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Background and purpose: Diabetes mellitus is a persistent hyperglycemic condition. Thai cuisine and medicine incorporate spices: nutmeg, mace, clove buds, cardamom, cinnamon, and coriander. The in vitro impacts of these spices on anti-diabetic, antioxidant, anti-inflammatory, and total phenolic and flavonoid content were assessed. Experimental approach: Alpha-amylase and alpha-glucosidase inhibition assays were conducted. Antioxidant potential was measured through DPPH and ABTS assays. Anti-inflammatory activity was determined by inhibiting nitric oxide generation in RAW 264.7 cells. Total phenolic content was quantified using the Folin Ciocalteu method, while total flavonoid content was estimated via the aluminum chloride colorimetric method. Findings/Results: Ethanolic and aqueous extracts of a blend of spices (Siam cardamom, nutmeg, mace, and clove buds), denoted as 4-GlurE and 4-GlurA, displayed concentration-dependent inhibition of alpha- glucosidase, with IC50 values of 0.373 and 0.435 mg/mL, respectively. 4-GlurE and 4-GlurA exhibited antioxidant activity, by ABTS·+ radical and DPPH scavenging capabilities. 4-GlurE demonstrated anti-inflammatory potential by reducing nitric oxide generation (IC50: 43.95 ± 2.47 μg/mL). 4-GlurE and 4-GlurA possessed total phenolic content (TPC) of 122.47 ± 1.12 and 148.72 ± 0.14 mg GAE/g, respectively. 4-GlurE exhibited a higher total flavonoid content (TFC) compared to the aqueous extract (340.33 ± 4.77 and 94.17 ± 3.36 mg QE/g). Cinnamon and clove aqueous extracts were more potent than acarbose in alpha-glucosidase inhibition with the highest antioxidant activity. Polyphenol levels (TPC and TFC) exhibited strong correlations with antioxidant capacity. Conclusions and implications: Findings are consistent with the traditional use of 4-Glur, with cinnamon, for diabetes prevention and treatment.

Holy basil (Ocimum sanctum L.) has been used extensively in Thai traditional medicine, where it is commonly utilized as a part of herbal remedies for treating various ailments. Cultivation methods using exogenous salicylic acid (SA) to induce secondary metabolites have been documented in various plant species. Nevertheless, there is no reported information available on holy basil. Thus, the present study aimed to investigate the impact of SA foliar application on the bioactive compounds and antioxidant activity of holy basil. SA at concentrations of 0.1, 0.5, 1.0, 1.5, 2.0, and 2.5 mM was foliar sprayed 30 days after transplanting (DAT) compared to spraying with tap water as the control. The plants were harvested at 33 DAT. Exogenous SA at 0.1–1.5 mM enhanced the contents of bioactive compounds and improved antioxidant activity. The highest contents of eugenol (17,829.53 ± 243.11 μg/g dry extract), total phenolics (444.10 ± 2.80 mg GAE/g dry extract), and total flavonoids (382.69 ± 6.49 mg QE/g dry extract) were achieved at 1.0 mM SA foliar application, which was 282.96, 1.76, and 2.14 times, respectively, over control. Furthermore, the greatest antioxidant activity was observed in the 1.0 mM SA treatment. In contrast, the 2.0 and 2.5 mM SA treatments had lower levels of antioxidant activity and bioactive compounds than the control. The results of this study suggest that exogenous 1.0 mM SA foliar application is an effective method to produce enriched bioactivity in holy basil.