Synergistic effect of Betulinic acid, Apigenin and Skimmianine (BASk) in high cholesterol diet rabbit: Involvement of CD36-TLR2 signaling pathway

BACKGROUND

Progression of chronic inflammatory disease, atherosclerosis is a multifactorial process. Cluster of differentiation 36 (CD36) mediated downstream activation of Toll like receptor 2 (TLR2) and NLRP3 (Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3) inflammasome signaling pathway actively participates during chronic inflammation. Nowadays, synergistic combinations of bioactive compounds attained priority in the field of drug discovery and development as therapeutic agents. An investigation regarding the anti-inflammatory potential of a novel drug formulation, BASk which is a combination of three bioactive compounds Betulinic acid (B):Apigenin (A):Skimmianine (Sk) remains the focus area of this research study. We also elucidate the molecular mechanism behind the therapeutic potential of BASk through CD36 mediated activation TLR2-NLRP3 signaling pathway.

METHODS

OxLDL induced hPBMCs used to screen out a suitable combination of BASk via MTT, COX, LOX, NOS and MPO assays. Hypercholesterolemia is induced in rabbits by supplementing with 1% cholesterol + 0.5% cholic acid and treated with BASk (2:2:1) (5 mg/Kg) and atorvastatin (10 mg/Kg) for 60 days. CD36, TLR2, NLRP3, NFκB, cytokines, endothelial damage were quantified by reverse transcription, real time PCR, ELISA, flow cytometry and histopathology.

RESULTS

hPBMCs pretreated with BASk at 2:2:1 ratio significantly decreased the activities of COX, 15-LOX, NOS and MPO on OxLDL induction than quercetin. Down regulation of CD36, TLR2, MyD88, TRAF6 by BASk further buttressed NLRP3 inflammasome activation mediated by the transcription factor NFκB. This is in correlation with the effect of BASk by balancing pro (IL-1β, IL-18) and anti-inflammatory (TGF-β) mediators in the aortic endothelial cells.

CONCLUSION

BASk exerted its anti-inflammatory potential by reducing pro-inflammatory mediators during cholesterol supplementation via down regulating CD36 mediated TLR2 - NLRP3 inflammasome cascade. This deciphers a synergistic combination named BASk (2:2:1) as a novel drug formulation against chronic inflammatory disease, atherosclerosis.

Scientific validation of anti-arthritic effect of Kashayams - A polyherbal formulation in collagen induced arthritic rats

BACKGROUND

Toll-like receptor-4 (TLR-4) mediates activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) resulting in induction of proinflammatory genes such as that encoding tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) which played a significant role in cartilage destruction of rheumatoid arthritis (RA). Low risk and better efficacy made herbal drugs more reliable than nonsteroid anti-inflammatory drugs (NSAIDS) in RA treatment. Gugguluthiktam Kashayam (GuK), Punarnavadi Kashayam (PuK) and Balaguluchiadi Kashayam (BgK) are ayurvedic polyherbal formulations prescribed in classical ayurvedic texts Sahasrayogam and Ashtangahridayam as medicines for the treatment of RA.

OBJECTIVE

The objective of the present study was to elucidate the molecular mechanism of anti-arthritic effect of these Kashayams on TLR-4 signal transduction pathway in collagen induced arthritic rats.

MATERIAL AND METHODS

The wistar rats grouped into group I - Normal, group II- Collagen induced arthritis (CIA), group III- CIA + BgK, group IV- CIA + PuK, group V- CIA + GuK, group VI - CIA + Indomethacin (3 mg/kg b.wt.). Treatment with Kashayam (2 ml/kg b.wt) started after 14 days of primary immunization with type II collagen and continued for a period of 45 days.

RESULTS

Arthritis index, C-reactive protein (CRP), rheumatoid factor (RF) and myeloperoxidase (MPO) in serum and protein level of TLR-4, myeloid differentiation factor 88 (MYD88), NF-κB, TNF-α, IL-1β, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 COX-2) and prostaglandin E-2 (PGE-2) in cartilage were significantly elevated in CIA rats. Further, treatment with Kashayams downregulated all these inflammatory mediators hitherto TLR-4-NF-kB signal transduction pathway except IL-10, an anti-inflammatory cytokine which showed a reverse effect.

CONCLUSION

This molecular mechanism of the investigation confirmed the clinical efficacy of Kashayams in preventing the progression of RA and gave an intuition of the scientific validation of Kashayams, an Ayurvedic classical medicine.

Dietary amaranths modulate the immune response via balancing Th1/Th2 and Th17/Treg response in collagen-induced arthritis

Imbalance between Th1/Th2 and Th17/Treg is crucial in RA progression. Various dietary factors can modulate the disease severity by restoring the balance in differentiation of CD4+ T cell subsets. Dietary amaranths hold an important part of diet as vegetables, where commonly consumed species includes Amaranthus cruentus (Ac), Amaranthus viridis (Av), and Amaranthus hybridus (Ah). The present study focuses on to evaluate whether these dietary amaranths can modulate the immune activation in collagen-induced arthritis. For in vivo study, Female Wistar rats were immunized with type II collagen and after immunization period, rats were separately supplemented with cooked Ac, Av, and Ah at 500 mg/100 g bwt concentration mixed with standard rat feed for 60 days. HPTLC fingerprint analysis identified peaks for compounds in these three amaranths. The results showed a protective role of immunomodulation in Th1/Th2 response of the three dietary amaranths, by significantly augmenting lymphocyte activation with increased IL-4 secretion, but decreased IFN-γ by cultured spleen lymphocytes subjected to collagen-induced inflammation. Moreover, Th17/Treg imbalance created by increase in IL-17 and decrease in IL-10 was significantly balanced by the three dietary supplemented groups. Furthermore, Th1/Th2 status reflected from Tbet/GATA3 ratio and Th17/Treg status reflected from RORγt/FOXP3 ratio was significantly decreased in the three dietary amaranth supplemented groups. Thus, dietary amaranths provide an immune-modulating role by keeping the balance between Th1/Th2 and Th17/Treg response in collagen-induced inflammation.

Isolation, identification and characterization of apigenin from Justicia gendarussa and its anti-inflammatory activity

Inflammatory responses during chronic diseases such as atherosclerosis, cancer etc., are harmful to host organisms. Generally NSAIDs are used to treat against these severe conditions but due to its adverse effects studies are going on with medicinal plants, since they are rich in bioactive compounds. Justicia gendarussa is one such plant which has been used as a remedial measure for treating inflammatory diseases since ancient time. Thus the present study involved in the isolation, characterization and identification of apigenin (flavonoid) from this plant and to elucidate its molecular mechanism against inflammation via TLR-NF-κB signaling pathway using ox-LDL induced hPBMCs in in vitro model. Methanolic extract was used for the isolation process and results showed that the F6 fraction collected from ethyl acetate through column chromatography showed 89% paw edema inhibition at a dose of 10 mg/kg in carrageenan induced rats. Purification of F6 by TLC with toluene: chloroform: acetone (8:5:7) and further characterization by ¹HNMR indicated the presence of bioactive compound, apigenin. In vitro studies revealed that pretreatment of ox-LDL induced hPBMCs with apigenin (25 μM) significantly (P < 0.05) reduced the levels of TLR4, MyD88, TRIF, TRAF6, NF-κB, COX-2, PGE2, IL-1β and TNF-α responsible for generating inflammation and elevated the level of anti-inflammatory cytokine, IL-10. These results indicate the therapeutic efficacy of bioflavonoid apigenin which was isolated from Justicia gendarussa against ox-LDL induced inflammation. Therefore apigenin can be treated as a suitable therapeutic agent against inflammatory diseases.

Ruthenium(ii) arene NSAID complexes: inhibition of cyclooxygenase and antiproliferative activity against cancer cell lines

Ru(ii)–arene complexes with NSAIDs as co-ligands show marked antiproliferative activity against cancer cell lines along with cyclooxygenase inhibition properties.

Anti-angiogenic effect of chebulagic acid involves inhibition of the VEGFR2- and GSK-3β-dependent signaling pathways

Inhibition of angiogenesis is a useful strategy to prevent cancer growth by targeting new vessels that grow to nourish actively proliferating tumor cells. Endothelial cells can use a number of different pathways to cause angiogenesis, and each step in these pathways can be targeted. The use of multi-targeted drugs is gaining much importance in this scenario. Our previous results have shown that chebulagic acid (a benzopyran tannin present in the fruits of Terminalia chebula) has anti-angiogenic properties. Thus, this study was designed to examine the molecular mechanism for the anti-angiogenic effects of chebulagic acid. Results from our investigations using molecular docking studies and human umbilical vein endothelial cells in culture suggested that chebulagic acid inhibits both GSK-3β-dependent β-catenin phosphorylation (an important mediator of VE-cadherin–β-catenin signaling) and VEGFR2 phosphorylation, which is an important step in VEGF signaling. Chebulagic acid inhibits angiogenesis by blocking both the VEGF–VEGFR2 complex and cell–cell contact dependent downstream signaling pathways.

Quercetin modulates toll-like receptor-mediated protein kinase signaling pathways in oxLDL-challenged human PBMCs and regulates TLR-activated atherosclerotic inflammation in hypercholesterolemic rats

Toll-like receptors (TLRs) are pattern recognition receptors that have a unique and essential function in innate immunity. The effect of quercetin on TLR-mediated downstream signaling mechanism and its effect on TLR-mediated MAP kinase and Akt pathways were studied in oxLDL-stimulated hPBMCs using specific inhibitors. The pretreatment of hPBMCs with specific TLR inhibitor, CLI-095, decreased the NF-κB nuclear translocation and TNF-α release by oxLDL. When the cells treated with inhibitor and quercetin together, the inhibition was more effective. The specific inhibitor for p38 MAPK, SB203580, reduced the phosphorylated p38 level and decreased the NF-κB activation and TNF-α release by oxLDL-challenged hPBMCs. This inhibitor showed enhanced inhibition when treated with quercetin together. The inhibitors for ERK1/2, PD98059, and for JNK, SP606125, also showed inhibitory effect on NF-κB activation and TNF-α release by oxLDL-simulated hPBMCs. Quercetin supplementation enhanced the inhibition of nuclear translocation of NF-κB and the release of cytokines. TLR4 inhibition study confirmed the downstream signaling mechanism mediated by NF-κB which is involved in the oxLDL-induced inflammatory response, and quercetin suppresses the cytokine, TNF-α release by modulating TLR-NF-κB signaling pathway. In addition to NF-κB signaling pathway, inflammation induced by oxLDL was also related to the activation of p38MAPK, ERK1/2 and JNK, and Akt pathways, and the protective effect of quercetin may be also related to the inhibition of activation of these pathways. Quercetin significantly downregulated the elevated mRNA expression of TLRs and cytokine TNF-α in HCD-fed atherosclerotic rats in vivo. As quercetin possesses inhibition on both TLR-NF-κB signaling pathway and TLR-mediated MAPK pathway, it is evident that it can be used as a therapeutic agent to ameliorate atherosclerotic inflammation. Since quercetin is the major flavonoid and forms the backbone of many other flavonoids and this study provides strong evidence that it has potent anti-inflammatory effect, quercetin may be a promising agent for the prevention and treatment of atherosclerosis and promote health by reducing harmful vascular inflammation.

Quercetin attenuates atherosclerotic inflammation and adhesion molecule expression by modulating TLR-NF-κB signaling pathway

Adhesion molecules expressed by activated endothelial cells play key role in regulating leukocyte trafficking to sites of inflammation. The present study attempted to explore whether the polyphenolic flavonoid quercetin influence leukocyte endothelial attraction and the involvement of TLR-NF-κB signaling pathway in the expression of adhesion molecules involved in the early development of atherosclerosis. Quercetin at 25μM concentration significantly reduced the HUVEC expression of VCAM-1 and ICAM-1 evidently enhanced by oxLDL. In addition, quercetin significantly downregulated the mRNA expression of MCP-1 and alleviated the nuclear translocation of NF-κB p65 subunit in oxLDL induced HUVECs. Western blot and PCR analyses revealed that quercetin significantly attenuated the expression of both protein and mRNA expression of TLR2 and TLR4. Quercetin supplementation significantly decreased the inflammatory mediators like COX, 5-LOX, MPO, NOS, CRP and the mRNA expression of the cytokine; IL-6 in hypercholesterolemic diet (HCD) fed atherosclerotic rats. The results demonstrate that quercetin is effective to regulate the atherosclerotic inflammatory process by inhibiting oxLDL induced endothelial leukocyte adhesion by attenuating the TLR-NF-κB signaling pathway in endothelial cells and decrease the inflammatory process induced by HCD in rats. Therefore, quercetin acts as anti-inflammatory and anti-atherogenic agent, which may have implications for strategies attenuating endothelial dysfunction-related atherosclerosis.

Mechanism of anti-inflammatory effect of tricin, a flavonoid isolated from Njavara rice bran in LPS induced hPBMCs and carrageenan induced rats

Njavara is an indigenous medicinal rice variety traditionally used in Ayurvedic system of medicine practiced in Kerala, India. Tricin is a bioflavonoid present in significantly higher levels in rice bran of Njavara. Present study attempted to identify the molecular target of tricin in TLR mediated signaling pathways by using lipopolysaccharide (LPS) induced human peripheral blood mononuclear cells (hPBMCs) and carrageenan induced paw edema in rats as experimental models. Tricin acted upstream in the activation of inflammation cascade by interfering with TLR4 activation, preferably by blocking the LPS induced activation of TLR4, MYD88 and TRIF proteins in hPBMCs. Subsequently, tricin significantly blocked the activation of downstream kinases like p38MAPK, JNK1/2 and IRF3. Thus the inhibitory effect of tricin on NF-κB and IRF3 together confirms the specific inhibition of both MYD88 dependent and TRIF dependent pathways. Tricin treatment also inhibited the pro-inflammatory effect of LPS by blocking the TLR4 signaling mediated activation of cytosolic phospholipase A2 (cPLA2), which is confirmed by specific inhibition of COX-2. Results demonstrated that in addition to NF-κB, tricin can prevent the activation of STAT proteins by significantly inhibiting the activation of both STAT1 and STAT3 via the down regulation of upstream phosphorylating enzymes like JAK1 and JAK2. The protective anti-inflammatory effect of tricin was also confirmed by in vivo experiments. Thus, this study provides strong evidence that tricin exerts its anti-inflammatory effect via a mechanism involving the TLR4/NF-κB/STAT signaling cascade.

Downregulation of inflammatory mediators and pro-inflammatory cytokines by alkaloids of Jeevaneeya rasayana in adjuvant-induced arthritis

Jeevaneeya rasayana is an ayurvedic polyherbal formulation, with antirheumatic potential. The present study investigates the therapeutic efficacy of isolated total alkaloid fraction of Jeevaneeya Rasayana (AJR) in treating rheumatoid arthritis in a rat model of Adjuvant-induced arthritis (AIA). Paw swelling, inflammatory mediators such as cyclooxygenase-2 (COX-2), matrix metalloproteinase-9 (MMP-9), level of prostaglandin E2 (PGE2), expression of cytokines and serum nitric oxide (NO) level were analyzed in experimental rats after an experimental period of 21 days. Arthritic induction significantly increased paw edema, and up regulated the inflammatory mediators and cytokines. Administration of AJR significantly reversed the paw edema, reduced the level of PGE2, serum NO and decreased the COX-2 activity in the paw tissue. AJR treatment also downregulated mRNA expression of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and MMP-9 in paw tissue. HPTLC analysis revealed the presence of 5 different alkaloid compounds in AJR. These findings suggest that the AJR have the therapeutic potential against adjuvant-induced arthritis.

Dolichos biflorus exhibits anti-inflammatory and antioxidant properties in an acute inflammatory model

Dolichos biflorus (Muthira) is a branched, suberect, and downing herb, native to most parts of India, and found at altitudes of up to 1000 m, whose seeds can be cooked and eaten. Nutrition plays a key role in building immunity and preventing noncommunicable diseases to a certain extent. The purpose of this study was to evaluate the anti-inflammatory and antioxidant effects of 70% methanolic extract of seeds of D. biflorus (DME) in carrageenan-induced inflammation. DME exhibited maximum percentage of oedema inhibition at a dose of 50 mg/kg at the 3^rd hour of carrageenan induction. The effect was higher than that of the standard drug Voveran. The activities of cyclooxygenase, lipoxygenase, nitric oxide synthase, myeloperoxidase, and malondialdehyde showed significant (p < 0.05) reduction whereas the activities of antioxidant enzymes, vitamins C, and reduced glutathione level were increased significantly (p < 0.05) on treatment with DME. Also levels of the acute phase protein, ceruloplasmin, were brought to their normal range in DME-treated rats. Phytochemical analysis showed that the extract contains alkaloids, flavonoids, carbohydrates, proteins, and tannins, which may contribute to its anti-inflammatory and antioxidant activity. Thus the results demonstrate the potential beneficiary effect of DME on carrageenan-induced inflammation in rats.

Oral administration of alkaloid fraction from Ruta graveolens inhibits oxidative stress and inflammation in hypercholesterolemic rabbits

CONTEXT

The anti-atherogenic effect of alkaloid fraction from Ruta graveolens Linn (Rutaceae) extract is suspected to be related to its activities of antioxidation and anti-inflammation.

OBJECTIVE

This study investigated the efficacy of alkaloid fraction isolated from Ruta graveolens (AFR) in reducing oxidative damage and inflammation in hypercholesteremic rabbits.

MATERIALS AND METHODS

The New Zealand white rabbits were randomly divided into three groups: Group I rabbits were fed with normal chow diet for 90 d. Group II rabbits were fed with 1% cholesterol-enriched diet. Group III rabbits were fed with 1% cholesterol-enriched diet together with AFR (10 mg/kg/daily for 90 d).

RESULTS AND DISCUSSION

The results showed that on treatment with AFR significantly lowered the level of total cholesterol and LDL-C and showed an increment in the level of HDL-C. LD50 of the AFR in rats is greater than 525 mg/kg. Activities of antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase and GSH level were decreased in cholesterol-fed rabbit and supplementation of AFR significantly enhanced the activities of these antioxidant enzymes and GSH level. Increased activities of enzymes such as cyclooxygenase-2, 15-lipoxygenase and myeloperoxidase were significantly suppressed by AFR administration. The acute phase proteins, total WBC count and TBARS concentrations were significantly increased by hypercholesteromic diet, which were significantly decreased by AFR treatment. Histopathological studies of aorta in cholesterol-fed rabbit showed plaque formation and significant changes in aortic wall. Administration of AFR showed no changes in aortic wall.

CONCLUSION

AFR reduces oxidative stress and inflammation and reduces the aortic pathology in hypercholesteromic rabbits.

Effect of 15-lipoxygenase metabolites on angiogenesis: 15(S)-HPETE is angiostatic and 15(S)-HETE is angiogenic

OBJECTIVE

15(S)-Hydroxyeicosatetraenoic acid [15(S)-HETE] and 15(S)-hydroperoxyeicosatetraenoic acid [15(S)-HPETE] are the products of arachidonic acid formed in the 15-lipoxygenase pathway. They have opposing effects on the inflammatory process. The present study was designed to examine the role of these metabolites on angiogenesis, which is critically associated with inflammatory conditions.

METHODS

Chick chorio-allantoic membrane (CAM), rat aortic rings and human umbilical vein endothelial cells (HUVECs) in culture were used to study the effect of 15(S)-HETE and 15(S)-HPETE on angiogenesis. Biochemical markers of angiogenesis were analysed by ELISA.

RESULTS

15(S)-HETE increased vessel density in chick CAM, induced sprouting in rat aortic rings and increased endothelial cell-cell contact and formation of tubular network-like structures in HUVECs. Furthermore, it up-regulated the expression of CD31, E-selectin and vascular endothelial growth factor (VEGF) in HUVECs, indicating its pro-angiogenic effect. 15(S)-HPETE, on the other hand, decreased vessel density in chick CAM, down-regulated the expression of E-selectin (<35 %), VEGF (<90 %) and CD31 (<50 %) and did not produce sprouting in aortic rings, suggesting an anti-angiogenic property. 15(S)-HETE-mediated up-regulation of CD 31 and VEGF was reversed by treatment with 15(S)-HPETE.

CONCLUSION

These results indicate the divergent effects of hydroxy and hydroperoxy products of 15-LOX on angiogenesis, highlighting the role of these products in the co-dependence of inflammation and angiogenesis.

Anti-inflammatory and antioxidative effects of mucilage of Trigonella foenum graecum (Fenugreek) on adjuvant induced arthritic rats

The aim of this study was to investigate anti-inflammatory and antioxidant effects of mucilage from fenugreek in adjuvant induced arthritis in rats. Arthritis was induced by intradermal injection of complete Freund's adjuvant into the right hind paw produce inflammation of the joint. The activities of inflammatory enzymes like cyclooxygenase, lipoxygenase and myeloperoxidase, and levels of nitrite and C-reactive protein were observed. Also oxidative stress was measured by analyzing the activity of catalase, superoxide dismutase, glutathione peroxidase and the levels of glutathione and vitamin C and lipid peroxidation. The blood parameters like ESR, total WBC, RBC and hemoglobin content was checked. Fenugreek mucilage exhibited maximum percentage of edema inhibition at a dose of 75 mg/kg on 21st day of adjuvant arthritis. The effect was higher than that of standard drug indomethacin. The activities of cyclooxygenase-2 and myeloperoxidase and concentration of thiobarbituric acid reactive substance (TBARS) were decreased and the activities of antioxidant enzymes, vitamins C and reduced glutathione level were increased on treatment with fenugreek mucilage. The increment in ESR and total WBC, reduction in RBC count and hemoglobin and aberrant changes to the C-reactive protein (CRP) levels observed in the arthritic animals were also found to be significantly restored in fenugreek mucilage treated rats. Histopathology of paw tissue showed decreased edema formation and cellular infiltration on supplementation with fenugreek mucilage. Thus the results demonstrated the potential beneficiary effect of fenugreek mucilage on adjuvant induced arthritis in rats.

Anti-inflammatory potential of an ethyl acetate fraction isolated from Justicia gendarussa roots through inhibition of iNOS and COX-2 expression via NF-κB pathway

Justicia gendarussa Burm.f. (J. gendarussa) is a plant used as traditional medicine in different parts of India and China to treat inflammatory disorders like rheumatoid arthritis. But its mechanism of anti-inflammatory action is still unclear. Hence in this context, the objective of our study is to reveal the mechanism of anti-inflammatory activity of J. gendarussa which would form an additional proof to the traditional knowledge of this plant. The anti-inflammatory function and mechanism(s) of action was studied in an ethyl acetate fraction isolated from methanolic extract of J. gendarussa roots (EJG). Anti-inflammatory studies were conducted on rats using partitioned fractions isolated from methanolic extract of J. gendarussa roots. In carrageenan-induced rat paw edema, ethyl acetate fraction brought about 80% and 93% edema inhibition at 3rd and 5th hour at a dose of 50 mg/kg, when compared to other extracts and Voveran. We investigated whether EJG inhibits the release of cycloxygenase (COX), 5-lipoxygenase (5-LOX), interleukin-6 (IL-6) and nuclear factor kappa B (NF-κB) in LPS stimulated human peripheral blood mononuclear cells (hPBMCs). Results shows that EJG dose dependently inhibited LPS-activated COX, 5-LOX, IL-6, and NF-κB in hPBMCs. EJG also reduced LPS induced levels of iNOS and COX-2 mRNA expression in hPBMCs. This study provides an insight into the probable mechanism(s) underlying the anti-inflammatory activity of EJG and therefore, we report the first confirmation of the anti-inflammatory potential of this traditionally employed herbal medicine in vitro.

Quercetin regulates oxidized LDL induced inflammatory changes in human PBMCs by modulating the TLR-NF-κB signaling pathway

Toll-like receptors (TLRs) have been shown to play a pivotal role in both innate and adaptive immune responses. TLR family is the essential recognition and signaling component of mammalian host defense. Both genetic and biochemical data support a common signaling pathway that finally leads to the activation of NF-κB and induction of the cytokines and co-stimulatory molecules required for the activation of the adaptive immune response. The present study was designed to examine the involvement of TLR2 and TLR4 in the oxidized LDL induced inflammation in human PBMCs and the effect of flavonoid quercetin on TLR-NF-κB signaling mechanism. LDL was isolated from human plasma and oxidation of LDL was done by incubating with 10 μM CuSO₄ overnight at 37°C. The isolated human PBMCs in culture were used as the model system. 50 μg/ml ox-LDL treatment significantly up regulated TLR2 and TLR4 expression in isol human PBMCs after 24 h of culture and this was down regulated by quercetin at 25 μM concentration. ox-LDL caused a significant activation of NF-κB as evidenced by the detection of enhanced p65 subunit in nuclear extracts. Supplementation of quercetin significantly modulates the NF-κB p65 nuclear translocation. The cytokine IL-6 production was significantly increased in ox-LDL treated group and was decreased by quercetin treatment. Quercetin mediated reduction of TLR2 and TLR4 expression and the inhibition of nuclear translocation of NF-κB p65 in turn decreased the inflammatory enzymes like 5-LOX and COX and also decreased the mRNA expression of inducible enzymes like COX-2 and iNOS. Quercetin inhibited the ox-LDL induced TLR2 and TLR4 expression at mRNA level and modulated the TLR-NF-κB signaling pathway thereby inhibited the cytokine production and down regulated the activity of inflammatory enzymes thus have protective effect against the ox-LDL induced inflammation in PBMCs.

Betulinic acid isolated from Bacopa monniera (L.) Wettst suppresses lipopolysaccharide stimulated interleukin-6 production through modulation of nuclear factor-kappaB in peripheral blood mononuclear cells

The purpose of this study was to investigate the anti-inflammatory function and mechanism(s) of action of an active component-betulinic acid isolated from Bacopa monniera. Betulinic acid, a pentacyclic triterpenoid markedly suppressed lipopolysaccharide (LPS) induced IL-6 production in blood mononuclear cells both in vivo and in vitro. Betulinic acid also prevented LPS induced nuclear translocation of p65 NF-kappaB in hPBMCs. LPS induced nuclear translocation of NF-kappaB and IL-6 production was also abolished by p38 and ERK MAPK inhibitors PD98059 and SB203580. Addition of each of these inhibitors to cell cultures along with betulinic acid caused significant downregulation of IL-6 production and inhibition of p65 NF-kappaB nuclear translocation. The inhibitory effect of both betulinic acid and the inhibitors was higher than that of cells treated with inhibitors alone. These results suggest that betulinic acid inhibited IL-6 production by preventing p65 NF-kappaB nuclear translocation and there is a possibility that this prevention of p65 nuclear translocation may involve p38 and ERK MAPKs as cross talks occur between MAPK and NF-kappaB pathways. This study provides an insight into the probable mechanism(s) underlying the anti-inflammatory and therapeutic properties of betulinic acid.

Anti-inflammatory and antioxidant effects of Jeevaneeya Rasayana: an ayurvedic polyherbal formulation on acute and chronic models of inflammation

The present study was aimed to establish the efficacy of Jeevaneeya Rasayana (JR), an ayurvedic polyherbal formulation, in adjuvant-induced arthritic (AIA) rat model with reference to mediators of inflammation. The methanolic (MJR), ethanolic (EJR), and water extracts (WJR) of JR were prepared and their anti-inflammatory activity in carrageenan-induced acute model was evaluated. MJR at a dose of 25 mg/kg showed significantly higher anti-inflammatory effect than EJR, WJR, and standard drug diclofenac. MJR also significantly decreased the paw edema in AIA rats. Activities of cyclooxygenase, 5-lipoxygenase, and myeloperoxidase were decreased significantly on treatment with MJR. Supplementation with MJR increases the activities of antioxidant enzymes and the level of glutathione content. The increment in the concentration of C-reactive protein, thiobarbituric acid reactive substance, and ceruloplasmin observed in arthritic rats were found to be significantly restored in MJR treated rats. Thus, the results demonstrated the potential beneficiary effect of methanolic extract of Jeevaneeya Rasayana on acute and chronic models of inflammation.

Inhibition of lipoxygenases and cyclooxygenase-2 enzymes by extracts isolated from Bacopa monniera (L.) Wettst

AIM OF THE STUDY

Bacopa monniera Linn is described in the Ayurvedic Materia Medica, as a therapeutically useful herb for the treatment of inflammation. In the current study, we investigated the anti-inflammatory activity of methanolic extract of Bacopa monniera (BME). For some experiments EtOAc and bacoside fractions were prepared from BME. The effect of these extracts in modulating key mediators of inflammation was evaluated.

MATERIALS AND METHODS

Carrageenan-induced rat paw edema, rat mononuclear cells and human whole blood assay were employed as in vivo and in vitro models.

RESULTS

In carrageenan-induced rat paw edema, BME brought about 82% edema inhibition at a dose of 100mg/kg i.p. when compared to indomethacin (INDO) (3mg/kg) that showed 70% edema inhibition. BME also significantly inhibited 5-lipoxygenase (5-LOX), 15-LOX and cyclooxygenase-2 (COX-2) activities in rat monocytes in vivo. Among the fractions tested in vitro, EtOAc fraction possessed significant 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with IC(50) value of 30 microg/ml compared to butylated hydroxyl toluene (IC(50) = 13 microg/ml). This fraction also exerted significant hydroxyl radical scavenging activity with IC(50) value of 25 microg/ml in comparison with quercetin (IC(50) = 5 microg/ml). Inhibitory effects of EtOAc and bacoside fractions on LOX and COX activities in Ca-A23187 stimulated rat mononuclear cells were also assessed. 5-LOX IC(50) values were 25 microg/ml for EtOAc, 68 microg/ml for bacosides and 2 microg/ml for nordihydroguaiaretic acid (NDGA) where as COX-2 IC(50) values were 1.32 microg/ml for EtOAc, 1.19 microg/ml for bacoside fraction and 0.23 microg/ml for indomethacin. EtOAc and bacoside fractions also brought about significant decrease in TNF-alpha release ex vivo.

CONCLUSION

Bacopa monniera possesses anti-inflammatory activity through inhibition of COX and LOX and downregulation of TNF-alpha.

Protective activity ofBacopa monniera Linn. on nicotine-induced toxicity in mice

Nicotine, a pharmacologically active component of cigarettes smoke causes devastating effects in important biomolecules of the cell through generation of free radicals leading to genomic instability. Bacopa monniera is a reputed drug in Ayurveda known for its hepatoprotective and DNA protective effects. In this study, an aqueous extract of Bacopa monniera (BAE, 50 mg/kg i.p.) was investigated for its ability to reduce nicotine-induced lipid peroxidation (LPO) and confer genoprotection in Swiss mice. Genoprotective effect was assayed using micronucleus (MN) assay. LPO status was studied by evaluating MDA levels and antioxidant status. Nicotine altered hepatic function as evident by increased ALP and GST levels and decreased SOD, catalase and GPx activities. BAE treatment restored antioxidant enzymes such as SOD, catalase and GPx in liver. BAE treatment also significantly reduced the frequency of micronuclei induced by nicotine by decreasing the incidence of micronucleated polychromatic erythrocytes (MN-PCE). Hepatic GSH, ALP and GST levels were brought to normal values indicating protection. The results of the present study suggest that BAE exerts protective effects by modulating the extent of lipid peroxidation and enhancing the antioxidant status.

A comparative study of antioxidants S-allyl cysteine sulfoxide and vitamin E on the damages induced by nicotine in rats

The dietary consumption of antioxidant-rich fruits and vegetables is inversely correlated with the incidence of various diseases like cardiovascular diseases and lung cancer. We have tried to find out how far the S-allyl cysteine sulfoxide (SACS) isolated from garlic (Allium Sativum L.) can combat the nicotine-induced peroxidative damage in rats. The effects have been compared with the standard antioxidant vitamin E. Administration of SACS or vitamin E (100 mg/kg) to nicotine (0.6 mg/kg) treated rats for 21 days showed decreased concentrations of thiobarbituric acid reactive substances, hydroperoxides, and conjugated dienes in liver, lungs, and heart as compared with the values found in rats treated with nicotine alone. The activities of catalase and superoxide dismutase increased. The levels of the antioxidants like vitamins A, C, and E in the liver and glutathione in all tissues increased significantly in SACS-treated or vitamin E fed rats. However, the antioxidant status was higher when vitamin E was administered as compared with SACS administered to nicotine-treated rats.

Antioxidant effect of onion oil (Allium cepa. Linn) on the damages induced by nicotine in rats as compared to alpha-tocopherol

The beneficial effects of onion oil as an antioxidant has been assessed in nicotine administered rats by studying whether the peroxidative damage caused by nicotine can be effectively combated with the onion oil and the effects compared to vitamin E, a highly efficient antioxidant. Lipid peroxidation products and antioxidant defence system have been studied in liver, lungs, and heart. The rats were injected with nicotine (0.6 mg/kg body wt.) and simultaneously given onion oil (100 mg/kg body wt.) or vitamin E (100 mg/kg body wt.) for 21 days. Concentration of free fatty acids, TBA reactive substances (TBARS), conjugated dienes and hydroperoxides were significantly increased in the tissues of nicotine treated rats as compared to normal rats. Onion oil supplemented to nicotine treated rats showed increased resistance to lipid peroxidation and the effect was near to that of vitamin E fed rats. The activity of catalase and superoxide dismutase decreased in nicotine treated rats. Antioxidants-glutathione content, vitamin C and retinol showed no significant difference but liver vitamin E content significantly decreased in nicotine treated rats. On onion oil or vitamin E supplementation, the concentration of antioxidants were significantly raised in all the tissues studied, however, a significantly increased concentration of glutathione, vitamin E and retinol was noticed in vitamin E+nicotine treated rats. Thus, these results indicate that onion oil is an effective antioxidant against the oxidative damage caused by nicotine as compared to vitamin E.

Antioxidant role of oils isolated from garlic (Allium sativum Linn) and onion (Allium cepa Linn) on nicotine-induced lipid peroxidation

Nicotine, a major component of tobacco, is partly responsible for the development of atherosclerosis. It has been suggested that antioxidant nutrients are protective against degenerative diseases. So we have studied the antioxidant effect of oils isolated from onion and garlic on nicotine-induced lipid peroxidation in rat tissues. The lipid peroxidation products and scavenging enzymes were assessed in liver, lungs, heart and kidney. The rats were treated with 0.6 mg nicotine/kg bw and simultaneously given 100 mg garlic or onion oils/kg bw for 21 d. Thiobarbituric acid reactive substances, conjugated dienes and hydroperoxides concentrations were significantly increased in the tissues of nicotine-treated rats. Both the garlic oil and onion oil supplementation to nicotine-treated rats increased resistance to lipid peroxidation. The activities of catalase, superoxide dismutase and glutathione peroxidase decreased in nicotine-treated rats, but there was a trend to increased glutathione content. With garlic oil or onion oil supplementation, nicotine-treated rats had increased activities of antioxidant enzymes and increased concentrations of glutathione. These results indicate that oils of garlic and onion are effective antioxidants against the oxidative damage caused by nicotine.

Vitamin C supplementation on hepatic oxidative stress induced by cigarette smoke

A study has been conducted to investigate whether the oxidative damage produced in the liver of rats exposed to cigarette smoke can be effectively combatted with vitamin C, one of the antioxidant vitamins. We assessed the liver antioxidants (vitamins E, C and A), scavenging enzymes and lipid peroxide products of rats exposed to cigarette smoke and simultaneously given vitamin C (200 mg 100 g[-1] body wt.) for 90 days. Malondialdehyde (MDA), conjugated dienes, hydroperoxides and free fatty acids (FFA) were significantly increased in liver of smoke-exposed groups. The activity of superoxide dismutase and catalase and vitamin E and C contents were significantly lower than controls. But vitamin A, glutathione (GSH) content and glutathione peroxidase (GSH Pxase) activity were enhanced. Vitamin C supplementation to smoke-exposed rats showed increased resistance to lipid peroxidation and increased activity of scavenging enzymes. The GSH content, vitamin C and FFA were brought to normal levels. Thus, this study seems to suggest that an intake of a mega dose of vitamin C can protect the liver from oxidant damage caused by cigarette smoke.

Vitamin C supplementation on hepatic oxidative stress induced by cigarette smoke

A study has been conducted to investigate whether the oxidative damage produced in the liver of rats exposed to cigarette smoke can be effectively combatted with vitamin C, one of the antioxidant vitamins. We assessed the liver antioxidants (vitamins E, C and A), scavenging enzymes and lipid peroxide products of rats exposed to cigarette smoke and simultaneously given vitamin C (200 mg 100 g[-1] body wt.) for 90 days. Malondialdehyde (MDA), conjugated dienes, hydroperoxides and free fatty acids (FFA) were significantly increased in liver of smoke-exposed groups. The activity of superoxide dismutase and catalase and vitamin E and C contents were significantly lower than controls. But vitamin A, glutathione (GSH) content and glutathione peroxidase (GSH Pxase) activity were enhanced. Vitamin C supplementation to smoke-exposed rats showed increased resistance to lipid peroxidation and increased activity of scavenging enzymes. The GSH content, vitamin C and FFA were brought to normal levels. Thus, this study seems to suggest that an intake of a mega dose of vitamin C can protect the liver from oxidant damage caused by cigarette smoke.

Effect of vitamin A supplementation on cigarette smoke-induced lipid peroxidation

The antioxidant activity of vitamin A against cigarette smoke-induced oxidative stress was investigated in rat tissues. The rats were exposed to cigarette smoke for 90 d and simultaneously given 5,000 IU vitamin A/kg body weight. Lipid peroxidation products, scavenging enzymes and free fatty acids were estimated in liver, lungs and heart. Cigarette smoke exposure increased the concentrations of malondialdehyde, conjugated dienes and hydroperoxides. The activities of superoxide dismutase and catalase were decreased, but glutathione content and glutathione peroxidase (GSSG-Pxase) activity were enhanced. Glutathione reductase (GSSG-Rase) activity was markedly inhibited. Vitamin A supplementation to smoke-exposed rats produced increased resistance to lipid peroxidation and increased the activities of scavenging enzymes, producing normal or higher enzyme activities. The activities of GSSG-Rase and GSSG-Pxase and the glutathione content reduced to normal levels. These results indicate that lipid peroxidation induced by cigarette smoke can be protected against by vitamin A supplementation and their protection may be due to vitamin A's antioxidant activities.

Purification and characterization of glucoamylase produced by Aspergillus niger in solid state fermentation

Glucoamylases produced by Aspergillus niger grown on wheat brain in solid cultures were purified. Four different forms, GA I, GA I', GA II and GA III, were found having apparent molecular weights of 112,000, 104,000, and 74,000 and 61,000 Da respectively. The enzymes are glycoproteins with a carbohydrate content of 16%, and optimal activity at 60 degrees C and pH 4.4. Activity was strongly inhibited by Hg2+ while Mn2+ and Fe2+ were stimulatory. The Km values for the degradation of starch and maltose were 3.5 and 7.8 mg ml-1, respectively.