Methods and compositions are disclosed for the prevention and/or treatment of immunological damage to skin exposed to ultraviolet irradiation. The compositions described herein include biologically active tamarind seed xyloglucan oligosaccharides obtained via treatment of tamarind xyloglucan with a fungal β-glucanase. Advantageously, the cytoprotective tamarind seed xyloglucan oligosaccharides are stable at ambient conditions. In one aspect, the composition includes an aqueous solution of tamarind seed xyloglucan oligosaccharides having a concentration of at least 10-6 μg per mL of the solution. In another aspect, the method includes preventing the suppression of delayed type hypersensitivity. In yet another aspect, the invention includes reducing the amount of interleukin-10 produced by keratinocytes in the skin.