Cellular Antioxidant Activity and Peroxidase Inhibition of Infusions from Different Aerial Parts of <i>Cassia occidentalis</i>

Cassia occidentalis L. is widely used in the world in traditional medicine and especially in some African countries for the treatment of various diseases. The aim of this study was to report the microscopic features, the chromatographic fingerprints and the cellular antioxidant activity and the peroxidase inhibition of infusions from different parts of this plant. Microscopically, leaf can be characterized by cells of the spongy mesophyll and parenchyma numerous cluster crystals of calcium oxalate, paracytic stomata, isolated calcium oxalate cluster crystals, covering and glandular trichomes, scalariform vessels, polyedric starch granules, lignified fibers;flowers by abundant covering and glandular trichomes, spirally thickened vessels and associated parenchyma, abundant pollen grains. Seeds were characterized by pluricellular non-glandular trichomes, epidermis of the testa with underlying oil cells, parenchymatous layers of the testa, thicker-walled cells of the endosperm, pollen grain. Phytochemical analysis revealed the presence of phenolic acids, flavonoids, iridoids, tannins and terpenes. TLC fingerprints of different parts were different and characteristic. They showed the presence of glycosylated flavonoids and phenolic acids as main phytochemicals for flowers, leaves and seedpods. ABTS and DPPH assays showed that infusion extracts have the ability to scavenge free radicals connected with their IC50 values ranging from 21.43 ± 1.25 to 566.24 ± 176.7 mg·mL-1. All extracts showed a weaker capacity to scavenge DPPH radical. Aqueous extracts displayed high cellular antioxidant activity at the concentrations range of 1 - 20 μg·mL-1 using LO-12 on monocytes HL 60. Flower and leave extracts showed more efficient effects on extracellular ROS production. Phenolic compounds could be major contributors to antioxidant activity of infusions of Cassia parts. In MPO (Myeloperoxidase) direct technique, all infusion extracts exhibited a dose-dependent inhibitory effect on MPO activity in the range concentrations of 1 to 20 μg·mL-1 with the leaves and flowers the most active. Obtained results support the potential therapeutic interest of all aerial parts of Cassia and could justify their use in traditional medicine and local nutraceutical resources.

Application of Total Error Strategy in Validation of Affordable and Accessible UV-Visible Spectrophotometric Methods for Quality Control of Poor Medicines

In the framework of fighting against the poor quality medicines sold in developing countries using classical analytical methods easily accessible in those countries, four UV-Visible spectrophotometric methods for one antimalarial (quinine) and two antibiotics (amoxicillin and metronidazole) have been developed and validated according to the total error strategy using the accuracy profiles as a decision tool. The dosing range was 2 - 10 μg/mL (for quinine sulfate in tablet), 4 - 12 μg/mL (for quinine bichlorhydrate in oral drop-metronidazole benzaote in oral suspension) and 15 - 35 μg/mL (for amoxicillin trihydrate in capsule). The validated methods were then applied in determining the content of some analogous medicines sold in the Democratic Republic of Congo. Thus, the proposed UV-Visible spectrophotometric methods are simple and suitable to quantify quinine, amoxicillin and metronidazole in different pharmaceutical forms.

Substandard/Falsification Antibacterial Agents: A Systematic Review of Liquid Chromatographic and Spectrophotometric Methods for Their Detection

Falsified antibacterial agents continue to pose serious public health problems around the world. They are notably responsible for resistance emergence in the treatment of infectious diseases that can lead to death. The aim of this study was to summarize the literature on the methods developed and validated to detect poor quality antibacterial agents in order to assess the impact of these available methods in the fighting against Counterfeit/substandard medicines. Thus, studies published in the time from January 2000 to July 2017, were accessible via Google Scholar and Pubmed and allowed to analyze 41 papers. The majority (30) of developed and validated methods concerned LC methods, 9 regarded UV/V is spectrophotometry and two studies simultaneously developed both methods. Antibacterial agents belonging to beta-lactams group were the most concerned by the methods developed and validated (39%), followed by quinolones (18%) and macrolides (12%). Regarding active ingredients, amoxicillin (12%) was the most concerned by the development and validation methods. In spite of several available methods to detect substandard drugs, antibacterial agents for which methods were developed and validated were the most concerned by worldwide detected non-conformities. The fight against this scourge should not be only limited by their detection, but it also requires an effective involvement of different actors notably: health authorities, international organizations, pharmaceutical industries etc.

Investigation of the Quality of Antibiotics-Based Amoxicillin for Monitoring of Some Different Medicine Markets of Democratic Republic of Congo

In order to combat the counterfeiting of drugs, adapted HPLC analytical USP methods were applied to evaluate the quality of the amoxicillin (with or without potassium clavulanate) powder for suspension sold in some Congolese markets. The adaptation has been done by modifying the column dimensions and adjusting the flow rate. According to the intended deployment of these methods in Democratic Republic of Congo (DRC), 3 factors (analyst, day and equipment) were involved in the validation step while applying the classic total error measurement approach with an accuracy profile as decision tool. Since adequate results were obtained in terms of selectivity, precision, trueness and accuracy (tolerance limits of life expectancy: ?6.0% and 3.8%) for levels of interest concentration, the methods have been considered for routine use on several samples from different provenances and collected in 4 major DRC cities. Out of 278 samples collected, 200 were eligible for analysis from which 28% were found under standards with several figures: pH failure, out of specification for amoxicillin content, absence of potassium clavulanate, physical modifications of the powders. As evidenced by these findings, medicines of low-quality continue to be a major public health problem requiring appropriate action to effectively address this problem.

Microscopic Features, Antioxidant and Antibacterial Capacities of Plants of the Congolese Cosmetopoeia, Raw Materials of Cosmeceuticals

Cosmeceuticals are the fastest growing products in the cosmetics field and represent a hybrid between cosmetics and drugs. The main benefits reported for cosmeceutical herbal extracts, used in skin care, include antioxidant and antimicrobial activities and the tyrosinase inhibiting effect. The aim of this study was to evaluate the antioxidant and antibacterial activities of extracts from Chromolaena odorata, Mitracarpus villosus, Senna alata, Tetradenia riparia, Cannabis sativa and Pterocarpus soyauxii used traditionally in the management of skin and skin annexes pathologies;additionally to determine their microscopical characteristics and their chromatographic fingerprints. Microscopic analyses showed the specific botanical microscopic characters for each plant that constitute the database useful for the identification and authentication of these botanicals. To the best of our knowledge, our work is the first to describe the microscopic histological characters of studied plants except for Cannabis sativa. The results of the TLC chromatographic analysis revealed the richness in phenolic compounds, terpenes in all extracts and Pterocarpus soyauxii contained coumarins. All extracts displayed high ABTS and DPPH radical-scavenging activities connected with their IC50 values at the concentration range of 1 - 125 μg/mL with Cannabis sativa and Pterocarpus soyauxii as the most active. All plant extracts exhibited antibacterial activity on Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus to varying degrees. Cannabis sativa exhibited strong effect on Staphylococcus aureus and Escherichia coli. Chromolaena odorata and Tetradenia riparia showed a marked effect on Escherichia coli. Although certain crude extracts from studied botanicals have been shown to be inactive, fractionation studies are needed to determine the active fractions. Obtained biological activities could be related to phytochemicals present in the organic extracts like phenolic compounds and terpenoids. The antioxidant and antibacterial activities of the studied species may have potential therapeutic interest and could justify their use in traditional medicine and local cosmeceutical resources, but further studies are needed, especially in vivo studies, to demonstrate the benefit of these extracts on skin and skin appendages care.