Methods: Anti-cholinesterase, anti-oxidant, and total phenolic and flavonoid contents were established using standard procedures.
Results: The three polyherbal extracts exhibited significant concentration dependent acetylcholinesterase (AChE) inhibitory activity (P = 0.001). The highest AChE inhibition was observed with the Neocare Herbal Tea (NHT) with 99.7% (IC50 = 324 μg/mL); whereas the Herbalin Complex Tea (HCT) and Phytoblis Herbal Tea (PHT) exhibited 73.8% (IC50 = 0.2 μg/mL) and 60.6% (IC50 = 0.7 μg/mL) inhibition, respectively, relative to eserine at 100% inhibition (IC50 = 0.9 μg/mL) at 200 μg/mL. The order of percentage increase in inhibition of AChE was NHT > HCT > PHT; while the order of decrease in potency was HCT > PHT > NHT.Radical scavenging activities of HCT, NHT and PHT were 82.13% (IC50 = 0.08 μg/mL), 77.43% (IC50 = 0.01 μg/mL) and 76.28% (IC50 = 0.3 μg/mL), respectively, at 1 mg/mL concentrations. The reducing power revealed a dose-dependent effect, with NHT > PHT > HCT. The order of total phenolics content in the extracts were PHT > HCT > NHT, and for total flavonoids content: PHT > NHT > HCT.
Conclusion: The three polyherbal standardised products possess significant acetylcholinesterase inhibitory activity and secondary metabolites that could collectively contribute to their memory-enhancing effects.
MATERIALS AND METHODS: Total phenolic content (TPC) and ascorbic acid equivalent antioxidant capacity (AEAC) were assessed using the Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, respectively. Minimum inhibitory dose (MID) against Gram-positive Micrococcus luteus, Staphylococcus aureus, and Bacillus cereus, and Gram-negative. Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa was assessed using the disc-diffusion method. Teas were extracted with hot water successively three times for one hour each time. The extracts were fractionated using Sephadex LH-20 column chromatography to obtain the NP and PT constituents.
RESULTS: Extraction yields ranged from 12 to 23%. Yields of NP fractions (70-81%) were much higher than those of PT fractions (1-11%), suggesting that the former are the major tea components. Ranking of antioxidant properties of extracts was green tea>black tea>herbal tea. For all six teas, antioxidant properties of PT fractions were significantly higher than extracts and NP fractions. Extracts and fractions of all six teas showed no activity against the three Gram-negative bacteria. Green teas inhibited all three Gram-positive bacteria with S. aureus being the least susceptible. Black and herbal teas inhibited the growth of M. luteus and B. cereus, but not S. aureus. The most potent were the PT fractions of Boh Cameron Highlands and Ho Yan Hor with MID of 0.01 and 0.03 mg/disc against M. luteus.
CONCLUSION: Results suggested that NP constituents are major contributors to the antioxidant and antibacterial properties of teas of C. sinensis. Although PT constituents have stronger antioxidant and antibacterial properties, they constitute only a minor component of the teas.
METHODS: Fifty-six female Sprague-Dawley rats were randomly allocated into eight groups (n = 7): SHAM (healthy sham control); OVX (ovarietomized) nontreated rats (negative control); OVX + Remifemin (100 mg/kg body weight), and 2% green tea extract (positive controls); OVX + OS 50% ethanolic and aqueous extracts, both at either 150 or 300 mg/kg. After 16 weeks, the rats' bones and blood were evaluated for osteoporosis indicators (protein and mRNA expressions), micro-computed tomography for bone histomorphometry, and three-point bending test for tibia mechanical strength.
RESULTS: The extracts dose-dependently and significantly (P