Phytotoxicity, cytotoxicity and chemical composition of Spondias mombin Linn. Stem bark

Background Spondias mombin Linn. is a tropical climate plant with wide applications in ethnomedicinal practice. This study evaluates the phytotoxicity, cytotoxicity and chemical composition of the plant’s stem bark. Methods Dried stem bark sample of Spondias mombin Linn. was subjected to exhaustive extraction and partitioned into sub-fractions (hexane-ethylacetate, ethylacetate, ethylacetate-methanol and methanol) by graded polarity technique. The phytotoxicity and cytotoxicity indices of the crude hydro-ethanol extract and fractions were evaluated using Lemna minor and brine shrimp lethality assays, respectively, while chemical composition of the oily hexane:ethylacetate fraction was determined by gas chromatography-mass spectroscopy (GC-MS) technique. Results Phytotoxicity was dose-dependent which ranged from low (crude plant extract), moderate (hexane-ethylacetate and methanol fractions), high (ethylaacetate-methanol fraction) to significant toxicity (ethylacetate fraction) at the highest dose. However, for brine shrimp lethality assay only hexane-ethylacetate (LD50: 284.02 μg/mL) and ethylacetate (LD50: 210.24 μg/mL) fractions were cytotoxic at the highest dose. The GC-MS profile of the oily hexane:ethylacetate fraction identified sixty-eight compounds comprising hydrocarbons, fatty acids, alcohols, steroids, nitrogen and fluoride-containing compounds, terpenes and esters. Conclusion This study concludes that fractions of Spondias mombin Lin. could be potentially toxic. While its phytotoxic potential can be useful in the agrochemical industry for the production of natural herbicides, its cytotoxic property can be cautiously harnessed for ethnomedicinal purposes.

Antibacterial Activity of Rosmarinus officinalis against Multidrug-Resistant Clinical Isolates and Meat-Borne Pathogens

Background. In developing countries, the prevalence of bacterial infections is quite rampant due to several factors such as the HIV/AIDS pandemic, lack of hygiene, overcrowding, and resistance to conventional antimicrobials. Hence the use of plant-based antimicrobial agents could provide a low-cost alternative therapy. Rosmarinus officinalis is reputed as a medicinal plant in Ethiopia; however, its antibacterial activity against many of the clinical isolates remains overlooked. Methods. Tender foliage of R. officinalis was collected and extracted in ethanol (EtOH) and evaluated for their antimicrobial activity against ten multidrug-resistant (MDR) clinical isolates, human type culture pathogens, and meat-borne bacterial isolates by employing agar well diffusion assay. Results. EtOH extract of R. officinalis efficiently subdued the growth of all tested MDR clinical isolates in varying degrees. Salmonella sp. and Staphylococcus aureus were found to be the most sensitive clinical isolates. Likewise, it efficiently repressed the growth of meat-borne pathogens, particularly, S. aureus and Salmonella sp. showing its potentiality to be used as a natural antibacterial agent in the meat processing industry. The mechanism of antibiosis of plant extract against meat-borne pathogens is inferred to be bactericidal. Chemical constituents of the crude plant extract were analysed by Gas Chromatography-Mass Spectroscopy (GC-MS), Fourier Transform Infrared (FT-IR), and UV-visible spectroscopy showing genkwanin (26%), camphor (13%), endo-borneol (13%), alpha-terpineol (12%), and hydroxyhydrocaffeic acid (13%) as the major compounds. Conclusion. Overall results of the present study conclude that R. officinalis could be an excellent source of antimicrobial agents for the management of drug-resistant bacteria as well as meat-borne pathogens.

Development and Optimization of Solanum Lycocarpum Polyphenol Oxidase-Based Biosensor and Application towards Paracetamol Detection

Purpose: The development biosensing technologies capable of delivering fast and reliable analysis is a growing trend in drug quality control. Considering the emerging use of plant-based polyphenol oxidases (PPO) as biological component of electrochemical biosensors, this work reports the first Solanum lycocarpum PPO biosensor and its use in the pharmaceutical analysis of paracetamol in tablet formulations. Methods: The biosensor was optimized regarding fruit maturation (immature and mature-ripe), vegetal extract volume to be used in biosensor construction as well as optimal pH of electrochemical cell fluid. Results: Results evidenced that the extract which rendered the biosensor with best analytical performance was from immature fruits, and the biosensor produced using 100 µL of crude plant extract promoted better faradaic signal gathering. Moreover, when neutral pH media was used in the electrochemical cell, the biosensor showcased best faradaic signal output from the used redox probe (catechol), suggesting thence that the method presents high sensibility for phenolic compounds detection. Furthermore, the biosensor was able to quantify paracetamol in a linear range from 50 to 300 μM, showcasing LoD and LoQ of 3 μM and 10 μM, respectively. Conclusion: after careful evaluation, this biosensor might be a low-cost alternative for conventional pharmaceutical quality control methods.

NMR-Based Chemical Profiling, Isolation and Evaluation of the Cytotoxic Potential of the Diterpenoid Siderol from Cultivated Sideritis euboea Heldr.

Diterpenes are characteristic compounds from the genus Sideritis L., possessing an array of biological activities. Siderol is the main constituent of the ent-kaurene diterpenes in Sideritis species. In order to isolate the specific compound and evaluate for the first time its cytotoxic activity, we explored the dichloromethane extract of cultivated Sideritis euboea Heldr. To track the specific natural bioactive agent, we applied NMR spectroscopy to the crude plant extract, since NMR can serve as a powerful and rapid tool both to navigate the targeted isolation process of bioactive constituents, and to also reveal the identity of bioactive components. Along these lines, from the rapid 1D 1H NMR spectrum of the total crude plant extract, we were able to determine the characteristic proton NMR signals of siderol. Furthermore, with the same NMR spectrum, we were able to categorize several secondary metabolites into chemical groups as a control of the isolation process. Therefore, this non-polar extract was explored, for the first time, revealing eleven compounds—one fatty acid ester; 2-(p-hydroxyphenyl)ethylstearate (1), three phytosterols; β-sitosterol (2), stigmasterol (3), and campesterol (4); one triterpenoid; ursolic acid (5), four diterpenoids; siderol (6), eubol (7), eubotriol (8), 7-epicandicandiol (9) and two flavonoids; xanthomicrol (10) and penduletin (11). The main isolated constituent was siderol. The antiproliferative potential of siderol was evaluated, using the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay, on three human cancer cell lines DLD1, HeLa, and A549, where the IC50 values were estimated at 26.4 ± 3.7, 44.7 ± 7.2, and 46.0 ± 4.9 μΜ, respectively. The most potent activity was recorded in the human colon cancer cell line DLD1, where siderol exhibited the lowest IC50. Our study unveiled the beneficial potential of siderol as a remarkable cytotoxic agent and the significant contribution of NMR spectroscopy towards the isolation and identification of this potent anticancer agent.

Validation of a Preformulated, Field Deployable, Recombinase Polymerase Amplification Assay for Phytophthora Species

Recombinase polymerase amplification (RPA) assays are valuable molecular diagnostic tools that can detect and identify plant pathogens in the field without time-consuming DNA extractions. Historically, RPA assay reagents were commercially available as a lyophilized pellet in microfuge strip tubes, but have become available in liquid form more recently—both require the addition of primers and probes prior to use, which can be challenging to handle in a field setting. Lyophilization of primers and probes, along with RPA reagents, contained within a single tube limits the risk of contamination, eliminates the need for refrigeration, as the lyophilized reagents are stable at ambient temperatures, and simplifies field use of the assays. This study investigates the potential effect of preformulation on assay performance using a previously validated Phytophthora genus-specific RPA assay, lyophilized with primers and probes included with the RPA reagents. The preformulated lyophilized Phytophthora RPA assay was compared with a quantitative polymerase chain reaction (qPCR) assay and commercially available RPA kits using three qPCR platforms (BioRad CFX96, QuantStudio 6 and Applied Biosystems ViiA7) and one isothermal platform (Axxin T16-ISO RPA), with experiments run in four separate labs. The assay was tested for sensitivity (ranging from 500 to 0.33 pg of DNA) and specificity using purified oomycete DNA, as well as crude extracts of Phytophthora-infected and non-infected plants. The limit of detection (LOD) using purified DNA was 33 pg in the CFX96 and ViiA7 qPCR platforms using the preformulated kits, while the Axxin T16-ISO RPA chamber and the QuantStudio 6 platform could detect down to 3.3 pg with or without added plant extract. The LOD using a crude plant extract for the BioRad CFX96 was 330 pg, whereas the LOD for the ViiA7 system was 33 pg. These trials demonstrate the consistency and uniformity of pathogen detection with preformulated RPA kits for Phytophthora detection when conducted by different labs using different instruments for measuring results.

Isolation, Characterization & Phytochemical Screening, Analytical Method Development and Validation for the Determination of Catechins in B.ciliata by RP HPLC Method

Ayurveda, an ancient system of medicines detailing a number of medicinal plants and their activities in human or animals. The present research work was aimed to develop an analytical procedure for the determination of catechins in the selected plant - B.Ciliata. It is famously known as stone flower/ stone breaker having various biological activities like anti urolithiatic, antiviral, antidiabetic antitumor and cardio protective activity. The methanolic extract of the plant is isolated and a method is developed by using RP HPLC for the determination of catechins in the crude plant extract using a C18 column (200*4.6mm, 5μ) and detected at 241 nm. The method is validated for its system suitability, Linearity, Accuracy, Precision, Robustness and sensitivity as per the ICH guidelines Q2(R1) to meet the analytical procedure in academic and industrial usage

Evaluation of Antimalarial Properties of Ficus platyphylla Del Leaf Extract in Mice

Aim: This study was aim at investigating the effect of crude petroleum ether leaf extract of Ficus platyphylla Del on Plasmodium berghei infected mice. Place and Duration of Study: This research was carried out at the department of biochemistry, Federal university of technology minna, Niger state Nigeria in 2014. Methodology: The crude plant extract of F. platyphylla was administered 72 hours at different doses post and pre infection for both the curative and prophylactic study respectively against residual infection. Mice were divided into 5 groups of 5 mice each, 3 of the groups where administered crude plants extract of F. platyphaylla at different doses (200, 400 and 600 mg/kg body weight) while the other two serve as negative and positive control group and were administered 0.5 ml and 50 mg/kg body weight respectively. Results: The extract at all doses produced significant (P<0.05) dose dependent chemo-suppressive activity with % inhibition of 38%, 61%, 74% and 81.8% for curative studies and 36.0%, 38.5%, 49.5% and 63.4% for prophylactic studies against the parasites at doses of 200 mg/kgbw, 400 mg/kgbw, 600 mg/kgbw of the extract and 50 mg/kgbw of Artesunate. All doses of the extract increased the survival time of the infected mice compared to the negative control group that was administered 0.5 ml normal saline. The variation in the values of Packed Cell Volume (PCV) for treated group before and after extract administration was not significant at (P<0.05). The phytochemical screening of the plant extract showed the presence of tannin, saponin, flavonoids, terpenoids, steroids, anthroquinone and phenol. Conclusion: The result of this study shows that F. Platyphylla leaf extract exhibited some antiplasmodial activity that could be exploited for safe, effective and affordable antimalaria regimen.