Betulinic acid attenuates lung injury by modulation of inflammatory cytokine response in experimentally-induced polymicrobial sepsis in mice.

Sepsis commonly progresses to acute lung injury (ALI), an inflammatory lung disease with high morbidity and mortality. Septic ALI is characterized by excessive production of proinflammatory mediators. It remained refractory to present therapies and new therapies need to be developed to improve further clinical outcomes. Betulinic acid (BA), a pentacyclic lupane group triterpenoid has been shown to have anti-inflammatory activities in many studies. However, its therapeutic efficacy in polymicrobial septic ALI is yet unknown. Therefore, we investigated the effects of BA on septic ALI using cecal ligation and puncture (CLP) model in mice. Vehicle or BA (3, 10, and 30mg/kg) was administered intraperitoneally, 3 times (0, 24 and 48h) before CLP and CLP was done on 49(th)h of the study. Survival rate was observed till 120h post CLP. Lung tissues were collected for analysis by sacrificing mice 18h post CLP. BA at 10 and 30mg/kg dose significantly reduced sepsis-induced mortality and lung injury as implied by attenuated lung histopathological changes, decreased protein and neutrophils infiltration. BA also decreased lung NF-κB expression, cytokine, intercellular adhesion molecule-1, monocyte chemoattractant protein-1 and matrix metalloproteinase-9 levels. These evidences suggest that, the protective effects of BA on lungs are associated with defending action against inflammatory response and BA could be a potential modulatory agent of inflammation in sepsis-induced ALI.

Anti-inflammatory and chondroprotective effects of atorvastatin in a cartilage explant model of osteoarthritis.

OBJECTIVE: This study aimed to assess the chondroprotective potential of atorvastatin in rat's cartilage explant culture model of osteoarthritis, stimulated by interleukin-1ß (IL-1ß). MATERIALS AND METHODS: The cartilage explants were treated with 20 ng/ml IL-1ß alone or with 20 ng/ml IL-1ß + various concentration of atorvastatin (1, 3, or 10 µM dissolved in DMSO) and incubated at 37 °C for 24 h. Also, control (0.25% DMSO), stimulated (20 ng IL-1ß) and treatment (atorvastatin 10 µM) cartilage explants were incubated without and with 1400W (10 µM). After 24 h of incubation, TNF-α, PGE2, MMP-13, TIMP-1, NO, and superoxide anion formation (O2(-)) concomitant with glycosaminoglycans (GAGs) were estimated in the medium. RESULTS: Atorvastatin inhibited IL-1ß-induced GAGs release, TNF-α, MMP-13, and O2(-) with no effect on TIMP-1 and NO. In addition, the source of NO in normal and atorvastatin-treated cartilage was eNOS, while for IL-1ß-stimulated cartilage it was iNOS. The cartilage degradation was associated with the combined effects of increased NO and O2 (-) rather than only NO. CONCLUSION: The present study suggests that atorvastatin has the ability to protect cartilage degradation following IL-1ß-stimulated cartilage in in vitro OA model and supports additional therapeutic application of atorvastatin in OA.

Betulinic acid negates oxidative lung injury in surgical sepsis model.

BACKGROUND: Sepsis commonly progresses to acute lung injury and is associated with high morbidity and mortality. Septic acute lung injury is characterized by severe oxidative stress response, remained refractory to present therapies, and new therapies need to be developed to improve further clinical outcomes. We determined the effect of betulinic acid (BA) on oxidative lung injury in mice using cecal ligation and puncture (CLP) model. MATERIALS AND METHODS: Five groups of mice (six in each group) received three pretreatments at 24-h interval before surgery. Surgery was done 1 h after last dosing. Sham and CLP control group mice received vehicle. BA was administered to other three groups of mice at 3, 10, and 30 mg/kg dose. Lung and plasma samples were collected for analysis by sacrificing the mice at 18 h of surgery. RESULTS: Compared with sham, CLP significantly increased total protein, nitrite, malondialdehyde, isoprostane, superoxide, protein carbonyl, oxidative stress index, inducible nitric oxide synthase protein, and histopathologic changes and reduced the superoxide dismutase, catalase activity, and total thiol levels in lungs and plasma, which were restored by BA pretreatment. CONCLUSIONS: BA pretreatment decreased the levels of oxidants, increased the levels of antioxidants in lungs and plasma thereby reducing the oxidative lung injury in CLP mice. Additionally, BA was found to scavenge the superoxide and nitric oxide radical in vitro. Thus, BA is suggested to be effective in treatment of oxidative lung injury in sepsis.

Effect of alcoholic extract of Entada pursaetha DC on monosodium iodoacetate-induced osteoarthritis pain in rats.

BACKGROUND & OBJECTIVES: Osteoarthritis (OA) is a degenerative disease characterized by joint pain and progressive loss of articular cartilage. Entada pursaetha has been traditionally used in the treatment of inflammatory disease, liver ailment, etc. In this study we investigated suppressive effect of ethanolic extract of E. pursaetha (EPE) on monosodium iodoacetate (MIA)-induced osteoarthritis pain and disease progression by histopathological changes in joints in a rat model. METHODS: OA was induced in right knee of rat by intra-articular injection of 3 mg of MIA and characterized by pathological progression of disease and pain of affected joint. Spontaneous movements, mechanical, thermal and cold sensitivity were monitored at days 0 (before drug and MIA injection), 7, 14 and 21 of MIA administration. EPE (30, 100 and 300 mg/kg), vehicle or etoricoxib (10 mg/ kg; reference drug) were administered daily for 21 days by oral route. RESULTS: EPE at various doses significantly reduced mechanical, heat, cold hyperalgesia and increased the horizontal and vertical movements in intra-articular MIA injected rats. EPE prevented the damage to cartilage structure and reduced the cellular abnormalities. Articular cartilage of rats treated with EPE at 300 mg/kg group was almost normal with well-developed smooth surface and chondrocytes were distributed individually or arranged in column. INTERPRETATION & CONCLUSIONS: The present findings showed that the EPE was not only able to mitigate pain and hyperalgesia but also inhibited MIA-induced cartilage degeneration in vivo. EPE may have the potential to become therapeutic modality in the treatment of osteoarthritis. However, further studies need to be done to confirm these findings in other models and clinical trials.

Effect of Trimeric Myricetin Rhamnoside (TMR) in Carrageenan-induced Inflammation and Caecal Ligation and Puncture-induced Lung Oxidative Stress in Mice.

The Eugenia jambolana is used in folklore medicine. Leaves of E. jambolana contain flavonoids as their active constituents which possess in vitro antiinflammatory, antioxidant and the antimicrobial activity. The aim of the present study was to investigate the antiinflammatory and antioxidant effects of a flavonoid glucoside, trimeric myricetin rhamnoside (TMR) isolated from leaves of E. jambolana. TMR was studied for antiinflammatory activity in carrageenan-induced hind paw oedema and antioxidant activity in lung by caecal ligation and puncture (CLP)-induced sepsis in mice. Results of the present study indicated that TMR significantly attenuated the oedema, myeloperoxidase (MPO), cytokines and prostaglandin levels in the paw after 5 h of carrageenan injection as compared to vehicle control. It also reduced the lung MPO, lipid peroxides, and serum nitrite plus nitrate levels and increased lung reduced glutathione levels 20 h of CLP as compared to vehicle control. Thus the results of this study concluded that the TMR appears to have potential benefits in diseases that are mediated by both inflammation and oxidative stress and support the pharmacological basis of use of E. jambolana plant as traditional herbal medicine for the treatment of inflammatory diseases.

Effect of S-methylisothiourea, an inducible nitric oxide synthase inhibitor, in joint pain and pathology in surgically induced model of osteoarthritis.

The aim of the present study was to evaluate in vivo modulatory effect of S-methylisothiourea (SMT), a preferential inhibitor of inducible nitric oxide synthase (iNOS) on pain and pathology in the surgical model of osteoarthritis (OA) in rats. The OA was produced by the anterior cruciate ligament transection (ACLT) and medial meniscectomy (MMx) of right knee. SMT was administered 1 day prior to the production of OA and continued up to day 42 postoperation. Mechanical hyperalgesia, thermal hyperalgesia, tail flick latency after repeated flexion and extension of OA knee and knee diameter of right knee were determined at weekly intervals. Serum levels of IL-1ß, TNF-α and nitrite concentration were determined at the end of the experiment. Glycosaminoglycan (GAG) content, collagen content and histopathological evaluation of articular cartilage were also determined at the end of the experiment. SMT reduced mechanical hyperalgesia and the serum levels of IL-1ß, TNF-α and nitrite. Further, SMT reduced the loss of GAG from articular cartilage. Microscopically, SMT reduced the severity of the cartilage lesion. The results indicate the effectiveness of SMT in attenuating the pain and pathology of experimental OA phase by reducing the production of nitric oxide and interleukin-1ß and tumor necrosis factor-α, which are known to play a major role in the pathophysiology of OA.

Analgesic activity of Eugenia jambolana leave constituent: a dikaempferol rhamnopyranoside from ethyl acetate soluble fraction.

CONTEXT: Eugenia jambolana Lam. (Myrtaceae) is a medicinal plant used in folk medicine for the treatment of diabetes, inflammation, and pain. OBJECTIVE: We investigated the antinociceptive effect of kaempferol-7-O-α-l-rhamnopyranoside]- 4'-O-4'-[kaempferol-7-O-α-l-rhamnopyranoside (EJ-01), isolated from the E. jambolana leaves. MATERIALS AND METHODS: EJ-01 (3, 10, and 30 mg kg(-1), orally) was assessed for peripheral (formalin-nociception and acetic acid-writhing) and central (hot plate and tail flick test) analgesic activity in mice and the in vitro anti-inflammatory activity (25, 50, and 100 µg mL(-1)) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. RESULTS AND DISCUSSION: EJ-01 (10 and 30 mg kg(-1)) significantly inhibited mean writhing counts (37.74 and 36.83) in acetic acid writhing and paw licking time (55.16 and 45.66 s) in the late phase of the formalin test as compared with the respective control (60.66 and 104.33 s). EJ-01 did not show analgesic activity in central pain models. Significant reduction in the tumor necrosis factor (TNF)-α (295.48, 51.20, and 49.47 pg mL(-1)) and interleukin (IL)-1ß (59.38, 20.08, and 15.46 pg mL(-1)) levels were observed in EJ-01-treated medium (25, 50, and 100 µg mL(-1)) as compared with vehicle-treated control values (788.67 and 161.77 pg mL(-1)), respectively. Significant reduction in total nitrite plus nitrate (NOx) levels (70.80 nmol) was observed in the EJ-01-treated medium (100 µg mL(-1)) as compared with the vehicle-treated value (110.41 nmol). CONCLUSION: EJ-01 is a valuable analgesic constituent of E. jambolana leaves and this study supports the pharmacological basis for the use of this plant in traditional medicine for curing inflammatory pain.

Anti-Cholera toxin activity of selected polyphenols from Careya arborea, Punica granatum, and Psidium guajava.

Introduction: Careya arborea, Punica granatum, and Psidium guajava are traditionally used to treat diarrheal diseases in India and were reported to show anti-Cholera toxin activity from our earlier studies. As polyphenols are reported to neutralize Cholera toxin (CT), the present study investigated the inhibitory activity of selected polyphenols from these plants against CTB binding to GM1 receptor using in silico, in vitro, and in vivo approaches. Methods: Molecular modelling approach was used to investigate the intermolecular interactions of selected 20 polyphenolic compounds from three plants with CT using DOCK6. Based on intermolecular interactions, two phenolic acids, Ellagic acid (EA) and Chlorogenic acid (CHL); two flavonoids, Rutin (RTN) and Phloridzin (PHD) were selected along with their respective standards, Gallic acid (GA) and Quercetrin (QRTN). The stability of docked complexes was corroborated using molecular dynamics simulation. Furthermore, in vitro inhibitory activity of six compounds against CT was assessed using GM1 ELISA and cAMP assay. EA and CHL that showed prominent activity against CT in in vitro assays were investigated for their neutralizing activity against CT-induced fluid accumulation and histopathological changes in adult mouse. Results and discussion: The molecular modelling study revealed significant structural stability of the CT-EA, CT-CHL, and CT-PHD complexes compared to their respective controls. All the selected six compounds significantly reduced CT-induced cAMP levels, whereas EA, CHL, and PHD exhibited > 50% binding inhibition of CT to GM1. The EA and CHL that showed prominent neutralization activity against CT from in vitro studies, also significantly decreased CT-induced fluid accumulation and histopathological changes in adult mouse. Our study identified bioactive compounds from these three plants against CT-induced diarrhea.

In Vitro and In Vivo Inhibitory Activities of Selected Traditional Medicinal Plants against Toxin-Induced Cyto- and Entero- Toxicities in Cholera.

Careya arborea, Punica granatum, Psidium guajava, Holarrhena antidysenterica, Aegle marmelos, and Piper longum are commonly used traditional medicines against diarrhoeal diseases in India. This study investigated the inhibitory activity of these plants against cytotoxicity and enterotoxicity induced by toxins secreted by Vibrio cholerae. Cholera toxin (CT) and non-membrane damaging cytotoxin (NMDCY) in cell free culture filtrate (CFCF) of V. cholerae were quantified using GM1 ELISA and cell-based assays, respectively. Hydro-alcoholic extracts of these plants and lyophilized juice of P. granatum were tested against CT-induced elevation of cAMP levels in CHO cell line, binding of CT to ganglioside GM1 receptor and NMDCY-induced cytotoxicity. Significant reduction of cAMP levels in CFCF treated CHO cell line was observed for all extracts except P. longum. C. arborea, P. granatum, H. antidysenterica and A. marmelos showed >50% binding inhibition of CT to GM1 receptor. C. arborea, P. granatum, and P. guajava effectively decreased cytotoxicity and morphological alterations caused by NMDCY in CHO cell line. Further, the efficacy of these three plants against CFCF-induced enterotoxicity was seen in adult mice ligated-ileal loop model as evidenced by decrease in volume of fluid accumulation, cAMP levels in ligated-ileal tissues, and histopathological changes in intestinal mucosa. Therefore, these plants can be further validated for their clinical use against cholera.

Effect of atorvastatin, a HMG-CoA reductase inhibitor in monosodium iodoacetate-induced osteoarthritic pain: implication for osteoarthritis therapy.

BACKGROUND: Oxidative stress is one of the main causes of pain and cartilage degradation in osteoarthritis. This study on atorvastatin, a HMG-CoA reductase inhibitor used in the treatment of hypercholesterolemia and prevention of coronary heart disease aimed to investigate its effect on hyperalgesia and cartilage damage in monosodium iodoacetate (MIA)-induced osteoarthritis model in rats. METHODS: Osteoarthritis was induced by a single intra-articular injection of 3mg MIA. After daily administration of atorvastatin (3, 10 and 30 mg/kg) for 20 days by oral gavage, pain was assessed on days 0, 1, 3, 7, 14 and 21. Histopathology of ipsilateral knee joint; oxidative markers and antioxidants in plasma were assessed on day 21. RESULTS: Atorvastatin attenuated hyperalgesia. The increased level of lipid peroxidation, superoxide, protein carbonyl; decreased activity of catalase, glutathione-S-transferase, reduced glutathione and total thiol levels in MIA rats were restored to the normal levels, however, superoxide dismutase and nitric oxide levels remained unaltered by atorvastatin. Further, atorvastatin reduced the MIA-induced histopathological alteration in the knee joint. CONCLUSION: Our study demonstrated that atorvastatin attenuates MIA-induced osteoarthritic pain and protect cartilage degradation through inhibition of oxidative stress suggesting its importance in osteoarthritic pain management.

Betulinic acid attenuates renal oxidative stress and inflammation in experimental model of murine polymicrobial sepsis.

Sepsis is a common cause of acute kidney injury (AKI) and is associated with substantial morbidity and mortality. Objective of the study was to evaluate the effect of betulinic acid, a triterpenoid in sepsis-induced AKI using cecal ligation puncture (CLP) mouse model. Mice subjected to CLP developed histologic AKI at 18h after CLP. There was an increase in renal proinflammatory response (nuclear factor-kappa B expression, tumor necrosis factor-alpha, interleukin (IL)-6 and IL-10), matrix metalloproteinase-9, plasma creatinine, renal neutrophil gelatinase-associated lipocalin and oxidant stress response (malondialdehyde, inducible nitric oxide synthase, total nitrite and superoxide); decrease in anti-oxidant levels (superoxide dismutase and catalase) at 18h of CLP. However, BA pretreatment at the doses of 10 and 30mg/kg prevented the CLP-induced kidney damage by restoring the aforementioned inflammatory mediators, oxidant and anti-oxidant imbalance. These evidences suggest that, the protective effects of BA on kidney are associated with defending action against inflammatory and oxidative stress response in CLP mice and BA could be potential therapeutic agent in sepsis-induced AKI.

Atorvastatin attenuates neuropathic pain in rat neuropathy model by down-regulating oxidative damage at peripheral, spinal and supraspinal levels.

Atorvastatin is an HMG-CoA reductase inhibitor used in the treatment of hypercholesterolemia and prevention of coronary heart disease. Oxidative stress is considered to be one of the main causes of neuropathic pain after nerve injury. This study aimed to investigate the effect of atorvastatin on oxidative stress and hyperalgesia in chronic constriction injury (CCI) model of neuropathic pain. Pain behaviour in rats was evaluated before and after atorvastatin administration using mechanical and heat hyperalgesia. The markers for oxidative stress in sciatic nerve, spinal cord and pre-frontal cortex (PFC) area of brain were biochemically detected in vehicle and atorvastatin-treated neuropathic CCI rats. Atorvastatin attenuated hyperalgesia. We found a significant increase in malondialdehyde (MDA), nitric oxide (NO), superoxide anion (O2(-)) and protein carbonyl along with a reduction in catalase (CAT), reduced glutathione (GSH), total thiol (SH) and glutathione-S-transferase (GST) and; increase in superoxide dismutase (SOD) levels in the sciatic nerve, spinal cord and PFC of the CCI-induced neuropathic rats. Reduced levels of enzymatic and non enzymatic antioxidants were restored by atorvastatin. The levels of MDA, O2(-), and protein carbonyl in these tissues were significantly reduced in the atorvastatin-treated CCI rats compared to the untreated CCI rats. Our study demonstrated that atorvastatin attenuates neuropathic pain through inhibition of oxidative stress in sciatic nerve, spinal cord and brain suggesting antioxidants as potential drugs in neuropathic pain management. This study provides a new application of atorvastatin in treatment of neuropathic pain.

Chondroprotective and anti-inflammatory effects of S-methylisothiourea, an inducible nitric oxide synthase inhibitor in cartilage and synovial explants model of osteoarthritis.

OBJECTIVES: To study the chondroprotective and anti-inflammatory potential of inducible nitric oxide synthase (iNOS) inhibitor S-methylisothiourea (SMT) in in-vitro model. METHODS: Rabbit cartilage explants were stimulated with recombinant human interleukin 1ß (rhIL-1ß), and the chondroprotective and anti-inflammatory effects of SMT were investigated. Rat synovial explants were stimulated with LPS, and the anti-inflammatory effect of SMT on synovium was studied. To examine the role of SMT in synovial inflammation mediated cartilage damage, LPS stimulated synovial explants were cultured with dead cartilage with or without SMT for 72 h. The culture medium was analysed for sulfated glycosaminoglycans (GAGs) and hydroxyproline as measure of proteoglycans and collagen degradation, respectively. KEY FINDINGS: SMT significantly reduced GAGs, hydroxyproline, matrix metalloproteinase (MMP)-13, tumour necrosis factor alpha (TNF-α), prostaglindin E2 (PGE2 ) and nitrite release in stimulated rabbit cartilage media indicating chondroprotective and anti-inflammatory effects of SMT in osteoarthritis (OA). Stimulated synovial explants caused release of nitrite, PGE2 , IL-1ß and TNF-α in the medium which were significantly reduced by SMT indicating its anti-inflammatory action. SMT significantly reduced GAGs and hydroxyproline in medium and shown protective effect against synovium-mediated cartilage damage. CONCLUSIONS: SMT inhibited cartilage degradation, synovial inflammation and synovium-mediated cartilage damage, suggesting that SMT may be an agent for pharmacological intervention in OA.

Antihyperalgesic and anti-inflammatory effects of atorvastatin in chronic constriction injury-induced neuropathic pain in rats.

Atorvastatin is a 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitor used in treatment of hypercholesterolemia and prevention of coronary heart disease. The aim of this study is to investigate the antihyperalgesic and anti-inflammatory effects of atorvastatin (3, 10, and 30 mg/kg by oral gavages for 14 days) in chronic constriction injury (CCI) model of neuropathic pain in rats. CCI caused significant increase in tumor necrosis factor-α, interleukin 1 beta, prostaglandin E2, along with matrix metalloproteases (MMP-2) and nerve growth factor (NGF) levels in sciatic nerve and spinal cord concomitant with mechanical and thermal hyperalgesia, which were significantly reduced by oral administration of atorvastatin for 14 days as compared to CCI rats. Our study demonstrated that atorvastatin attenuates neuropathic pain through inhibition of cytokines, MMP-2, and NGF in sciatic nerve and spinal cord suggesting that atorvastatin could be an additional therapeutic strategy in management of neuropathic pain.

Effect of iNOS inhibitor S-methylisothiourea in monosodium iodoacetate-induced osteoathritic pain: implication for osteoarthritis therapy.

Much information is available on the role of nitric oxide (NO) in osteoarthritis (OA). However, its role has not been studied in the monosodium iodoacetate (MIA)-induced model of osteoarthritic pain. The present study was undertaken in rats to investigate the effect of iNOS inhibitor S-methylisothiourea (SMT) in MIA-induced osteoathritic pain and disease progression in rats. Osteoarthritis was produced by single intra-articular injection of the MIA in the right knee joint on day 0. Treatment groups were orally gavazed with different doses of SMT (10, 30 and 100mg/kg) and etoricoxib (10mg/kg) daily for 21 days. On days 0, 3, 7, 14 and 21, pain was measured and histopathology of right knee joint was done on day 21. SMT produced analgesia in a dose-dependent manner as shown by mechanical, heat hyperalgesia, knee vocalization, knee squeeze test, and spontaneous motor activity test. SMT reduced NO production in synovial fluid. Histopathological findings indicated that SMT reduced disease progression as evident from complete cartilage formation in rats treated with SMT at 30 mg/kg. In conclusion, the results indicate that SMT attenuates the MIA-induced pain and histopathological changes in the knee joint. The antinociceptive and antiarthritic effects of SMT were mediated by inhibiting cartilage damage and suppression of NO in synovial fluid. It is suggested that SMT has potential as a therapeutic modality in the treatment of osteoarthritis.