPS plus IFN-γ-induced RAW264.7 cells. Major compounds in GIE were evaluated using GC-MS and found 16 volatile compounds presenting in the extract. GIE exhibited antioxidant activity by scavenging the intracellular reactive oxygen species (ROS) production and increasing superoxide dismutase 2 (SOD2) mRNA expression in LPS plus IFN-γ-induced RAW264.7 cells. GIE showed anti-inflammatory activity through suppressing nitric oxide (NO), proinflammatory cytokine production interleukin 6 (IL-6) and also downregulation of the expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and IL-6 mRNA levels in LPS plus IFN-γ-induced RAW264.7 cells. Mechanism studies showed that GIE suppressed the NF-κB p65 nuclear translocation and slightly decreased the phosphorylation of NF-κB p65 (p-NF-κB p65) protein. Our studies applied the synchrotron radiation-based FTIR microspectroscopy (SR-FTIR), supported by multivariate analysis, to identify the FTIR spectral changes based on macromolecule alterations occurring in RAW264.7 cells. SR-FTIR results demonstrated that the presence of LPS plus IFN-γ in RAW264.7 cells associated with the increase of amide I/amide II ratio (contributing to the alteration of secondary protein structure) and lipid content, whereas glycogen and other carbohydrate content were decreased. These findings lead us to believe that GIE may prevent oxidative damage by scavenging intracellular ROS production and activating the antioxidant gene, SOD2, expression. Therefore, it is possible that the antioxidant properties of GIE could modulate the inflammation process by regulating the ROS levels, which lead to the suppression of proinflammatory cytokines and genes. Therefore, GIE could be developed into a novel antioxidant and anti-inflammatory agent to treat and prevent diseases related to oxidative stress and inflammation.

The Potential Role of Gymnema inodorum Leaf Extract Treatment in Hematological Parameters in Mice Infected with Plasmodium berghei

“…This plant is indigenous in Southeast Asia including Thailand, particularly in the northern part of the country, and is widely consumed [ 6 ]. G. inodorum leaf extract showed high antioxidant and anti-inflammatory activities with polyphenols and flavonoids as the major compounds [ 7 ]. It has also been found that the leaf extract of G. inodorum could decrease blood glucose by inhibiting glucose absorption [ 8 , 9 ].…”

Protective Effects of Gymnema inodorum Leaf Extract on Plasmodium berghei-Induced Hypoglycemia, Dyslipidemia, Liver Damage, and Acute Kidney Injury in Experimental Mice

“…The dose of 500 mg/kg GIE was the most effective compared with the doses of 100 and 250 mg/kg. There was a possibility that apart from polyphenols and other compounds in GIE such as flavonoids, alkaloids, triterpenoids, saponins, quercetins, and gymnemic acids, they may have resulted individually or synergistically in the observed antihypoglycemic, antidyslipidemia, hepatoprotective, and nephroprotective activities of GIE treatment in the present study [ 10 , 14 , 45 ]. This extract might stimulate some antioxidant enzymes involved in the fight against oxidative stress, causing less damage to the host.…”

“…This extract might stimulate some antioxidant enzymes involved in the fight against oxidative stress, causing less damage to the host. The recent finding showed the antioxidant properties of GIE by regulating the reactive oxygen species production and activating the antioxidant gene, superoxide dismutase 2 expression, which leads to the suppression of proinflammatory cytokines, interleukin 6 (IL-6), and production and downregulation of inflammatory genes such as cyclooxygenase-2, inducible nitric oxide synthase, and IL-6 mRNA levels in murine macrophages [ 14 ]. Consistent with the reports on the pharmacological properties of G. sylvestre , gymnemic acid might play a crucial role in the protective effects through antioxidant and anti-inflammatory activities [ 46 ].…”

“…G. inodorum has the potential to inhibit glucose absorption and decrease blood glucose levels [11][12][13]. Moreover, it was found that G. inodorum leaf extract presented high antioxidant activity with polyphenols as significant constituents [14]. However, no scientific evidence on the therapeutic effect of G. inodorum has ever been reported in malariainfected mice.…”

Characterization, Antioxidant and Anti-Inflammation Capacities of Fermented Flammulina velutipes Polyphenols

“…RAW264.7 cells were cultured for 12 h in a working solution containing 10% fetal bovine serum, 1% double antibody (100 IU/mL penicillin and 100 IU/mL streptomycin), and 90% Dulbecco’s modified eagle medium (DMEM) in an incubator (Heracell 240i, Waltham, USA) at 37 °C and 5% CO 2 [ 48 ].…”