Efficacy study of Curcuma longa l. and Terminalia chebula retz. against dncb-induced atopic dermatitis in mice

Atopic dermatitis (AD) presents formidable challenges in Veterinary Dermatology due to its persistent nature and diverse clinical manifestations, including itching, redness, swelling, and skin lesions. Despite advancements in therapeutic interventions like topical corticosteroids and immunomodulatory agents, a significant portion of AD patients continue to struggle with persistent symptoms and frequent flare-ups. This study aimed to explore the effectiveness of Curcuma longa L. (CL) and Terminalia chebula Retz. (TC) alone and in combination in alleviating AD-like symptoms. A total of 54 Swiss albino mice (6 normal; 48 DNCB-treated) were divided into nine groups. Group A served as the normal control, while Group B had AD-like symptoms induced through repeated application of 2,4-dinitrochlorobenzene (DNCB) on the ear and dorsal skin (positive control). From the 14th day onwards, Group C received standard Dexamethasone treatment at 3mg, Group D was administered Curcuma longa L. extract at 100mg, and Group E received Terminalia chebula Retz. Extract at 100mg. Groups F through H received varying concentrations (50mg, 100mg, and 200mg) of both extracts in combination, while the vehicle Carbopol was topically applied in Group I for two weeks to assess their anti-pruritic effects. Results indicated that both Curcuma Longa and Terminalia Chebula extracts, either individually or combined, alleviated DNCB-induced AD-like symptoms, demonstrated by improvements in body weight gain, reductions in skin lesions, dermatitis scores, ear thickness, and total leukocyte count values. Histopathological analysis revealed that the combination of Curcuma Longa and Terminalia Chebula extracts at 100mg and 200mg doses reduced inflammatory cell infiltration into DNCB-induced skin lesions. Moreover, this combination also decreased the DNCB-induced elevation of Th2 cytokines interleukin (IL)-4 and Th1 cytokines IFN-γ. These findings suggest that combining Curcuma Longa and Terminalia Chebula extracts holds promise as a therapeutic approach for managing atopic dermatitis.