Preliminary in vitro evaluation of methanolic extracts of Laccifer lacca Kerr. Resin and Albizia lebbeck Seeds (L.) Benth for anti-melogenic activity on hTERT-immortalized dermal melanocyte cell line

Melasma, dermatological hyperpigmentation condition characterized by excessive melanin production and frequent recurrence, while current therapies often provide limited long-term benefit. Laccifer lacca Kerr. resin and Albizia lebbeck (L.) Benth seeds are herbal remedies used in Ayurveda that are still understudied but may offer natural anti-melanogenic agent. A preliminary in vitro assessment was performed on hTERT-immortalized dermal melanocytes and a tyrosinase inhibition assay was performed to assess the anti-melanogenic potential of drug extracts. The raw materials were procured, authenticated, and subjected to physicochemical evaluation. Methanolic extracts were prepared, and stock solutions (10 mg/mL) were made in DMSO. Cell viability was assessed by MTT assay, followed by intracellular ROS analysis using DCFH-DA and flow cytometry, and tyrosinase inhibition using a colorimetric screening kit. Statistical analysis was performed using one-way ANOVA with Tukey’s HSD test ( p < 0.05) in SPSS v17.0 and GraphPad Prism 8. Cell viability responses were not concentration-dependent in a strict sense. The extracts showed strong antioxidant activity, with Laccifer lacca Kerr. (40 µg/mL) and Albizia lebbeck (L.) Benth (20 µg/mL) reducing intracellular ROS by approximately 84.9% and 85.2%, respectively, comparable to kojic acid (85.4%; p < 0.0001). In the tyrosinase inhibition assay, Laccifer lacca Kerr. and Albizia lebbeck (L.) Benth achieved maximum inhibition of 84.24% and 83.98%. The extract combination also exhibited significant inhibition of enzymes with activity within the range of those of kojic acid. Methanolic extracts of Laccifer lacca Kerr. resin and Albizia lebbeck (L.) Benth seeds demonstrated promising antioxidant and tyrosinase inhibitory activities, evidenced by reduced intracellular ROS levels and inhibition of tyrosinase activity. However, these findings are preliminary, because the study was limited to ROS assessment in hTERT melanocytes and a cell-free tyrosinase assay. Further investigations involving melanin quantification, molecular analyses are required to validate their anti-melanogenic potential and therapeutic applicability.