Percorrer por autor "Oliveira, Sonia M. R."
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- Comparative efficacy of Knema retusa extract delivery via PEG-b-PCL, niosome, and their combination against Acanthamoeba triangularis genotype T4: characterization, inhibition, anti-adhesion, and cytotoxic activityPublication . Chimplee, Siriphorn; Mitsuwan, Watcharapong; Zulkifli, Masyitah; Eawsakul, Komgrit; Ongtanasup, Tassanee; Sangkanu, Suthinee; Mahboob, Tooba; Oliveira, Sonia M. R.; Wiart, Christophe; Ramamoorthy, Siva; Pereira, Maria de Lourdes; Saravanabhavan, Shanmuga Sundar; Wilairatana, Polrat; Nissapatorn, VeeranootBackground. Acanthamoeba spp. is a waterborne, opportunistic protozoan that can cause amebic keratitis and granulomatous amebic encephalitis. Knema retusa is a native tree in Malaysia, and its extracts possess a broad range of biological activities. Niosomes are non-ionic surfactant-based vesicle formations and suggest a future targeted drug delivery system. Copolymer micelle (poly(ethylene glycol)-block-poly(?-caprolactone); PEG-b-PCL) is also a key constituent of niosome and supports high stability and drug efficacy. To establish Knema retusa extract (KRe) loading in diverse nanocarriers via niosome, PEG-b-PCL micelle, and their combination and to study the effect of all types of nanoparticles (NPs) on Acanthamoeba viability, adherent ability, elimination of adherence, and cytotoxicity. Methods. In this study, we characterized niosomes, PEG-b-PCL, and their combination loaded with KRe and tested the effect of these NPs on Acanthamoeba triangularis stages. KRe-loaded PEG-b-PCL, KRe-loaded niosome, and KRe-loaded PEG-b-PCL plus niosome were synthesized and characterized regarding particle size and charge, yield, encapsulation efficiency (EE), and drug loading content (DLC). The effect of these KRe-loaded NPs on trophozoite and cystic forms of A. triangularis was assessed through assays of minimal inhibitory concentration (MIC), using trypan blue exclusion to determine the viability. The effect of KRe-loaded NPs was also determined on A. triangularis trophozoite for 24–72 h. Additionally, the anti-adhesion activity of the KRe-loaded niosome on trophozoites was also performed on a 96-well plate. Cytotoxicity activity of KRe-loaded NPs was assessed on VERO and HaCaT cells using MTT assay. Results. KRe-loaded niosome demonstrated a higher yielded (87.93 ± 6.03%) at 286 nm UV-Vis detection and exhibited a larger size (199.3 ± 29.98 nm) and DLC (19.63 ± 1.84%) compared to KRe-loaded PEG-b-PCL (45.2 ± 10.07 nm and 2.15 ± 0.25%). The EE (%) of KRe-loaded niosome was 63.67 ± 4.04, which was significantly lower than that of the combination of PEG-b-PCL and niosome (79.67 ± 2.08). However, the particle charge of these NPs was similar (?28.2 ± 3.68 mV and ?28.5 ± 4.88, respectively). Additionally, KRe-loaded niosome and KRe-loaded PEG-b-PCL plus niosome exhibited a lower MIC at 24 h (0.25 mg/mL), inhibiting 90–100% of Acanthamoeba trophozoites which lasted 72 h. KRe-loaded niosome affected adherence by around 40–60% at 0.125–0.25 mg/mL and removed Acanthamoeba adhesion on the surface by about 90% at 0.5 mg/mL. Cell viability of VERO and HaCaT cells treated with 0.125 mg/mL of KRe-loaded niosome and KRe-loaded PEG-b-PCL plus niosome exceeded 80%. Conclusion. Indeed, niosome and niosome plus PEG-b-PCL were suitable nanocarrier-loaded KRe, and they had a greater nanoparticle property to test with high activities against A. triangularis on the reduction of adherence ability and demonstration of its low toxicity to VERO and HaCaT cells.
- Malaria: the importance of phytochemicals as sources of alternative medicinesPublication . Yu-Ping, Lau; Mendonca, Diana; Sheng-Khai, Lau; Phan-Sing, Yu Audrey; Chimplee, Siriphorn; Chuprom, Julalak; Boonhok, Rachasak; Mahboob, Tooba; Oliveira, Sonia M. R.; Rajagopal, Mogana; Pereira, Maria L.; Girol, Ana P.; Nissapatorn, VeeranootMalaria is a zoonotic disease caused by parasites from the Plasmodium genus. This parasite is transmitted to humans when bitten by female Anopheles mosquitos. Five species of Plasmodium are known to infect humans: P. malariae, P. ovale, P. knowlesi, P. falciparum, and P. vivax. Of these, P. falciparum is associated with the highest probability of severe infection. This parasite's lifecycle involves a sexual stage and an asexual stage. The first takes place in the mosquito and the second in humans. The diagnosis of malaria can be done by microscopy, rapid diagnostic tests or molecular methods, the latter being the most accurate. As for the treatment of this disease, artemisinin, chloroquine, primaquine, and tafenoquine are the principal components used in today's available treatments. Vaccination is also an important factor in the fight against malaria, and, presently, there are two available vaccines, RTS, S/AS01 and R21/Matrix-M. Several phytochemicals effective against malaria are also found in plant species used in traditional medicine. Examples are Azadirachta indica, Gossypium barbadense, Toddalia asiatica, Alstonia scholaris, Carica papaya, Andrographis paniculata, and Strychnos ligustrina. Furthermore, compounds from three wild nutmeg species have also been proven effective against P. falciparum. The medicinal properties of phytochemicals like alkaloids, phenolic compounds and terpenes have even allowed the investigation of drug-resistant malaria strains. When it comes to preventing malaria transmission, insecticide treated nests and indoor residual spraying have been proven to reduce transmission rates. For pregnant women, intermittent preventive treatment of malaria is also recommended. The need for the development of innovative treatment and prevention strategies is urgent due to the emergence of resistant strains. Hence, we present an overview of the available treatment and prevention strategies currently approved and employed while focusing on the potential of phytochemicals as targets for further studies that can lead to the development of new medicines.