Anti-aging potential of some freshwater microalgae extracts
| dc.contributor.author | Sithole, Siphesihle Zamajobe. | |
| dc.date.accessioned | 2024-07-15T13:38:49Z | |
| dc.date.available | 2024-07-15T13:38:49Z | |
| dc.date.issued | 2023 | |
| dc.description | A Thesis submitted to the Faculty of Science, Agriculture and Engineering in fulfilment of the requirements for the Degree of Master of Science in the Department of Biochemistry and Microbiology at the University of Zululand, South Africa [2023]. | |
| dc.description.abstract | The aging of the skin is a progressive, multi- faceted phenomenon that alters skin tissue and is impacted by both intrinsic and external causes. Age and genetics contribute to intrinsic aging, whereas ultraviolet radiation (UVR) contributes to extrinsic aging. Intrinsic aging is a predetermined process that produces fine wrinkles, whereas long-term UVR exposure (classified as photo-aging) causes patchy hyperpigmentation, dilated blood vessels, epidermal hyper proliferation, and sunburn. Existing skincare products for anti-aging are known to include hazardous substances associated with an elevated skin cancer risk. As a result, there is a need to look for natural alternative cosmetic items. Thus, this study aimed to assess the anti- aging potential of freshwater microalgal extracts. Freshwater samples collected from the University of Zululand environment were enriched with BG-11 and cultured under UV illumination. Out of the ten (10) pure colonies isolated from the culture and characterised through 16s RNA, Cylindrospermum alatosporum (NR125682.1) and Loriellopsis cavernicola (NR117881.1) were cultivated for biomass. Dried biomass was sequentially extracted with solvents with varying polarities namely hexane, dichloromethane (DCM) and ethanol. The phytochemical screening of the extract was conducted using GC-MS and FTIR. The antioxidant activities of the microalgal extracts were estimated by various in vitro assays including the scavenging of 1.1-Diphenyl-2-picryl hydrazil (DPPH), 2.2- Azinobis 3-ethylbenzothiazoline-6-sulfonate (ABTS), hydroxyl (·OH) radicals and metal ion chelating, In vitro experiments were conducted to explore the inhibition of aging enzymes, namely collagenase, elastase, hyaluronidase, and tyrosinase. UVB and UVA photoprotective activity of the microalgal extracts was also investigated. Antibacterial susceptibility testing was conducted on commensals, Propionibacterium acnes and Staphylococcus aureus. The results obtained indicate that the extracts contained phenols and sulfhydryl groupcontaining compounds that could be responsible for certain biological activities of importance to this study. The extracts were average scavengers of synthetic radicals (IC50 values in the range from 6.5 – 48.6 μg/ml) but were potent metal ion chelators (44.3- 75.7 μg/ml). All extracts inhibited (in vitro) tyrosinase (≈ 47.87%), hyaluronidase (≈ 89.51%), and collagenase (≈ 76.67%) activities, but were poor inhibitors of elastase (≈16.43%). UVA and UVB photoprotective activity were exhibited by the extracts with L cavernicola exhibiting better UVB photoprotective activity (SPF 14.67 – 78.96). besides, this is observed for antimicrobial activity against strains of Staphylococcus aureus (ATCC 25923 and APO25177.1) and Propionibacterium acnes Kwik-stikTM. In conclusion, C alatosporum (NR125682.1) and L cavernicola (NR117881.1) possess the potential to be exploited as anti-aging agents. | |
| dc.identifier.uri | https://uzspace.unizulu.ac.za/handle/10530/2568 | |
| dc.language.iso | en | |
| dc.publisher | University of Zululand | |
| dc.title | Anti-aging potential of some freshwater microalgae extracts | |
| dc.title.alternative | Freshwater microalgae extracts | |
| dc.type | Thesis |