Plant bioactives [6]-gingerol (GING), epigallocatechin gallate (EGCG) and asiaticoside (AS) and vitamin E, such as tocotrienol-rich fraction (TRF), have been reported to possess anticancer activity. In this study, we investigated the apoptotic properties of these bioactive compounds alone or in combination on glioma cancer cells. TRF, GING, EGCG and AS were tested for cytotoxicity on glioma cell lines 1321N1 (Grade II), SW1783 (Grade III) and LN18 (Grade IV) in culture by the (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) (MTS) assay. With the exception of AS, combinations of two compounds were tested, and the interactions of each combination were evaluated by the combination index (CI) using an isobologram. Different grades of glioma cancer cells showed different cytotoxic responses to the compounds, where in 1321N1 and LN18 cells, the combination of EGCG + GING exhibited a synergistic effect with CI = 0.77 and CI = 0.55, respectively. In contrast, all combinations tested (TRF + GING, TRF + EGCG and EGCG + GING) were found to be antagonistic on SW1783 with CI values of 1.29, 1.39 and 1.39, respectively. Combined EGCG + GING induced apoptosis in both 1321N1 and LN18 cells, as evidenced by Annexin-V FITC/PI staining and increased active caspase-3. Our current data suggests that the combination of EGCG + GING synergistically induced apoptosis and inhibits the proliferation 1321N1 and LN18 cells, but not SW1783 cells, which may be due to their different genetic profiles.
Oil palm (Elaeis guineensis) leaf extract (OPLE) possesses good ex vivo vasodilation and antioxidant properties. This study evaluated the catechin-rich OPLE antioxidant, antihypertensive, and cardiovascular effects in normal and nitric oxide (NO)-deficient hypertensive rats. OPLE was administered orally (500 mg/kg of body weight/day) to normotensive Wistar rats and N(ω)-nitro-L-arginine methyl ester (L-NAME)-induced NO-deficient hypertensive rats. OPLE significantly (Pcatechins extracted from an alternative source, namely, oil palm leaf, for use as a medicinal food for hypertension and cardiovascular ailments.
The scopoletin (coumarin) and epicatechin (flavonoid) rich Morinda citrifolia L. (MC) Noni leaves are non-toxic (unlike the fruits) and consumed as vegetables. The anti-osteoarthritis effects of the MC leaf extract against joint cartilage degradation and inflammation were investigated through cartilage explant cultures and pre-clinical animal study. Osteoarthritis were induced by intra-articular monosodium iodoacetate injection into the right knee. The extract, scopoletin and epicatechin, suppressed glycosaminoglycan and nitric oxide release from the cartilage explant in the presence of Interleukin-1β. After 28 days, the extract treatment reduced the in vivo serum levels and joint tissues mRNA expressions for joint cartilage degradation, aggrecanase, and collagenase biomarkers. The extract increased the bone formation marker PINP levels, besides improving the articular cartilage structure and chondrocytes cellularity. The extract improved bone formation/repair, subchondral bone structure, strength and integrity, as well as cartilage synthesis by suppressing inflammation, nitric oxide production, joint catabolism by proteases, and oxidative stress. PRACTICAL APPLICATIONS: The scopoletin (coumarin) and epicatechin (flavonoid) rich Morinda citrifolia (Noni) leaves may be used as vegetables, functional food ingredient, or dietary supplements to suppress osteoarthritis progression against joint cartilage degradation and inflammation. The extract, scopoletin, or epicatechin, suppressed glycosaminoglycan, and nitric oxide release from the cartilage. The Morinda citrifolia leaf extract suppressed inflammation, nitric oxide production, tissues catabolism by proteases and oxidative stress to help reduce joint cartilage degradation, besides improving the articular cartilage structure, chondrocytes health, subchondral bone structure, bone formation/repair, and cartilage synthesis.
Postmenopausal estrogen deficiency often causes bone density loss and osteoporosis. This study evaluated the effects of an oral administration of oil palm leaf extract (OPL) on bone calcium content and structure, bone density, ash weights, and serum total alkaline phosphatase (T-ALP) of estrogen-deficient ovariectomized (OVX) rats.