Antioxidant and antiaging activities of Cinnamomum burmannii, Michelia champaca and their combinations.

Aging is a natural skin process that occurs due to intrinsic and extrinsic factors, such as excessive exposure to ultraviolet light (photoaging). The mechanism of damage involves the production of excess free radicals that trigger oxidative stress in the skin. Determining the natural products that have high antioxidant activities as antiaging is important. Cinnamomum burmannii and Michelia champaca are typical Aceh plants that are believed to have high antioxidant effects. The aim of this study was to determining the contents of C. burmannii and M. champaca as well as to determine the antioxidant and antiaging activities of either individually or combinations. The qualitative phytochemical and semi-quantitative analysis of the extracts were measured using gas chromatography-mass spectroscopy (GC-MS). The antioxidant activity was examined by radical scavenging using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method while the antiaging activity was measured using the tyrosinase enzyme inhibition test. The phenolic and flavonoid contents of C. burmannii were higher than M. champaca (66.34 vs 24.71 mg gallic acid equivalent/gr and 80.52 vs 60.20 mg quercetin equivalent/gr, respectively. The inhibitory concentration (IC50) of M. champaca extract in inhibiting DPPH indicated that M. champaca had a better antioxidant activity than C. burmannii. The combination of C. burmannii and M. champaca extracts had a lower IC50 compared to M. champaca alone. C. burmannii and M. champaca extracts had a weak potential to inhibit tyrosinase activity (IC50 value ≥1000 µg/mL). In conclusion, this study indicates that M. champaca and C. burmannii have strong antioxidant activities and these might associate with polyphenol contents.

Anti-Diabetic Potential of Murraya Koenigii (L.) and its Antioxidant Capacity in Nicotinamide-Streptozotocin Induced Diabetic Rats.

AIM AND OBJECTIVE: The present study aims to investigate whether the antihyperglycemic effect of Murraya koenigii is mediated by antioxidant properties and insulin mimetic effect. METHODS: Thirty Spraque-Dawley rats were induced hyperglycemia by streptozotocin and nicotinamide (STZ-NA). The STZ-NA diabetic rats were treated with an ethanolic extract of Murraya koenigii 200 mg/kg b.w and 400 mg/kg b.w. One group was treated with glibenclamide (1 mg/kg b.w). After the administration of Murraya koenigii extract and glibenclamide for four weeks, the rats were sacrificed. Blood and organ samples were collected under a fasting condition. The body weight and blood glucose levels were measured. Hepatic enzymes were determined using a commercial kit, protein levels were estimated by Bradford's method, and plasma insulin was assayed by an ELISA kit. Malondialdehyde (MDA) and reduced glutathione (GSH) levels were estimated by the TBA-Wills method and Ellman's method, respectively. RESULTS: Ethanolic extract of Murraya koenigii showed a significant reduction in blood glucose level at both doses, 200 and 400 mg/kg b.w. In addition, Murraya koenigii exhibited a profound antioxidant effect with decreased MDA level and increased GSH level, particularly at the 200 mg/kg b.w. and significantly decreased the HOMA-IR index. CONCLUSIONS: The present study reveals that Murraya koenigii possesses antidiabetic activity and antioxidant effects on STZ-NA induced diabetes mellitus.