Use of herbal preparations in the treatment of oxidant-mediated inflammatory disorders

Antioxidant effects of the chestnut (Castanea crenata) inner shell extract in t-BHP-treated HepG2 cells, and CCl4- and high-fat diet-treated mice

The antioxidant effects of chestnut inner shell extract (CISE) were investigated in a tert-butylhydroperoxide (t-BHP)-treated HepG2 cells, and in mice that were administered carbon tetrachloride (CCl(4)) and fed a high-fat diet (HFD). Pre-incubation with CISE significantly blocked the oxidative stress induced by t-BHP treatment in HepG2 cells (P<0.05) and preserved the activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase compared to group treated with t-BHP only. Similarly, the CCl(4)- and HFD-induced reduction of antioxidant enzymes activities in liver was prevented by CISE treatment compared to control groups. Furthermore, hepatic lipid peroxidation were remarkably lower (P<0.05) in the CISE-treated groups with t-BHP or HFD. To determine the active compound of CISE, the fractionation of CISE has been conducted and scoparone and scopoletin were identified as main compounds. These compounds were also shown to inhibit the t-BHP-induced ROS generation and reduction in antioxidant enzyme activity in an in vitro model system. From these results, it was demonstrated that CISE has the ability to protect against damage from oxidative stressors such as t-BHP, CCl(4) and HFD in in vitro and in vivo models. The CISE might be useful for the prevention of oxidative damage in liver cells and tissues.

Effect of hexane fraction of leaves of Cinnamomum tamala Linn on macrophage functions

The leaves of Cinnamomum tamala Linn (Lauraceae), component of Indian spices are associated with hypoglycemic property in Ayurveda; however, no report is available towards its immunomodulation property, which has been explored here. The dried powder of CT leaves was extracted with hexane and solvent free extract (CTH) was given orally to rats for 10 days, in various doses. Its effect was studied on peritoneal macrophage functions, and was compared with ascorbic acid (1,000 mg/kg, immune-stimulant) and cyclophosphamide (10 mg/kg, immune-suppressant). CTH significantly suppressed phagocytosis activity (EC(50) 2,355 +/- 52.45 mg/kg), reduced production of superoxide (EC(50) 275.91 +/- 10.21 microg/ml) and cellular NADPH (EC(50) 384.959 +/- 4.85 microg/ml) content in concentration dependent manner. It also inhibited LPS induced production of nitric oxide (EC(50) 143.75 +/- 3.40 microg/ml) and iNOS protein expression (EC(50) 183.132 microg/ml). Thus, it could be suggested that non-polar hexane fraction of leaves of C. tamala possesses immunosuppressive property, which is mediated through modulation of innate immunity.

Berberine suppresses proinflammatory responses through AMPK activation in macrophages

Berberine (BBR) has been shown to improve several metabolic disorders, such as obesity, type 2 diabetes, and dyslipidemia, by stimulating AMP-activated protein kinase (AMPK). However, the effects of BBR on proinflammatory responses in macrophages are poorly understood. Here we show that BBR represses proinflammatory responses through AMPK activation in macrophages. In adipose tissue of obese db/db mice, BBR treatment significantly downregulated the expression of proinflammatory genes such as TNF-alpha, IL-1beta, IL-6, monocyte chemoattractant protein-1 (MCP-1), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Consistently, BBR inhibited LPS-induced expression of proinflammatory genes including IL-1beta, IL-6, iNOS, MCP-1, COX-2, and matrix metalloprotease-9 in peritoneal macrophages and RAW 264.7 cells. Upon various proinflammatory signals including LPS, free fatty acids, and hydrogen peroxide, BBR suppressed the phosphorylation of MAPKs, such as p38, ERK, and JNK, and the level of reactive oxygen species in macrophages. Moreover, these inhibitory effects of BBR on proinflammatory responses were abolished by AMPK inhibition via either compound C, an AMPK inhibitor, or dominant-negative AMPK, implying that BBR would downregulate proinflammatory responses in macrophages via AMPK stimulation.

On the use of herbal medicines in management of inflammatory bowel diseases: a systematic review of animal and human studies

Because of potential adverse events and lack of effectiveness of standard therapies, the use of complementary and alternative medicines (CAM), particularly of herbal therapies, for inflammatory bowel disease (IBD) is increasing. Results from the use of herbal therapies for managing IBD are promising, and no serious adverse events have been reported from them. Herbal therapies show their benefit in managing IBD by different mechanisms such as immune system regulation, antioxidant activity, inhibition of leukotriene B4, inhibition of nuclear factor-kappa B (NF-kappaB), and antiplatelet activity. In this paper, all reported herbal therapies established in animal IBD models or used for managing human IBD are systematically reviewed and their possible mechanisms of action discussed. Conducting clinical trials with high quality and validity (randomized, double blinded, controlled, on a large number of patients) to obtain more conclusive results about the use of herbal therapies in IBD is recommended.

7-Epiclusianone, a tetraprenylated benzophenone, relaxes airway smooth muscle through activation of the nitric oxide-cGMP pathway

This study was undertaken to investigate the putative mechanism(s) underlying the antispasmodic effect of 7-epiclusianone, a naturally occurring compound isolated from the plant Garcinia brasiliensis. Guinea pig tracheal rings were mounted in tissue baths filled with Krebs' solution, and the contractile response to distinct stimuli was measured in the presence or absence of 7-epiclusianone. We also tested the effect of 7-epiclusianone on methacholine-evoked airways obstruction in BALB/c mice using barometric plethysmography. 7-Epiclusianone (10 microM) inhibited epithelium-intact tracheal ring contraction induced by allergen, histamine, 5-hydroxytryptamine, or carbachol challenge. The relaxation effect was abrogated by epithelium removal, the presence of nitric-oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) (100 microM), or soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) (10 microM). 7-Epiclusianone (1-100 microM) induced a dose-dependent increase in the intracellular cGMP levels of cultured tracheal rings. The relaxation effect of 7-epiclusianone was also inhibited by K(+) channel blockers tetraethylammonium (10 microM), glibenclamide (1 microM), or apamin (1 microM), but not by 9-(tetrahydro-2'-furyl)adenine (SQ22,536) (100 microM), an adenylate cyclase inhibitor. In epithelium-intact tracheal rings, 7-epiclusianone also inhibited Ca(2+)-induced contractions in K(+) (60 mM)-depolarized preparations, but it seemed ineffective in assays in which epithelium-denuded tracheal ring preparations were used. Oral administration of 7-epiclusinone (25-100 mg/kg) dose-dependently inhibited airway obstruction triggered by aerosolized methacholine (6-25 mg/ml), in a mechanism sensitive to L-NAME (20 mg/kg). In conclusion, the relaxation effect of 7-epiclusinone seems to be mediated by epithelium-, nitric oxide-, and cGMP-dependent mechanisms. Furthermore, oral administration of 7-epiclusianone reduces episodes of bronchial obstruction, warranting further research on this compound regarding a putative application in asthma therapy.