Background: Melasma is a challenging hyperpigmentation disorder without absolute treatment. Aims: This study aimed to evaluate the effects of intradermal botulinum toxin A (BoNT‐A) on melasma and the protective effects of BoNT‐A on UVA‐induced melanogenesis in B16F10 melanoma cells. Patients/Methods: This study is a split‐face randomized, double‐blind, placebo‐controlled trial in 12 melasma patients who received intradermal abobotulinumtoxinA injection into melasma lesions. An in vitro study was also conducted in B16F10 melanoma cells treated with different concentrations of BoNT‐A prior to exposure to UVA. Cell viability and cellular melanogenesis were determined. Results: The adjusted MASI scores on the BoNT‐A side were significantly lower than the control at 3 months after injection, 2.8 versus 4.5 ( p < 0.001), respectively. BoNT‐A injection significantly reduced the MASI score at 2 and 3 months compared with the baseline of 4.1–3.2 (22%) ( p < 0.001) and 2.8 (31.7%) ( p < 0.001), respectively. Melanin content and tyrosinase activity in B16F10 cells with or without UVA irradiation were significantly reduced by treatment with BoNT‐A in a dose‐dependent manner without causing cytotoxicity. Conclusions: BoNT‐A has a potentially beneficial effect in the treatment of melasma due to its antimelanogenic effect. Trial Registration: Clinical Trial Registry identifier: TCTR20250118001

The rhizomes of Boesenbergia rotunda (fingerroot) and its bioactive compound, panduratin A, exhibit potent anti-inflammatory, antioxidant, and anti-proliferative properties. The aim of this study was to investigate the anti-melanogenic (including anti-tyrosinase) effects of B. rotunda extract and panduratin A in B16F10 melanoma cells induced by UVA radiation. The effects of the compounds on fibroblast proliferation and migration were also assessed by scratch wound healing assays in human primary fibroblasts. The results showed that B. rotunda extract and panduratin A significantly reduced tyrosinase activity and cellular melanogenesis induced by UVA radiation in a dose-dependent manner. The compounds also demonstrated inhibitory effects on fibroblast cell migration and proliferation. These findings suggest that B. rotunda extract may have potential therapeutic effects on skin hyperpigmentation and fibroproliferative skin disorders.

Background Melasma is a common skin pigmentation disorder. Acupuncture shows benefits for patients with melasma, although no standardized method or optimal number of sessions have been determined. Objective To comparatively assess clinical outcomes of melasma between five vs ten standard acupuncture sessions. Methods We performed a prospective observational cohort study in all melasma patients at the Acupuncture Clinic, King Chulalongkorn Memorial Hospital, Bangkok, Thailand. All patients were treated with standard acupuncture procedure twice a week and were evaluated after the fifth and the tenth sessions of acupuncture, with a follow-up one week after the last session. Participants were divided into two treatment groups: Groups A and B received five and ten acupuncture sessions respectively. Melasma outcomes were assessed by using the Melanin Index (MI), Melasma Area and Severity Index (MASI), patient-reported improvement scores and acupuncture-related adverse events. Results Of 113 participants, 67 received five sessions of acupuncture treatment while 39 received ten sessions. 7 participants did not finish treatment. After five sessions of acupuncture in Group A, the mean MI decreased by 28.7 (95%CI -38.5 to -18.8), whereas the median MASI decreased by 3.4 (−6.9, -1.2) points. After ten sessions of acupuncture in Group B, the mean MI decreased by 31.3 (95%CI -45.0 to -17.6), whereas the median MASI decreased by 5.4 (−9.9, - 3.0) points. The first five sessions of acupuncture had a higher effect on the change in magnitude than the last five sessions, although there was no statistically significant difference. However, ten-session of acupuncture, had not reached the peak benefit on melasma yet. Further studies should be done with a higher number of sessions to determine the optimal rounds of treatment. Twenty-nine participants reported minor side effects, mostly consisting of persistent pain and small hematoma. Group B had RR of having adverse events 1.8 times (95% CI 1.0-3.4) compared to group A. Conclusion Acupuncture has a potential dose-response effect on clinical and patient-reported melasma outcomes with minor side effects.

Background: Acupuncture shows benefits for patients with melasma, although no optimal number of sessions have been determined.Methods: The prospective observational study was conducted in melasma patients who were treated with acupuncture procedures two times a week and were evaluated after the 5th and the 10th sessions of acupuncture, with a 1-week follow-up after the last session. Participants Groups A and B received five and 10 acupuncture sessions, respectively. Melasma was assessed by using the melanin index (MI), melasma area and severity index (MASI), patient-reported improvement scores, and acupuncture-related adverse events.Results: Out of 113 participants, 67 received five sessions of acupuncture treatment while 39 received 10 sessions. At 1 week after five sessions of acupuncture in Group A, the mean MI decreased by 28.7 (95% CI −38.5 to −18.8, p < 0.001), whereas the median MASI decreased by 3.4 (95% CI −6.9 to −1.2, p < 0.001) points. At 1 week after ten sessions of acupuncture in Group B, the mean MI decreased by 31.3 (95% CI −45 to −17.6, p < 0.001), whereas the median MASI decreased by 5.4 (95%CI −9.9 to −3, p < 0.001) points. The first five sessions of acupuncture had a higher incremental effect than the last five sessions, although there was no statistically significant difference. Twenty-nine participants reported minor side effects. Group B had a risk ratio (RR) of having adverse events 1.8 times (95% CI 1.0–3.4, p = 0.05) compared with Group A.Conclusion: Short acupuncture regimens of 5–10 sessions in melasma seem to be effective and practical with minor side effects.