A cytotoxicity and sub-acute toxicity study on tea leaves cultivated in Sabah

The present work investigated the cytotoxicity capacity of the MDA-MB-231 (human cancer-derived), A549 (human lung cancer-derived), Caov3 (human ovarian cancer-derived), and HeLa (human cervical cancer-derived) cell lines on a wide range of tea leaves; green tea, black tea, tea waste, and compost from Sabah. A group of male and female Sprague Dawley rats was used to screen the sub-acute toxicity of green tea extract in tea leaves from Sabah for 28 d. Results revealed that the ethanol extract of tea leaves had strong cytotoxic activity against all cancer lines. Tea waste showed higher cytotoxicity when extracted using hot water. The ethanol extract of black tea leaves exhibited the highest inhibitory activity against the proliferation of Caov3, whereas the ethanol extract of green tea leaves exhibited a promising cytotoxic activity against MDA-MB-231 and HeLa cell lines. Toxicity studies showed decreased testes weight and increased liver weight in male rats that were administered with 5000 mg/kg of tea extract. This coincided with the significant increase portrayed by enzyme alanine aminotransferase (ALT) in the serum of treated male rats in the 5000 mg/kg dose group. Moreover, there was an increase of alkaline phosphatase (ALP) and ALT for the female rats in the 5000 mg/kg dose group. The increased levels of ALT and ALP enzymes, as well as liver weight, signified mechanical trauma in the liver of male and female rats in the 5000 mg/kg dose group

Flavanols and Flavonols Content of Camellia sinensis with Different Maturity Stage Planted at Cameron Highland and Sabah Tea Plantation in Malaysia

This study was done to determine and compare the nutritional composition of ash, crude protein, crude fat and fiber, as well as the content of flavanols (EGCG, EGC, ECG and EC) and flavonols (quercetin and kaempferol) in tea planted in Cameron Highland (CH) and Sabah tea Plantation (ST) with different maturity stages (young, matured and old leaves). Young tea leaves in both CH and ST had the highest content of crude fat, protein and fiber and the values decreased as the leaves aged. Interestingly, crude protein content in all maturity stages of CH and ST were higher than in commercial tea (13.81%) with the range of 15.41 - 16.35% and 14.20 - 15.32% respectively. Meanwhile, ash content in ST (8.59 - 13.49%) was higher compared to CH (5.06 - 5.14%) and values decreased from young to old leaves. CH leaves had the highest moisture content (8.18 - 8.55%) followed by ST (5.23 - 9.20%), and commercial tea (5.7%). The order of flavanol in young leaves of CH and ST, and commercial tea leaves was ECG > EGCG > EGC > EC but for mature and old leaves the order was ECG > EGC > EGCG > EC with the only difference was in EGC and EGCG. The content of flavonol quercetin and kaempferol in CH were 3.51 mg/g and 4.05 mg/g respectively. Meanwhile, in ST leaves the values were 1.79 mg/g and 3.35 mg/g respectively, and both CH and ST showed that the highest content of flavonol was observed in young leaves and decreased as leaves aged

Effects of extraction conditions on characterization of gelatin from water buffalo (Bubalus bubalis) skin

The study aimed to determine the characteristics of gelatin from water buffalo (Bubalus bubalis) skin pre-treated with NaOH and Ca(OH)2 at different concentrations (0.3 M, 0.5 M and 0.7 M) and extracted at 65˚C for 6 hrs and 24 hrs respectively. The gelatin obtained was evaluated for its moisture, protein and ash content, UV-vis absorption value, colour, emulsifying and foaming properties. The highest yield (20.25%) was observed for gelatin extracted by 0.5 M NaOH at 24 hrs extraction time. For alkaline pre-treatment, it was found that NaOH was more efficient than Ca(OH)2 in terms of preparing the skin for subsequent extraction process. The protein content of the extracted gelatin samples was in the range of 71.76% - 87.83%, showing that the varying processing conditions are sufficiently to recover protein from the raw material. Ash content for all samples was in agreement with USDA standard, which was below than 3%. The extracted gelatin had varying pH values which were from 5.47 to 7.02. The gelatin was colourless with ‘L’ values of more than 80, except for 0.7 M Ca(OH)2 at 24 hrs which showed slightly darker properties. The intensity of the UV-vis absorption spectrum showed that a high absorption peak was observed at 6 hrs of extraction time (230 – 250 nm) compared to 24 hrs extraction time. Emulsifying properties of buffalo gelatin increased with increasing concentrations of alkaline except for 0.7 M NaOH and 0.7 M Ca(OH)2 for both extraction time. Meanwhile, foam expansion of the gelatin extracted from the different extraction conditions was observed to have a significant difference (p < 0.05) for all samples. To our knowledge, buffalo skin has the potential to be an alternative source of gelatin in the diversified industrial application by modifying the extraction conditions in order to produce gelatin with desired quality