The Administration of 4-Hexylresorcinol Accelerates Orthodontic Tooth Movement and Increases the Expression Level of Bone Turnover Markers in Ovariectomized Rats.

Surgical methods for accelerating orthodontic tooth movement are limited by possible damage to the tooth root and patient discomfort. 4-Hexylresorcinol (4HR) has been shown to increase bone remodeling and may potentially facilitate tooth movement. This study investigated the (1) effect of 4HR administration on osteoblast-like cells and (2) effect of 4HR administration on tooth movement in ovariectomized rats. Saos-2 cells were treated with either 4HR or solvent (control). Protein expression levels were investigated 2, 8, and 24 h after treatment. Thirty ovariectomized Sprague-Dawley rats were divided into two experimental groups (A and B) and one control group. After installation of an orthodontic tooth movement device, groups A and B received subcutaneous weekly injections of 4HR (1.28 and 128 mg/kg). Micro-computerized tomography and histological analyses were performed after 2 weeks of tooth movement. The application of 4HR elevated expression of osteogenic markers in Saos-2 cells. Movement of the first molars was significantly greater in rats administered 4HR. Furthermore, the expression of bone morphogenic protein-2, receptor activator of nuclear factor kappa-B ligand, osteocalcin, and tartrate-resistant acid phosphatase were increased after 4HR administration. 4HR application demonstrated increased expression of osteogenic markers in Saos-2 cells and accelerated orthodontic tooth movement in rats.

Bactericidal activity of hexylresorcinol lozenges against oropharyngeal organisms associated with acute sore throat.

OBJECTIVE: For the majority of people with acute sore throat, over-the-counter treatments represent the primary option for symptomatic relief. This study evaluated the in vitro bactericidal activity of lozenges containing the antiseptic hexylresorcinol against five bacteria associated with acute sore throat: Staphylococcus aureus, Streptococcus pyogenes, Moraxella catarrhalis, Haemophilus influenzae and Fusobacterium necrophorum. RESULTS: Hexylresorcinol 2.4 mg lozenges were dissolved into 5 mL of artificial saliva medium. Inoculum cultures were prepared in triplicate for each test organism to give an approximate population of 108 colony-forming units (cfu)/mL. Bactericidal activity was measured by log reduction in cfu. Greater than 3log10 reductions in cfu were observed at 1 min after dissolved hexylresorcinol lozenges were added to S. aureus (log10 reduction cfu/mL ± standard deviation, 3.3 ± 0.2), M. catarrhalis (4.7 ± 0.4), H. influenzae (5.8 ± 0.4) and F. necrophorum (4.5 ± 0.2) and by 5 min for S. pyogenes (4.3 ± 0.4). Hexylresorcinol lozenges achieved a > 99.9% reduction in cfu against all tested organisms within 5 min, which is consistent with the duration for a lozenge to dissolve in the mouth. In conclusion, in vitro data indicate that hexylresorcinol lozenges offer rapid bactericidal activity against organisms implicated in acute sore throat.

Botulinum Toxin Conjugated With Silk Fibroin and 4-Hexylresorcinol.

PURPOSE: The objective of this study was to evaluate whether silk fibroin (SF) incorporated into 4-hexylresorcinol (4HR) could increase botulinum toxin-A (BTX-A) activity. MATERIAL AND METHODS: In total, 30 rats were used for this study. The animals were divided into 6 groups according to the injected materials (SA: saline only; SF; 4HR; B2: 2 units of BTX-A; B2 + SF + 4HR: combination of B2, SF, and 4HR; B5: 5 units of BTX-A). Serial sonography was used for the evaluation of muscle thickness after injection. Immunohistochemical staining was used for the evaluation of myosin type II (myo2) and Bcl-2 protein expression. RESULTS: The relative thickness of the masseter muscle in B2 group was 66.14% ±â€Š4.55% to the preinjection level; in B2 + SF + 4HR group was 54.59% ±â€Š4.83%, and in B5 group was 56.19% ±â€Š8.28%. Any BTX-injected group showed significantly lower value of the relative muscle thickness compared to SA, SF, or 4HR group (P < 0.001 for all). The difference of relative muscle thickness between B2 group and B2 + SF + 4HR group was statistically significant (P < 0.001). The intensity of myo2 immunostaining in B5, B2, and B2 + SF + 4HR group was significantly higher than those in the other groups (P < 0.05). CONCLUSIONS: When 2 units of BTX was incorporated to SF and 4HR, combination formula showed similar activity to those of 5 units of BTX.

Efficacy and Tolerability of a Skin Brightening/Anti-Aging Cosmeceutical Containing Retinol 0.5%, Niacinamide, Hexylresorcinol, and Resveratrol.

Consumers are increasingly interested in over-the-counter skin care products that can improve the appearance of photodamaged and aging skin. This 10-week, open-label, single- center study enrolled 25 subjects with mild to moderate hyperpigmentation and other clinical stigmata of cutaneous aging including fine lines, sallowness, lack of clarity, and wrinkling. Their mean age was 53.4±7.7 years. The test product contained retinol 0.5% in combination with niacinamide 4.4%, resveratrol 1%, and hexylresorcinol 1.1% in a moisturizing base. Subjects were provided a skin care regimen including a cleanser, hydrating serum, moisturizer, and an SPF 30 sunscreen for daily use. The test product was applied only at night.

The use of this skin brightening/anti-aging cosmeceutical was found to provide statistically significant improvements in all efficacy endpoints by study end. Fine lines, radiance, and smoothness were significantly improved as early as week 2 (P<.001). By week 4, hyperpigmentation, overall skin clarity, evenness of skin tone, and wrinkles showed statistically significant improvement compared to baseline. Mild retinoid dermatitis including flaking and redness occurred early in the study as reflected by tolerability scores. By week 10, subjects reported no stinging, itching, dryness, or tingling.

The results of this open-label clinical study suggest that a topical cream containing retinol 0.5% in combination with niacinamide, resveratrol, and hexylresorcinol is efficacious and tolerable for skin brightening/anti-aging when used with a complementary skin care regimen including SPF 30 sun protection.

J Drugs Dermatol. 2016;15(7):863-868.

[Induction of the NO synthesis in lactobacilli under stress conditions].

An increase in the nitric oxide (NO) biosynthesis in Lactobacillus plantarum 8P-A3 cells takes place under strong stress influence, which leads to a considerable decrease in the microbial cell viability: heating at 70 degrees C and 80 degrees C, prolonged cultivation, toxic effect of hexylresorcinol. The factors, which do not lead to cell death, such as heating at 60 degrees C, 50 microg/ml homoserine lactone, Bacillus intermedius 7P ribonuclease (binase) in concentrations up to 300 microg/ml, do not induce NO synthesis. The activation of the NO biosynthesis in response to stress treatment evidences to universality of key-mechanisms of stress response in cells differing in the level of their organization as well as to important role of nitric oxide in them.

Randomised, double-blind, placebo-controlled study of a single dose of an amylmetacresol/2,4-dichlorobenzyl alcohol plus lidocaine lozenge or a hexylresorcinol lozenge for the treatment of acute sore throat due to upper respiratory tract infection.

PURPOSE: Sore throat is a frequent reason for seeking medical care but few prescription options are available. Lozenges are effective in delivering active ingredients to the throat. This study was conducted to determine the analgesic efficacy of two lozenges one containing amylmetacresol (AMC)/2,4-dichlorobenzyl alcohol (DCBA) and lidocaine and one containing hexylresorcinol  versus placebo in patients with acute sore throat due to upper respiratory tract infection (URTI). METHODS: This was a multicentre, randomised, double-blind, parallel group, placebo-controlled study. In total, 190 patients were randomised 1:1:1 to a single dose of AMC/DCBA + lidocaine, hexylresorcinol or placebo lozenge. Subjective ratings of throat soreness, difficulty swallowing, swollen throat, numbing, and sore throat relief were obtained up to 2 hours post dose. Patient and investigator global ratings and a consumer questionnaire were also collected. The primary endpoint was the change from baseline in severity of throat soreness for both lozenges versus placebo at 2 hours post dose. RESULTS: The hexylresorcinol lozenge demonstrated superiority over placebo for primary and secondary efficacy variables including those related to throat soreness, sore throat relief and difficulty swallowing; the AMC/DCBA + lidocaine lozenge was also superior to placebo for secondary endpoints at various time points but did not reach significance for the primary efficacy variable. Both lozenges had a rapid onset of action from 1-10 minutes post dose for the AMC/DCBA + lidocaine lozenge and 1-5 minutes post dose for the hexylresorcinol lozenge. Numbness was reported from 1 minute post dose with the AMC/DCBA + lidocaine lozenge and was greatest at 15 minutes. Numbness was reported from 5 minutes post dose with the hexylresorcinol lozenge and was greatest at 10 minutes. Both lozenges were well tolerated. CONCLUSIONS: Both AMC/DCBA + lidocaine and hexylresorcinol lozenges provided rapid and effective sore throat relief in patients with URTI.

Topical antiseptics for the treatment of sore throat block voltage-gated neuronal sodium channels in a local anaesthetic-like manner.

Lozenges for the treatment of sore throat provide relief of discomfort in cases of oral inflammation. This effect has not been fully explained so far. Here, we have examined the proposition that key components of pharmaceutical preparations for the treatment of sore throat which are routinely regarded antiseptics might have sodium channel-blocking, i.e. local anaesthetic-like effects. We investigated the effects of hexylresorcinol, amylmetacresol and dichloro-benzylalcohol on voltage-operated neuronal (Na(V)1.2) sodium channels heterologously expressed in HEK 293 cells in vitro. Hexylresorcinol, amylmetacresol and dichloro-benzylalcohol reversibly blocked depolarisation-induced whole-cell sodium inward currents. The half-maximum blocking concentrations (EC(50)) at -150 mV were 23.1, 53.6 and 661.6 microM, respectively. Block induced by hexylresorcinol and amylmetacresol was increased at depolarised potentials and use-dependent during trains of depolarisations applied at high frequency (100 Hz) indicating that both drugs bind more tightly to inactivated conformations of the channel. Estimates for the inactivated state affinity were 1.88 and 35 microM for hexylresorcinol and amylmetacresol, respectively. Hexylresorcinol and amylmetacresol are 10-20 fold more potent than the local anaesthetic lidocaine in blocking sodium inward current. Both drugs show an increased effect at depolarised membrane potentials or in conditions of high-frequency discharges.

Exposure time and the effect of hexylresorcinol on bacterial aggregates.

The bactericidal effect of hexylresorcinol was assessed using bacterial aggregates. Increased drug concentration resulted in decreased survival of bacteria when the aggregates were exposed to hexylresorcinol for at least eight hours. This indicates that this drug may be effective against dental plaque only when available for long periods of time.