Antioxidants of commercial interest from Homalium tomentosum attenuates hepatocellular necrosis: Insights from experimental and computational studies.

Homalium tomentosum (Vent.) Benth, is a valuable agroforestry species and has industrial importance high-quality wood is used for malas, the manufacture of matches, and is suitable for making a wide range of articles. Nevertheless, leaves and bark are relatively rich in phenols and flavonoids, used for medicinal purposes. In this study, phenols and flavonoids rich in bio-privileged antioxidants in ethyl-acetate extracted fractions of bark (HTEB), and leaves (HTEL) at 300, and 400 mg/kg were examined in carbon tetrachloride (CCl4)-induced hepatotoxicity in experimental rats. HTEB and HTEL (400) showed improvement in liver structural integrity, but, HTEB400 significantly improved serum (total protein, TP; alkaline phosphatase, ALP; total bilirubin, TB; serum glutamate oxaloacetate transaminase, SGOT, and serum glutamate pyruvate transaminase, SGPT), and hepatic oxidative (catalase, CAT; thiobarbituric acid reactive species, TBARS; reduced glutathione, GSH; superoxide dismutase, SOD), and inflammatory (transforming growth factor, TGF-ß; ineterleukin-6, IL-6) biomarkers accompanied by histopathological improvements of the liver. GC-MS analysis of HTEB and HTEL identified 14 and 18 compounds, but physicochemical properties of 3-major antioxidants of HTEB (levoglucosenone, (+)-borneol, α-N-normethadol), and HTEL (2-coumaranone, salicyl alcohol, D-allose) were satisfied for the parameters molecular weight, no. of H-acceptor and H-donor, partition co-efficient (clogP), and topological polar surface area (tPSA) of Lipinski's rule. ADME-Tox properties were directly related to the biological activities of HTEB and HTEL. Molecular docking investigation of α-N-normethadol showed the highest binding energy against TGF-ß and IL-6 than other antioxidants. HTEB and HTEL were powerful antioxidant potential, but levoglucosenone, (+)-borneol, and α-N-normethadol of HTEB demonstrated better activities in neutralizing reactive oxygen species (ROS) to preserve cellular membrane integrity in liver cirrhosis as found evidence in restoring the liver inflammatory cytokines. This study confirmed the economic interest of H. tomentosum bark as crude material for the preparation of biobased materials for the pharmaceutical and food industries.

Wound Healing Activity of Topical Herbal Gels Containing Barringtonia acutangula Fruit Extract: In silico and In vivo Studies.

The current study describes the efficacy of B. acutangula fruit extract in wound healing via incorporation within topical gels. B. acutangula fruit extract was produced by solvent extraction method. The bioactive extract was incorporated within Carbopol 940-based topical gels, which were applied topically over the excision and incision wounds. The change in healing process was observed till 20 days. The percentages of closure of excision wound area were 92.89 % and 93.43 %, when treated with topical herbal gels containing B. acutangula fruit extract of 5 % and 10 %, respectively. The tensile strengths of incision area in rats treated with topical herbal gels containing 5 % and 10 % methanol extract of B. acutangula fruits were found to be 25±5.12 g and 30±4.10 g, respectively. The wound healing activity of topical herbal gels containing B. acutangula fruit extract in rats was found to be significant when compared with that of the reference standard and untreated groups. In addition, in silico studies suggested about good skin permeability and binding to the proteins responsible for delaying wound healing. It can be concluded that this topical herbal gels containing B. acutangula fruit extract could be used clinically for the treatment of wounds.

Network pharmacology-based elucidation of bioactive compounds and experimental exploration of antidiabetic mechanisms of Hydrolea zeylanica.

This investigation systematically explored the underlying antidiabetic mechanism of Hydrolea zeylanica (HZH) by the approach of network pharmacology and experimental validation in restoring glucose homeostasis, and inflammation in high fat diet fed-streptozotocin (HFD/STZ)-induced type II diabetes (T2DM) rats. Network pharmacology analysis was conducted on 32 bioactive components of HZH. In silico ADME prediction, and physicochemical analysis of 32 compounds were used to assess their drug-likeness. Common targets between selected compounds, and T2DM were subjected for GO enrichment. Compound-target-pathway network was predicted with selected compounds and targets. HZH (300 and 400 mg/kg) were considered for GLUTs expression, and inflammation cytokines in T2DM rats. Network pharmacology showed the core relationship between 13 selected compounds, and 194 key target genes in insulin resistance, type II diabetes mellitus, insulin signaling pathways in T2DM. AKT1, AKT2, GSK3B, IL6, INSR, MAPK8, PPARA, GLUT1, GLUT2, GLUT4 were observed as the key targets in PPI network. HZH-400 significantly restored glucose homeostasis, and inflammatory markers in T2DM rats. It altered GLUT2, GLUT4 expression in liver, and skeletal muscle to normal. Bioactive compounds of HZH were found to control blood sugar level by modulating insulin resistance, type II diabetes mellitus, insulin signaling pathways, and glucose homeostasis, which in turn improved glucose uptake, insulin production in diabetes as shown in network pharmacology and glucose transporter expression studies.

Homalium zeylanicum attenuates streptozotocin-induced hyperglycemia and cellular stress in experimental rats via attenuation of oxidative stress imparts inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Homalium zeylanicum (Gardner) Benth (Salicaceae) leaves are being used as folklore medicine to treat diabetes by the local folk of Andhra Pradesh, India. The medicinal claim of this plant with hypoglycaemic effects was initially studied by the authors. Results demonstrated the important antioxidant activities of the hydroalcohol fraction of leaves of H. zeylanicum leaves (HAHZL) were positively correlated with phenols and flavonoids contents. AIM OF THE STUDY: Based on the previous findings, additional research is needed to examine the efficacy of using HAHZL to treat hyperglycemia. We therefore investigated in vitro and in vivo glycemic response of HAHZL, and evaluation of possible mechanism of bioactive molecules in mitigating streptozotocin-induced cellular stress in experimental rats via attenuation of oxidative stress imparts inflammation. METHODS: GC-MS/MS analysis of HAHZL was carried out to identify bioactive constituents. In vitro antidiabetic (α-glucosidase, α-amylase) and anti-inflammatory activities were investigated. HFD/low-STZ-prompted diabetic Wistar rats were administered with HAHZL (300 and 400 mg/kg; oral) for 28 days. Blood serum, oxidative stress, inflammation, DNA damage, and antidiabetic markers of pancreas and liver were determined. Histopathological studies of liver and pancreas were performed to assess the protective role of HAHZL. RESULTS: GC-MS/MS study revealed 7 bioactive compounds e.g., Phenol, 4-ethenyl-, acetate (28.68%), hydroquinone (9.10%), n-hexadecanoic acid (0.55%), phytol (0.57%), arbutin (17.65%), Vitamin E (1.04%), ß-Sitosterol (1.54%) which possess antioxidant, anti-inflammatory and anti-diabetic activities. HAHZL showed significant in vitro glycemic response as evidenced by the inhibition of α-amylase, and α-glucosidase activities. Lineweaver-Burk plot revealed that HAHZL exhibited competitive and mixed competitive inhibition towards α-amylase and α-glucosidase, respectively. HAHZL at 400 mg/kg modulated the pathophysiology associated with HFD/STZ-induced type2 diabetes mellitus and significantly (p < 0.001) improved antihyperglycemic (SG, SI, HOMA-IR, and HbA1C), antidyslipidemic (TC, HDL-C, LDL-C, and TG), antioxidative (MDA, SOD, CAT, GSH, and 8-OHdG) and anti-inflammatory (TNF-α, and CRP) markers in serum, pancreas and liver. In vitro and in vivo test results were corroborated by the improvement of pancreatic and hepatic tissue architecture in diabetic rats. CONCLUSION: HAHZL bearing bioactive components phenol, 4-ethenyl-,acetate, hydroquinone, n-hexadecanoic acid, arbutin, phytol, vitamin E and ß-sitosterol balanced glycemic level by normalising the levels of glycaemic indices, lipid profile, pancreas and liver functional markers in STZ-induced T2DM rats.

The modulatory role of prime identified compounds in Geophila repens in mitigating scopolamine-induced neurotoxicity in experimental rats of Alzheimer's disease via attenuation of cholinesterase, ß-secretase, MAPt levels and inhibition of oxidative stress imparts inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Geophila repens (L.) I.M. Johnst (Rubiaceae) is a small perennial creeper native to India, China, and other countries in Southeast Asia. The hot decoction of leaves is used orally for memory enhancing by the local folk of Andhra Pradesh, India. The ethnomedicinal claim of G. repens as memory enhancer was initially studied by the authors. Results demonstrated the important antioxidant and anticholinesterase activities of isolated molecule Pentylcurcumene and bioactive hydroalcohol extract of leaves of G. repens (GRHA). AIM OF THE STUDY: Based on the previous findings, additional research is needed to examine the efficacy of GRHA for memory enhancing properties. We therefore investigated the modulatory role of prime identified compounds in GRHA in mitigating scopolamine-induced neurotoxicity in experimental rats of Alzheimer's disease (AD) via attenuation of cholinesterase, ß-secretase, MAPt levels and inhibition of oxidative stress imparts inflammation. METHODS: Scopolamine (3 mg/kg) induced experimental rats of AD were treated with GRHA (300, 400 mg/kg) for 14 days. During the experimental period, elevated T-maze and locomotion-activity were performed to assess learning and memory efficacy of GRHA. At the end of the experiment, biochemical, neurochemical, neuroinflammation and histopathological observation of brain cortex were examined. GC-MS/MS analysis reported 31 compounds, among them 8 bioactive compounds possess antioxidant, neuroinflammation, neuroprotective activities, and were considered for docking analysis towards cholinesterase, ß-secretase activities in AD. RESULTS: GRHA 400 significantly improved learning and memory impairment with the improvement of oxidative stress (MDA, SOD, GSH, CAT), DNA damage (8-OHdG), neurochemical (AChE, BuChE, BACE1, BACE2, MAPt), neuroinflammation (IL-6, TNF-α) markers in neurotoxic rats. Docking studies of 8 compounds demonstrated negative binding energies for cholinesterase and ß-secretase indicating high affinity for target enzymes in AD. Test results were corroborated by the improvement of cellular tissue architecture of brain cortex in AD rats. CONCLUSION: Synergistic action of genistin, quercetin-3-D-galactoside, 9,12,15-octadecatrienoic-acid methyl-ester, phytol, retinal, stigmasterol, n-hexadecanoic acid, ß-sitosterol in GRHA restores memory-deficits via attenuation of cholinesterase, ß-secretase, MAPt level and inhibition of oxidative-stress imparts inflammation in AD.

The modulatory role of prime identified compounds in the bioactive fraction of Homalium zeylanicum in high-fat diet fed-streptozotocin-induced type 2 diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Homalium zeylanicum (Gardner) Benth. is a medicinal plant traditionally used in controlling diabetes which thus far has been assessed by the authors only to a very limited extent. PURPOSE: To fill the research gap in the literature review, we investigated the antihyperglycemic effects of hydro alcohol fraction of bark of H. zeylanicum (HAHZB) by modulating oxidative stress and inflammation in high-fat diet fed-streptozotocin (HFD/STZ)-induced type-2 diabetic rats. MATERIALS AND METHODS: To understand the antioxidant capacity of HAHZB, oxygen radical absorbance capacity (ORAC) and cell-based antioxidant protection in erythrocytes (CAP-e) were performed. GC-MS/MS analysis was performed to assess the bioactive components in HAHZB. HFD/STZ-induced diabetic rats were treated orally with HAHZB (300 and 400 mg/kg) for 28 days. After the end of the experiment, marker profiling and histopathological observation of blood and pancreas were examined. The study also highlights interaction between diabetes, oxidative stress and inflammation by examining the increased pro-inflammatory cytokines e.g. TNF-α and C-reactive protein (CRP) promotes DNA damage e.g. oxidation of 8-hydroxy-2-deoxyguanosine (8-OHdG) in chronic hyperglycaemia. RESULTS: In ex vivo cellular antioxidant capacity of -CAP-e and ORAC assays, HAHZB showed remarkable free radical scavenging ability in a dose dependent manner. GC-MS/MS analysis identified 28 no. of compounds and out of which, oleic acid (1.03%), ethyl tridecanoate (11.77%), phytol (1.29), 9,12-octadecadienoic acid, methyl ester, (E,E)-(5.97%), stigmasterol (1.30%) and ß-sitosterol (2.86%) have antioxidant, anti-inflammatory and anti-diabetic activities. HAHZB 400 mg/kg significantly (p < 0.001) improved the lipid profile (TC: 74.66 ± 0.59, HDL-C: 22.08 ± 0.46, LDL-C: 38.06 ± 0.69, and TG: 171.92 ± 1.01 mg/dL) as well as restoring antidiabetic markers (SG: 209.62 ± 1.05 mg/dL, SI: 15.07 ± 0.11 µIU/mL, HOMA-IR: 7.79 ± 0.04 %, and HbA1C: 8.93 ± 0.03 %) and renal functional markers (Tg: 291.26 ± 0.57 pg/mL, BUN: 23.79 ± 0.14 mg/dL, and Cr: 1.34 ± 0.04 mg/dL) in diabetic rats. Oxidative stress markers of pancreas (MDA: 3.65 ± 0.17 nM TBARS /mg protein, SOD: 3.14 ± 0.28 U/mg protein, CAT: 7.88 ± 0.23 U/mg protein, GSH: 12.63 ± 0.28 µM/g of tissue) were restored to normal as evidenced by histological architecture of pancreatic islet cells. The increased level of pro-inflammatory cytokines and oxidative DNA damage were significantly restored (TNF-α: 54.48 ± 3.19 pg/mL, CRP: 440.22 ± 7.86 ng/mL, and 8-OHdG: 63.65 ± 1.84 ng/mL) by HAHZB in diabetic rats. CONCLUSION: The present findings confirm that the presence of bioactive compounds in HAHZB exert therapeutic protective effect by decreasing oxidative, inflammation and pancreatic ß-cell damage in oxidative stress induced diabetic rats.

Computational and experimental validation of free radical scavenging properties of high-performance thin-layer chromatography quantified phenyl myristate in Homalium nepalense.

Phenyl myristate was isolated from Homalium nepalense, which is known for its therapeutic virtues in traditional medicine. However, the study of radical scavenging-capacity of phenyl myristate is limited by its relatively low abundance in medicinal plants. We have studied the isolation, structure-elucidation, and bioactivities of high-performance thin-layer chromatography validated phenyl myristate from hydroalcohol-extract of bark of H. nepalense. The chemical structure of phenyl myristate was elucidated by spectroscopic methods. The chromatography was performed on high-performance thin-layer chromatography aluminum plates coated with silica-gel 60 F254 . Determination and quantitation of phenyl myristate were performed by densitometric-scanning at 254 nm (chloroform-methanol, 9:1, v/v; Rf 0.49). The method was validated according to International Council for Harmonisation guidelines in terms of linearity, specificity, sensitivity, accuracy, precision, robustness, and stability. Linearity-range of phenyl myristate was 100-500 ng/5 µL with correlation-coefficient r2  = 0.9997. Limits of detection and quantitation were 3.35 and 10.17 ng, respectively. Phenyl myristate showed significant free-radical-scavenging activities in 2,2-diphenyl-1-picrylhydrazyl, oxygen-radical-absorbance-capacity, and ex vivo cell-based-antioxidant-protection-in-erythrocytes assays. Molecular-docking approach of phenyl myristate showed effective binding at active sites of human serum albumin (HSA) with the lowest binding energy (-8.4 kcal/mol) that was comparable with ascorbic acid (-5.0 kcal/mol). These studies provide mechanistic insight into the potential free radical scavenging activities of phenyl myristate.

Ameliorative effects of Hydrolea zeylanica in streptozotocin-induced oxidative stress and metabolic changes in diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Hydrolea zeylanica L. Vahl. (Hydroleaceae) is an aquatic medicinal plant used as leafy vegetable in some parts of India. In south Odisha and Hazaribag district of Jharkhand, India, decoction of leaves is used as household remedy for diabetes. To our knowledge, no prior studies have examined the antidiabetic activity of H. zeylanica to validate its ethnomedicinal claim. PURPOSE: With this aim in mind, we examined the bioactivity of hydroalcohol fraction of leaves of H. zeylanica (HAHZ) in streptozotocin-induced oxidative stress in diabetic rats. MATERIALS AND METHODS: In vitro antidiabetic and free radical scavenging activities of different fractions of H. zeylanica were performed. The most effective bioactive fraction e.g. HAHZ was considered for kinetic studies to understand the mode of inhibition of α-glucosidase and α-amylase. To understand the chemical composition, GC-MS/MS and LC-MS/MS analysis of HAHZ were performed. To find out the molecular mechanism of action of HAHZ, streptozotocin-induced oxidative stress and metabolic changes in diabetic rats were studied. RESULTS: HAHZ demonstrated significantly higher radical scavenging and antidiabetic activities. Kinetic analysis revealed that HAHZ inhibited α-glucosidase competitively, and α-amylase mixed competitively. To understand the chemical composition, GC-MS/MS and LC-MS/MS analysis of HAHZ identified 32 compounds and among which R-limonene (0.52%), perillartine (0.41%), N-formyl-L-lysine (1.49%), limonen-6-ol, pivalate (1.43%), lidocaine (1.70%) and gamolenic acid (2.80%) were reported to have antioxidant and antidiabetic activities. HAHZ-400 mg/kg showed significant (p < 0.001) improvement in serum markers (SGOT, SGPT, ALP, total bilirubin, total protein, triglycerides, total cholesterol, HDL-C, LDL-C) and oxidative markers (MDA, SOD, CAT, GSH) in serum, liver and pancreas at effective dose dependent manner. In histopathological observation, HAHZ-400 mg/kg showed marked improvement in restoring cellular architecture of liver and pancreas. CONCLUSION: In diabetic rats, the improvement in glycemic control mechanism was achieved upon stimulating insulin secretion by R-limonene, perillartine, N-formyl-L-lysine, limonen-6-ol, pivalate, lidocaine and gamolenic acid of HAHZ.

Isolation, identification, and quantification of Pentylcurcumene from Geophila repens: A new class of cholinesterase inhibitor for Alzheimer's disease.

The aerial part of Geophila repens (L.) I.M. Johnst (Rubiaceae) has been used in India to improve intelligence and memory for a long time. As part of our ongoing efforts in discovering potential bioactive compounds from G. repens, we have studied the isolation, identification, and quantification of a new class of cholinesterase inhibitor from G. repens for Alzheimer's disease (AD). Terpene was isolated from hydroalcohol extract of G. repens (GRHA) and its structure was identified "Pentylcurcumene" by spectroscopic data. HPTLC fingerprint analysis was performed and good separation was achieved in mobile phase (benzene:methanol; 7.5:2.5, v/v, 254 and 366 nm; Rf 0.51). The method was validated using ICH guidelines in terms of linearity, specificity, sensitivity, accuracy, precision, robustness and stability. In cellular antioxidant studies e.g. DPPH, oxygen-radical-absorbance-capacity (ORAC) and cell-based-antioxidant-protection-in-erythrocytes (CAP-e) assays showed that, Pentylcurcumene showed remarkably different degrees of antioxidant activities in dose-dependent manner. Pentylcurcumene demonstrated anticholinesterase activities e.g. IC50 of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition were 73.12 ±â€¯0.56 and 97.65 ±â€¯0.46 µg/ml, respectively. To better understand enzyme kinetics, Lineweaver-Burk plot of Pentylcurcumene displayed the highest affinity with competitive inhibition (reversible) towards both AChE (Vmax 0.8) and BChE (Vmax 0.6). An improved and advanced HPTLC tool of bioautography detection of Pentylcurcumene has been successfully demonstrated its anticholinesterase activities. Molecular docking simulations of Pentylcurcumene (ligand) and enzymes (proteins) exhibited the binding of ligand at active sites of AChE (human/rat) and BChE (human/homology) efficiently and also predicted the hydrophobic interaction of drug towards different amino acid residue within proteins. As per the results of antioxidant study and with the support of molecular docking analysis, it is concluded that Pentylcurcumene could be a potential first-line cholinesterase-inhibitor for AD.

Ameliorative effect of Homalium zeylanicum against carbon tetrachloride-induced oxidative stress and liver injury in rats.

Objective is to evaluate the ameliorative effects of Homalium zeylanicum in carbon tetrachloride-induced oxidative stress and liver injury in rats. To establish the nature of antioxidant principles in the bioactive ethyl acetate fractions of bark (HZEB) and leaf (HZEL); oxygen radical absorbance capacity (ORAC) and cell-based antioxidant protection in erythrocytes (CAP-e) assays were performed. From acute toxicity study, HZEB and HZEL at 200 and 300 mg/kg b.w., were relatively safe at their effective doses. The degree of protection was measured by using biochemical parameters such as serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), total bilirubin (TB) and total protein (TP) contents. Hepatic markers e.g. thiobarbituric acid reactive species (TBARS), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) were evaluated along with histopathological observations of liver tissues. Both fractions showed significant improvement in restoring SGOT, SGPT, ALP, TB and TP level. TBARS, SOD, CAT and GSH levels were significantly altered towards normal values. Both fractions at 300 mg/kg showed remarkable improvement in liver markers as compared to silymarin. Histopathological examinations showed reduction in hepatic necrosis and appeared normal hepatocellular architecture in HZEB and HZEL treated groups. In CAP-e assay, IC50 of HZEB (54.66 mg/mL) was higher than HZEL (60.88 mg/mL) and in ORAC assay, AUC of HZEB and HZEL were 33.46, 21.29 respectively and results were comparable with trolox. GC-MS and LC-MS analysis identified a total no. of 44 compounds. Few compounds were identified as bioactive compounds e.g. catechol (7.23%), tetraacetyl-d-xylonic nitrile (3%), oleic acid (0.49%), 2,6-bis(1,1-dimethylethyl)-phenol (3.71%), 3,4,5-trimethoxy-phenol (0.31%), and conifer alcohol (7.41%). The presence of antioxidant principles in both fractions were responsible for hepatoprotective activities, however, the presence of catechol (7.23%) in the bark part imparted better activities in protecting liver than leaf of H. zeylanicum.

The ameliorative effect of Homalium nepalense on carbon tetrachloride-induced hepatocellular injury in rats.

The purpose of this study was to evaluate ameliorative effects of Homalium nepalense Benth. (Flacourtiaceae) on CCl4-induced hepatocellular injury in rats. Oxygen-radical absorbance-capacity (ORAC) and cell-based-antioxidant-protection-in-erythrocytes (CAP-e) were performed and found that the ethyl acetate fractions of bark (HNEB) and leaf (HNEL) showed a remarkable degree of antioxidant activities in a dose dependent manner. Antioxidant potential HNEB was higher than HNEL and was comparable with trolox. HNEB and HNEL at 300 and 400 mg/kg showed significant hepatoprotective activities against CCl4-induced hepatotoxicity as evidenced by restoration of SGOT, SGPT, ALP, TB and TP level. The level of TBARS, SOD, CAT and GSH were significantly improved and restored towards normal value. Both fractions at 400 mg/kg showed remarkable improvements in marker levels as comparable to silymarin. Histopathological observations of liver tissues revealed the reduction of necrosis with appearance of sinusoidal space, central vein, and bile duct both in case of HNEB and HNEL. GC-MS and LC-MS confirmed occurrence of a total 53 no. of phytocompounds in HNEB and HNEL. Based on their retention times-(RT) and mass-to-charge-ratios-(m/z), some of the major bioactive compounds were catechol (5.89%), 5-hydroxymethylfurfural (5.87%), salicylic acid (4.89%), eugenol (1.60%), doconexent (0.31%), ß-sitosterol (1.59%), 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (1.15%), coniferyl alcohol (2.99%), hexadecanoic acid methyl ester (1.05%), and betulin (1.20%). H. nepalense possesses significant hepatoprotection effect because of its antioxidant constituents.

Features and outcomes of drugs for combination therapy as multi-targets strategy to combat Alzheimer's disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Alzheimer's disease (AD), a deleterious neurodegenerative disorder that impairs memory, cognitive functions and may lead to dementia in late stage of life. The pathogenic cause of AD remains incompletely understood and FDA approved drugs are partial inhibitors rather than curative. Most of drugs are synthetic or natural products as galanthamine is an alkaloid obtained from Galanthus spp. Huperzine A, an alkaloid found in Huperzia spp., gingkolides a diterpenoids from Gingko biloba and many ethnobotanicals like Withania somnifera (L.) Dunal., Physostigma venenosum Balf., Bacopa monnieri (L.) Wettst., Centella asiatica (L.) Urb. have been used by traditional Indian, Chinese, and European system of medicines in AD. Clinical significance opioid alkaloid in Papaver somniferum has shown another dimension to this study. Over exploitation of medicinal plants with limited bioactive principles has provided templates to design synthetic drugs in AD e.g. rivastigmine, phenserine, eptastigmine based on chemical structure of physostigmine of Physostigma venenosum Balf. Even ZT-1 a prodrug of Hup A and memogain a prodrug of galantamine has achieved new direction in drug development in AD. All these first-line cholinesterase-inhibitors are used as symptomatic treatments in AD. Single modality of "One-molecule-one-target" strategy for treating AD has failed and so future therapies on "Combination-drugs-multi-targets" strategy (CDMT) will need to address multiple aspects to block the progression of pathogenesis of AD. Besides, cholinergic and amyloid drugs, in this article we summarize proteinopathy-based drugs as AD therapeutics from a variety of biological sources. In this review, an attempt has been made to elucidate the molecular mode of action of various plant products, and synthetic drugs investigated in various preclinical and clinical tests in AD. It also discusses current attempts to formulate a comprehensive CDMT strategy to counter complex pathogenesis in AD. MATERIALS AND METHODS: Information were collected from classical books on medicinal plants, pharmacopoeias and scientific databases like PubMed, Scopus, GoogleScholar, Web of Science and electronic searches were performed using Cochrane Library, Medline and EMBASE. Also published scientific literatures from Elsevier, Taylor and Francis, Springer, ACS, Wiley publishers and reports by government bodies and documentations were assessed. RESULTS: 60 no. of natural and synthetic drugs have been studied with their significant bioactivities. A decision matrix designed for evaluation of drugs for considering to the hypothetic "CDMT" strategy in AD. We have introduced the scoring pattern of individual drugs and based on scoring pattern, drugs that fall within the scoring range of 18-25 are considered in the proposed CDMT. It also highlights the importance of available natural products and in future those drugs may be considered in CDMT along with the qualified synthetic drugs. CONCLUSION: A successful validation of the CDMT strategy may open up a debate on health care reform to explore other possibilities of combination therapy. In doing so, it should focus on clinical and molecular relationships between AD and CDMT. A better understanding of these relationships could inform and impact future development of AD-directed treatment strategies. This strategy also involves in reducing costs in treatment phases which will be affordable to a common man suffering from AD.

In vitro biological assessment of Homalium zeylanicum and isolation of lucidenic acid A triterpenoid.

Homalium zeylanicum (Gardner) Benth. (Flacourtiaceae) is a medicinal plant useful in controlling rheumatism, inflammation and diabetes. The objective of this work evaluates in vitro antioxidant, antidiabetic, and antiinflammatory properties of hydroalcohol extract of bark of H. zeylanicum (HAHZ). It also describes isolation and structure determination of lucidenic acid A, which is the first report in this plant. In order to explain the role of antioxidant principles, DPPH, nitric oxide, hydroxyl, superoxide and metal chelating assays were performed. Antidiabetic and anti-inflammatory activities were investigated by quantifying α-amylase, α-glucosidase and protein denaturation inhibitory activities of HAHZ. Biochemical estimations were performed. The chemical structure of the triterpenoid was elucidated using 1H, 13C NMR and high resolution-MS. IC50 of DPPH, nitric oxide, hydroxyl, superoxide and metal chelating activities were of 36.23 ± 0.27, 40.11 ± 0.32, 35.23 ± 0.57, 43.34 ± 0.22 and 11.54 ± 0.08 µg/mL, respectively. IC50 of α-amylase and α-glucosidase activities were 29.12 ± 0.54, and 18.55 ± 0.15 µg/mL. Total phenolic and total flavonoid contents were recorded at 233.65 mg/g GAE and 172.7 mg/g QE. Regarding kinetic behaviour, HAHZ showed competitive inhibition on α-glucosidase and mixed competitive inhibition on α-amylase. Lucidenic acid A was confirmed by spectroscopic studies. Anti-inflammatory activity of lucidenic acid A was determined by using protein denaturation assay with IC50 13 µg/mL but HAHZ showed 30.34 ± 0.13 µg/mL. Phenols and flavonoids could be attributed to inhibition of intestinal carbohydrases for anti-diabetic activities whereas triterpenoids could be responsible for anti-inflammatory activity of H. zeylanicum.

Chemistry of withaferin-A: chemo, regio, and stereoselective synthesis of novel spiro-pyrrolizidino-oxindole adducts of withaferin-A via one-pot three-component [3+2] azomethine ylide cycloaddition and their cytotoxicity evaluation.

Withaferin-A (WA) has attracted the attention of chemists as well as biologists due to its interesting structure and various bio-activities. In light of the promising biological importance of WA as well as pyrrolidine-2-spiro-3'-oxindole ring system, we became interested in the synthesis of a combined motif involving both the ring systems via the 1,3-dipolar cycloaddition of WA at Δ(2)-bond of the α,ß-unsaturated carbonyl system. We now report a facile, atom-economic synthesis of novel spiro-pyrrolizidino-oxindole adducts of withaferin-A (10 compounds) via the intermolecular cycloaddition of azomethine ylides generated in situ from proline and isatins/acenaphthoquinone. The reaction is highly chemo, regio, and stereoselective affording the cis-fused products with ß-orienting hydrogen. The structures were determined by 1D/2D NMR spectroscopic data analysis and unequivocally confirmed by X-ray crystallographic analysis in some cases. Bioevaluation of the compounds against six cancer lines (e.g., CHO, HepG2, HeLa, HEK 293, MDCK-II, and Caco-2) identified 4 promising potential anticancer compounds.