Introduction: Moringa oleifera Lam. is a miracle tree that has been widely utilised in folklore medicine due to its immense amount of phenolic constituents that could treat various ailments. Different techniques have been imple- mented to extract the phenolic but the parameters may not be optimised to further enhance the amount of phenolic extracted. Thus, the work aimed to enhance phenolic content and antioxidant activity of M. oleifera through RSM methodology, which is rapid and convenience. Methods: At first, antioxidant activity of different parts of M. oleifera (leaves, stem, pod and seed) were investigated. The plant part with the highest antioxidant activity was selected for the optimisation of extraction condition using RSM. In RSM, temperature (XA), extraction time (XB) and solid-liquid ratio (XC) were employed to study the effects on yield, total phenolics, flavonoids and antioxidant activity. Then, the optimum extraction condition obtained via RSM was utilised in LC-MS and HPLC analysis to determine the poten- tial bioactive constituents. Results: The leaves of M. oleifera displayed the highest antioxidant activity as compared to other plant parts. The optimum extraction condition obtained for the leaves extract was: temperature (XA): 82°C, extraction time (XB): 48 min and solid-liquid ratio (XC): 1:30 g/mL (w/v). Meanwhile, LC-MS revealed the presence of gallic acid, chlorogenic acid, quercetin, kaempferol and 3-O-glucoside kaempferol. HPLC analysis detected six compounds; gallic acid, epicatechin gallate, chlorogenic acid, myricetin, quercetin and kaempferol. Conclusion: The optimisation are promising to improve yield and antioxidant activity in M. oleifera as compared to non-conven- tional extractions.
Introduction: There are numerous studies on the therapeutic properties of Artocarpus heterophyllus. However, stud- ies on the aqueous extraction of A. heterophyllus leaves are limited. This present study was conducted to optimize the extraction conditions of A. heterophyllus leaves to yield the highest phenolic, flavonoids and antioxidant contents. Methods: Response surface methodology (RSM) was employed to obtain a higher phenolic extraction parameter(s) of A. heterophyllus leaves using Central Composite Design (CCD). The antioxidant activity was then determined via ABTS (2,29-azinobis (3 ethylbenzothiazoline-6-sulfonic acid)) and DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay and analysis of the individual phenolics was performed by high performance liquid chromatography (HPLC). Results: The optimum extraction conditions with higher phenolics content and antioxidant activity was achieved at 81°C, 100 min and 40 mL/g sample with a good desirability value of 0.87. Under these optimized parameters, total phenolics and flavonoids were 174.48 ± 4.05 mg GAE/g sample and 21.44 ± 0.05 mg RE/g sample, respectively. Meanwhile, antioxidant activity via ABTS and DPPH assays were 90.88% ± 0.09 and 87.22% ± 0.62, respectively. Finally, under optimal extraction conditions revealed 4 compounds identified as chlorogenic acid, quercetin, rutin and kaempferol. Conclusion: The optimisation are promising to improve phenolic yield and antioxidant activity in A. heterophyllus leaves. It also proved that A. heterophyllus leaves can be used as an alternative natural antioxidant especially in medicinal applications since all identified compound possess significant biological activities for human health.
Chemoprevention has become an important area in cancer research due to the failure of current therapeutic modalities. Epidemiological and preclinical studies have demonstrated that nutrition plays a vital role in the etiology of cancer. This study was conducted to determine the chemopreventive effects of germinated brown rice (GBR) in rats induced with colon cancer. GBR is brown rice that has been claimed to be richer in nutrients compared to the common white rice. The male Sprague Dawley rats (6 weeks of age) were randomly divided into 5 groups: (G1) positive control (with colon cancer, unfed with GBR), (G2) fed with 2.5 g/kg of GBR (GBR (g)/weight of rat (kg)), (G3) fed with 5 g/kg of GBR, (G4) fed with 10 g/kg of GBR and (G5) negative control (without colon cancer, unfed with GBR). GBR was administered orally once daily via gavage after injection of 15 mg/kg of body weight of azoxymethane (AOM) once a week for two weeks, intraperitonially. After 8 weeks of treatment, animals were sacrificed and colons were removed. Colonic aberrant crypt foci (ACF) were evaluated histopathologically. Total number of ACF and AC, and multicrypt of ACF, and the expression of beta-catenin and COX-2 reduced significantly (p < 0.05) in all the groups treated with GBR (G2, G3 and G4) compared to the control group (G1). Spearman rank correlation test showed significant positive linear relationship between total beta-catenin and COX-2 score (Spearman's rho = 0.616, p = 0.0001). It is demonstrated that GBR inhibits the development of total number of ACF and AC, and multicrypt of ACF, reduces the expression of beta-catenin and COX-2, and thus can be a promising dietary supplement in prevention of colon cancer.