Oxidative stress has been known to contribute to Alzheimer’s disease. Acetylcholinesterase (AChE) enzyme may lead to Alzheimer’s disease as a neurotransmitter. Antioxidants may have protective activities against oxidative damage and Alzheimer’s disease. Acetylcholinesterase inhibitors also can be used in the treatment of various neurological disorders for management of Alzheimer’s disease. This study aimed to determine antioxidant and anticholinesterase effects of Garcinia picrorrhiza Miq. fruit extract (GpKar) and its compounds, xanthone. Antioxidant activity was measured by H2O2 scavenging inhibitory activity, while anticholinesterase activity was measured using modified Ellman method. GpKar has higher H2O2 scavenging inhibitory activity (IC50= 967.28 µg/ml) compared to xanthone (IC50= 1198.95 µg/ml). In the anticholinesterase inhibitory activity, GpKar has lower activity (IC50= 70.25 µg/ml) compared to xanthone (11.80 µg/ml). In summary, GpKar has higher antioxidant activity but lower anticholinesterase activity compared to its compounds, xanthone. However, GpKar has potency as antioxidant agent to prevent Alzheimer’s disease.

Extract of G. picrorrhiza has potential to increase antioxidant, anticollagenase, and antielastase activities. Therefore, more investigations need for identification of the active compounds in G. picrorrhiza extract involved in antioxidant and antiaging activities.

BACKGROUND: The number of obesity cases is still increasing worldwide and has reached an epidemic scale. Plants are known to have a protection role in the development of obesity, however their antioxidant and anti-obesity activities have not widely known. This study was conducted to assess the in vitro antioxidant and anti-obesity activities of different types of freeze-dried fruits cultivated in Indonesia, especially Canarium sp., Averrhoa bilimbi L. and Malus domestica.METHODS: Total phenolic content of freeze-dried fruits was identified by Folin-Ciocalteu method, while the total flavonoid content was measured by aluminium chloride colorimetric assay. To assessed the antioxidant activity, 2,2-diphenyl 1-picrylhydrazyl (DPPH) scavenging activity assay and 2,2’-azino-bis (3-ethylbenzothiazoline6-sulphonic acid) (ABTS) reducing activity assay were performed. The α-amylase and lipase inhibitory activity assay were performed to assess the anti-obesity activity. For comparison, hydroxycitric acid (HCA) compound was also assessed with DPPH, ABTS, α-amylase and lipase assays.RESULTS: A. bilimbi had the highest total phenol content (6.35 µg GAE/mg), meanwhile M. domestica had the highest total flavonoid content (2.06 µg QE/mg). A. bilimbi also showed the highest antioxidant activity both in DPPH and ABTS assay, with inhibitory concentration (IC50)=279.99 µg/mL and 631.78 µg/mL, respectively. The freeze-dried M. domestica had the highest anti-α-amylase activity (IC50=258.85 µg/mL), while Canarium sp. had the highest anti-lipase activity (IC50=118.66 µg/mL).CONCLUSION: Freeze-dried fruits demonstrate in vitro benefits toward obesity. A. bilimbi has potent antioxidant activity and is beneficial against obesity-related adverse health effect by relieving oxidative stress. M. domestica and Canarium sp. hamper the fat accumulation by reducing the carbohydrate absorption and dietary lipid.KEYWORDS: antioxidant, anti-obesity, Canarium sp., Averrhoa bilimbi L., Malus domestica, hydroxycitric acid

Red pomegranate (Punica granatum L.) contains punicalagin (elagitanin) which has strong antioxidant activity. This study aims to examine the antioxidant activity of steeping tea from red pomegranate peel. This research is observational with red pomegranate peel as the research object. The red pomegranate peel is processed into simplicia, then some of the simplicia is brewed in boiling water at 100 °C and the other part is made of ethanol extract. Steeping tea and ethanol extract at a dose of 1.25; 2.5; 5; 10; and 20 ppm were measured for its antioxidant activity by the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) method. As a control, ascorbic acid was used. The antioxidant activity is expressed in IC50. Data were analyzed by one-way Analysis of Variance. The results showed that the IC50 of steeping tea was 17.59 ppm, ethanol extract was 9.58 ppm, and ascorbic acid was 2.98 ppm. There was no significant difference in the IC50 between brewed tea, ethanol extract and ascorbic acid (p = 0.05). It was concluded that P. granatum L peel in the form of tea infusion had lower antioxidant activity than the ethanol and ascorbic acid extracts, but statistically all three showed the same strong antioxidant activity.

Diabetes mellitus (DM) is a disease that can be identified by high levels of blood glucose. Garcinia plants have been widely used for many traditional medicines as antioxidant, anticancer, antidiabetics, and antiinflammation. The antioxidant and antidiabetic activities of (Garcinia picrorrhiza Miq.) or sesoot fruit extract were evaluated in this study and compared with xanthone. The antioxidant and antidiabetic of ethanolic ripe sesoot (G. picrorrhiza Miq.) fruit extract (GpKar) was evaluated by 2,2-Azinobis 3-ethyl benzothiazoline 6-sulfonic acid (ABTS •+ ) reducing activity, α-Glucosidase, β-Glucosidase, and α-amylase inhibitor activity. GpKar showed higher ABTS •+ -reducing activity (IC 50 = 49.30 µg/mL) than xanthone (IC 50 = 404.30 µg/mL). GpKar showed IC 50 = 109.32 µg/mL for α-glucosidase inhibitory activity, while xanthones had a better activity (IC 50 = 33.97 µg/mL). GpKar also showed lower α-amylase inhibitory activity and β-Glucosidase (IC 50 = 126.01 and 9432.09 µg/mL) compared to xanthone (IC 50 = 44.32 and 405.03 µg/mL, respectively). The compounds of GpKar are proven to have antioxidant and antidiabetic activities. Therefore, it will be industrially relevant to develop a natural medicine for decreasing DM risk, thus evaluating the antioxidant and antidiabetic effect of G. picrorrhiza by a pre-clinic study is needed.