First report on the synthesis and structural studies of trans-Phakellistatin 18: a rotamer of marine natural product phakellistatin 18.

Phakellistatin peptides from marine organisms are the sources of proline-rich cyclic peptides with reported significant antitumor activities. Phakellistatin 18 (1), reported from marine sponge Phakellia fusca, contains three proline-peptide linkages in cis form. We attempted the total synthesis of natural product 1 through solution-phase macrocyclization approach, as a result, the synthetic cyclic peptide 2 was obtained as a rotamer of natural product having all three proline residues in trans-conformation. Here, we describe the synthesis, structural, and cytotoxicity studies of trans-Phakellistatin 18 (2), and its analog [Ala1,3,6]-Phakellistatin 18 (3). Detailed NMR studies were carried out to characterize the synthesized peptides, and anti-cancer screening was performed by using MTT assay. The synthetic trans-Phakellistatin 18 (2) (IC50=67.5 ± 2.938 µM) showed comparable cytotoxicity against HepG2 cancer cell line with standard drug doxorubicin (IC50=63.88 ± 6.48 µM). Here, the first synthetic and structural studies on trans-Phakellistatin 18 (2), and its anticancer screening against HepG2 cell line was reported.

A new sesquiterpene, prosoterpene, from Prosopis africana (Guill. & Perr.) Taub.

A new sesquiterpene (Prosoterpene, 1) and eleven reported compounds (2-12) of several classes, such as flavonoids, alkaloids, phenolic acids, and long-chain alcohols, were isolated from the BuOH extract of Prosopis africana (Guill. & Perr.) Taub. Compounds 2-10 were reported for the first time from this plant. Isomers 11 and 12 were separated for the first time. Extensive spectroscopic techniques and literature comparisons were used to characterise their structures. Furthermore, compounds 3, 5-8, and 10-12 were performed for anti-glycation and cytotoxicity activities. Compound 3 (quercetin-3-O-α-L-rhamnoside) exhibited moderate anti-glycation activity. All tested compounds were non-cytotoxic against MCF-7 (breast cancer), NCI-H460 (lung cancer), Hela (cervical cancer), and BJ (normal human fibroblast) cell lines.

Piperine attenuates the cancerous activity response in Neuro-2a cell line.

Interactions of cancer cells with their microenvironment play a significant role in defining the severity of the disease. In search of novel compounds with anti-inflammatory and anticancerous capabilities, the effects of purified compound piperine were investigated in Neuro-2a cell line. The neuronal lineage of Neuro-2a cell line was confirmed by using antibody against ß-III tubulin protein. The cells were treated with different concentrations of piperine (µM: 10, 50 and 100) for 48 hrs at 37ºC. A dose of 100 µM was selected that induces a 50% inhibition in the cell growth calculated by MTT and morphometery assays. The result shows that in the presence of piperine neurite outgrowth was decreased in a dose dependent manner. The gene expression of TN-C, TNfnD and TnfnC were significantly reduced whereas the expression intensities of TnfnA1, TnfnA2, CSPGs and Laminin were significantly elevated when compared to their respective untreated controls. Similarly proinflammatory marker COX-2 expression was significantly inhibited in the presence of piperine when compared to untreated controls. This is the first time we have illustrated that irrespective of increased expressions of CSPGs, a significant reduction in Tenascin-C and its TNfnD and TNfnC domains are necessary to inhibit the tumor progression. Taken together, the capabilities of piperine to induce an apoptosis by decreasing the neurite outgrowth, proliferation rate and expression of TN-C and COX-2 in Neuro-2a cell line confirmed for its anticancerous and anti-inflammatory potential.

Neurite outgrowth properties of Calotropis procera: In search for a neuroprotectant.

In view of the well-documented medicinal properties of Calotropis procera (CP), the present study was designed to evaluate the neuroprotective effect of the extract. We have prepared a methanolic extract of Calotropis procera and screen varying concentration of CP (20, 30, 40, 50 and 70µg/ml) for the stimulatory potency on neurite outgrowth. The stimulatory effect of CP on neurite outgrowth was assessed in primary hippocampal neurons. Neurite lengths were measured using optika provison analysis software. Neuritogenesis was further analyzed by immunostaining by using specific neuronal marker ß III-tubulin. The data show that neurite outgrowth from hippocampal neurons were significantly enhanced in the presence of CP (40µg/ml). The most stimulatory neurite outgrowth effects were appeared after 48hrs incubation of neurons with CP (40µg/ml). These data confirm that CP extract could promote invitro hippocampal neurite outgrowth in a dose-dependent manner. Our results indicate that CP can be used as a healthy dietary supplement for the cognitive functions of the brain.

Neuroprotective capabilities of Vitex negundo in primary hippocampal neurons.

Vitex negundu (Vn) is a well-known aromatic shrub commonly used as a traditional folk medicine famous for its potential pharmacological and biological activities. Several chemical compounds are extracted and identified from the different parts of the Vn such as leaves, root, seeds and flowers. Number of researches reported the herb as antimicrobial, anti-androgenic, anti-osteoporotic, and anti-tumour, anti-cancer, anti-inflammatory, anti-oxidant, anti-hyperglycemic and hepatoprotective. The effects of Vn on neurite outgrowth have not been identified till now. Therefore present study was designed to investigate the neurite outgrowth effects of Vn extract in hippocampal neurons. Neurons from P0 mice were isolated and cultured in defined medium containing the different concentrations of Vn (20, 30, 40, 50, 100, 150 and 200 µg/ml) for 48 hrs. The presence of the neurites was confirmed by using ßIII-tubulin antibody which specifically labels only the neurites. Morphometric analysis was done by using Optika Pro-Vision software. The data show that Vn at 30 and 40 µg/ml significantly increased the mean average length of the longest neurite whereas at 150 and 200 µg/ml it significantly decreased the mean average length of the 10 longest neurite in hippocampal neurons. Nevertheless Vn did not show any significant effects on the sum of all the neurite lengths at any concentrations tested. Taken together the result shows that methanolic extract of Vn has potential to produce long neurites at 30 and 40 µg/ml and therefore can be act as a neuroprotective agent in the future drug development.