Essential oil from Citrus depressa peel exhibits antimicrobial, antioxidant and cancer chemopreventive effects.

BACKGROUND: Many diseases may be caused by pathogens and oxidative stress resulting from carcinogens. Earlier studies have highlighted the antimicrobial and antioxidant effects of plant essential oils (EO). It is crucial to effectively utilize agricultural waste to achieve a sustainable agricultural economy and protect the environment. The present study aimed to evaluate the potential benefits of EO extracted from the discarded peels of Citrus depressa Hayata (CD) and Citrus microcarpa Bunge (CM), synonyms of Citrus deliciosa Ten and Citrus japonica Thunb, respectively. RESULTS: Gas chromatography-mass spectrometry analysis revealed that the main compounds in CD-EO were (R)-(+)-limonene (38.97%), γ-terpinene (24.39%) and linalool (6.22%), whereas, in CM-EO, the main compounds were (R)-(+)-limonene (48.00%), ß-pinene (13.60%) and γ-terpinene (12.07%). CD-EO exhibited inhibitory effects on the growth of common microorganisms, including Candida albicans, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. However, CM-EO showed only inhibitory effects on E. coli. Furthermore, CD-EO exhibited superior antioxidant potential, as demonstrated by its ability to eliminate 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonate free radicals. Furthermore, CD-EO at a concentration of 100 µg mL-1 significantly inhibited 12-O-tetradecanoylphorbol-13-acetate-induced cancer transformation in mouse epidermal JB6 P+ cells (P < 0.05), possibly by up-regulating protein expression of nuclear factor erythroid 2-related factor 2 and its downstream antioxidant enzymes, such as NAD(P)H:quinone oxidoreductase 1, heme oxygenase-1 and UGT1A. CONCLUSION: These findings suggest that CD-EO exhibits inhibitory effects on pathogenic microorganisms, possesses antioxidant properties and has cancer chemopreventive potential. © 2024 Society of Chemical Industry.

Chemoprevention of lotus leaf ethanolic extract through epigenetic activation of the NRF2-mediated pathway in murine skin JB6 P+ cell neoplastic transformation.

Background and aim: Skin is one barrier protecting from environmental risk factors that can make skin cells cancerous through DNA damage and oxidative stress. The nuclear factor erythroid 2-related factor 2 (NRF2) pathway is an anti-stress defense system that can be regulated by DNA methylation and histone modification. Dietary phytochemicals have chemopreventive properties that can inhibit or delay carcinogenesis. The lotus leaf is a traditional medicinal plant containing many polyphenols whose extracts show many biological activities, including antioxidant, anti-obesity, and anti-cancer. This study aim to investigate the effect of lotus leaves on neoplastic transformation in murine skin JB6 P+ cells. Experimental procedure: Lotus leaves were extracted with water (LL-WE) and ethanol (LL-EE), and the LL-WE residues were further extracted with ethanol (LL-WREE). JB6 P+ cells were treated with different extracts. The chemoprotective effect would be evaluated by heme oxygenase 1 (HO-1), NAD(P)H quinone oxidoreductase (NQO1), and UDP glucuronosyltransferase family 1 member A1 (UGT1A1) expression. Results and conclusion: LL-EE contained higher total phenolics and quercetin among extracts. In mouse skin JB6 P+ cells with 12-O-tetradecanoylphorbol-13-acetate treatment, LL-EE showed the greatest potential to suppress skin carcinogenesis. LL-EE activated the NRF2 pathway by upregulating antioxidant and detoxification enzymes upregulates antioxidant and detoxification enzymes, including HO-1, NQO1, and UGT1A1, and downregulates DNA methylation, which might be caused by lower DNA methyltransferase and histone deacetylase levels. Therefore, our results show that LL-EE reduces the neoplastic transformation of skin JB6 P+ cells, potentially by activating the NRF2 pathway and regulating epigenetic DNA methylation and histone acetylation.

Molecular mechanisms of garlic-derived allyl sulfides in the inhibition of skin cancer progression.

Skin cancer is a serious concern whose incidence is increasing at an alarming rate. Allyl sulfides-i.e., sulfur metabolites in garlic oil-have been demonstrated to have anticancer activity against several cancer types, although the mechanisms underlying these effects remain enigmatic. Our previous study showed that diallyl trisulfide (DATS) is more potent than mono- and disulfides against skin cancer. DATS inhibits cell growth of human melanoma A375 cells and basal cell carcinoma (BCC) cells by increasing the levels of intracellular reactive oxygen species (ROS) and DNA damage and by inducing G2/M arrest, endoplasmic reticulum (ER) stress, and mitochondria-mediated apoptosis, including the caspase-dependent and -independent pathways. This short review focuses on the molecular mechanisms of garlic-derived allyl sulfides on skin cancer prevention.