<p>Chitosan And N, N, N-Trimethyl Chitosan Nanoparticle Encapsulation Of <em>Ocimum Gratissimum</em> Essential Oil: Optimised Synthesis, In Vitro Release And Bioactivity</p>

Abstract

Background: The encapsulation of plant essential oils (EOs) with polymeric materials (e.g. chitosan (CS) and N, N, N-trimethyl chitosan (TMC)) and the further reduction of the polymers into their nano sizes are gaining research interest in nanotechnology due to potential applications in medical drug delivery systems as well as the food and pharmaceutical industry. The present study reports a novel approach for the synthesis of Ocimum gratissimum essential oil (OGEO)-loaded CS and TMC nanoparticles with distinct bioactive and physiochemical properties. Methods: The OGEO-loaded CS and TMC nanoparticles were characterised using various microscopic and spectroscopic techniques. The bioactive compounds in Ocimum gratissimum methanolic extract (OG-MeOH) and EOs was evinced with gas chromatography-mass spectrometry (GC-MS). Total phenolic content (TPC) of OGEO and OG-MeOH was determined using the Folin-Ciocalteu method. The in vitro drug release kinetic pattern was ascertained by membrane dialysis, while antioxidant activity was determined by the 2,2-diphenyl-1picrylhydrozyl (DPPH) free radical scavenging method. The disc diffusion method was used for antibacterial activity evaluation, while MTT and a trypan blue dye exclusion assay were used to assess cytotoxic activity on MDA-MB-231 breast cancer cells. Results: GC-MS analysis revealed components that have not been previously reported for Ocimum gratissimum. The maximum OGEO cumulative drug release percentage in vitro was observed at pH 3 for both OGEO-loaded chitosan nanoparticles (OGEO-CSNPs) and OGEOloaded N, N, N-trimethyl chitosan nanoparticles (OGEO-TMCNPs). The antioxidant activity of OGEO-CSNPs and OGEO-TMCNPs never reached a steady state after 75 h. OGEO-TMCNPs exhibited antibacterial activity at a lower concentration for both Gram-negative and Gram-positive food pathogens. In vitro cytotoxicity revealed the increased toxicity of OGEO-TMCNPs on MDA-MB-231 breast cancer cell lines. Conclusion: OGEO-loaded CS and TMC nanoparticles were synthesised using a novel material optimisation approach. The synthesised nanoparticles have shown a promising application in the pharmaceutical and food industries.

Effect of extraction temperature and solvent type on the bioactive potential of Ocimum gratissimum L. extracts

“…For the cancer cells treated with OGM-40, membrane blebs were also observed after 48 h of incubation. This is an indication of cell apoptosis, as suggested by Onyebuchi and Kavaz 7 . The high antiproliferative activity of OGM-40 compared to the rest of the extracts is likely a result of oxidative stress generation within the cell membrane.…”

“…Moreover, a study by Shahidi and Zhong 6 demonstrated the link between oxidative stress and the pathophysiology of several health conditions. Ocimum gratissimum L. often called clove basil or scent leaf, is indigenous to coastal, savannah, and tropical areas 7 , and is mostly found in tropical areas such as West Africa, Asia, Brazil, and India 8 . Ethnomedicinal applications have been reported for the plant due to its flowers and leaves being rich in polyphenols and other bioactive compounds 9 .…”

Essential Oils and Their Main Chemical Components: The Past 20 Years of Preclinical Studies in Melanoma

“…Table 6 shows studies in which the antioxidant effects of EOs and their components have been analyzed using cell-free assays or melanoma models. Artemisia argyi -DPPH, ABTS, metal-ion chelation [28] Atriplex undulata -Crocin bleaching inhibition, DPPH [29] Cinnamomum cassia Cinnamaldehyde B16 [32] Chrysanthemum boreale Makino -DPPH, ABTS [31] Cryptomeria japonica -B16 [220] Cuminum Cyminum -DPPH, superoxide anion radical-scavenging activity, β-carotene/linoleic acid [35] Curcuma aromatica -DPPH [36] Curcuma kwangsiensis -DPPH [37] Dalbergia pinnata -DPPH, ABTS [39] Eucalyptus camaldulensis -DPPH, ABTS, B16-F10 [41] Eugenia uniflora -DPPH, β-carotene/linoleic acid [43] Glechoma hederacea β-carotene/linoleic acid, B16 [44] Helichrysum microphyllum -DPPH, ABTS [45] Hypericum hircinum -DPPH, ABTS [47] Lavandula augustifolia -B16-F10 [49] Melaleuca quinquenervia 1,8-Cineole, α-pipene, α-terpineol B16 [53] Ocimum basilicum -DPPH, hypoxanthine/xanthine oxidase [58] Ocimum gratissimum -DPPH, hypoxanthine/xanthine oxidase [58,237] Ocimum micranthum -DPPH, hypoxanthine/xanthine oxidase [58] Ocimum tenuiflorum -DPPH, hypoxanthine/xanthine oxidase [58] Table 6. Cont.…”

Nanoencapsulation of Plant Volatile Organic Compounds to Improve Their Biological Activities

“…Mesoporous silica nanoparticle Antibacterial [7] Pepper VOCs Mesoporous silica nanoparticle Antibacterial [113] Coleus aromaticus VOCs Silver nanoparticle Antibacterial [168] Eugenia caryophyllata VOCs Chitosan nanoparticle Antifungal [143] Carvacrol Nanoemulsion Antifungal [169] Zataria multiflora VOCs Solid lipid nanoparticle Antifungal [146] Cymbopogon citratus VOCs Poly (D,L-lactide-co-glycolide) nanoparticles Antiviral [148] Artemisia arborescens VOCs Nanoliposome Antiviral [149] Santolina insularis VOCs Nanoliposome Antiviral [150] Curcuma longa & Cymbopogon citratus VOCs Chitosan-alginate nanocapsule Anticancer [151] Ocimum Gratissimum VOCs Chitosan nanoparticle Trimethyl chitosan nanoparticle Anticancer [152] Citral Bovine serum albumin nanoparticle Anticancer [154] Citrus bergamia VOCs Nanoliposome Anticancer [155] Ginger & frankincense VOCs Nanoemulsion Anticancer [157] Origanum glandulosum VOCs Sodium alginate nanocapsule, nanoemulsion Anticancer [158] Mentha spicata VOCs Nanoemulsion Anticancer [170] Citral Solid lipid nanoparticle Anticancer [171] Nigella sativa VOCs Gold nanoparticle Anticancer, antibacterial [117] fection of catfish with a very low concentration (5 µL/L) of volatiles is more environmentally safe and cost-effective [137]. The antibiofilm effects of free cinnamon oil and nanoliposomes carrying the oil were tested against MRSA by Cui et al The logarithmic value of a viable MRSA population in the biofilms treated with cinnamon oil was decreased by 1.49 times whereas those treated with cinnamon oil-loaded nanoliposomes led to the reduction of MRSA cells by 2.45 times.…”

“…Trimethyl Ch-NPs carrying Ocimum gratissimum VOCs, and free volatile compounds, were tested for impact on cell viability and antiproliferation of breast cancer (MDA-MB-231) cells. After 48 h incubation, the viability of MDA-MB-231 cells was reduced to approximately 40 % in response to treatment of 50 µg/mL of volatile-laden Ch-NPs, which exhibited more cytotox-icity against cancer cells than free volatiles, causing about 70 % cell viability at the same concentration [152]. It is thought that the Ch-NPs could penetrate the cancer cell membranes and cause DNA damage, leading to defects in the cellular genes [153].…”