Catherine Kern

Dr. Catherine Kern

Seppic Research and Innovation, Castres, Occitanie, France
orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 July 2024 in Nutrients
Verified
Journal Article
Open access
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Vincenzo NobileVincenzo Nobile
Vincenzo Nobile
SDStéphanie Dudonné
Stéphanie Dudonné
CKCatherine Kern
Catherine Kern
GRGloria Roveda
Gloria Roveda
CGChristine GARCIA
Christine GARCIA
Strategies for successful aging, including the use of food supplements, are part of the approach to support skin youthfulness. To demonstrate the efficacy of fermented bilberry extract (FBE) against skin aging and uneven complexion, a clinical trial was carried out on 66 subjects with visible “crow’s feet” wrinkles, mild-to-moderate skin slackness, and uneven skin tone. The wrinkle depth, skin smoothness (Ra) and roughness (Rz), skin firmness (R0) and elasticity (R2), skin coloration (ITA°), and skin antioxidant capacity were measured before and after 28 (D28), 56 (D56), and 84 (D84) days of product use (either FBE or a placebo). These parameters were also integrated with a clinical evaluation, carried out by a dermatologist, and a self-assessment questionnaire to align the measured efficacy with the visual or perceived efficacy. At D84, the wrinkle depth had decreased by 10.6%, Ra had improved by 7.9%, Rz had decreased by 7.3%, R0 had improved by 13.3%, R2 had improved by 12.4%, and skin antioxidant capacity had increased by 20.8%. ITA° increased by 20.8% and was accompanied by a decrease in the skin’s redness component by 16.8% and an increase in the lightness component by 2.2%. The variation of all the above-mentioned parameters was statistically significant between the FBE and PL groups. Our findings demonstrate the efficacy of FBE in improving skin aging and complexion evenness.

29 August 2023 in Microorganisms
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Journal Article
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NFNico Forraz
Nico Forraz
CBCécile Bize
Cécile Bize
ADAnne-Laure Desroches
Anne-Laure Desroches
CMClément Milet
Clément Milet
PPPauline Payen
Pauline Payen
CMColin McGuckin
Colin McGuckin
Acne-prone skin is associated with dysbiosis involving Cutibacterium acnes (C. acnes) and Staphylococcus epidermidis (S. epidermidis) causing increased seborrhea in sebaceous glands (SG) and inflammation. Human primary sebocytes were cultivated using 1.106 UFC/mL C. acnes Type IA (facial acne, ATCC6919) and/or 1.105 UFC/mL S. epidermidis (unknown origin, ATCC12228) for 48 h in our SEB4GLN-optimized media without antibiotics. Bacteria and sebocytes were enumerated and assessed to determine their viability. Lipid production was imaged and quantified via Nile Red staining. SG with hair follicles were microdissected from healthy skin and cultured using 1.105 UFC/mL C. acnes Type 1A and/or 1.104 UFC/mL S. epidermidis (wild-type facial skin strain) through prior fixation and immunostaining for MC5R, C. acnes and nuclei (DAPI) via Z-stack confocal microscopy bioimaging (Leica SP5X & FIJI software, Version 2.9.0). C. acnes growth was not impacted when co-cultivated with sebocytes (2D) or SG (3D) models. Phylotype IA stimulated sebocyte lipid production, which had no impact on viability. The S. epidermidis reference strain overproliferated, inducing sebocyte mortality. For 3D SG model, culture conditions were optimized using a wild-type facial skin strain at a lower concentration, 1:10 ratio to C. acnes, reduced contact time, sequential inoculation and rinsing step. Bioimaging revealed strong C. acnes labeling in the active areas of the pilosebaceous unit. S. epidermidis formed biofilm, which was distributed across the SG via non-specific fluorescence imaging. We developed an innovative model of a sebaceous gland that mimics acne-prone skin with lipid overproduction and virulent phylotype IA C. acnes inoculation.

23 March 2022 in Food & Nutrition Research
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Journal Article
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CKCatherine Kern
Catherine Kern
CGChristian Gombert
Christian Gombert
ARAlicia Roso
Alicia Roso
CGChristine Garcia
Christine Garcia
Sensitive skin is a common condition that affects many people in the world, especially women. This syndrome is defined by the occurrence of unpleasant sensations such as stinging and burning in response to stimuli that should not normally provoke such sensations. Coriander seed oil (CSO) is a 100% virgin oil of coriander seeds and boasts a specific composition of fatty acids, mainly petroselinic acid (60–75%). It has demonstrated its ability to regulate inflammation (NF-κB pathway) and nociception (TRPA1 pathway), two mechanisms supporting sensitive skin, in previous in vitro research. It was, therefore, a good candidate to be tested in vivo on sensitive skin conditions. A pilot clinical study was conducted to evaluate the effect of this ingredient on healthy women showing excessive skin reactions, mainly redness and discomfort when subjected to external stress. The results showed that the daily consumption of 200 mg of CSO for 28 days effectively reduced redness induced by stripping stress and itching induced by stinging stress. It also improved the perception of skin sensitivity and reactivity after 56 days of consumption. These clinical results confirmed that CSO is a promising ingredient to contribute to reducing reactivity in sensitive skin.

25 September 2020 in OCL
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Journal Article
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CKCatherine Kern
Catherine Kern
CGChristian Gombert
Christian Gombert
ARAlicia Roso
Alicia Roso
CGChristine Garcia
Christine Garcia
Sensitive skin is a common condition that concerns many people in the world. This syndrome is defined by the occurrence of unpleasant sensations such as stinging and burning in response to stimuli that normally should not provoke such sensations. The main hypothesis attributed to the occurrence of sensitive skin is the disruption of the epidermal barrier and a greater penetration of substances such as irritants. In keratinocytes, the NF-κB pathway, which plays an important role in orchestrating inflammatory responses, is then activated. Regulation of this activation is a key issue to control inflammation. Due to the wide variety of sensory symptoms, neurosensory dysfunction also represents a mechanism to be considered. Some of the cutaneous nerve endings express TRPA1, a sensor of skin barrier insult, which is involved in a variety of physiological or cellular processes including nociception, itch and neurogenic inflammation. Regulation of such sensor activation is also an issue to consider to control neurosensory dysfunction. Coriander seed oil is a 100% virgin oil of coriander seeds and boasts a unique composition of fatty acids. The soothing effect of coriander seed oil on sensitive skins was investigated by studying its capacity to regulate NF-κB and TRPA1 activation. Coriander seed oil allowed the regulation of NF-κB activation induced by TNF-α in an in vitro model of inflammation in keratinocytes. It also regulated the activation of TRPA1 induced by allyl isothiocyanate in an in vitro model of keratinocytes-neurons co-culture. These results are in favor of a soothing effect of coriander seed oil.

27 November 2023 in International Journal of Cosmetic Science
Verified
Journal Article
Open access
SDStéphanie Dudonné
Stéphanie Dudonné
CKCatherine Kern
Catherine Kern
CGChristine Garcia
Christine Garcia
Objective: Hair loss is a major source of psychological distress for affected people. Safe and natural ingredients are therefore needed to help reduce hair loss and stimulate hair growth. This pilot clinical study aimed at exploring the efficacy of a wheat polar lipid complex (WPLC, Ceramosides™), containing sphingolipids and digalactosyl diglycerides, on hair characteristics improvement in women showing acute hair shedding.Methods: Sixty‐six women presenting a proportion of hair in the telogen phase greater than 15% were recruited and allocated to two groups, each including at least 10 postmenopausal women. For 84 days, participants consumed 30 mg/day of the WPLC supplement, or the placebo. Their hair characteristics were assessed after 56 and 84 days using phototrichogram evaluations of hairs in anagen/telogen phases, measuring hair shedding by a pull test, hair diameter and elongation at break point, hair growth and scalp sebum content. Hair density and volume were also clinically evaluated. All these parameters were also investigated in the subgroup of postmenopausal women.Results: WPLC supplementation decreased telogen hair density/proportion while increasing the anagen hair density/proportion. These effects were significant compared with the placebo as early as within 56 days. It also led to reduced hair shedding upon pull test analyses. If no changes were evidenced in hair diameter, WPLC improved hair growth and resistance to breakage after 84 days. Clinical evaluations also showed hair density and volume improvement. Furthermore, supplementation decreased scalp sebum content in women with oily hair. The beneficial effects were also observed in the subgroup of postmenopausal women. Finally, WPLC supplementation improved participants' perception of their hair conditions.Conclusion: Through a reducing effect on hair shedding and a stimulating effect on hair reappearance and growth, WPLC dietary supplementation was shown to significantly reduce hair loss in women.

1 December 2003 in Annals of the New York Academy of Sciences
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Journal Article
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CBChristian Billard
Christian Billard
CQClaire Quiney
Claire Quiney
RTRuoping Tang
Ruoping Tang
CKCatherine Kern
Catherine Kern
FAFlorence Ajchenbaum‐Cymbalista
Florence Ajchenbaum‐Cymbalista
JKJean‐Pierre Kolb
Jean‐Pierre Kolb