Anti-inflammatory effect of the hydralcoholic extract of Zingiber officinale rhizomes on rat paw and skin edema

Anti-Inflammatory Bioactivities in Plant Extracts

The medical ethnobotanical knowledge propagated over generations in the coastal regions of the Eastern Mediterranean, including Lebanon, is one that has built on several ancient cultures and civilizations of these regions. Recent interest in medical ethnobotany and the use of medicinal herbs in treating or preventing ailments has rejuvenated interest in folk medicine practices, especially those transcendent across generations. According to Eastern Mediterranean folk medicine practices, herbal remedies that treat many inflammation-related ailments were typically based on plant bioactive water extracts or decoctions. Studies have shown that active anti-inflammatory ingredients in water extracts include many natural chemicals such as phenols, alkaloids, glycosides, and carbohydrates. The intent of this manuscript is twofold: first, to review the literature that describes anti-inflammatory bioactivities in plant extracts of different plant genera; and second, to evaluate indigenous folk remedies used by folk doctors to treat inflammatory ailments in this region of the world. For this aim, the reported literature of five plant genera assumed to possess anti-inflammatory bioactivities and typically prescribed by folk doctors to treat inflammation-related ailments is reviewed.

Development of gas chromatography-mass spectrometry with microwave distillation and simultaneous solid-phase microextraction for rapid determination of volatile constituents in ginger

In this study, gas chromatography-mass spectrometry (GC-MS) following microwave distillation and solid-phase microextraction (MD-SPME) was developed for the analysis of essential oil compounds in fresh ginger. In the proposed method, the isolation, extraction and concentration of volatile components in ginger were carried out in one single step, using the MD-SPME technique, and the analytes on the SPME fiber were analyzed by GC-MS. Some parameters, including SPME fiber coating, microwave power and irradiation time, were optimized. The optimal experiment parameters obtained were: 65 microm PDMS/DVB SPME fiber, a microwave power of 400 W and an irradiation time of 2 min. To demonstrate its feasibility, MD-SPME was compared with conventional SPME for the extraction of essential oil compounds in fresh ginger. Using MD-SPME followed by GC-MS, 54 compounds were separated and identified in ginger, which mainly included geranial (5.25%), zingiberene (15.48%), beta-sesquiphellandrene (5.54%) and beta-phellandrene (22.84%), whereas only 39 compounds were separated and identified by conventional SPME followed by GC-MS. The relative standard deviation (R.S.D.) values of less than 10% show that the proposed method has good repeatability. The result show that MD-SPME, followed by GC-MS, is a simple, rapid, solvent-free method for the determination of volatile compounds in ginger.

Anti-diabetic and hypolipidaemic properties of ginger (Zingiber officinale) in streptozotocin-induced diabetic rats

In the present study, the hypoglycaemic potentials of ginger (Zingiber officinale) were studied in rats. An aqueous extract of raw ginger was administered daily (500 mg/kg, intraperitoneally) for a period of 7 weeks to streptozotocin (STZ)-induced diabetic rats. Fasting blood serum was analysed for blood glucose, cholesterol and triacylglycerol levels. The STZ-injected rats exhibited hyperglycaemia accompanied with weight loss, indicating their diabetic condition. At a dose of 500 mg/kg, raw ginger was significantly effective in lowering serum glucose, cholesterol and triacylglycerol levels in the ginger-treated diabetic rats compared with the control diabetic rats. The ginger treatment also resulted in a significant reduction in urine protein levels. In addition, the ginger-treated diabetic rats sustained their initial weights during the treatment period. Moreover, ginger decreased both water intake and urine output in the STZ-induced diabetic rats. The present results indicate that raw ginger possesses hypoglycaemic, hypocholesterolaemic and hypolipidaemic potential. Additionally, raw ginger is effective in reversing the diabetic proteinuria observed in the diabetic rats. Thus, ginger may be of great value in managing the effects of diabetic complications in human subjects.

Lack of chemopreventive effects of ginger on colon carcinogenesis induced by 1,2-dimethylhydrazine in rats

Ginger (Zingiber officinale Roscoe) has been proposed as a promising candidate for cancer prevention. Its modifying potential on the process of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) was investigated in male Wistar rats using the aberrant crypt foci (ACF) assay. Five groups were studied: Groups 1-3 were given four s.c. injections of DMH (40 mg/kg b.w.) twice a week, during two weeks, whereas Groups 4 and 5 received similar injections of EDTA solution (DMH vehicle). After DMH-initiation, the animals were fed a ginger extract mixed in the basal diet at 0.5% (Group 2) and 1.0% (Groups 3 and 4) for 10 weeks. All rats were killed after 12 weeks and the colons were analyzed for ACF formation and crypt multiplicity. The rates of cell proliferation and apoptosis were also evaluated in epithelial colonic crypt cells. Dietary consumption of ginger at both dose levels did not induce any toxicity in the rats, but ginger meal at 1% decreased significantly serum cholesterol levels (p<0.038). Treatment with ginger did not suppress ACF formation or the number of crypts per ACF in the DMH-treated group. Dietary ginger did not significantly change the proliferative or apoptosis indexes of the colonic crypt cells induced by DMH. Thus, the present results did not confirm a chemopreventive activity of ginger on colon carcinogenesis as analyzed by the ACF bioassay and by the growth kinetics of the colonic mucosa.

The modulatory effects of the volatile oil of ginger on the cellular immune response in vitro and in vivo in mice

The aim of this study was to investigate the immunomodulatory effects of the volatile oil of ginger (Zingiber officinale Roscoe) in vitro and in vivo in mice. In vitro, the volatile oil of ginger (0.001-10 ng/mL) significantly inhibited T lymphocyte proliferation (P < 0.01), decreased the number of the total T lymphocytes and T helper cells (P < 0.01) in a concentration-dependent manner, but increased the percentage of T suppressor cells to the total T lymphocytes in the mice. In addition, the volatile oil of ginger (0.001-10 ng/mL) inhibited IL-1alpha secretion by the mice peritoneal macrophages in a concentration-dependent manner. In vivo, oral administration of the volatile oil of ginger in the doses of 0.125, 0.25 and 0.5 g/kg body weight dose-dependently weakened the delayed type of hypersensitivity response to 2,4-dinitro-1-fluorobenzene in the sensitized mice (P < 0.05). These results suggest that the volatile oil of ginger influences both cell-mediated immune response and nonspecific proliferation of T lymphocyte, and may exert beneficial effects in a number of clinical conditions, such as chronic inflammation and autoimmune diseases.

Suppressive effects of mioga ginger and ginger constituents on reactive oxygen and nitrogen species generation, and the expression of inducible pro-inflammatory genes in macrophages

We previously conducted screening tests of the chloroform extracts from a total of 89 species of Japanese plant food items for their suppressive effects on superoxide (O(2) ()) generation through both NADPH oxidase and xanthine oxidase, and reported that mioga ginger (Zingiber mioga Roscoe) indicated the strongest suppressive activities. In this study, the suppressive effects of mioga ginger constituents, aframodial, and galanal B, together with [6]-gingerol and galanolactone occurring in ginger, on free radical generation and inducible proinflammatory gene expressions were investigated. Of these constituents, aframodial (20 microM) exhibited marked suppressive effects on 12-O-tetradecanoylphorbol-13-acetate-induced O(2) () generation in HL-60 cells and lipopolysaccharide (LPS)/interferon-gamma-induced nitric oxide (NO) generation in RAW264.7 cells (inhibition rates [IRs]=84.6% and 95.9%, respectively). Aframodial also strongly suppressed the stimulated HL-60 cell-induced mutagenicity in AS52 cells (IR=95.9%). The LPS-induced expression of inducible proinflammatory genes such as inducible NO synthase, interleukin (IL)-1beta, IL-6, and granulocyte-macrophage colony-stimulating factor was significantly abolished (IRs=99.1%, 74.6%, 74.0%, and 64.4%, respectively) by aframodial. In addition, degradation of the inhibitor of nuclear factor kappaB was suppressed by this compound (IR=100%), suggesting that the suppression of nuclear factor kappaB activation, at least in part, is involved. Taken together, these results suggest that aframodial has potent antioxidative and anti-inflammatory potentials, and may be a promising candidate in prevention and/or therapy for chronic inflammationassociated carcinogenesis.

Zingiberis rhizoma: a comprehensive review on the ginger effect and efficacy profiles

Zingiberis rhizoma is used as a broadspectrum antiemetic. We, therefore, conducted a comprehensive review of the literature to summarize the pharmacological and clinical effects of this popular plant material. Although clinical and experimental studies suggest that ginger has some antiemetic properties, clinical evidence beyond doubt is only available for pregnancy-related nausea and vomiting. Meta-analyses could not demonstrate the postoperative antiemetic effectiveness, and effect in motion sickness or nausea/vomiting of other ethiology. It also remains to be confirmed that proprietary ginger preparations are clinically useful to alleviate osteoarthritic or other pain, although there is no doubt that ginger constituents interfere with the inflammatory cascade and the vanilloid nociceptor. Ginger exerts in vitro antioxidative, antitumorigenic and immunomodulatory effects and is an effective antimicrobial and antiviral agent. Animal studies demonstrate effects on the gastrointestinal tract, the cardiovascular system, on experimental pain and fever, antioxidative, antilipidemic and antitumor effects, as well as central and other effects. The most relevant human pharmacological studies require a confirmatory study to exclude interaction of ginger preparations with platelet aggregation. Pharmacokinetic data are only available for [6]-gingerol and zingiberene. Preclinical safety data do not rule out potential toxicity, which should be monitored especially following ginger consumption over longer periods.

Radioprotection by plant products: present status and future prospects

The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.