MARINE INGREDIENTS
excessive proliferation can lead to atopic dermatitis and other skin conditions.16,17,18 These three bacteria coexist on the skin in equilibrium, participating in the integrity of the skin and its barrier functions while protecting it against external aggressions. However, imbalances caused by external factors, such as pollution, UV radiation, stress, genetics and diet, can significantly modify bacterial communities, leading to skin redness, sensitivity, irritation, itching, dullness, inflammation and/or dehydration.16,18
Therefore, restoring
microbial balance is important for skin health. Staphylococcus epidermidis has an important
role in skin microflora, thus identifying an extract with growth-enhancing properties would be beneficial for overall skin health and equilibrium. The impact of the Codium NaDES extract on the growth of S. epidermidis (ATCC® 14990™) in a nutrient-depleted medium was tested in vitro. The extract was supplemented at
concentrations of 3%, 1%, 0.3% and 0.1%, and its impact on bacterial growth was compared to that of a negative control (the medium without supplementation) and a positive control (glucose at 1%). A kinetic study of bacterial growth was carried out over 24 hours, with the variation in optical density measured by spectrophotometry at 600 nm.
Glucose supplementation significantly (p<0.001)
increased S. epidermidis growth in the nutrient- depleted medium by 62% versus the negative control (Figure 2). The extract exhibited maximum activity at concentrations of 1% and 3%, significantly (p<0.001) promoting S. epidermidis growth by 140% and 136% over the negative control and by 48% and 45% over the positive control, respectively. It is therefore possible that S. epidermidis used
the active molecules present in the Codium NaDES extract to grow more efficiently in a nutrient- depleted medium, achieving better results than with glucose. This would give the Codium NaDES extract a potentially important prebiotic effect. An in vitro test was conducted to evaluate
the ability of Codium NaDES extract to restore the balance of the skin microbial population after washing. The test was conducted using reconstructed human epidermis (RHE). The extract was tested at a concentration of 1% against a control sample that was not pretreated with the extract. First, the RHE was pretreated with or without the extract for 24 hours. Three bacterial strains, Staphylococcus
epidermidis, Cutibacterium acnes and S. aureus, were added and left to adhere for four hours, after which the initial balance between the three microorganisms was measured. The RHE were then washed to remove the non-adherent bacteria, re- treated with or without the extract, and incubated for 20 hours.
The final microbial balance was measured. The
commensal bacterium S. epidermidis represented 50% of the initial microbial balance, while S. aureus and C. acnes represented 25% each, amounting to 1×107
, 5×106 and 5×106 CFU/RHE respectively
(Figures 3 and 4). Following washing and a 20-hour incubation
period, it was observed that the total bacterial load had significantly decreased (p<0.001) compared
www.personalcaremagazine.com
5.0E+06 0.0E+00
T0 Control T24h
Figure 4: Distribution of the three bacterial strains, Staphylococcus epidermidis, Cutibacterium acnes and S. aureus, before (T0) and after washing and a 20-hour incubation period for the control and the extract at 1% as bacterial counts in reconstructed the human epidermis (CFU/RHE)
TGF-β 20 mg/mL 0 -5
-10 -15
-20 -25 -30 -35 -40
Extract 0.5% Extract 0.05% Extract 1%
2.5E+07 2.0E+07 1.5E+07 1.0E+07
77 S. epidermidis ■
S.aureus ■
C.acnes ■
* * ***
Figure 5: Variations in the interleukin (IL)-8 concentration induced by a positive control (TGF-β) and the Codium NaDES extract at two concentrations in % compared to UVA-stressed fibroblasts. Significant differences compared to the negative control determined by Student t-test are indicated by stars (***) p<0.001; (*) p<0.05
to the initial state for both the control and Codium NaDES extract conditions, with no significant difference between the two. Recolonisation by S. epidermidis was similar (p = 0.289) in both conditions and amounted to 4.49×106
CFU/RHE for the control and Codium NaDES extract conditions respectively. This represented 48.6% and 49.2% of the final
total bacterial load, reaching similar proportions to the initial load despite lower bacterial counts (Figures 3 and 4). However, the recolonisation of pathogenic bacteria occurred differently in the two conditions. In the control condition, the proportion of C.
acnes was greatly reduced after washing and a 20-hour incubation period, reaching only 2.4% of the final total bacterial load. Meanwhile, the proportion of S. aureus increased to 49.3%, resulting in bacterial counts similar to those in the initial condition. In the Codium NaDES extract condition, the
proportions of C. acnes and S. aureus were 15.8% and 35.1%, respectively (Figure 3). This indicated a better return to equilibrium for the three strains: the proportion of C. acnes increased at
and 5.05×106
the expense of S. aureus, without affecting the proportion of S. epidermidis. Thus, the Codium NADES extract respected the commensal bacterium and modulated the diversity of pathogenic flora compared to the control.
Skin soothing Skin redness, or erythema, is one of the most common dermatological concerns. It is caused by hyperaemia (an increased blood flow) in the superficial capillaries. On the face, skin redness is usually found across on the nasolabial fold, the nose and the cheekbones.19 It can be triggered by various factors, such as
environment (UV radiation, heat, cold, wind or dry air), chemical exposure (cleansing products, fragrance, cosmetics, pollution), psychological state (stress, emotions) and/or hormonal fluctuations. Manifestations of skin redness often include
other skin sensations, including prickling, burning, itching, tightness and/or dryness. The phenomenon can either be transient or persistent.19
Anti-inflammatory, hydrating and/or soothing products could thus be used for a gentle April 2026 PERSONAL CARE MAGAZINE
Variation in % compared to UVA- stressed fibroblasts
Bacterial count of the 3 strains on the reconstructed human epidermis (CFU/RHE)
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152
