The effects of selected samples on the bio-stimulatory capacity and anti-aging effects of red light on human skin cells
- Authors: Rudolph, Carlen
- Date: 2024-04
- Subjects: Cell culture -- Technique , Dermatologic agents , Collagen , Biochemistry -- Technique
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64347 , vital:73677
- Description: Photobiomodulation (PBM) has gained a remarkable interest in the cosmeceutical industry, with research demonstrating supporting evidence for its use as anti-aging and skin-rejuvenating strategies. It is defined as photons at a non-thermal irradiance or non-ionizing photonic energy that trigger photochemical changes within the cellular structure to alter certain biological activities. Lasers were the main focus during the developmental years of light-based treatments, but since the introduction of non-ablative, light-emitting diode (LED) devices, the focus has changed because of the reduced concerns associated with lasers, such as costs, ablation cutting, thermally coagulating tissue, no downtime needed after treatment, and no trained staff needed for operation. The precise biochemical mechanism for PBM is still to be elucidated; however, accepted theories suggest that it has an influence on the activity of cytochrome c oxidase, a complex located in the electron transport chain, or on the viscosity of the interfacial water layer (IWL) of the mitochondrial membrane. The interaction of those cellular components with the light then leads to the primary responses of increased ROS, ATP production, and intracellular calcium, which ultimately leads to the stimulation of secondary responses that are desired for skin rejuvenation and anti-aging, such as cell proliferation and collagen production. There is controversy surrounding photobiomodulation (PBM), mostly because of the incomplete understanding behind its biochemical mechanism and the number of parameters that require optimization; however, it still poses as a promising field for research into anti-aging properties, as seen in the literature. Besides the use of devices for skin rejuvenation and anti-aging strategies, it is not uncommon to see plant extracts and other natural products being used in current skin care products for the same reason? This is mostly because of their promising bioactivities, some of which include antioxidant, anti-inflammatory, anti-bacterial, collagen-stimulating, and cell-proliferating activities. The aim of this study was to investigate the bio-stimulatory capacity of red light on skin cells and to evaluate possible effects it could have in combination with samples that already show promising anti-aging properties in research. The samples that were selected for this study are: Aspalathus linearis (rooibos) unfermented extract, L-ascorbic acid 2-phosphate, mangrove bee honey, stingless bee honey, Sargassum oligocystum (brown seaweed) and Ulva fasciata (green seaweed).It was found that red light irradiation did indeed stimulate the primary responses of ROS, ATP production, and intracellular calcium levels in HaCaT keratinocytes, as proposed in the hypothesised theory. However, none of the proposed secondary responses to cell proliferation or collagen production were demonstrated. In fact, the opposite was observed for cell proliferation and collagen production, where red light irradiation seemed to be cytostatic towards Hs27 fibroblast cells and caused significant decreases in collagen production. Red light energy dosages of 10, 20 and 30 J/cm2, yielded different primary responses with 20 and 30 J/cm2 generally causing more significant stimulation than that of 10 J/cm2. It should also be noted that even if the desired secondary responses were not observed in this study, it does not mean that red light does not have the capacity to still stimulate them. It is clear that the responses are energy dosage-dependent, and it is suggested that lower energy dosages could possibly lead to cell proliferation and that longer incubation periods post-irradiation are required before measuring the endpoint of collagen production. For the combination of red light irradiation and selected test samples, it was demonstrated that the order of samples that yielded the best outcomes is: stingless bee honey > mangrove bee honey > U. fasciata > S. oligocystum > 2-PAA > green rooibos. Unexpected results were demonstrated for green rooibos in the presence and absence of red light, which included decreased ATP production and collagen biosynthesis. Further investigation is therefore needed to have a better understanding of these unanticipated results. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Rudolph, Carlen
- Date: 2024-04
- Subjects: Cell culture -- Technique , Dermatologic agents , Collagen , Biochemistry -- Technique
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64347 , vital:73677
- Description: Photobiomodulation (PBM) has gained a remarkable interest in the cosmeceutical industry, with research demonstrating supporting evidence for its use as anti-aging and skin-rejuvenating strategies. It is defined as photons at a non-thermal irradiance or non-ionizing photonic energy that trigger photochemical changes within the cellular structure to alter certain biological activities. Lasers were the main focus during the developmental years of light-based treatments, but since the introduction of non-ablative, light-emitting diode (LED) devices, the focus has changed because of the reduced concerns associated with lasers, such as costs, ablation cutting, thermally coagulating tissue, no downtime needed after treatment, and no trained staff needed for operation. The precise biochemical mechanism for PBM is still to be elucidated; however, accepted theories suggest that it has an influence on the activity of cytochrome c oxidase, a complex located in the electron transport chain, or on the viscosity of the interfacial water layer (IWL) of the mitochondrial membrane. The interaction of those cellular components with the light then leads to the primary responses of increased ROS, ATP production, and intracellular calcium, which ultimately leads to the stimulation of secondary responses that are desired for skin rejuvenation and anti-aging, such as cell proliferation and collagen production. There is controversy surrounding photobiomodulation (PBM), mostly because of the incomplete understanding behind its biochemical mechanism and the number of parameters that require optimization; however, it still poses as a promising field for research into anti-aging properties, as seen in the literature. Besides the use of devices for skin rejuvenation and anti-aging strategies, it is not uncommon to see plant extracts and other natural products being used in current skin care products for the same reason? This is mostly because of their promising bioactivities, some of which include antioxidant, anti-inflammatory, anti-bacterial, collagen-stimulating, and cell-proliferating activities. The aim of this study was to investigate the bio-stimulatory capacity of red light on skin cells and to evaluate possible effects it could have in combination with samples that already show promising anti-aging properties in research. The samples that were selected for this study are: Aspalathus linearis (rooibos) unfermented extract, L-ascorbic acid 2-phosphate, mangrove bee honey, stingless bee honey, Sargassum oligocystum (brown seaweed) and Ulva fasciata (green seaweed).It was found that red light irradiation did indeed stimulate the primary responses of ROS, ATP production, and intracellular calcium levels in HaCaT keratinocytes, as proposed in the hypothesised theory. However, none of the proposed secondary responses to cell proliferation or collagen production were demonstrated. In fact, the opposite was observed for cell proliferation and collagen production, where red light irradiation seemed to be cytostatic towards Hs27 fibroblast cells and caused significant decreases in collagen production. Red light energy dosages of 10, 20 and 30 J/cm2, yielded different primary responses with 20 and 30 J/cm2 generally causing more significant stimulation than that of 10 J/cm2. It should also be noted that even if the desired secondary responses were not observed in this study, it does not mean that red light does not have the capacity to still stimulate them. It is clear that the responses are energy dosage-dependent, and it is suggested that lower energy dosages could possibly lead to cell proliferation and that longer incubation periods post-irradiation are required before measuring the endpoint of collagen production. For the combination of red light irradiation and selected test samples, it was demonstrated that the order of samples that yielded the best outcomes is: stingless bee honey > mangrove bee honey > U. fasciata > S. oligocystum > 2-PAA > green rooibos. Unexpected results were demonstrated for green rooibos in the presence and absence of red light, which included decreased ATP production and collagen biosynthesis. Further investigation is therefore needed to have a better understanding of these unanticipated results. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-04
Aspects of the bioavailability of topical corticosteroid formulations
- Authors: Magnus, Ashley Denis
- Date: 2013-02-12
- Subjects: Adrenocortical hormones -- Therapeutic use , Dermatologic agents , Transdermal medication -- Evaluation , Dermatopharmacology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3843 , http://hdl.handle.net/10962/d1009516 , Adrenocortical hormones -- Therapeutic use , Dermatologic agents , Transdermal medication -- Evaluation , Dermatopharmacology
- Description: Two possible variables of the McKenzie/Stoughton blanching assay, namely amount applied to the test site and occlusion time have been investigated. Subsequently, two topical steroid preparations, Synalar cream (0,025% fluocinolone acetonide) and Betnovate cream (0,1% betamethasone 17-valer ate) were extemporaneously diluted with five and six placebo bases respectively. Taking cognizance of the two possible variables, these diluted preparations were assessed in vivo using a modified version of the McKenzie/Stoughton blanching assay for blanching activity over a 14 month period. It was found that the base E45, which is slightly alkali, had the greatest effect on both preparations. In the case of betamethasone 17-valerate this base c aused the conversion to the less active isomer, betamethasone 21-valerate whereas at the end of the 14 month test period it was found that the Synalar/E45 dilution contained no fluocinolone acetonide. Quantitative analysis of all the diluted preparations by high performance liquid chromatography using a reverse-phase system was performed. The data obtained f r om the systematic stUdies of the effects of varying concentrations and occlusion times were presented at the Eleventh National Congress of the South African Pharmacological Society. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Authors: Magnus, Ashley Denis
- Date: 2013-02-12
- Subjects: Adrenocortical hormones -- Therapeutic use , Dermatologic agents , Transdermal medication -- Evaluation , Dermatopharmacology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3843 , http://hdl.handle.net/10962/d1009516 , Adrenocortical hormones -- Therapeutic use , Dermatologic agents , Transdermal medication -- Evaluation , Dermatopharmacology
- Description: Two possible variables of the McKenzie/Stoughton blanching assay, namely amount applied to the test site and occlusion time have been investigated. Subsequently, two topical steroid preparations, Synalar cream (0,025% fluocinolone acetonide) and Betnovate cream (0,1% betamethasone 17-valer ate) were extemporaneously diluted with five and six placebo bases respectively. Taking cognizance of the two possible variables, these diluted preparations were assessed in vivo using a modified version of the McKenzie/Stoughton blanching assay for blanching activity over a 14 month period. It was found that the base E45, which is slightly alkali, had the greatest effect on both preparations. In the case of betamethasone 17-valerate this base c aused the conversion to the less active isomer, betamethasone 21-valerate whereas at the end of the 14 month test period it was found that the Synalar/E45 dilution contained no fluocinolone acetonide. Quantitative analysis of all the diluted preparations by high performance liquid chromatography using a reverse-phase system was performed. The data obtained f r om the systematic stUdies of the effects of varying concentrations and occlusion times were presented at the Eleventh National Congress of the South African Pharmacological Society. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
A study of the transdermal drug diffusion properties of rooperol tetra-acetate
- Authors: Pefile, Sibongile C.
- Date: 1998 , 2013-08-29
- Subjects: Transdermal medication , Skin absorption , Dermatologic agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3838 , http://hdl.handle.net/10962/d1007649 , Transdermal medication , Skin absorption , Dermatologic agents
- Description: The rapidly growing interest in the potential use of topical drug delivery formulations has resulted in increased use of the skin as a vital port for drug delivery. Extensive research has been conducted in designing vehicles capable of delivering a desired amount of drug to a specific site, to produce the desired pharmacological response. Rooperol tetra-acetate is a lipophilic, cytotoxic drug with the potential for use in the treatment of solar keratosis. For effective pharmacological action, delivery of the drug to the epidermal/dermal junction of the skin is required. A study of the topical penetration properties of rooperol tetra-acetate from different topical bases, each possessing different physico-chemical properties, was performed. The assessment involved a comparison of the diffusion properties under occlusive and non occlusive conditions when the drug was formulated into a gel, Cetomacrogol Cream B.P. (oil-inwater), Simple Ointment B.P. and an extemporaneously prepared water-in-oil topical cream. The in vitro experiments were conducted using polydimethylsiloxane and rat membrane mounted in a Franz diffusion cell. The topical permeation kinetics of rooperol tetra-acetate were determined by exploring the release characteristics of the active ingredient from the vehicles formulated and the permeability properties of the drug through the membranes employed. Further studies involved investigating the utilization of supersaturated systems intended to increase the thermodynamic activity of the drug when formulated into a propylene glycol/water vehicle (with and without polymer). To measure the release of rooperol tetra-acetate into the skin from a topical base it was necessary to, firstly, develop a suitable quantitative method for the analysis of the active drug in the aqueous receptor phase of in vitro diffusion cells. The second stage of product development was the design of an effective delivery system to facilitate the release of the diffusant from its base. A high performance liquid chromatographic method was utilized for the identification and quantification of the active drug. As validation is an important aspect in the development and subsequent utilization of an analytical procedure, the developed HPLC technique was validated by determining the precision, accuracy, range, limit of quantitation and sensitivity of the system. Lastly, the stability of rooperol tetra-acetate at elevated temperatures was assessed and a stability profile of the drug was generated for the three-month period of analysis. The results obtained following chromatographic analysis of the receptor phase sampled during the diffusion experiments indicate that the gel and oil-in-water formulations most effectively promoted the diffusion of rooperol tetra-acetate across polydimethylsiloxane membrane. The water-in-oil system exhibited lower flux rates and the ointment showed the least drug release. Occlusion of the topical vehicle increased the diffusitivity of the permeant from all formulations analysed. The permeation assessment results of the supersaturated systems showed enhanced diffusion of rooperol tetra-acetate across polydimethylsiloxane and rat membrane. The high thermodynamic activity existing in supersaturated systems most effectively increased the driving force for drug diffusion resulting in enhanced percutaneous penetration of rooperol tetra-acetate beyond the release and transport limitations of saturated solutions. These results provide the basis on which an effective topical drug delivery vehicle may be designed for this new drug entity.
- Full Text:
- Date Issued: 1998
- Authors: Pefile, Sibongile C.
- Date: 1998 , 2013-08-29
- Subjects: Transdermal medication , Skin absorption , Dermatologic agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3838 , http://hdl.handle.net/10962/d1007649 , Transdermal medication , Skin absorption , Dermatologic agents
- Description: The rapidly growing interest in the potential use of topical drug delivery formulations has resulted in increased use of the skin as a vital port for drug delivery. Extensive research has been conducted in designing vehicles capable of delivering a desired amount of drug to a specific site, to produce the desired pharmacological response. Rooperol tetra-acetate is a lipophilic, cytotoxic drug with the potential for use in the treatment of solar keratosis. For effective pharmacological action, delivery of the drug to the epidermal/dermal junction of the skin is required. A study of the topical penetration properties of rooperol tetra-acetate from different topical bases, each possessing different physico-chemical properties, was performed. The assessment involved a comparison of the diffusion properties under occlusive and non occlusive conditions when the drug was formulated into a gel, Cetomacrogol Cream B.P. (oil-inwater), Simple Ointment B.P. and an extemporaneously prepared water-in-oil topical cream. The in vitro experiments were conducted using polydimethylsiloxane and rat membrane mounted in a Franz diffusion cell. The topical permeation kinetics of rooperol tetra-acetate were determined by exploring the release characteristics of the active ingredient from the vehicles formulated and the permeability properties of the drug through the membranes employed. Further studies involved investigating the utilization of supersaturated systems intended to increase the thermodynamic activity of the drug when formulated into a propylene glycol/water vehicle (with and without polymer). To measure the release of rooperol tetra-acetate into the skin from a topical base it was necessary to, firstly, develop a suitable quantitative method for the analysis of the active drug in the aqueous receptor phase of in vitro diffusion cells. The second stage of product development was the design of an effective delivery system to facilitate the release of the diffusant from its base. A high performance liquid chromatographic method was utilized for the identification and quantification of the active drug. As validation is an important aspect in the development and subsequent utilization of an analytical procedure, the developed HPLC technique was validated by determining the precision, accuracy, range, limit of quantitation and sensitivity of the system. Lastly, the stability of rooperol tetra-acetate at elevated temperatures was assessed and a stability profile of the drug was generated for the three-month period of analysis. The results obtained following chromatographic analysis of the receptor phase sampled during the diffusion experiments indicate that the gel and oil-in-water formulations most effectively promoted the diffusion of rooperol tetra-acetate across polydimethylsiloxane membrane. The water-in-oil system exhibited lower flux rates and the ointment showed the least drug release. Occlusion of the topical vehicle increased the diffusitivity of the permeant from all formulations analysed. The permeation assessment results of the supersaturated systems showed enhanced diffusion of rooperol tetra-acetate across polydimethylsiloxane and rat membrane. The high thermodynamic activity existing in supersaturated systems most effectively increased the driving force for drug diffusion resulting in enhanced percutaneous penetration of rooperol tetra-acetate beyond the release and transport limitations of saturated solutions. These results provide the basis on which an effective topical drug delivery vehicle may be designed for this new drug entity.
- Full Text:
- Date Issued: 1998
Tropical corticosteroid bioequivalence testing comparison of chromameter and visual data
- Authors: Demana, Patrick Hulisani
- Date: 1998
- Subjects: Dermatopharmacology , Dermatologic agents , Skin absorption
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3755 , http://hdl.handle.net/10962/d1003233 , Dermatopharmacology , Dermatologic agents , Skin absorption
- Description: The major criticism of the human skin blanching assay is the subjective nature of grading the response. Recently the American FDA released a Guidance document for topical corticosteroid bioequi valence testing. The guidelines require the use of a chromameter as a reliable method to estimate skin blanching. The purpose of this study was to evaluate the recommendations of this document for appropriateness by comparing visual and chromameter data. The visually-assessed blanching assay methodology routinely practised in our laboratories was modified to comply with the specifications of the Guidance. The preliminary trial indicated that the training period that is required for a novice to be classified as an experienced observer is not a major problem. The major trend that emerged from the pilot study was that visual assessment was better than the chromameter. Longer dose durations were found to be more discriminatory than shorter durations. The visual data were best described by the sigmoid Emax model and the chromameter data were best described by the simple Emax model. The pivotal results indicated that the D2/Dj criterion to determine sample size of "acceptable blanchers" produced only few subjects suggesting that the validity of this criterion requires extensive investigations. The estimates of the Locke's confidence interval method were simiJar to those for the general simple formula. However, due to undefined parameters of the Locke's method in the Guidance, the validity of the Locke's method requires evaluation. The chromameter b-scale parameter was the least sensitive in estimating skin blanching whereas the a- and L-scale parameters produced similar results. Poor correlation between visual and chromameter was noted indicating that the visual method is still the best method.
- Full Text:
- Date Issued: 1998
- Authors: Demana, Patrick Hulisani
- Date: 1998
- Subjects: Dermatopharmacology , Dermatologic agents , Skin absorption
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3755 , http://hdl.handle.net/10962/d1003233 , Dermatopharmacology , Dermatologic agents , Skin absorption
- Description: The major criticism of the human skin blanching assay is the subjective nature of grading the response. Recently the American FDA released a Guidance document for topical corticosteroid bioequi valence testing. The guidelines require the use of a chromameter as a reliable method to estimate skin blanching. The purpose of this study was to evaluate the recommendations of this document for appropriateness by comparing visual and chromameter data. The visually-assessed blanching assay methodology routinely practised in our laboratories was modified to comply with the specifications of the Guidance. The preliminary trial indicated that the training period that is required for a novice to be classified as an experienced observer is not a major problem. The major trend that emerged from the pilot study was that visual assessment was better than the chromameter. Longer dose durations were found to be more discriminatory than shorter durations. The visual data were best described by the sigmoid Emax model and the chromameter data were best described by the simple Emax model. The pivotal results indicated that the D2/Dj criterion to determine sample size of "acceptable blanchers" produced only few subjects suggesting that the validity of this criterion requires extensive investigations. The estimates of the Locke's confidence interval method were simiJar to those for the general simple formula. However, due to undefined parameters of the Locke's method in the Guidance, the validity of the Locke's method requires evaluation. The chromameter b-scale parameter was the least sensitive in estimating skin blanching whereas the a- and L-scale parameters produced similar results. Poor correlation between visual and chromameter was noted indicating that the visual method is still the best method.
- Full Text:
- Date Issued: 1998
Aspects of the bioavailability of topical corticosteroid formulations
- Authors: Magnus, Ashley Denis
- Date: 1979
- Subjects: Adrenocortical hormones , Dermatopharmacology , Dermatologic agents , Transdermal medication
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3724 , http://hdl.handle.net/10962/d1001458
- Description: Two possible variables of the McKenzie/Stoughton blanching assay, namely amount applied to the test site and occlusion time have been investigated. Subsequently, two topical steroid preparations, Synalar cream (0,025% fluocinolone acetonide) and Betnovate cream (0,1% betamethasone 17- valerate) were extemporaneously diluted with five and six placebo bases respectively. Taking cognizance of the two possible variables, these diluted preparations were assessed in vivo using a modified version of the McKenzie/Stoughton blanching assay for blanching activity over a 14 month period. It was found that the base E45, which is slightly alkali, had the greatest effect on both preparations. In the case of betamethasone 17-valerate this base caused the conversion to the less active isomer, betamethasone 21-valerate whereas at the end of the 14 month test period it was found that the Synalar/E45 dilution contained no fluocinolone acetonide. Quantitative analysis of all the diluted preparations by high performance liquid chromatography using a reverse-phase system was performed. The data obtained from the systematic studies of the effects of varying concentrations and occlusion times were presented at the Eleventh National Congress of the South African Pharmacological Society
- Full Text:
- Date Issued: 1979
- Authors: Magnus, Ashley Denis
- Date: 1979
- Subjects: Adrenocortical hormones , Dermatopharmacology , Dermatologic agents , Transdermal medication
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3724 , http://hdl.handle.net/10962/d1001458
- Description: Two possible variables of the McKenzie/Stoughton blanching assay, namely amount applied to the test site and occlusion time have been investigated. Subsequently, two topical steroid preparations, Synalar cream (0,025% fluocinolone acetonide) and Betnovate cream (0,1% betamethasone 17- valerate) were extemporaneously diluted with five and six placebo bases respectively. Taking cognizance of the two possible variables, these diluted preparations were assessed in vivo using a modified version of the McKenzie/Stoughton blanching assay for blanching activity over a 14 month period. It was found that the base E45, which is slightly alkali, had the greatest effect on both preparations. In the case of betamethasone 17-valerate this base caused the conversion to the less active isomer, betamethasone 21-valerate whereas at the end of the 14 month test period it was found that the Synalar/E45 dilution contained no fluocinolone acetonide. Quantitative analysis of all the diluted preparations by high performance liquid chromatography using a reverse-phase system was performed. The data obtained from the systematic studies of the effects of varying concentrations and occlusion times were presented at the Eleventh National Congress of the South African Pharmacological Society
- Full Text:
- Date Issued: 1979
The in vivo and quantitative assessment of topical corticosteroid formulations
- Authors: Coleman, Gerald Leslie
- Date: 1978 , 2013-10-14
- Subjects: Dermatopharmacology , Dermatologic agents , Skin absorption , Adrenocortical hormones -- Therapeutic use , Transdermal medication -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3857 , http://hdl.handle.net/10962/d1013337
- Full Text:
- Date Issued: 1978
- Authors: Coleman, Gerald Leslie
- Date: 1978 , 2013-10-14
- Subjects: Dermatopharmacology , Dermatologic agents , Skin absorption , Adrenocortical hormones -- Therapeutic use , Transdermal medication -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3857 , http://hdl.handle.net/10962/d1013337
- Full Text:
- Date Issued: 1978
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