Thai medicinal plants modulate nitric oxide and tumor necrosis factor-alpha in J774.2 mouse macrophages

Biotechnological Intervention and Secondary Metabolite Production in Centella asiatica L

Centella asiatica L., commonly known as Gotu kola, Indian pennywort, and Asiatic pennyworts, is an herbaceous perennial plant that belongs to the family Apiaceae and has long been used in the traditional medicine system. The plant is known to produce a wide range of active metabolites such as triterpenoids including asiatic acid, asiaticoside, brahmoside, and madecassic acid along with other constituents including centellose, centelloside, and madecassoside, etc., which show immense pharmacological activity. Due to its beneficial role in neuroprotection activity, the plant has been considered as a brain tonic. However, limited cultivation, poor seed viability with low germination rate, and overexploitation for decades have led to severe depletion and threatened its wild stocks. The present review aimed to provide up-to-date information on biotechnological tools applied to this endangered medicinal plant for its in vitro propagation, direct or indirect regeneration, synthetic seed production, strategies for secondary metabolite productions including different elicitors. In addition, a proposed mechanism for the biosynthesis of triterpenoids is also discussed.

Protective Role of Natural Products in Glioblastoma Multiforme: A Focus on Nitric Oxide Pathway

In spite of therapeutic modalities such as surgical resection, chemotherapy, and radiotherapy, Glioblastoma Multiforme (GBM) remains an incurable fatal disease. This necessitates further therapeutic options that could enhance the efficacy of existing modalities. Nitric Oxide (NO), a short-lived small molecule, has been revealed to play a crucial role in the pathophysiology of GBM. Several studies have demonstrated that NO is involved in apoptosis, metastasis, cellular proliferation, angiogenesis, invasion, and many other processes implicated in GBM pathobiology. Herein, we elaborate on the role of NO as a therapeutic target in GBM and discuss some natural products affecting the NO signaling pathway.

Dry powder inhalation formulation of chitosan nanoparticles for co-administration of isoniazid and pyrazinamide

Co-loaded isoniazid and pyrazinamide chitosan nanoparticles were formulated using the ionic gelation method. The formulations were adjusted to five mass ratios of tripolyphosphate (TPP) and chitosan at three TPP concentrations. Particle size, polydispersity index, zeta potential, and encapsulation efficiency were used to evaluate all formulations. The results revealed that the ratio of TPP to chitosan had the highest impact in generating chitosan nanoparticles. The selected nanoparticle formulations were freeze-dried, and the obtained dry powders were characterized using scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and Fourier-transform infrared spectroscopy to confirm the interaction of loaded drug and formulation excipients. The aerosolized performance of dry powders was also evaluated using the Andersen cascade impactor. A mass median aerodynamic diameter of 3.3-3.5 µm, % fine particle fraction of 30-44%, and 92-95% emitted dose were obtained from all formulations. The dry powder formulations were not toxic to the respiratory tract cell lines. Furthermore, they did not provoke alveolar macrophages into producing inflammatory cytokines or nitric oxides, indicating that the formulations are safe and could potentially be used to deliver to respiratory tract for tuberculosis treatment.

Mechanisms of Medicinal Plant Activity on Nitric Oxide (NO) Bioavailability as Prospective Treatments for Atherosclerosis

Background and objective:

Atherosclerosis is one of the leading causes of human morbidity globally and reduced bioavailability of vascular nitric oxide (NO) has a critical role in the progression and development of the atherosclerotic disease. Loss of NO bioavailability, for example via a deficiency of the substrate (L-arginine) or cofactors for endothelial nitric oxide synthase (eNOS), invariably leads to detrimental vascular effects such as impaired endothelial function and increased smooth muscle cell proliferation, deficiency of the substrate (Larginine) or cofactors for eNOS. Various medicinal plants and their bioactive compounds or secondary metabolites with fewer side effects are potentially implicated in preventing cardiovascular disease by increasing NO bioavailability, thereby ameliorating endothelial dysfunction. In this review, we describe the most notable medicinal plants and their bioactive compounds that may be appropriate for enhancing NO bioavailability, and treatment of atherosclerosis.

Methods:

The material in this article was obtained from noteworthy scientific databases, including Web of Science, PubMed, Science Direct, Scopus and Google Scholar.

Results:

Medicinal plants and their bioactive compounds influence NO production through diverse mechanisms including the activation of the nuclear factor kappa B (NF-κB) signaling pathway, activating protein kinase C (PKC)-α, stimulating protein tyrosine kinase (PTK), reducing the conversion of nitrite to NO via nitrate-nitrite reduction pathways, induction of eNOS, activating the phosphatidylinositol 3-kinase (PI3K)/serine threonine protein kinase B (AKT) (PI3K/AKT/eNOS/NO) pathway and decreasing oxidative stress.

Conclusion:

Medicinal plants and/or their constituent bioactive compounds may be considered as safe therapeutic options for enhancing NO bioavailability and prospective preventative therapy for atherosclerosis.

RGD-decorated solid lipid nanoparticles enhance tumor targeting, penetration and anticancer effect of asiatic acid

Aim: Asiatic acid (AA) is a promising anticancer agent, however, its delivery to glioblastoma is a major challenge. This work investigates the beneficial therapeutic efficacy of RGD-conjugated solid lipid nanoparticles (RGD-SLNs) for the selective targeting of AA to gliblastoma. Materials & methods: AA-containing RGD-SLNs were prepared using two different PEG-linker size. Targetability and efficacy were tested using monolayer cells and spheroid tumor models. Results: RGD-SLNs significantly improved cytotoxicity of AA against U87-MG monolayer cells and enhanced cellular uptake compared with non-RGD-containing SLNs. In spheroid models, AA-containing RGD-SLNs showed superior control in tumor growth, improved cytotoxicity and enhanced spheroid penetration when compared with AA alone or non-RGD-containing SLNs. Conclusion: This study illustrates the potential of AA-loaded RGD-SLNs as efficacious target-specific treatment for glioblastoma.

Centella asiatica modulates cancer cachexia associated inflammatory cytokines and cell death in leukaemic THP-1 cells and peripheral blood mononuclear cells (PBMC's)

Background

Cancer cachexia is associated with increased pro-inflammatory cytokine levels. Centella asiatica (C. asiatica) possesses antioxidant, anti-inflammatory and anti-tumour potential. We investigated the modulation of antioxidants, cytokines and cell death by C. asiatica ethanolic leaf extract (C_LE) in leukaemic THP-1 cells and normal peripheral blood mononuclear cells (PBMC’s).

Methods

Cytotoxcity of C_LE was determined at 24 and 72 h (h). Oxidant scavenging activity of C_LE was evaluated using the 2, 2-diphenyl-1 picrylhydrazyl (DPPH) assay. Glutathione (GSH) levels, caspase (−8, −9, −3/7) activities and adenosine triphosphate (ATP) levels (Luminometry) were then assayed. The levels of tumour necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β and IL-10 were also assessed using enzyme-linked immunosorbant assay.

Results

C_LE decreased PBMC viability between 33.25–74.55% (24 h: 0.2–0.8 mg/ml C_LE and 72 h: 0.4–0.8 mg/ml C_LE) and THP-1 viability by 28.404% (72 h: 0.8 mg/ml C_LE) (p < 0.0001). Oxidant scavenging activity was increased by C_LE (0.05–0.8 mg/ml) (p < 0.0001). PBMC TNF-α and IL-10 levels were decreased by C_LE (0.05–0.8 mg/ml) (p < 0.0001). However, PBMC IL-6 and IL-1β concentrations were increased at 0.05–0.2 mg/ml C_LE but decreased at 0.4 mg/ml C_LE (p < 0.0001). In THP-1 cells, C_LE (0.2–0.8 mg/ml) decreased IL-1β and IL-6 whereas increased IL-10 levels (p < 0.0001). In both cell lines, C_LE (0.05–0.2 mg/ml, 24 and 72 h) increased GSH concentrations (p < 0.0001). At 24 h, caspase (−9, −3/7) activities was increased by C_LE (0.05–0.8 mg/ml) in PBMC’s whereas decreased by C_LE (0.2–0.4 mg/ml) in THP-1 cells (p < 0.0001). At 72 h, C_LE (0.05–0.8 mg/ml) decreased caspase (−9, −3/7) activities and ATP levels in both cell lines (p < 0.0001).

Conclusion

In PBMC’s and THP-1 cells, C_LE proved to effectively modulate antioxidant activity, inflammatory cytokines and cell death. In THP-1 cells, C_LE decreased pro-inflammatory cytokine levels whereas it increased anti-inflammatory cytokine levels which may alleviate cancer cachexia.

Factors Affecting Enhanced Permeation of Amphotericin B Across Cell Membranes and Safety of Formulation

The aim of this study was to determine amphotericin B (AmB) permeation across lipid bilayer membranes mounted on Transwell® and to observe the phagocytosis of the AmB and the AmB-lipid formulations by alveolar macrophage (AM) cell lines using a fluorescence microscope. The lipid bilayer membranes were prepared from phospholipid and ergosterol as well as phospholipid and cholesterol in a ratio (67:33 mol%). AmB-lipid formulations were prepared from AmB incorporated with four lipid derivatives during a lyophilization process. In vitro cytotoxicity studies were carried out on kidney cells by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The levels of nitric oxide production by AMs exposed to these AmB-lipid formulations were determined by the Griess reaction. Phagocytosis of the AmB-lipid formulations was carried out using AM cells. The lipid bilayer membranes and AmB-lipid formulations were successfully prepared. In vitro cytotoxicity results showed less toxicity to kidney cells than pure AmB, and a 1,000-fold less production of nitric oxide by NR8383 cell lines was obtained when compared to lipopolysaccharide. Permeation results were two- to fivefold higher than for pure AmB in the ergosterol containing lipid bilayer and two- to fourfold higher than AmB in the cholesterol containing compositions, both of which were enough to kill the fungi according to their MICs and MFCs. AM phagocytosed the AmB-lipid formulations. We suggest that these products especially the AmB-sodium deoxycholate sulfate are potential candidates for targeting AM cells for the treatment of invasive pulmonary aspergillosis.

Possible Involvement of Nitric Oxide Modulatory Mechanisms in the Neuroprotective Effect of Centella asiatica Against Sleep Deprivation Induced Anxiety Like Behaviour, Oxidative Damage and Neuroinflammation

Sleep deprivation (SD) is an experience of inadequate or poor quality of sleep that may produce significant alterations in multiple neural systems. Centella asiatica (CA) is a psychoactive medicinal herb with immense therapeutic potential. The present study was designed to explore the possible nitric oxide (NO) modulatory mechanism in the neuroprotective effect of CA against SD induced anxiety like behaviour, oxidative damage and neuroinflammation. Male laca mice were sleep deprived for 72 h, and CA (150 and 300 mg/kg) was administered alone and in combination with NO modulators for 8 days, starting five days before 72-h SD exposure. Various behavioural (locomotor activity, elevated plus maze) and biochemical (lipid peroxidation, reduced glutathione, catalase, nitrite levels and superoxide dismutase activity), neuroinflammation marker (TNF-alpha) were assessed subsequently. CA (150 and 300 mg/kg) treatment for 8 days significantly improved locomotor activity, anti-anxiety like effect and attenuated oxidative damage and TNF α level as compared to sleep-deprived 72-h group. Also while the neuroprotective effect of CA was increased by NO antagonists, it was diminished by NO agonists. The present study suggests that NO modulatory mechanism could be involved in the protective effect of CA against SD-induced anxiety-like behaviour, oxidative damage and neuroinflammation in mice.

Anti-glioma activity and the mechanism of cellular uptake of asiatic acid-loaded solid lipid nanoparticles

Asiatic acid (AA), a pentacyclic triterpene found in Centella Asiatica, has shown neuroprotective and anti-cancer activity against glioma. However, owing to its poor aqueous solubility, effective delivery and absorption across biological barriers, in particular the blood brain barrier (BBB), are challenging. Solid lipid nanoparticles (SLNs) have shown a promising potential as a drug delivery system to carry lipophilic drugs across the BBB, a major obstacle in brain cancer therapy. Nevertheless, limited information is available about the cytotoxic mechanisms of nano-lipidic carriers with AA on normal and glioma cells. This study assessed the anti-cancer efficacy of AA-loaded SLNs against glioblastoma and their cellular uptake mechanism in comparison with SVG P12 (human foetal glial) cells. SLNs were systematically investigated for three different solid lipids; glyceryl monostearate (MS), glyceryl distearate (DS) and glyceryl tristearate (TS). The non-drug containing MS-SLNs (E-MS-SLNs) did not show any apparent toxicity towards normal SVG P12 cells, whilst the AA-loaded MS-SLNs (AA-MS-SLNs) displayed a more favourable drug release profile and higher cytotoxicity towards U87 MG cells. Therefore, MS-SLNs were chosen for further in vitro studies. Cytotoxicity studies of SLNs (± AA) were performed using MTT assay where AA-SLNs showed significantly higher cytotoxicity towards U87 MG cells than SVG P12 normal cells, as confirmed by flow cell cytometry. Cellular uptake of SLNs also appeared to be preferentially facilitated by energy-dependent endocytosis as evidenced by fluorescence imaging and flow cell cytometry. Using the Annexin V-PI double staining technique, it was found that these AA-MS-SLNs displayed concentration-dependent apoptotic activity on glioma cells, which further confirms the potential of exploiting these AA-loaded MS-SLNs for brain cancer therapy.

Gotu Kola (Centella asiatica): Nutritional Properties and Plausible Health Benefits

Centella asiatica L. (Gotu Kola) is a nutritionally important plant and a valued traditional medicine in South East Asia. In this review, the chemical composition, nutritional values, and health benefits of C. asiatica have been discussed in detail to emphasize its usage as traditional food and medicine. C. asiatica is one of the most commonly used green leafy vegetables (GLVs) in some countries including Sri Lanka due to its high amounts of medicinally important triterpenoids and beneficial carotenoids. It is consumed in the form of GLVs and in the preparation of juice, drink, and other food products. It is also known to contain vitamins B and C, proteins, important minerals, and some other phytonutrients such as flavonoids, volatile oils, tannins, and polyphenol. In vitro and in vivo studies have shown important health benefits like antidiabetic, wound-healing, antimicrobial, memory-enhancing, antioxidant, and neuroprotecting activities. However, detailed scientific approaches on clinical trials regarding health benefits and nutritional values of C. asiatica are limited, hindering the perception of its benefits, mechanisms, and toxicity in order to develop new drug prototypes. In vitro studies have shown that the method of processing C. asiatica has an impact on its nutritional values and health-related beneficial compounds. The composition of its compounds is influenced by different biotic and abiotic factors which need to be studied in detail to provide information to the public in order to maximize the usage of this valuable plant.

In Vitro Antileukemic Activity of Xanthosoma sagittifolium (Taioba) Leaf Extract

Xanthosoma sagittifolium Schott is a herb of the Araceae family, popularly known as taioba, which is consumed as food in some regions of Brazil, Africa, and Asia. This species has already been evaluated for the antifungal activities. However, based on its potential antitumor activity, the present study further aimed to examine the antitumor, as well as chelation, activity of X. sagittifolium leaf extract. Results showed that hydroethanolic extract of X. sagittifolium leaves (HEXs-L) exhibits cytotoxic effects against the immortalized line of human T-lymphocytic (Jurkat) and myelogenous (K562) leukemia cells, but not nontumor RAW 264.7 macrophages or NIH/3T3 fibroblasts. HEXs-L inhibited 50.3% of Jurkat cell proliferation, reducing by 20% cells in G2/M phase, but increasing cells in sub-G1 phase, thereby inducing apoptosis by 54%. In addition, HEXs-L inhibited NO production by 59%, as determined by Griess reaction, and chelated 93.8% of free Fe(II), as demonstrated by ferrozine assay. Phytochemical studies were carried out by ESI-MS, identifying apigenin di-C-glycosides as major compounds. Overall, this work revealed that leaf extract of Xanthosoma sagittifolium presented chelating activity and in vitro antitumor activity, arresting cell cycle and inducing apoptosis of leukemia cells, thus providing evidence that taioba leaves may have practical application in cancer therapy.

Moringa oleifera pod inhibits inflammatory mediator production by lipopolysaccharide-stimulated RAW 264.7 murine macrophage cell lines

Pro-inflammatory mediators produced during inflammatory response have been demonstrated to initiate and aggravate pathological development of several chronic diseases. Plant bioactive constituents have been reported to exert anti-inflammatory activities. Various parts of Moringa oleifera have long been used as habitual diets and traditional remedy along the tropical region. Anti-inflammatory activity of boiled M. oleifera pod extract was assessed by measuring pro-inflammatory mediator expression in the lipopolysaccharide-induced murine RAW264.7 macrophage cells. Prior treatment with 31-250 μg/mL M. oleifera extract for 1 h inhibited elevation of mRNA and protein level of interleukine-6, tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclooxygenease-2, induced by lipopolysaccharide for 24 h in a dose-dependent manner. The suppressive effect was mediated partly by inhibiting phosphorylation of inhibitor kappa B protein and mitogen-activated protein kinases. These results indicate that the anti-inflammatory activity from bioactive compounds present in the M. oleifera pod constituents may contribute to ameliorate the pathogenesis of inflammatory-associated chronic diseases.

Levofloxacin-proliposomes: opportunities for use in lung tuberculosis

Levofloxacin (LEV) is a relatively new-generation fluoroquinolone antibiotic that has good activity against Mycobacterium tuberculosis. The aims of this study were to develop and evaluate LEV-proliposomes in a dry powder aerosol form for pulmonary delivery. LEV-proliposomes containing LEV, soybean phosphatidylcholine, cholesterol and porous mannitol were prepared by a spray drying technique. The physicochemical properties of LEV-proliposomes were determined using a cascade impactor, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The toxicity of proliposomes to respiratory-associated cell lines and its potential to provoke immunological responses from alveolar macrophages (AMs) were evaluated. Antimycobacterial activity using flow cytometry and an in vivo repeated dose toxicity test in rats were carried out. LEV-proliposomes were successfully prepared with mass median aerodynamic diameters of 4.15-4.44 μm and with fine particle fractions (aerosolized particles of less than 4.4 µm) of 13%-38% at 60 L/min. LEV-proliposomes were less toxic to respiratory-associated cells than LEV, and did not activate AMs to produce inflammatory mediators that included interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nitric oxide. The minimum inhibitory concentration (MIC) against M. bovis of LEV and LEV-proliposomes containing LEV 10% were 1 and 0.5 µg/mL, respectively. The efficacy of LEV-proliposomes against M. bovis was significantly higher than that of free LEV (p < 0.05). The efficacy of the LEV-proliposomes against M. tuberculosis was equal to that of the free LEV (MIC = 0.195 µg/mL). In a repeated dose toxicity study in rats, renal and liver toxicity was not observed. LEV-proliposomes should now be tested as an alternative formulation for delivering LEV to the lower airways.

Rhinacanthus nasutus protects cultured neuronal cells against hypoxia induced cell death

Rhinacanthus nasutus (L.) Kurz (Acanthaceae) is an herb native to Thailand and Southeast Asia, known for its antioxidant properties. Hypoxia leads to an increase in reactive oxygen species in cells and is a leading cause of neuronal damage. Cell death caused by hypoxia has been linked with a number of neurodegenerative diseases including some forms of dementia and stroke, as well as the build up of reactive oxygen species which can lead to diseases such as Huntington's disease, Parkinson's disease and Alzeheimer's disease. In this study we used an airtight culture container and the Mitsubishi Gas Company anaeropack along with the MTT assay, LDH assay and the trypan blue exlusion assay to show that 1 and 10 µg mL⁻¹ root extract of R. nasutus is able to significantly prevent the death of HT-22 cells subjected to hypoxic conditions, and 0.1 to 10 µg mL⁻¹ had no toxic effect on HT-22 under normal conditions, whereas 100 µg mL⁻¹ reduced HT-22 cell proliferation. We also used H₂DCFDA staining to show R. nasutus can reduce reactive oxygen species production in HT-22 cells.

Isoniazid proliposome powders for inhalation-preparation, characterization and cell culture studies

The aims of this study were to develop proliposome powders containing isoniazid (INH) in a dry powder aerosol form. INH-proliposome powders were prepared by a spray drying method. Proliposome physicochemical properties were determined using cascade impactor, X-ray diffraction and differential scanning calorimetry. The toxicity of proliposomes to respiratory-associated cell lines and its potential to provoke immunological responses from alveolar macrophages (AM) were determined. Free INH and INH-proliposome bioactivities were tested in vitro and in AM infected with Mycobacterium bovis (M. bovis). Aerosolization properties of INH-proliposome powders at 60 L/min, the powders showed mass median aerodynamic diameters of 2.99–4.92 μm, with fine particle fractions (aerosolized particles less than 4.4 μm) of 15–35%. Encapsulation of INH was 18–30%. Proliposome formulations containing INH to mannitol ratios of 4:6 and 6:4 exhibited the greatest overlapping peak between the drug and mannitol. INH-proliposomes were evidently nontoxic to respiratory-associated cells, and did not activate AM to produce inflammatory mediators—including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nitric oxide—at a toxic level. The efficacy of INH-proliposome against AM infected with M. bovis was significantly higher than that of free INH (p < 0.05). INH-proliposomes are potential candidates for an alternative tuberculosis treatment.

Anti-inflammatory activity of Lychnophora passerina, Asteraceae (Brazilian "Arnica")

ETHNOPHARMACOLOGICAL RELEVANCE

Lychnophora passerina (Asteraceae), popularly known as "arnica," is used to treat inflammation, pain, rheumatism, contusions, bruises and insect bites in Brazilian traditional medicine.

MATERIALS AND METHODS

The anti-inflammatory activity of crude ethanolic extract of aerial parts of L. passerina and its ethyl acetate and methanolic fractions had their abilities to modulate the production of NO, TNF-α and IL-10 inflammatory mediators in LPS/IFN-γ-stimulated J774.A1 macrophages evaluated. Moreover, the crude ethanolic extract and derived fractions were also in vivo assayed by carrageenan-induced paw oedema in mice.

RESULTS

In vitro assays showed remarkable anti-inflammatory activity of L. passerina crude ethanolic extract (EE) and its ethyl acetate (A) and methanolic (M) fractions, through the inhibition of production of NO and TNF-α inflammatory mediators and induction of production of IL-10 anti-inflammatory cytokine. In vivo assays showed anti-inflammatory activity for EE 10% ointment, similar to the standard drug diclofenac gel. The A and M fraction ointments 20% presented anti-inflammatory activity.

CONCLUSION

The results obtained showed that possible anti-inflammatory effects of EE and its A and M fractions may be attributed to inhibition pro-inflammatory cytokines production, TNF-α and NO and to increased IL-10 production. EE, A and M ointments showed topical in vivo anti-inflammatory activity. The in vivo anti-inflammatory activity of EE of L. passerina may be related to synergistic effects of different substances in the crude extract. Therefore, traditional use of aerial parts of L. passerina in the inflammatory conditions could be beneficial to treat topical inflammatory conditions, as evidenced by the present study.

Traditionally used Thai medicinal plants: in vitro anti-inflammatory, anticancer and antioxidant activities

AIMS OF THE STUDY

In order to assess traditional Thai claims about the therapeutic potential of medicinal plants and to select plants for future phytochemical research, nine plant species with anti-inflammatory uses were selected from Thai textbooks and assessed for their in vitro anti-inflammatory, antiproliferative and antioxidant activities.

METHODS

Nuclear factor-kappaB (NF-kappaB) inhibitory effects in stably transfected HeLa cells were determined by luciferase assay, and effects on LPS-induced pro-inflammatory mediators prostaglandin E2 (PGE2), interleukin (IL)-6, IL-1beta, and tumour necrosis factor (TNF)alpha in primary monocytes were assessed by ELISA. Cytotoxic activities were examined against HeLa cells, human leukaemia CCRF-CEM cells and the multidrug-resistant CEM/ADR5000 subline using the MTT and XTT tests. However, a redox status has been linked with both inflammation and cancer, antioxidant effects were also assessed using the DPPH, lipid-peroxidation, and Folin-Ciocalteau methods.

RESULTS

Among all the nine species, Gynura pseudochina var. hispida and Oroxylum indicum showed the most promising NF-kappaB inhibitory effects with the lowest IC(50) values (41.96 and 47.45 microg/ml, respectively). Muehlenbeckia platyclada did not inhibit the NF-kappaB activation but effectively inhibited the release of IL-6, IL-1beta and TNF-alpha with IC(50) values ranging between 0.28 and 8.67 microg/ml. Pouzolzia indica was the most cytotoxic against CCRF-CEM cells and the multidrug-resistant CEM/ADR5000 cells (9.75% and 10.48% viability, at 10 microg/ml, respectively). Rhinacanthus nasutus was the most potent cytotoxicity against HeLa cells (IC(50) 3.63 microg/ml) and showed specific cytotoxicity against the multidrug-resistant CEM/ADR5000 cells (18.72% viability at 10 microg/ml, p<0.0001 when compared to its cytotoxicity against CCRF-CEM cells). Moreover, Oroxylum indicum showed a high level of antioxidant activity by inhibiting lipid-peroxidation (IC(50) 0.08 microg/ml).

CONCLUSIONS

This study provides in vitro evidence for the use of the Thai plants, most importantly Gynura pseudochina var. hispida, Oroxylum indicum and Muehlenbeckia platyclada as Thai anti-inflammatory remedies and these plants are now a priority for further phytochemical research.

Monitoring safety of liposomes containing rifampicin on respiratory cell lines and in vitro efficacy against Mycobacterium bovis in alveolar macrophages

Rifampicin-encapsulated liposome suspensions were prepared by a chloroform-film method and converted to dry powders by freeze-drying with mannitol as a cryoprotectant. The liposome suspension had multilamellar nanovesicles with 50% rifampicin encapsulation. The liposome dry powder comprised particles with a mass median aerodynamic diameter of 3.4 mum, with 60% present as a fine particle fraction. Rifampicin-encapsulated liposomes were evidently nontoxic to respiratory associated cells, including bronchial epithelial cells, small airway epithelial and alveolar macrophages (AMs). Furthermore, the liposomes did not activate AMs to produce interleukin-1 beta, tumor necrosis factor-alpha, and nitric oxide at a level that would cascade to other inflammatory effects. The minimum inhibitory concentrations against Mycobacterium bovis was 0.2 and 0.8 microM for liposomes containing rifampicin and free rifampicin, respectively. The less negatively charged reconstituted liposome displayed the greatest activity against intracellular growth of M. bovis.

Anti-inflammatory activities of extracts of Thai spices and herbs with lipopolysaccharide-activated RAW 264.7 murine macrophages

Nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) play important roles in inflammatory processes. This study examined whether 13 spices/herbs commonly used in Thai dishes modulate the production of NO and TNF-alpha by the RAW 264.7 mouse macrophage cell line pretreated with plant extracts (1-100 microg/mL) prior to activation by bacterial lipopolysaccharide (LPS). Tested plant tissues were extracted with ethanol with the exception of roselle, which was extracted with 70% acetone. Eight of the 13 plant extracts inhibited NO and TNF-alpha production in a dose-dependent manner without exerting cytotoxicity. Extract from Limnophila aromatica (Kyeng) was the most robust suppressor of NO production, followed by dill, kaffer lime, chili, Teaw, mint, sweet basil, and pea eggplant, respectively (range of 50% inhibitory concentration [IC(50)] = 11.4-74.6 microg/mL). Kyeng also exhibited the greatest inhibition of TNF-alpha production (IC(50) = 10.5 microg/mL). IC(50) values for NO and TNF-alpha production in LPS-activated RAW 264.7 cells for these extracts were highly correlated (r = 0.772, P = .025). These results suggest that extracts from some spices/herbs in the habitual Thai diet possess anti-inflammatory activity. Moreover, the results support the use of NO production in LPS-activated RAW 264.7 cells as a rapid and cost-effective tool for screening the anti-inflammatory activity of extracts of spices/herbs.

An ethnobotanical study of traditional anti-inflammatory plants used by the Lohit community of Arunachal Pradesh, India

AIM OF THE STUDY

Most people especially in rural areas depend on herbal medicines to treat many diseases including inflammation-related ailments such as rheumatism, muscle swelling, cut wound, accidental bone fracture, insect bites, pains and burn by fire and hot water. The objectives of this study were: to catalog ethno-medicinal plants of Lohit community, ecological status, indigenous folk medicinal uses, morphological parts used and to determine their reported pharmacological studies.

MATERIALS AND METHODS

The ethnobotanical information on traditional medicinal plants exclusively used for management of inflammation-related ailments by the Khampti community of Arunachal Pradesh, India was based on first-hand field survey work through semi-structured interviews.

RESULTS AND CONCLUSION

A total of 34 species in 32 genera and 22 families were encountered during the field survey. Botanical families such as Asteraceae, Euphorbiaceae, Zingiberaceae and Lamiaceae were represented by the highest numbers of species reported in this study. Thirteen plant species, namely: Bombax ceiba, Canarium strictum, Chloranthus erectus, Xanthium indicum, Lycopodium clavatum, Coleus blumei, Batrachospermum atrum, Chlorella vulgaris, Marchantia palmata, Marchantia polymorpha, Eria pannea, Sterculia villosa and Alpinia galanga are reported for the first time for the treatment of inflammation-related diseases.

In vitro and in vivo modulation of cartilage degradation by a standardized Centella asiatica fraction

Osteoarthritis (OA) is a degenerative joint disease in which focal cartilage destruction is one of the primary features. The present study aims to evaluate the effect of a Centella asiatica fraction on in vitro and in vivo cartilage degradation. Bovine cartilage explants and bovine chondrocytes cultured in alginate were stimulated with IL-1 beta in the presence or absence of different concentrations (2, 5 and 10 microg/ml) of a standardized Centella asiatica triterpenes (CAT) fraction. The CAT fraction inhibited the IL-1 beta-induced proteoglycan (PG) release and nitric oxide (NO) production by cartilage explants in a dose-dependent manner. The IL-1 beta-induced reduction in PG synthesis and proliferation of chondrocytes cultured in alginate were counteracted by the CAT fraction at a concentration of 10 microg/ml. In a zymosan-induced acute arthritis model, the CAT fraction inhibited PG depletion without modulating joint swelling and inflammatory cell infiltration. In conclusion, the present study demonstrated for the first time that the tested Centella asiatica fraction was able to inhibit the zymosan-induced cartilage degradation in vivo without affecting the zymosan-induced inflammatory cell infiltration and joint swelling. The in vitro data indicate that the cartilage protective activity might at least partially be induced by the inhibition of NO production. The overall results indicate a possible disease modifying osteoarthritic activity of the Centella asiatica fraction.

Early effects triggered by Larrea divaricata Cav. on murine macrophages at apoptotic concentrations

Decoction and infusion of Larrea divaricata were tested at apoptotic concentrations (1 and 4 mg/ml) on peritoneal murine macrophages. Consistent changes were observed after incubation with 4 mg/ml decoction. Phagocytosis of zymosan, lysosomal enzyme activity, nitric oxide production, TNF-alpha release, and expression of CD14, TLR4, and CR3 increased significantly. Decoction at 1 and 4 mg/ml increased the binding of LPS-FITC. Apoptosis triggered by L. divaricata decoction is consequence of cell activation. The effects are independent of nordihydroguaiaretic acid. This "activation and death" could be the mechanism of L. divaricata to exert the antituberculosis effect known in folk medicine.

Chitosan oligosaccharide (COS) inhibits LPS-induced inflammatory effects in RAW 264.7 macrophage cells

The focus of this study was to clarify the relation between the nitric oxide (NO) production and cytokine expression including tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), and also investigated the effect of COS on LPS stimuli from RAW 264.7 cell. The lipopolysaccharide (LPS) of Gram-negative bacteria induces the expression of cytokines and potent inducers of inflammatory cytokines such as TNF-alpha and IL-6. In this experiment, upon stimulation with increasing concentrations of chitosan, the LPS-stimulated TNF-alpha and IL-6 secretion was significantly recovered within the incubation media of RAW 264.7 cells. Consistently, RT-PCR with mRNA and Western blot with anti-cytokine antiserum including TNF-alpha and IL-6 showed that the amount of TNF-alpha and IL-6 secretion in the incubation media recovered with the concentration of chitosan. The LPS-stimulated NO secretion was significantly recovered within the 6h and 12h incubation media of RAW 264.7 cells, too. The recovery effect of chitosan on IL-6 and NO secretion may be induced via the stimulus of TNF-alpha in RAW 264.7 cell. These results once again suggest that chitosan oligosaccharide may have the anti-inflammatory effect via the stimulus of TNF-alpha in the LPS-stimulated inflammation in RAW 264.7 cells.