In this study, procyanidins fractions of dimers and trimers (F1-F2) from the Leucosidea sericea total extract (LSTE) were investigated for their chemical constituents. The total extract and the procyanidins were employed in the synthesis of gold nanoparticles (Au NPs) and fully characterized. Au NPs of 6, 24 and 21 nm were obtained using LSTE, F1 and F2 respectively. Zeta potential and in vitro stability studies confirmed the stability of the particles. The enzymatic activity of LSTE, F1, F2 and their corresponding Au NPs showed strong inhibitory alpha-amylase activity where F1 Au NPs demonstrated the highest with IC 50 of 1.88 µg/mL. On the other hand, F2 Au NPs displayed the strongest alpha-glucosidase activity at 4.5 µg/mL. F2 and F2 Au NPs also demonstrated the highest antioxidant activity, 1834.0 ± 4.7 µM AAE/g and 1521.9 ± 3.0 µM TE/g respectively. The study revealed not only the ability of procyanidins dimers (F1 and F2) in forming biostable and bioactive Au NPs but also, a significant enhancement of the natural products activities, which could improve the smart delivery in future biomedical applications.Biomolecules 2020, 10, 452 2 of 24 applying nanoparticles through the green route is their biocompatibility [5]. Many green synthesized nanoparticles have demonstrated interesting biological activities [5,10] including antimicrobial and antidiabetic properties.Diabetes mellitus has undoubtedly become a serious health challenge. More worrisome is type II diabetes mellitus (T2DM), which accounts for 90% of diabetes mellitus. It occurs as a result of the inefficient processing of insulin [11]. As of 2017, the population of adults between the ages of 20 and 79 that suffered from diabetes was 425 million [12]. This is equivalent to 9.9% of the world's population [12]. By estimation, this disease would have drastically increased by 48% in 28 years if not properly managed [13]. Although drugs like miglitol, vigliobose as well as acarbose are available in the market, they are costly and their continuous use is associated with side effects like diarrhea, dropsy, heart failure, damage to the liver, weight gain, abdominal pain, hyperglycemia, and flatulence, necessitating the need for more potent and newer remedies [14][15][16].It is well established that bioactive compounds in various plants possess significant effects in delaying and management of T2DM [17]. Extracts from different plants have been reported as alpha-glucosidase and alpha-amylase inhibitors [18][19][20][21][22][23][24][25][26][27]. Additionally, biologically synthesized Au NPs using plant extracts showed interesting antidiabetic activity. The extracts of Chamalcostus cuspidatus [28], Gymnema sylvestre [29], Cassia fistula stem bark [30], Hericium erinaceus [31], Turbinaria conoides [32], Sambucus nigra [33] and Sargassum swartzi [34] displayed antidiabetic activities in various investigations. Silver/gold NPs of Ocimum basilicum [35] and cinnamon extract [36] also lowers glucose levels. The use of single molecules as reducing/stabilizing agents for ...

The re-investigation of a methanolic extract of Salvia africana-lutea collected from the Cape Floristic Region, South Africa (SA), afforded four new abietane diterpenes, namely 19-acetoxy-12-methoxycarnosic acid (1), 3β-acetoxy-7α-methoxyrosmanol (2), 19-acetoxy-7α-methoxyrosmanol (3), 19-acetoxy-12-methoxy carnosol (4), and two known named clinopodiolides A (5), and B (6), in addition to four known triterpenes, oleanolic, and ursolic acids (7, 8), 11,12-dehydroursolic acid lactone (9) and β-amyrin (10). The chemical structural elucidation of the isolated compounds was determined on the basis of one and two dimensional nuclear magnetic resonance (1D and 2D NMR), high-resolution mass spectrometry (HRMS), ultra violet (UV), fourier transform infrared (IR), in comparison with literature data. The in vitro bio-evaluation against alpha-glucosidase showed strong inhibitory activities of 8, 10, and 7, with the half inhibitory concentration (IC50) values of 11.3 ± 1.0, 17.1 ± 1.0 and 22.9 ± 2.0 µg/mL, respectively, while 7 demonstrated the strongest in vitro alpha-amylase inhibitory activity among the tested compounds with IC50 of 12.5 ± 0.7 µg/mL. Additionally, some of the compounds showed significant antioxidant capacities. In conclusion, the methanolic extract of S. africana-lutea is a rich source of terpenoids, especially abietane diterpenes, with strong antioxidant and anti-diabetic activities that can be helpful to modulate the redox status of the body and could therefore be an excellent candidate for the prevention of the development of diabetes, a disease where oxidase stress plays an important role.

Animal waste materials are rarely used in the synthesis of nanoparticles compared to microorganisms and plant materials. The use of animal fur (goat) in synthesis could assist in turning waste to wealth. Thus, potentials of animal fur in the synthesis of silver nanoparticles (AF-AgNPs), its biological activities and safety through cytogenotoxicity were investigated. Animal fur (1 g) was hydrolyzed with 100 ml of 0.1 M NaOH at 90 °C for 1 h, cooled and centrifuged at 4000 rpm for 30 min. The extract (1 ml) was added to 1 mM AgNO3 (40 ml) to reduce Ag+ to its nanoparticles. The AF-AgNPs was characterized using UV–vis spectroscopy, Fourier-transform-infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and Energy Dispersive X-ray (EDX) analysis. Larvicidal, antioxidant, anticoagulant and thrombolytic potentials of AF-AgNPs were studied. Onion bulbs (20) were exposed to 0.01, 0.10, 1.0, 10.0 and 100.0 μg/ml of AF-AgNPs solution for its cytogenotoxicity study with AgNO3 solution and distilled water as controls. Microscopic (24, 48 and 72 h) assessment of the onion cells and macroscopic (72 h) evaluation of the roots were also studied. The AF-AgNPs solution was brownish with surface plasmon resonance at 419 nm. Evaluation of FTIR spectra showed that protein molecules were used as capping and stabilization agents. The AF-AgNPs had size range of 11.67-31.47 nm, caused 60-100% mortality of exposed Anopheles mosquito larvae in 12 h, and scavenged DPPH (40-59%) and hydrogen peroxide (75-94%). The nanoparticles also exhibited anticoagulant and thrombolytic potentials on human blood with 25% lysis compared to 13% observed for only extract. Various chromosomal aberrations and growth inhibition were induced by AF-AgNPs especially at 72 h of 100 μg/ml. Extract from animal fur was explored in biogenic synthesis of nanoparticles and found to have high potentials as antioxidant, anticoagulant, thrombolytic agents. Inhibition of cell growth observed especially at highest concentration can be explored in anticancer drugs though with caution due to AF-AgNPs potential to induce chromosomal aberrations.

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Background The plant Holarrhena floribunda ( H. floribunda ; G. Don) is indigenous to sub-Saharan Africa and is traditionally used to treat several ailments. The present study was carried out to isolate and characterize bioactive compounds with anti-proliferative activity present in H. floribunda extracts. Methods Compounds were isolated from H. floribunda using the bioassay-guided fractionation technique of repeated column chromatography and the step-wise application of the MTT reduction assay to assess antiproliferative bioactivity. The structures of the compounds were identified mainly using NMR. The effects of the isolated compounds on the viability, cell cycle and proliferation of human cancer cell lines (MCF-7, HeLa and HT-29) as well as the non-cancerous human fibroblast cell line (KMST-6) were investigated. Results Bioassay-guided fractionation yielded two steroidal alkaloids: holamine ( 1) and funtumine ( 2 ). The MTT reduction assay shows that both compounds exhibited selective dose-dependent cytotoxicity against the cancer cell lines studied. The isolated compounds induced cell cycle arrest at the G 0 /G 1 and G 2 /M phases in the cancer cell lines with significant reduction in DNA synthesis. The results obtained show that the cancer cells (MCF-7, HeLa and HT-29) used in this study were more sensitive to the isolated compounds compared to the noncancerous fibroblast cells (KMST-6). Conclusion The ability of the isolated compounds to cause cell cycle arrest and reduce DNA synthesis raises hopes for their possible development and use as potent anticancer drugs. However, more mechanistic studies need to be done for complete validation of the efficacy of the two compounds.

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Aqueous extract of Opuntia ficus-indica (OF) was employed to reduce salt solutions of silver nitrate, gold chloride and silver nitrate/gold chloride to OFAgNPs, OFAuNPs, and OFAg-AuNPs respectively. Characterization of the particles was carried out using different standard methods, and their antimicrobial and antioxidant activities were also evaluated. The UV-vis spectroscopy showed silver, gold and silver-gold alloys nanoparticles with surface plasmon resonance at 462, 545 and 539 nm, respectively. The significant FTIR peaks: OFAgNPs (3300 and 1635 cm−1), OFAuNPs (3288 and 1635 cm−1) and OFAg-AuNPs (3307 and 1637 cm−1) for synthesized nanoparticles pointed to protein as both capping and stabilizing agent. Generally, particles were spherical with size range of 27-38 nm, 11-28 nm and 15-54 nm for silver, gold and silver-gold alloys nanoparticles respectively. OFAgNPs gave highest antagonistic effects against tested bacteria (35-82%), followed by OFAg-AuNPs (12-75%) and AuNPs (11-48%). The fungal inhibition of 44-70% for OFAgNPs, 42-79% for OFAuNPs and 52-92% for OFAg-AuNPs were obtained. DPPH scavenging activities were obtained as follows: OFAgNPs (52.25–57.50%), OFAuNPs (37.07-59.07%) and OFAg-AuNPs (37.07-63.00%) at tested concentrations of 20–100 µg/ml, which were dose-dependent in comparison with standard BHA (42.57–91.27%) and ascorbic acid (52.13–84.20%). The bleaching inhibition assay of ABTS showed activities of 41.33–61.83% (OFAgNPs), 27.37-50.60% (OFAuNPs) and 32.83-44.33% (OFAg-AuNPs). The synthesized nanoparticles demonstrated an excellent antioxidant and antimicrobial activity. The current study, to the best of our knowledge, is the first time to use Opuntia ficus-indica to synthesize silver, gold and silver-gold alloys nanoparticles.

Natural plant products with potent growth inhibition and apoptosis induction properties are extensively being investigated for their cancer chemopreventive potential. Holarrhena floribunda (HF) is used in a wide range of traditional medicine practices. The present study investigated the antiproliferative and apoptosis induction potential of methanolic leaf extracts of HF against breast (MCF-7), colorectal (HT-29), and cervical (HeLa) cancer cells relative to normal KMST-6 fibroblasts. The MTT assay in conjunction with the trypan blue dye exclusion and clonogenic assays were used to determine the effects of the extracts on the cells. Caspase activities were assayed with Caspase-Glo 3/7 and Caspase-9 kits. Apoptosis induction was monitored by flow cytometry using the APOPercentage and Annexin V-FITC kits. Reactive oxygen species (ROS) was measured using the fluorogenic molecular probe 5-(and-6)-chloromethyl-2′,7′-dichlorofluorescein diacetate acetyl ester and cell cycle arrest was detected with propidium iodide. Dose-response analyses of the extract showed greater sensitivity in cancer cell lines than in fibroblast controls. Induction of apoptosis, ROS, and cell cycle arrest were time- and dose-dependent for the cancer cell lines studied. These findings provide a basis for further studies on the isolation, characterization, and mechanistic evaluation of the bioactive compounds responsible for the antiproliferative activity of the plant extract.