Design, synthesis and biological evaluation of 1,3,6-trisubstituted ß-carboline derivatives for cytotoxic and anti-leishmanial potential.

In the present study, 23 derivatives of 1,3,6-trisubstituted ß-carboline were synthesized and evaluated for cytotoxic potential against four human cancer cells, namely A-549, HeLa, Hep G2 and MCF-7 as well as anti-leishmanial activity against Leishmania donovani (MHOM/80/IN/Dd8) promastigotes. Among the studied compounds, compounds 13c and 13q showed potent cytotoxic activity better than the parent compound 10. For instance, compound 13c was found to be the most cytotoxic with IC50 of 4.72, 3.59, 3.65 and 4.17 µM against A-549, HeLa, Hep G2 and MCF-7 respectively, while for compound 13q, IC50 were 15.47, 5.30, 6.15 and 13.39 µM against the same cancer cells respectively. Further, these two compounds were found to be apoptotic in A-549 and MCF-7 cells when observed using Annexin V/propidium iodide staining under confocal microscope. All the compounds were also tested for anti-leishmanial potential. In which, compounds 13u and 13c were found to show moderate inhibition with IC50 of 23.5±9.0 and 68.0±0.0 µM respectively, while compound 10 was the most active with IC50 of 9.0±2.8 µM, suggesting the modification at C-6 detrimental for anti-leishmanial activity. Interestingly, amongst all, compound 13c was found to be the most active for cytotoxic and moderately active for anti-leishmanial activity which can be further developed as a lead for these disease areas.

2'-Hydroxy flavanone derivatives as an inhibitors of pro-inflammatory mediators: Experimental and molecular docking studies.

2'-Hydroxy flavanone (1) was previously isolated from Mimosa pudica (L.) whole plant and was found to exhibit anti-inflammatory effects in vitro. There are also reports on anti-inflammatory properties of compounds bearing flavanone/chromone nucleus. Taking this into account, fourteen derivatives of 2'-hydroxy flavanone (1) were synthesized and evaluated against pro-inflammatory mediators (TNF-α, IL-1ß and NO) in in vitro and in vivo models. Results directed that among the synthesized compounds, four derivatives (11-14) showed profound inhibition of pro-inflammatory mediators as compared to the lead molecule. Further, 11-14 demonstrated comparable anti-inflammatory activity with ibuprofen in carrageenan-induced rat paw edema assay and appreciable inhibition of lipopolysaccharide (LPS) induced pro-inflammatory mediators (TNF-α and IL-1ß) in Sprague Dawley (SD) rats. The synthesized compounds were further subjected to molecular docking analysis and in silico prediction of pharmacokinetic properties.

Synthesis and anti-leishmanial activity of 1-aryl-ß-carboline derivatives against Leishmania donovani.

ß-carbolines from various natural and synthetic sources have been known to show diverse biological activities. As a part of our current ongoing project to search for potent natural product-derived anti-leishmanial compounds, we have synthesized a series of substituted 1-aryl-ß-carboline derivatives. A total of 22 compounds were synthesized and tested in vitro against Leishmania donovani, out of which 6 compounds (4, 5, 10, 11, 19 and 22) showed notably more activity than the standard miltefosine (IC(50) 12.07±0.82 µM), with compound 4 being the most potent (IC(50) 2.16±0.26 µM).

One pot synthesis and anticancer activity of dimeric phloroglucinols.

A series of dimeric phloroglucinol compounds were synthesized in a single step using commercially available phloroglucinol and methanesulfonic acid. Based on the reported anticancer activity of plant derived dimeric phloroglucinols, these synthesized compounds were evaluated for their in vitro anti-proliferative activities against various cancer cell lines. Several compounds demonstrated in vitro cytotoxic effects across a wide array of tumor cell types. The compound 29 with pyridin-3-yl group on linker methylene and two diisovaleryl phloroglucinol moieties was found to be the most active in all the five cancer cell lines having a low IC(50) of 5.5 µM in colon cancer cell lines (HCT116).

Synthesis and evaluation of beta-carboline derivatives as inhibitors of human immunodeficiency virus.

A series of beta-carboline derivatives were synthesized by utilizing aromatization and chemoselective alkylation method recently reported from our laboratory. Synthesized derivatives were evaluated for anti-HIV activity in human CD4+ T cell line (CEM-GFP) infected with HIV-1 NL(4.3) virus. 1-Formyl-beta-carboline-3-carbxylic acid methyl ester (15) showed inhibition of human immunodeficiency virus at IC(50)=2.9 microM.

Biomimetic synthesis and anti-HIV activity of dimeric phloroglucinols.

Plants are an important source of a variety of bioactive compounds with different modes of action. Anti-HIV agents from plant sources can be useful in developing novel therapies for inhibiting HIV infection. Based on the reported anti-HIV activity of plant derived phloroglucinols, several new dimeric phloroglucinols were synthesized in the present study by varying substitution on aromatic ring and at methylene bridge. Some of the synthesized compounds have shown good HIV inhibitory activity in a human CD4+ T cell line (CEM-GFP) infected with HIV-1 NL(4.3) virus isolate. Structure-activity studies indicate that phenyl, 4-benzyloxy-1-phenyl and cyclohexyl substitution at methylene bridge gave compounds with better anti-HIV activity. Compounds 22 and 24 showed highest anti-HIV activity with an IC(50) of 0.28 microM and 2.71 microM, respectively, former was more active than the positive standard AZT in cell based assay.

Synthesis and anti-HIV activity of alkylated quinoline 2,4-diols.

Naturally occurring quinolone alkaloids, buchapine (1) and compound 2 were synthesized as reported in literature and evaluated for anti-HIV potential in human CD4+ T cell line CEM-GFP, infected with HIV-1(NL4.3) virus by p24 antigen capture ELISA assay. The compounds 1 and 2 showed potent inhibitory activity with IC(50) value of 2.99 and 3.80microM, respectively. Further, 45 alkylated derivatives of quinoline 2,4-diol were synthesized and tested for anti-HIV potential in human CD4+ T cell line CEM-GFP. Among these, 13 derivatives have shown more than 60% inhibition. We have identified three most potent inhibitors 6, 9 and 23; compound 6 was found to be more potent than lead molecule 1 with IC(50) value of 2.35microM and had better therapeutic index (26.64) as compared to AZT (23.07). Five derivatives 7, 19a, 19d, 21 and 24 have displayed good noticeable anti-HIV activity. All active compounds showed higher CC(50) values which indicate that they have better therapeutic indices.

Anti-inflammatory, cyclooxygenase (COX)-2, COX-1 inhibitory, and free radical scavenging effects of Rumex nepalensis.

Evaluation of the topical anti-inflammatory activity of chloroform and ethyl acetate extracts of RUMEX NEPALENSIS roots in a TPA-induced acute inflammation mouse model demonstrated a significant reduction in ear edema. The extracts were further tested on purified enzymes for COX-1 and COX-2 inhibition to elucidate their mechanism of action, and a strong inhibition was observed. Six anthraquinones and two naphthalene derivatives were isolated from the ethyl acetate extract. Among the isolated compounds, emodin was found to be a potent inhibitor with slight selectivity towards COX-2, and nepodin exhibited selectivity towards COX-1. Emodin, endocrocin, and nepodin also exhibited significant topical anti-inflammatory activity in mice. Interestingly, nepodin showed better radical scavenging activity than trolox and ascorbic acid against DPPH and ABTS radicals. The strong radical scavenging activity of chloroform and ethyl acetate extracts could be explained by the presence of nepodin as well as by the high phenolic content of the ethyl acetate extract. Thus, the anti-inflammatory effect of R. NEPALENSIS roots was assumed to be mediated through COX inhibition by anthraquinones and naphthalene derivatives and through the radical scavenging activities of naphthalene derivatives.

Natural products drug discovery research in India: status and appraisal.

Discovery of a new drug is time consuming and laborious process. Natural products have long been a thriving source for the discovery of new drugs due to their chemical diversity and ability to act on various biological targets. The phytochemical exploration of indigeneous flora has contributed to some extent in this race for the discovery of new drugs. The traditional Indian systems of medicine has been a part of our lifestyle since ages and the classical texts like Ayurveda and Charak Samhita have served as materia medica for this purpose. This review focuses on the contributions made from India in the drug discovery and development process and provides future directions in the area.

Synthesis, biological evaluation and molecular docking of aryl hydrazines and hydrazides for anticancer activity.

Aryl hydrazine and hydrazide analogues were synthesized based on p-tolyl hydrazine, isolated as a breakdown product of a secondary metabolite from the mushroom, Agaricus bisporus, and tested to be highly active molecule than 5-fluorouracil in in vitro anticancer studies. The synthesized analogues were tested for anticancer activity using NCI protocol. Anolgues 12 and 15 emerged as molecules with significant in vitro anticancer activity. Molecular docking study revealed the binding orientations of aryl hydrazines and hydrazides analogues in the active sites of thymidylate synthase.

Antileishmanial phenylpropanoids from Alpinia galanga (Linn.) Willd.

Hexane, chloroform and ethyl acetate extracts (100 microg/ml) of Alpinia galanga rhizomes exhibited significant activity in vitro against promastigotes of L. donovani. Twelve compounds namely, methyleugenol (1), p-coumaryl diacetate (2), 1'-acetoxychavicol acetate (3), 1'-acetoxyeugenol acetate (4), trans-p-acetoxycinnamyl alcohol (5), trans-3,4-dimethoxycinnamyl alcohol (6), p-hydroxybenzaldehyde (7), p-hydroxycinnamaldehyde (8), trans-p-coumaryl alcohol (9), galangin (10), trans-p-coumaric acid (11) and galanganol B (12) were isolated from these extracts. Of these, compounds 2, 3, 4 and 5 were found most active in vitro against promastigotes of L. donovani with IC50 values of 39.3, 32.9, 18.9 and 79.9 microM respectively. This is the first report of antileishmanial activity of the extracts and isolated constituents of A. galanga.

Dihydrocapsiate supplementation prevented high-fat diet-induced adiposity, hepatic steatosis, glucose intolerance, and gut morphological alterations in mice.

Despite the lipolytic and thermogenic properties of capsaicin, its putative use as a weight-lowering dietary supplement has been limited because of the burning sensation caused by capsaicin when it comes in contact with mucous membranes. A potential alternative to capsaicin are the capsinoids, nonpungent capsaicin analogs that exhibit effects similar to capsaicin. Whereas the antiobesity properties of capsinoids have been reported, the effectiveness of FDA-approved synthetic dihydrocapsiate has not yet been investigated. In the present study, we hypothesized that dihydrocapsiate might ameliorate high-fat diet (HFD)-induced metabolic disorders in a manner similar to capsaicin and therefore can be its nonpungent alternative. To test this hypothesis, HFD-fed mice were orally administered dihydrocapsiate (2 and 10mg/kg body weight) for 12weeks. Dihydrocapsiate modestly reduced the HFD-induced weight gain and significantly prevented the associated hyperglyceridemia and hyperinsulinemia while improving glucose tolerance. Histological and gene expression analysis showed that dihydrocapsiate significantly prevented the lipid accumulation in white adipose tissue and brown adipose tissue via targeting genes involved in energy expenditure and mitochondrial biogenesis, respectively. Dihydrocapsiate corrected hepatic triglyceride concentrations and normalized expression of genes regulating hepatic lipid and glucose metabolism. Moreover, dihydrocapsiate administration significantly improved gut morphology and altered gut microbial composition, resulting in reduced host energy availability. Collectively, these results indicate that dihydrocapsiate administration improved glucose tolerance, prevented adiposity and hepatic steatosis, as well as improved HFD-induced gut alterations, positing dihydrocapsiate as a potential food ingredient for the dietary management of HFD-induced metabolic alterations.

Pancreatic lipase inhibitors from natural sources: unexplored potential.

The prevalence of obesity is increasing at an alarming rate, but, unfortunately, only a few medications are currently on the market. Obesity is primarily regarded as a disorder of lipid metabolism and the enzymes involved in this process could be selectively targeted to develop antiobesity drugs. Recently, newer approaches for the treatment of obesity have involved inhibition of dietary triglyceride absorption via inhibition of pancreatic lipase (PL) as this is the major source of excess calories. Natural products provide a vast pool of PL inhibitors that can possibly be developed into clinical products. This article reviews various extracts and secondary metabolites from plants and microbial origin with PL inhibitory activity that can be focused for drug development programs.

Kodo millet whole grain and bran supplementation prevents high-fat diet induced derangements in a lipid profile, inflammatory status and gut bacteria in mice.

The protective role of kodo millet whole grain and bran supplementation in diet induced obesity has not been investigated. Here we have studied the role of kodo millet supplementation in age matched Swiss albino mice that were randomly divided into groups and fed their respective diets for 16 weeks. A high fat diet increased weight gain, reduced glucose tolerance, increased serum lipids, altered hepatic and adipocyte gene expression and caused dysbiosis in the intestinal beneficial bacteria. Kodo millet supplementation did not affect weight gain but it improved glucose tolerance and prevented an increase in the serum cholesterol and lipid parameters (P ≤ 0.05), modulated adipogenesis related gene expression, decreased serum IL-6 and LPS levels (P ≤ 0.05), promoted selected beneficial gut bacterial abundances (Lactobacillus sp., Bifidobacteria, Akkermansia and Roseburia spp.) and improved the total short chain fatty acid production (P ≤ 0.05) and acetate levels (P ≤ 0.05) in cecal contents. This study provides evidence that kodo millet supplementation alleviates high-fat diet induced changes and hence can be incorporated as a functional ingredient for the management of obesity.

Modulating TNF-alpha signaling with natural products.

Natural products have been, and continue to be, a major source of pharmacologically active substances from which drugs can be developed. Currently, tumor necrosis factor-alpha (TNF-alpha) inhibitors from natural origins are being advanced for the treatment of inflammatory disorders. Elevated TNF-alpha synthesis has been associated with the development of diabetes, septic shock, tumorigenesis, rheumatoid arthritis, psoriatic arthritis and inflammatory bowel disease. Currently, only protein-based drugs are available for the clinical inhibition of TNF-alpha activity. Small-molecule drugs that can regulate TNF-alpha levels or activity might provide a cost-effective alternative to protein-based therapeutics. This review briefly highlights the physiological and pathological roles of TNF-alpha, and covers those natural compounds capable of interfering with TNF-alpha activity.

A review on biological sources, chemistry and pharmacological activities of pinostrobin.

Pinostrobin, a dietary bioflavonoid discovered more than 6 decades ago in the heart-wood of pine (Pinus strobus), has depicted many pharmacological activities including anti-viral, anti-oxidant, anti-leukaemic, anti-inflammatory and anti-aromatase activities. It is an inhibitor of sodium channel and Ca(2+) signalling pathways and also inhibits intestinal smooth muscle contractions. In spite of the fact that pinostrobin has an application as functional foods, till-to-date no comprehensive review on pinostrobin has been carried out. Hence, the present review deals with the biological sources, chemistry and pharmacological activities of pinostrobin.

Online antioxidant activity and ultra-performance LC-electrospray ionisation-quadrupole time-of-fight mass spectrometry for chemical fingerprinting of Indian polyherbal formulations.

A HPLC-DAD-DPPH method was developed for evaluating the 1, 1-diphenyl-2-picryl hydrazyl free radical scavenging activity of ethylacetate extracts of different polyherbal formulations (draksarista, draksava, lohasava and arvindasava) by using RP-18e column. The ethylacetate extract from polyherbal, 'draksarista' exhibited maximum free radical scavenging activity (99.9 ± 0.38%) followed by draksava (99.8 ± 0.34%), lohasava (98.5 ± 0.30%) and arvindasava (42.3 ± 0.34%) at 100 µg mL(-1). Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionisation-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study chemical composition of the ethylacetate extracts of formulations. The characteristic electrospray mass ionisation reveals the dominance of polyphenols and their glycosides in the four polyherbal formulations.

Cinnamaldehyde supplementation prevents fasting-induced hyperphagia, lipid accumulation, and inflammation in high-fat diet-fed mice.

Cinnamaldehyde, a bioactive component of cinnamon, is increasingly gaining interest for its preventive and therapeutic effects against metabolic complications like type-2 diabetes. This study is an attempt to understand the effect of cinnamaldehyde in high-fat diet (HFD)-associated increase in fasting-induced hyperphagia and related hormone levels, adipose tissue lipolysis and inflammation, and selected cecal microbial count in mice. Cinnamaldehyde, at 40 µM dose, prevented lipid accumulation and altered gene expression toward lipolytic phenotype in 3T3-L1 preadipocyte cell lines. In vivo, cinnamaldehyde coadministration prevented HFD-induced body weight gain, decreased fasting-induced hyperphagia, as well as circulating leptin and leptin/ghrelin ratio. In addition to that, cinnamaldehyde altered serum biochemical parameters related to lipolysis, that is, glycerol and free fatty acid levels. At transcriptional level, cinnamaldehyde increased anorectic gene expression in hypothalamus and lipolytic gene expression in visceral white adipose tissue. Furthermore, cinnamaldehyde also decreased serum IL-1ß and inflammatory gene expression in visceral white adipose tissue. However, cinnamaldehyde did not modulate the population of selected gut microbial (Lactobacillus, Bifidibaceria, and Roseburia) count in cecal content. In conclusion, cinnamaldehyde increased adipose tissue lipolysis, decreased fasting-induced hyperphagia, normalized circulating levels of leptin/ghrelin ratio, and reduced inflammation in HFD-fed mice, which augurs well for its antiobesity role.

Activity-guided investigation of Carissa carandas (L.) roots for anti-inflammatory constituents.

The present study was structured to investigate the anti-inflammatory potential of the extracts, fractions and compounds isolated from Carissa carandas (L.) roots. Bioassay guided fractionation of methanol extract based on inhibitory potential towards proinflammatory mediators (TNF-α, IL-1ß and nitric oxide (NO)) led to the identification of stigmasterol (1), lupeol (2), oleanolic acid (3), carissone (4) and scopoletin (5) as potential anti-inflammatory agents. Carissone (4) (IC50 = 20.1 ± 2.69 µg/mL) and scopoletin (5) (IC50 = 24.6 ± 1.36 µg/mL) exhibited significant inhibition of NO production comparable to specific NO inhibitor (L-NAME; IC50 = 19.82 ± 1.64 µg/mL) without affecting the cell viability. Also, 4 and 5 at a concentration of 30 µM were found to inhibit 41.88-53.44% of TNF-α and IL-1ß. To the best of our knowledge, this is the first report displaying the anti-inflammatory effects of C. carandas (L.) roots, partially mediated by inhibition of TNF-α, IL-1ß and NO.