Chutha Sae-Wong

Suppressive effects of methoxyflavonoids isolated from Kaempferia parviflora on inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE The rhizomes of Kaempferia parviflora Wall. ex Baker have been traditionally used in Thailand to treat abscesses, gout, and peptic ulcers. AIM Previously, we reported that the chloroform fraction of a Kaempferia parviflora extract had an inhibitory effect on rat paw-edema. In the present study, we isolated the constituents of this fraction and investigated the anti-inflammatory mechanism against nitric oxide (NO) production, tumor necrosis factor-α (TNF-α) and the expression of inducible nitric oxide synthase (iNOS) as well as phosphorylated extracellular signal-regulated kinase (p-ERK), and phosphorylated c-Jun N-terminal kinase (p-JNK). In addition, effects of trimethylapigenin (4) on the enzyme activities of protein kinases possibly leading to iNOS expression were examined to clarify the targets. MATERIALS AND METHODS The chloroform fraction was isolated using silica gel column chromatography and HPLC. Isolated compounds were tested against NO and TNF-α using RAW264.7 cells. Cytotoxicity and iNOS, p-ERK and p-JNK expression were also examined. RESULTS Three active components, 5,7-dimethoxyflavone (2), trimethylapigenin (4), and tetramethylluteolin (5), markedly inhibited the production of NO in lipopolysaccharide (LPS)-activated RAW264.7 cells. Compounds 2, 4, and 5 moderately inhibited production of TNF-α. Compounds 2, 4, and 5 strongly inhibited expression of iNOS mRNA and iNOS protein in a dose-dependent manner, but did not inhibit p-ERK or p-JNK protein expression. The most active compound, 4, did not inhibit the enzyme activity of inhibitor of κB kinases or mitogen-activated protein kinases, but inhibited that of spleen tyrosine kinase (SYK). CONCLUSION The mechanism responsible for the anti-inflammatory activity of methoxyflavonoids from the chloroform fraction of the rhizomes of Kaempferia parviflora is mainly the inhibition of iNOS expression, and the inhibition of SYK by 4 may be involved in the suppression of LPS-induced signaling in macrophages.

Antinociceptive activity of the methanolic extract of Kaempferia galanga Linn. in experimental animals.

Kaempferia galanga Linn. (Zingiberaceae) presents many chemical constituents of the volatile oil extracted from the rhizome. The rhizome of Kaempferia galanga is used by people in many regions for relieving toothache, abdominal pain, muscular swelling and rheumatism. In this study we investigated the antinociceptive activity in mice and rats using acetic acid-induced writhing, formalin, hot plate and tail-flick tests. The extract at test doses of 50, 100 and 200 mg/kg, p.o. clearly demonstrated antinociceptive activity in all tests. This activity was dose- and time-dependent. The extract administered at 200 mg/kg, p.o. had a stronger antinociceptive effect than aspirin (100 mg/kg, p.o.) but less than morphine (5 mg/kg, s.c.). Naloxone (2 mg/kg, i.p.) abolished the antinociceptive action of both morphine (5 mg/kg, s.c.) and the extract (200 mg/kg, p.o.) in a similar manner. In conclusion, the methanol extract of Kaempferia galanga markedly demonstrated the antinociceptive action in experimental animals. The antinociceptive mechanisms appear to be both peripherally and centrally mediated actions and the opioid receptors are probably involved. Therefore, our studies support the use in traditional medicine of Kaempferia galanga against pain caused by various disorders.

Thymic stromal lymphopoietin‐induced interleukin‐17A is involved in the development of IgE‐mediated atopic dermatitis‐like skin lesions in mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with elevated levels of allergen‐specific IgE. Although thymic stromal lymphopoietin (TSLP) and interleukin‐17A (IL‐17A) have been considered as important factors in allergic diseases, their relationships in AD have not been fully defined. Here, we show the contribution of TSLP‐induced IL‐17A responses to IgE‐mediated AD‐like skin lesions. BALB/c mice passively sensitized by intraperitoneal injections of ovalbumin (OVA)‐specific IgE monoclonal antibody (mAb) were challenged with OVA applied to the skin six times. Treatment with anti‐TSLP mAb during the second to sixth challenges inhibited IgE‐mediated AD‐like skin lesions and IL‐17A production in lymph nodes. Furthermore, the increased number of IL‐17A‐producing CD4+ and γδ T cells in lymph nodes and neutrophilic inflammation in the skin were reduced by anti‐TSLP mAb. These findings prompted us to examine the roles of IL‐17A. Treatment with anti‐IL‐17A mAb suppressed the AD‐like skin lesions and neutrophilic inflammation; anti‐Gr‐1 mAb also inhibited them. Furthermore, treatment with CXCR2 antagonist reduced the AD‐like skin lesions and neutrophilic inflammation accompanied by the reduction of IL‐17A production; the increased CXCR2 expression in the epidermal cells was suppressed by anti‐TSLP mAb. Meanwhile, these treatments, except for anti‐Gr‐1 mAb, inhibited the increased mast cell accumulation in the skin. Collectively, the mechanism of IgE mediating IL‐17A‐producing CD4+ and γδ T cells through TSLP by repeated antigen challenges is involved in AD‐like skin lesions associated with skin inflammation, such as neutrophil and mast cell accumulation; TSLP may regulate CXCR2 signalling‐induced IL‐17A production.

Intratracheal exposure to Fab fragments of an allergen‐specific monoclonal antibody regulates asthmatic responses in mice

Fab fragments (Fabs) maintain the ability to bind to specific antigens but lack effector functions due to the absence of the Fc portion. In the present study, we tested whether Fabs of an allergen‐specific monoclonal antibody (mAb) were able to regulate asthmatic responses in mice. Asthmatic responses were induced in BALB/c mice by passive sensitization with anti‐ovalbumin (OVA) polyclonal antibodies (pAbs) (day 0) and by active sensitization with OVA (days 0 and 14), followed by intratracheal (i.t.) challenge with OVA on day 1 and days 28, 29, 30 and 35. Fabs prepared by the digestion of an anti‐OVA IgG1 (O1‐10) mAb with papain were i.t. administered only once 30 min before antigenic challenge on day 1 or day 35. The results showed that i.t. administration of O1‐10 Fabs with OVA markedly suppressed the early and/or late phases of asthmatic responses caused by passive and active sensitization. Similar results were obtained when Fabs of anti‐OVA IgG2b mAb (O2B‐3) were i.t. administered. In contrast, neither i.t. injection of intact 01‐10/O2B‐3 nor systemic injection of O1‐10 Fabs suppressed the asthmatic responses. In vitro studies revealed that the capture of OVA by O1‐10 Fabs prevented the subsequent binding of intact anti‐OVA pAbs to the captured OVA. These results suggest that asthmatic responses may be down‐regulated by the i.t. exposure to Fabs of an allergen‐specific mAb via a mechanism involving the capture of allergen by Fabs in the respiratory tract before the interaction of intact antibody and allergen essential for the induction of asthmatic responses.

The antioxidant and anti-cadmium toxicity properties of garlic extracts

Cadmium (Cd) contamination is a highly dangerous international problem because it can transfer into the food chain and become bioaccumulated, endangering human health. Cd detoxication is very interesting particularly the method providing no undesirable side effects. Cd also causes lipid oxidation that leads to undesired food quality. Garlic (Allium sativum L.) has been used as conventional food and in herbal therapy and folklore medicine as an antibacterial, antitumorogenic, and antioxidant agent for over 5000 years. In the present work, fresh garlic and pickled garlic extracted with distilled water was brought to determine antioxidant activities in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging assay, ferric reducing ability power (FRAP) assay, chelating activities, superoxide, and hydroxyl scavenging assay. The data showed that pickled garlic extracts significantly possessed more DPPH, ABTS, FRAP, superoxide, and hydroxyl scavenging assays as 11.86, 13.74, 4.9, 46.67, and 15.33 g trolox equivalent/g sample, respectively, compared with fresh one as 7.44, 7.62, 0.01, 4.07, and 8.09 g trolox equivalent/g sample, respectively. However, iron chelating activity of fresh garlic extract was higher than that of pickled garlic while there was no significant difference in the copper chelating activity of both extracts. For anti-Cd properties, pickled garlic was more effective than fresh garlic and contained less toxicity than standard diallyl disulfide (DADS). Therefore, therapeutic properties of pickled garlic favored its consumption compared with fresh and standard DADS for its antioxidant and anti-Cd properties.

Allergen-specific regulation of allergic rhinitis in mice by intranasal exposure to IgG1 monoclonal antibody Fab fragments against pathogenic allergen

Fab fragments (Fabs) have the ability to bind to specific antigens but lack the Fc portion for binding to receptors on immune and inflammatory cells that play a critical role in allergic diseases. In the present study, we investigated whether Fabs of an allergen-specific IgG1 monoclonal antibody (mAb) inhibited allergic rhinitis in mice. BALB/c mice sensitized by intraperitoneal injections of ovalbumin (OVA) plus alum on days 0 and 14 were intranasally challenged with OVA on days 28-30, and 35. Fabs prepared by the digestion of an anti-OVA IgG1 mAb (O1-10) with papain were also intranasally administered 15min before each OVA challenge. The results showed that treatment with O1-10 Fabs significantly suppressed the sneezing frequency, associated with decrease of OVA-specific IgE in the serum and infiltration by mast cells in the nasal mucosa seen following the fourth antigenic challenge; additionally, the level of mouse mast cell protease-1, a marker of mast cell activation, in serum was decreased. Furthermore, infiltration of eosinophils and goblet cell hyperplasia in the nasal mucosa at the fourth challenge were inhibited by treatment with O1-10 Fabs. In conclusion, these results suggest that intranasal exposure to Fabs of a pathogenic antigen-specific IgG1 mAb may be effective in regulating allergic rhinitis through allergen capture by Fabs in the nasal mucosa before the interaction of the intact antibody and allergen.

Topical skin treatment with Fab fragments of an allergen-specific IgG1 monoclonal antibody suppresses allergen-induced atopic dermatitis-like skin lesions in mice.

Fab fragments (Fabs), which lack effector functions due to the absence of the Fc portion, maintain the ability to bind to specific allergens. In the present study, we examined whether Fabs of an allergen-specific IgG1 monoclonal antibody (mAb) were able to regulate allergen-induced atopic dermatitis-like skin lesions in mice. BALB/c mice passively sensitized with ovalbumin (OVA)-specific IgE mAb were repeatedly challenged with OVA applied to the skin after sodium dodecyl sulfate treatment. Fabs prepared by the digestion of anti-OVA IgG1 mAb (O1-10) with papain were applied to the skin 30min before the OVA challenges followed by measurement of clinical symptoms including erythema/hemorrhage, edema, scarring/dryness, and excoriation/erosion of the skin. Treatment with O1-10 Fabs, but not intact O1-10, showed inhibition of clinical symptoms (P<0.01) induced by the repeated OVA challenges in the sensitized mice; O1-10 Fabs suppressed histological changes such as epidermal hyperplasia (P<0.01) and the accumulation of mast cells (P<0.01) and neutrophils (P<0.01). Furthermore, treatment with O1-10 Fabs inhibited the increase in levels of IL-13 (P<0.01) and IL-17A production (P<0.05) in the lymph nodes of the sensitized mice. Additionally, the increased level of OVA in serum following the repeated OVA challenges in the sensitized mice was reduced by the treatment (P<0.05). These results suggest that topical application of pathogenic allergen-specific IgG1 mAb Fabs to the skin of mice is effective in suppressing allergen-induced atopic dermatitis-like skin lesions, suggesting that allergen-specific mAb Fabs could be used as a tool to regulate allergen-induced atopic dermatitis.

Oral spray containing plant-derived compounds is effective against common oral pathogens

OBJECTIVES Plant-derived compounds are a good source of therapeutic agents and inhibitors of inflammatory process. Dental caries, periodontal diseases and candidiasis are common oral infections caused by virulent biofilms. The objectives of this study were to develop oral spray containing plant-derived compounds; α-mangostin (α-MG) and/or lawsone methyl ether (2-methoxy-1,4-naphthoquinone) (LME) and determine its antimicrobial, anti-biofilm, and anti-inflammatory activities. DESIGN Oral spray formulations were prepared containing α-MG (5 mg/ml) and/or LME (250 μg/ml). Antimicrobial activity against Candida albicans, Streptococcus mutans, and Porphyromonas gingivalis and anti-biofilm formation activities were determined as well as cytotoxicity and anti-inflammatory effects. RESULTS The oral spray demonstrated antimicrobial activity against all three of the oral pathogens tested with stronger effects on C. albicans and S. mutans than P. gingivalis. The formulation containing α-MG (2.5 mg/ml) and LME (125 ug/ml) reduced growth of the microorganisms about 1-2 Log CFU/ml at 1-3 h and the killing effects were complete at 24 h. Based on biofilm assay, the oral spray containing both α-MG and LME showed greater inhibitory effects than those with α-MG or LME. In addition, the oral spray containing both α-MG and LME demonstrated more inhibition of nitric oxide production than α-MG alone. All the formulations were safe and demonstrated greater anti-inflammatory activity at lower concentration (<6.25 μg/ml) than at a higher concentration. CONCLUSION Oral spray containing α-MG and/or LME is effective against common oral pathogens without significant cytotoxicity. Thus, it has the potential to prevent the infections and may serve as adjunctive treatment to conventional therapy.