Main Points and Findings for Thesis Write-up
Introduction
The study investigates the inhibitory effects of Myrothamnus flabellifolius on
tyrosinase activity, a key enzyme involved in melanin synthesis.
The focus is on evaluating the potential of bioactive compounds
in Myrothamnus flabellifolius as skin-lightening agents in skincare
formulations.
Experimental Overview
Tyrosinase activity was measured via L-DOPA oxidation, with absorbance
indicating enzyme activity.
A control sample without inhibitor demonstrated the baseline enzyme
activity, characterized by a steep increase in absorbance over time.
Two samples containing Myrothamnus flabellifolius extract at different
concentrations were tested to assess inhibitory effects.
Key Findings
Control Sample: Exhibited a steep, steady increase in absorbance,
indicating full tyrosinase activity and no inhibition.
Sample 1: Showed a flatter, slower increase in absorbance compared to the
control, indicating significant inhibition of tyrosinase activity.
Sample 2: Displayed an intermediate rate of increase—faster than Sample 1
but slower than the control—suggesting partial inhibition.
Data Interpretation
The reduced slope of absorbance over time in the presence of Myrothamnus
flabellifolius extract indicates effective inhibition of tyrosinase.
The degree of inhibition correlates with extract concentration, with higher
concentrations likely producing greater inhibitory effects.
Polyphenolic compounds in Myrothamnus flabellifolius are hypothesized to
bind to tyrosinase, blocking L-DOPA oxidation and reducing melanin
synthesis.
Implications for Skin Care
The inhibitory activity suggests that Myrothamnus flabellifolius contains
bioactive compounds capable of modulating melanin production.
Such compounds could be developed into natural skin-lightening agents or
antioxidants in cosmetic formulations.
The dose-dependent inhibition underscores the potential for optimizing
extract concentrations for maximal efficacy.
Summary Table
Sample Absorbance Trend Inhibition Level Interpretation
Control Steep, steady increase None Full enzyme activity; baseline for comparison
Sample 1 Flatter, slower increase Significant inhibition Strong inhibitory effect; potential for skin-lightening
Sample 2 Intermediate increase Partial inhibition Moderate inhibitory effect; dose-dependent response
Conclusion
The bioactive compounds in Myrothamnus flabellifolius demonstrate
promising tyrosinase inhibitory activity.
These findings support further exploration of the extract's constituents for
development as natural skin depigmenting agents.
Quantitative analysis of inhibition at various concentrations can optimize
formulation strategies for skincare applications.
This summary provides a structured overview of your research findings,
which can be used to guide your thesis write-up. You can elaborate on each
section, providing detailed explanations, methodologies, and discussions
based on the extracted data.
If you need further assistance with specific sections or additional analysis,
feel free to ask!
2….
Findings
1. Figure 1: Evaluation of Antioxidant Activity Using the ABTS Assay
The negative control wells (Ethanol, A1 & B1) retained the original ABTS
color, confirming no antioxidant activity.
The positive control wells (Ascorbic acid, A2 & B2) turned colorless,
indicating strong antioxidant activity.
Plant extracts from the old sample (A3 & A4) turned yellow, while extracts
from the new sample (B3 & B4) turned light green, suggesting partial
antioxidant activity in the new sample and no activity in the old sample.
2. Figure 2: Dose-Dependent Antioxidant Activity Using the ABTS
Assay
The negative control wells (D1 & E1) remained green, indicating no
antioxidant activity.
The positive control wells (D2 & E2) changed color to colorless, showing
strong antioxidant activity.
The minimal effective concentration was found to be D3 (10 mg/ml for the
old sample) and E5 (2.5 mg/ml for the new sample).
These findings suggest that the new sample of Myrothamnus flabellifolius
exhibits antioxidant activity, while the old sample does not. The results also
indicate a dose-dependent response in antioxidant activity.
If you need further analysis or specific visualizations based on these findings,
please let me know!
Summary for Thesis Structure
1. Introduction
Rationale for studying bioactive compounds in Myrothamnus
flabellifolius and their potential applications in skin care.
2. Materials and Methods
Sample Collection:
Plant samples were sourced from Main Mall and an external site within
Gaborone to assess natural variability.
Samples were stored in brown envelopes to prevent degradation of
morphological features and bioactive compounds.
Extract Preparation:
Dried plant material was ground into a fine powder.
1g of powder was extracted with 6ml of 99% ethanol, shaken for 5 minutes,
and centrifuged for 10 minutes to separate the supernatant.
The ethanol was evaporated, and the extract was weighed to determine
yield, then stored in foil-covered vials protected from light.
Extraction of Bioactive Compounds:
Bioassays were conducted to evaluate antioxidant activity and tyrosinase
inhibition.
3. Bioassays and Key Procedures
Antioxidant Assay:
Objective: Characterize antioxidant properties by measuring free radical
scavenging ability.
Preparation:
ABTS solution was prepared, and potassium persulphate was added to form
the ABTS stock.
A working solution was diluted and stored at 4°C.
Controls: Negative (60% ethanol) and positive (ascorbic acid) controls were
established.
Procedure: Wells were loaded with ABTS, controls, and plant extracts at
various concentrations, with serial dilutions prepared.
Outcome: Minimum Effective Concentration (MEC) was determined by the
lowest concentration showing significant color change.
Tyrosinase-Inhibitory Assay:
Objective: Evaluate potential skin depigmentation activity via inhibition of
L-DOPA conversion.
Enzyme Extraction: Mushrooms were used to extract polyphenol oxidase
(PPO).
Assay Procedure: Plant extracts were mixed with L-DOPA and mushroom
enzyme, and absorbance was measured over time.
Outcome: Inhibition of tyrosinase activity was indicated by reduced
absorbance compared to controls.
4. Relevant Data and Findings
Extraction Yield: Quantified after ethanol evaporation (exact values not
provided but critical for yield calculation).
Antioxidant Activity: Colorimetric changes from blue to colorless across
dilutions, with MEC determined by the lowest concentration with significant
color change.
Tyrosinase Inhibition: Decreased absorbance in samples with plant
extracts compared to controls, indicating potential for skin depigmentation
applications.
5. Results
Quantitative data on extract yield.
Antioxidant activity profile and MEC.
Tyrosinase inhibition efficacy.
6. Discussion
Correlation between bioactive compounds and observed activities.
Implications for skin care applications, especially antioxidant and
depigmentation effects.
7. Conclusion
Potential of Myrothamnus flabellifolius as a natural source of bioactive
compounds for skin health.
This structured summary provides a clear framework for your thesis. You can
elaborate on each section, providing detailed explanations, methodologies,
and discussions based on the extracted data. If you need further assistance
with specific sections or additional analysis, feel free to ask!
Main Points and Findings for Thesis Write-up
1. Introduction
There is a steep increase in absorbance over time for the control. This suggests that the
mushroom extract which catalyzes the oxidation of L-DOPA, leading to the formation of
dopachrome is fully active. Since there is no inhibitor (Myrothamnus flabellifolius) in the
control, the reaction proceeds uninhibited, resulting in a steady rise in absorbance hence
it serves as the baseline for comparing inhibition effects in two samples of different
concentrations (figure 1).
However, there is a flatter, slower increase in absorbance in sample 1 compared to
control. The reduced slope indicates inhibition. Plant polyphenols are likely to bind to
tyrosinase, blocking L-DOPA oxidation. In addition, there is an intermediate trend in
sample 2 where absorbance is faster than Sample 1 but slower than the control. Hence
there is partial inhibition (less suppression than Sample 1) but still significant compared
to the control.
Figure 1: Inhibitory Effect of Myrothamnus flabellifolius on Tyrosinase Activity Measured by L-
DOPA Oxidation
The study investigates the inhibitory effects of Myrothamnus flabellifolius on tyrosinase activity,
a key enzyme involved in melanin synthesis.
The focus is on evaluating the potential of bioactive compounds in Myrothamnus flabellifolius as
skin-lightening agents in skincare formulations.
3. Experimental Overview
4.
Tyrosinase activity was measured via L-DOPA oxidation, with absorbance indicating enzyme
activity.
A control sample without inhibitor demonstrated the baseline enzyme activity, characterized by a
steep increase in absorbance over time.
Two samples containing Myrothamnus flabellifolius extract at different concentrations were
tested to assess inhibitory effects.
3. Key Findings
Control Sample: Exhibited a steep, steady increase in absorbance, indicating full tyrosinase
activity and no inhibition.
Sample 1: Showed a flatter, slower increase in absorbance compared to the control, indicating
significant inhibition of tyrosinase activity.
Sample 2: Displayed an intermediate rate of increase—faster than Sample 1 but slower than the
control—suggesting partial inhibition.
4. Relevant Data and Findings
Extraction Yield: Quantified after ethanol evaporation (exact values not provided but critical for
yield calculation).
Antioxidant Activity: Colorimetric changes from blue to colorless across dilutions, with MEC
determined by the lowest concentration with significant color change.
Tyrosinase Inhibition: Decreased absorbance in samples with plant extracts compared to
controls, indicating potential for skin depigmentation applications.
5. Results
Quantitative data on extract yield.
Antioxidant activity profile and MEC.
Tyrosinase inhibition efficacy.
6. Discussion
Correlation between bioactive compounds and observed activities.
Implications for skin care applications, especially antioxidant and depigmentation effects.
7. Conclusion
Potential of Myrothamnus flabellifolius as a natural source of bioactive compounds for skin
health.
This structured summary provides a clear framework for your thesis. You can elaborate on each
section, providing detailed explanations, methodologies, and discussions based on the extracted
data. If you need further assistance with specific sections or additional analysis, feel free to ask!
