Acne and Barrier Functions
The extracts of H rhamnoides and Cassia fistula in a combined formulation were found to be effective in lowering skin sebum content in humans with grade I and grade II acne vulgaris in a 2014 single-blind, randomized, placebo-controlled, split-face study with two groups of 25 patients each (aged 18-37 years).15 Khan and colleagues have also reported that a sea buckthorn oil-in-water emulsion improved barrier function in human skin as tested by a tewameter and corneometer (noninvasive probes) in 13 healthy males with a mean age of 27 ± 4.8 years.16
Anti-Aging, Antioxidant, Antibacterial, Skin-Whitening Activity
Zaman and colleagues reported in 2011 that results from an in vivo study of the effects of a sea buckthorn fruit extract topical cream on stratum corneum water content and transepidermal water loss indicated that the formulation enhanced cell surface integrin expression thus facilitating collagen contraction.17
In 2012, Khan and colleagues reported amelioration in skin elasticity, thus achieving an anti-aging result, from the use of a water-in-oil–based hydroalcoholic cream loaded with fruit extract of H rhamnoides, as measured with a Cutometer.18 The previous year, some of the same researchers reported that the antioxidants and flavonoids found in a topical sea buckthorn formulation could decrease cutaneous melanin and erythema levels.
More recently, Gęgotek and colleagues found that sea buckthorn seed oil prevented redox balance and lipid metabolism disturbances in skin fibroblasts and keratinocytes caused by UVA or UVB. They suggested that such findings point to the potential of this natural agent to confer anti-inflammatory properties and photoprotection to the skin.19
In 2020, Ivanišová and colleagues investigated the antioxidant and antimicrobial activities of H rhamnoides 100% oil, 100% juice, dry berries, and tea (dry berries, leaves, and twigs). They found that all of the studied sea buckthorn products displayed high antioxidant activity (identified through DPPH radical scavenging and molybdenum reducing antioxidant power tests). Sea buckthorn juice contained the highest total content of polyphenols, flavonoids, and carotenoids. All of the tested products also exhibited substantial antibacterial activity against the tested microbes.20
Burns and Wound Healing
In a preclinical study of the effects of sea buckthorn leaf extracts on wound healing in albino rats using an excision-punch wound model in 2005, Gupta and colleagues found that twice daily topical application of the aqueous leaf extract fostered wound healing. This was indicated by higher hydroxyproline and protein levels, a diminished wound area, and lower lipid peroxide levels. The investigators suggested that sea buckthorn may facilitate wound healing at least in part because of elevated antioxidant activity in the granulation tissue.3
A year later, Wang and colleagues reported on observations of using H rhamnoides oil, a traditional Chinese herbal medicine derived from sea buckthorn fruit, as a burn treatment. In the study, 151 burn patients received an H rhamnoides oil dressing (changed every other day until wound healing) that was covered with a disinfecting dressing. The dressing reduced swelling and effusion, and alleviated pain, with patients receiving the sea buckthorn dressing experiencing greater apparent exudation reduction, pain reduction, and more rapid epithelial cell growth and wound healing than controls (treated only with Vaseline gauze). The difference between the two groups was statistically significant.21