Diastereoselective allylation-based asymmetric total synthesis of 1,10-seco-guaianolides.

A Cr(II)-mediated Nozaki-Hiyama allylation of aldehydes with functionalized chiral allylbromolactone paved the way to easily access ß-hydroxy-aryl/alkyl-α-methylene-γ-butyrolactones in good yields with high diastereoselectivities. A subsequent undemanding translactonization was orchestrated in the efficient first asymmetric total synthesis of two 1,10-seco-guaianolides as a valuable extension of the strategy developed.

Host-parasite interactions during Plasmodium infection: Implications for immunotherapies.

Malaria is a global infectious disease that remains a leading cause of morbidity and mortality in the developing world. Multiple environmental and host and parasite factors govern the clinical outcomes of malaria. The host immune response against the Plasmodium parasite is heterogenous and stage-specific both in the human host and mosquito vector. The Plasmodium parasite virulence is predominantly associated with its ability to evade the host's immune response. Despite the availability of drug-based therapies, Plasmodium parasites can acquire drug resistance due to high antigenic variations and allelic polymorphisms. The lack of licensed vaccines against Plasmodium infection necessitates the development of effective, safe and successful therapeutics. To design an effective vaccine, it is important to study the immune evasion strategies and stage-specific Plasmodium proteins, which are targets of the host immune response. This review provides an overview of the host immune defense mechanisms and parasite immune evasion strategies during Plasmodium infection. Furthermore, we also summarize and discuss the current progress in various anti-malarial vaccine approaches, along with antibody-based therapy involving monoclonal antibodies, and research advancements in host-directed therapy, which can together open new avenues for developing novel immunotherapies against malaria infection and transmission.

Polyherbal Medicine Divya Sarva-Kalp-Kwath Ameliorates Persistent Carbon Tetrachloride Induced Biochemical and Pathological Liver Impairments in Wistar Rats and in HepG2 Cells.

Divya Sarva-Kalp-Kwath (SKK) is a poly-herbal ayurvedic medicine formulated using plant extracts of Boerhavia diffusa L. (Nyctaginaceae), Phyllanthus niruri L. (Euphorbiaceae), and Solanum nigrum L. (Solanaceae), described to improve liver function and general health. In the present study, we have explored the hepatoprotective effects of SKK in ameliorating carbon tetrachloride (CCl4) induced liver toxicity using in-vitro and in-vivo test systems. Chemical analysis of SKK using Liquid Chromatography-Mass Spectroscopy (LC-MS-QToF) and High-Performance Liquid Chromatography (HPLC) revealed the presence of different bioactive plant metabolites, known to impart hepatoprotective effects. In human hepatocarcinoma (HepG2) cells, co-treatment of SKK with CCl4 effectively reduced the hepatotoxicity induced by the latter. These effects were confirmed by studying parameters such as loss of cell viability; release of hepatic injury enzymatic biomarkers- aspartate aminotransferase (AST), and alkaline phosphatase (ALP); and changes in reactive oxygen species and in mitochondrial membrane potentials. In-vivo safety analysis in Wistar rats showed no loss in animal body weight, or change in feeding habits after repeated oral dosing of SKK up to 1,000 mg/kg/day for 28 days. Also, no injury-related histopathological changes were observed in the animal's blood, liver, kidney, heart, brain, and lung. Pharmacologically, SKK played a significant role in modulating CCl4 induced hepatic injuries in the Wistar rats at a higher dose. In the 9 weeks' study, SKK (200 mg/kg) reduced the CCl4 stimulated increase in the release of enzymes (ALT, AST, and ALP), bilirubin, total cholesterol, and uric acid levels in the Wistar rats. It also reduced the CCl4 stimulated inflammatory lesions such as liver fibrosis, lymphocytic infiltration, and hyper-plasticity. In conclusion, SKK showed pharmacological effects in improving the CCl4 stimulated liver injuries in HepG2 cells and in Wistar rats. Furthermore, no adverse effects were observed up to 10× higher human equivalent dose of SKK during 28-days repeated dose exposure in Wistar rats. Based on the literature search on the identified plant metabolites, SKK was found to act in multiple ways to ameliorate CCl4 induced hepatotoxicity. Therefore, polyherbal SKK medicine has shown remarkable potentials as a possible alternative therapeutics for reducing liver toxicity induced by drugs, and other toxins.

Super Critical Fluid Extracted Fatty Acids from Withania somnifera Seeds Repair Psoriasis-Like Skin Lesions and Attenuate Pro-Inflammatory Cytokines (TNF-α and IL-6) Release.

(1) Background: Withania somnifera Dunal (Ashwagandha) is a widely used medicinal herb in traditional medicinal systems with extensive research on various plant parts. Surprisingly, seeds of W. somnifera have never been investigated for their therapeutic potential. (2) Methods: W. somnifera seeds were extracted for fatty acids (WSSO) using super critical fluid extraction, and was analyzed by gas chromatography. Its therapeutic potential in psoriasis-like skin etiologies was investigated using a 12-O tetradecanoyl phorbol 13-acetate (TPA)-induced psoriatic mouse model. Psoriatic inflammation along with psoriatic lesions and histopathological scores were recorded. WSSO was also tested on murine macrophage (RAW264.7), human epidermoid (A431), and monocytic (THP-1) cells, stimulated with TPA or lipo poly-saccharide (LPS) to induce pro-inflammatory cytokine (IL-6 and TNF-α) release. NFκB promoter activity was also measured by luciferase reporter assay. (3) Results: Topical application of WSSO with concurrent oral doses significantly reduced inflammation-induced edema, and repaired psoriatic lesions and associated histopathological scores. Inhibition of pro-inflammatory cytokines release was observed in WSSO-treated A431 and THP-1 cells, along with reduced NFκB expression. WSSO also inhibited reactive nitrogen species (RNS) in LPS-stimulated RAW264.7 cells. (4) Conclusion: Here we show that the fatty acids from W. somnifera seeds have strong anti-inflammatory properties, along with remarkable therapeutic potential on psoriasis-like skin etiologies.

Cytokines Driven Anti-Inflammatory and Anti-Psoriasis Like Efficacies of Nutraceutical Sea Buckthorn (Hippophae rhamnoides) Oil.

Psoriasis is a chronic inflammatory skin disease characterized by circumscribed, red, thickened plaques with overlying silvery white scales. It is associated with the release of pro-inflammatory mediators that lead to the development of edema and distress. Here we show the anti-inflammatory and anti-psoriatic efficacies of a neutraceutical sea buckthorn oil (SBKT) derived from the fruit pulp of Hippophae rhamnoides. Chemical analysis of the SBKT showed the presence of 16 major saturated, mono-, and polyunsaturated fatty acids components, imparting significant nutritional values. Efficacy of the SBKT in modulating psoriasis and associated inflammation was first tested in vitro using human monocytic (THP-1) cells. SBKT induced cytotoxicity at a dose of ≥25 µl/ml. Treatment of the lipopolysaccharide-stimulated THP-1 cells with SBKT subdued the enhanced release of intracellular reactive nitrogen species and expression of NF-κB protein, in a concentration-dependent manner. This was accompanied by a reduction in the release of downstream pro-inflammatory cytokines: Interleukin-1ß and interleukin-6. Tumor necrosis factor-α released in the stimulated THP-1 cells were also inhibited by SBKT dose of 5 µl/ml. In vivo oral and topical treatment with SBKT in the Carrageenan-stimulated paw edema model, showed a significant decrease in paw volume and edema. In the 12-O tetradecanoyl phorbol 13-acetate (TPA) stimulated CD-1 mice psoriasis-like model, concurrent oral and tropical SBKT treatments substantially reduced ear edema and ear biopsy weights. Histopathologically, significant reduction in ear epidermal thickness and skin lesion scores was observed in the SBKT-treated animals. In conclusion, SBKT showed anti-inflammatory and anti-psoriasis-like efficacies in healing chemical-induced inflammation and psoriasis. The possible mode of action of SBKT was found through inhibition of reactive nitrogen species, and downregulation of NF-κB protein and pro-inflammatory cytokines. Thus, the present data suggest that Sea buckthorn oil can be used as an anti-inflammatory and anti-psoriatic nutraceutical.

Anti-Inflammatory and Anti-Arthritic Efficacies of an Indian Traditional Herbo-Mineral Medicine "Divya Amvatari Ras" in Collagen Antibody-Induced Arthritis (CAIA) Mouse Model Through Modulation of IL-6/IL-1ß/TNF-α/NFκB Signaling.

Rheumatoid arthritis (RA) is defined as a chronic autoimmune inflammatory disorder that causes damage to limb joints and progressive injuries to secondary organs. Medical practitioners prescribe Methotrexate (MTX) as standard care medicine for treating RA. However, the long-term application of MTX has shown to have adverse health-related effects. Divya Amvatari Ras (DAR), an Indian Ayurvedic herbo-mineral formulation, has been described in ancient texts to provide relief from RA inflammation associated distress. Therefore, in the present study, we explored the biocompatibility, anti-inflammatory, and anti-arthritic efficacy of DAR using in vivo and in vitro disease models. Using carrageenan (CA)-stimulated Wistar rat paw edema model, we showed a reduction in inflammation-induced paw edema at human equivalent dose of DAR. Anti-rheumatic efficacy of DAR was studied using collagen-antibody cocktail (C-Ab) Induced Arthritis (CAIA) mouse model. The onset of RA in the CAIA mice was determined using parameters such as the increase in arthritis score, and induction of disease associated lesions in the ankle and knee joints, and increase in mechanical and thermal hyperalgesia. Treatment of CAIA animals with a human equivalent dose of DAR significantly reversed the RA-associated pathogenesis. These effects were comparable with the standard of care RA drug, MTX. DAR acted at multiple levels of inflammation associated with RA to reduce progressive pathogenesis. Animal serum biochemistry showed DAR was capable of ameliorating RA induced increase in liver enzyme Alanine Aminotransferase (ALT) and pro-inflammatory cytokine interleukin 6 (IL-6). In the lipopolysaccharide stimulated THP-1 cells, DAR was found to inhibit the release of IL-6, IL-1ß, TNF-α, and upstream inflammatory gene regulatory protein, NFκB. The study endorsed the anti-arthritic and anti-inflammatory activity of the Indian Traditional herbo-mineral medicine, DAR. These results also confirm that DAR was highly biocompatible and would show minimal health-related side effects than those associated with standard of care MTX. Taken together, we show that the DAR could be utilized as a promising alternative or complementary therapy for treating rheumatoid arthritis.

Herbo-mineral formulation 'Ashwashila' attenuates rheumatoid arthritis symptoms in collagen-antibody-induced arthritis (CAIA) mice model.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder that affects joints of hands and feet and introduces injury in secondary organs such as cardiac tissue. In the present study, we induced RA in male Balb/c mice (CAIA) using collagen-antibody cocktail (C-Ab) and lipopolysaccharide intraperitoneal injections. Induction of RA in the animals was detected through the loss of body weight, food, and water consumption, pedal edema, increased arthritis score of the paw and ankle, increase in radiological and histological lesion score of ankle and knee joints and enhanced pain perception in the C-Ab induced RA animals. Ashwashila is a herbo-mineral medicine from Indian Ayurvedic system. Human equivalent doses of Ashwashila (ASHW) and standard of care, Methotrexate were given to the CAIA animals for two weeks. ASHW treatment significantly reversed the effect of C-Ab with reduced pedal edema, arthritis score, radiological and histological lesion scores in ankle-joint, knee-joint and articular cartilage, reduced pain perception. These effects were comparable with the Methotrexate treatment. In human monocytic (THP-1) cells, ASHW was found to be biocompatible at in-vitro test doses. The anti-arthritis mechanism of action for ASHW was established through the suppression of pro-inflammatory cytokines such as IL-1ß, IL-6, TNF-α; and upstream regulator, NF-κB. Taken together, we show the pre-clinical efficacy of ASHW in reducing RA associated symptoms by controlling inflammation and suggest it as a potential therapeutic candidate for rheumatoid arthritis.

Evaluation of polyherbal ayurvedic formulation 'Peedantak Vati' for anti-inflammatory and analgesic properties.

ETHNOPHARMACOLOGICAL RELEVANCE: Peedantak Vati (PV) is a polyherbal ayurvedic formulation, which is regularly prescribed by the ayurvedic practitioner for the inflammatory disorders and joints pain in India. It is composed of 23 different herbs and minerals, described in ayurvedic text for their anti-inflammatory and analgesic properties. AIM OF THE STUDY: To investigate anti-inflammatory and anti-nociceptive potential of 'Peedantak Vati' using in vitro and in vivo methods. MATERIALS AND METHODS: In-vitro anti-inflammatory activity of PV was studied by estimating nitric oxide (NO) and LPS-induced pro-inflammatory cytokines IL-6 and TNF-α, using murine macrophage RAW264.7 and human monocyte THP-1 cell lines. PV's anti-inflammatory potential was studied in vivo using carrageenan-induced rat paw edema model. Similarly, anti-nociceptive property of PV was evaluated using hot plate, tail flick, formalin and writhing tests on CD-1 mice. Phytochemical profiling of hydro-alcoholic extract of PV was done using HPLC and HPTLC techniques to identify different marker compounds. These identified marker compounds were confirmed using LC-MS/MS analysis. RESULTS: In vitro results strongly suggest that, PV significantly (p < 0.001) inhibited NO release and LPS-stimulated pro-inflammatory cytokines IL-6 and TNF-α, in murine RAW264.7 and human THP-1 cells. Further, PV demonstrated significant (p < 0.05) anti-inflammatory activity at different time points after carrageenan injection with maximum effect at 2 h (40.4 ±â€¯5.2% at 400 mg/kg). Similarly, PV significantly (p < 0.05) decreased nociceptive pain, studied using hot plate, tail flick, formalin and writhing tests. Moreover, HPLC and HPTLC methods were developed for the standardization of PV. Five marker phytocompounds viz. rutin, caffeic acid, colchicine, withaferin A and curcumin were identified and quantified by HPLC and HPTLC methods. The presence of these phytoconstituents was confirmed by LC-MS/MS analysis. CONCLUSION: The findings of the study strongly suggest that, the polyherbal ayurvedic formulation 'Peedantak Vati' possesses remarkable anti-inflammatory and analgesic property, providing potent alternative for currently available allopathic medicines such as non steroidal anti-inflammatory drugs (NSAIDs).

Regulation of Plasmodium falciparum development by calcium-dependent protein kinase 7 (PfCDPK7).

Second messengers such as phosphoinositides and calcium are known to control diverse processes involved in the development of malaria parasites. However, the underlying molecular mechanisms and pathways need to be unraveled, which may be achieved by understanding the regulation of effectors of these second messengers. Calcium-dependent protein kinase (CDPK) family members regulate diverse parasitic processes. Because CDPKs are absent from the host, these kinases are considered as potential drug targets. We have dissected the function of an atypical CDPK from Plasmodium falciparum, PfCDPK7. The domain architecture of PfCDPK7 is very different from that of other CDPKs; it has a pleckstrin homology domain adjacent to the kinase domain and two calcium-binding EF-hands at its N terminus. We demonstrate that PfCDPK7 interacts with PI(4,5)P2 via its pleckstrin homology domain, which may guide its subcellular localization. Disruption of PfCDPK7 caused a marked reduction in the growth of the blood stage parasites, as maturation of rings to trophozoites was markedly stalled. In addition, parasite proliferation was significantly attenuated. These findings shed light on an important role for PfCDPK7 in the erythrocytic asexual cycle of malaria parasites.

PK4, a eukaryotic initiation factor 2α(eIF2α) kinase, is essential for the development of the erythrocytic cycle of Plasmodium.

In response to environmental stresses, the mammalian serine threonine kinases PERK, GCN2, HRI, and PKR phosphorylate the regulatory serine 51 of the eukaryotic translation initiation factor 2α (eIF2α) to inhibit global protein synthesis. Plasmodium, the protozoan that causes malaria, expresses three eIF2α kinases: IK1, IK2, and PK4. Like GCN2, IK1 regulates stress response to amino acid starvation. IK2 inhibits development of malaria sporozoites present in the mosquito salivary glands. Here we show that the phosphorylation by PK4 of the regulatory serine 59 of Plasmodium eIF2α is essential for the completion of the parasite's erythrocytic cycle that causes disease in humans. PK4 activity leads to the arrest of global protein synthesis in schizonts, where ontogeny of daughter merozoites takes place, and in gametocytes that infect Anopheles mosquitoes. The implication of these findings is that drugs that reduce PK4 activity should alleviate disease and inhibit malaria transmission.

PfPI3K, a phosphatidylinositol-3 kinase from Plasmodium falciparum, is exported to the host erythrocyte and is involved in hemoglobin trafficking.

Polyphosphorylated phosphoinositides (PIPs) are potent second messengers, which trigger a wide variety of signaling and trafficking events in most eukaryotic cells. However, the role and metabolism of PIPs in malaria parasite Plasmodium have remained largely unexplored. Our present studies suggest that PfPI3K, a novel phosphatidylinositol-3-kinase (PI3K) in Plasmodium falciparum, is exported to the host erythrocyte by the parasite in an active form. PfPI3K is a versatile enzyme as it can generate various 3'-phosphorylated PIPs. In the parasite, PfPI3K was localized in vesicular compartments near the membrane and in its food vacuole. PI3K inhibitors wortmannin and LY294002 were effective against PfPI3K and were used to study PfPI3K function. We found that PfPI3K is involved in endocytosis from the host and trafficking of hemoglobin in the parasite. The inhibition of PfPI3K resulted in entrapment of hemoglobin in vesicles in the parasite cytoplasm, which prevented its transport to the food vacuole, the site of hemoglobin catabolism. As a result, hemoglobin digestion, which is a source of amino acids necessary for parasite growth, was attenuated and caused the inhibition of parasite growth.

Dissection of mechanisms involved in the regulation of Plasmodium falciparum calcium-dependent protein kinase 4.

Recent studies have demonstrated that calcium-dependent protein kinases (CDPKs) are used by calcium to regulate a variety of biological processes in the malaria parasite Plasmodium. CDPK4 has emerged as an important enzyme for parasite development, because its gene disruption in rodent parasite Plasmodium berghei causes major defects in sexual differentiation of the parasite ( Billker, O., Dechamps, S., Tewari, R., Wenig, G., Franke-Fayard, B., and Brinkmann, V. (2004) Cell 117, 503-514 ). Despite these findings, it is not very clear how PfCDPK4 or any other PfCDPK is regulated by calcium at the molecular level. We report the biochemical characterization and elucidation of molecular mechanisms involved in the regulation of PfCDPK4. PfCDPK4 was detected on gametocyte periphery, and its activity in the parasite was regulated by phospholipase C. Even though the Junction Domain (JD) of PfCDPK4 shares moderate sequence homology with that of the plant CDPKs, it plays a pivotal role in PfCDPK4 regulation as previously reported for some plant CDPKs. The regions of the J-domain involved in interaction with both the kinase domain and the calmodulin-like domain were mapped. We propose a model for PfCDPK regulation by calcium, which may also prove useful for design of inhibitors against PfCDPK4 and other members of the PfCDPK family.