Cyperus rotundus L. exhibits promising potential for the development of functional foods due to its documented pharmacological and biological activities. This study investigated the antioxidant and anti-diabetic properties of C. rotundus kombucha. The results demonstrated potent antioxidant activity with an IC₅₀ value of 76.7 ± 9.6 µL/mL for the DPPH assay and 314.2 ± 16.9 µL/mL for the ABTS assay. Additionally, the kombucha demonstrated alpha-glucosidase inhibitory with an IC₅₀ value of 142.7 ± 5.2 µL/mL. This in vitro antioxidant potential was further validated in vivo using Drosophila. Drosophila fed a high-sugar diet and supplemented with pure kombucha revealed significant increases in DPPH and ABTS free radical scavenging activity. Drosophila on a high-sugar diet supplemented with varying kombucha concentrations manifested enhanced resistance to oxidative stresses induced by H₂O₂ and paraquat. Concurrently, there was a notable decline in lipid peroxidation levels. Additionally, significant upregulations in CAT, SOD1, and SOD2 activities were observed when the high-sugar diet was supplemented with kombucha. Furthermore, in vivo assessments using Drosophila demonstrated significant reductions in alpha-glucosidase activity when fed with kombucha (reduced by 34.04%, 13.79%, and 11.60% when treated with 100%, 40%, and 10% kombucha, respectively). A comprehensive GC-MS and HPLC analysis of C. rotundus kombucha detected the presence of antioxidative and anti-glucosidase compounds. In conclusion, C. rotundus kombucha exhibits considerable antioxidant and anti-diabetic properties, demonstrating its potential as a beneficial beverage for health promotion.

Introduction: Cyperus rotundus L. is suspected of having anti-obesity properties. The purpose of this study was to determine the anti-obesity property of hydroethanolic C. rotundus extract (HECE) using Drosophila as a model organism. Methods: In vitro inhibition of lipase activity by C. rotundus extract was investigated. The effects of C. rotundus extract on obesity-related characteristics, including body weight, triglyceride content, and lifespan extension were evaluated in Drosophila fed a high-fat diet (HFD). The effect of the extract on the reduction of oxidative stress associated with obesity was assessed in vivo using antioxidant assays in Drosophila. Results: HECE inhibited lipase activity in vitro with an IC50 of 128.24 ± 3.65 μg/mL. In vivo lipase inhibition experiments demonstrated that feeding Drosophila 10 mg/mL HECE or 2 μM orlistat lowered lipase activity by 21.51 (P < 0.05) and 42.86% (P < 0.01) and triglyceride levels by 20.67 (P < 0.05) and 28.39% (P < 0.01), respectively, compared to those of the untreated group. After 10 mg/mL HECE or 2 μM orlistat supplementation, an increase in the mean survival rate (10.54 (P < 0.05) and 13.90% (P < 0.01), respectively) and climbing ability (25.03 (P < 0.01) and 28.44% (P < 0.01), respectively) was observed compared to those of flies fed a HFD. The paraquat and H2O2 challenge tests revealed that flies fed HECE in a mixed HFD showed increased survival on flies fed a HFD. Conclusion: This study demonstrates the beneficial effects of dietary HECE supplementation on suppressing pancreatic lipase activity and lowering triglyceride levels and oxidative stress, leading to increased lifespan in Drosophila fed a HFD.

The stem of Cassia siamea L. (Fabaceae) has been used in traditional Thai medicine as a longevity remedy. The objective of this study was to investigate the effect of ethanolic stem extract of C. siamea (CSE) on the life span of Drosophila melanogaster. The results showed that a diet containing 10 mg/mL CSE could significantly extend the mean life span of D. melanogaster by 14% compared with the control diet (P < 0.01). The maximum life span was 74, 78, and 84 days in control, CSE (5 mg/mL) and CSE (10 mg/mL) groups, respectively. Supplementation of CSE at 10 mg/mL also significantly increases the activity of superoxide dismutase (SOD) and catalase (CAT) at days 25 and 40 compared with the control diet. Treatment of CSE at 5 and 10 mg/mL significantly increased the climbing ability of D. melanogaster both on days 25 and 40 compared with the control flies. Paraquat and H2O2 challenge test showed that flies fed with CSE at 10 mg/mL had a longer survival time than the control flies (P < 0.01). This study provides supportive evidence that supplementation with CSE prolonged life span and reduced oxidative stress in D. melanogaster.