In Vitro Evaluation of Stem Extracts and Essential Oils from Sawdust of Cedrus atlantica (Endl.) G. Manetti ex Carrière for their Photoprotective and Antihyperglycemic Activities

Cedrus atlantica commonly called Atlas cedar, is a prominent forest tree with numerous medicinal values. This study aimed to evaluate the photoprotective and in vitro antihyperglycemic activities of stem extracts and essential oils from sawdust of Cedrus atlantica. The extracts of C. atlantica (cyclohexane, ethyl acetate, ethanol, aqueous) and its essential oils (H0, H1, H2) were assessed for their ability to absorb ultraviolet (UV) rays (UVA and UVB) and to inhibit the enzymes α-amylase and α-glucosidase. Zinc oxide served as a positive control for UV absorption, while acarbose was used as the standard for enzyme inhibition assays. The results revealed strong photoprotective potential for C. atlantica extracts. F1 and F3 were the most effective for UVA absorption, with absorbance values of 1.968 ± 0.001 and 1.820 ± 0.017, respectively. For UVB absorption, F3 and F4 had the highest absorbance values (2.019 ± 0.010 and 2.120 ± 0.001, respectively). All extracts showed higher SPF values than zinc oxide (12.62 ± 0.02), with F1 (SPF = 20.48 ± 0.10) and F2 (SPF = 20.40 ± 0.07) showing the best results. Essential oils exhibited much lower photoprotective activity. In the antihyperglycemic assays, F2 showed the highest α-amylase inhibition (IC50 = 95.90 ± 0.02 μg/mL), while F1 exhibited the strongest α-glucosidase inhibition (IC50 = 27.50 ± 0.24 μg/mL). The essential oil fraction H1 was also active, outperforming acarbose in both assays. These findings suggest that C. atlantica has promising potential as natural sunscreen and antidiabetic therapies. Further research is needed to identify active compounds.