Alpinia conchigera (lengkuas kecil) merupakan sejenis tumbuhan herba yang sering digunakan sebagai rawatan alternatif
dalam bidang perubatan tradisional. Kajian ini dijalankan untuk menilai kesan sitotoksik, genotoksik serta mod kematian
sel yang disebabkan oleh ekstrak heksana A. conchigera ke atas sel hepar Chang. Asai MTT selama 24 jam telah dijalankan
untuk mengenal pasti peratus viabiliti sel hepar Chang setelah dirawat dengan ekstrak heksana A. conchigera. Keputusan
menunjukkan terdapat penurunan viabiliti sel secara signifi kan (p < 0.05) dengan nilai IC50 (8.6 μg/ml) berbanding kawalan
negatif. Berdasarkan nilai IC50 ini, pewarnaan AO/PI dilakukan untuk menentukan mod kematian sel hepar Chang iaitu sama
ada secara apoptosis atau nekrosis. Didapati bahawa terdapat perbezaan secara signifi kan (p < 0.05) bagi mod kematian
sel hepar Chang secara apoptosis berbanding kawalan negatif. Dalam kajian ini, penentuan tahap kerosakan DNA sel
hepar Chang turut dilakukan dengan menggunakan asai komet beralkali dengan nilai IC10 dan IC25 yang diperoleh daripada
asai MTT (4 μg/ml dan 6 μg/ml) masing-masing. Setelah sel hepar Chang dirawat dengan ekstrak heksana A. conchigera
selama 2 jam, didapati terdapat perbezaan secara signifi kan (p < 0.05) bagi peratus kerosakan DNA bagi kumpulan rawatan
berbanding kawalan negatif. Kesimpulannya, ekstrak heksana A. conchigera memberi kesan sitotoksik dan genotoksik
terhadap sel hepar Chang serta menyebabkan kematian sel secara apoptosis.
The effects of Andrographis paniculata and Orthosiphon stamineus extracts on the in vitro glucuronidation of 4-methylumbelliferone (4MU) by recombinant human UGTs, UGT1A1, UGT1A3, UGT1A6, UGT1A7, UGT1A8, UGT1A10, UGT2B7 and UGT2B15 were determined. The potential inhibitory effects of both of the extracts on the activity of each of the UGT isoforms were investigated using 4MU as the substrate. Incubations contained UDP-glucuronic acid (UDPGA) as the cofactor, MgCl(2), cell lysate of respective isoform, and 4MU at the approximate apparent K(m) or S(50) value of each isoform. Final concentrations of Andrographis paniculata and Orthosiphon stamineus extracts used were 0.025, 0.25, 2.5, 25 and 50 microg/mL and 0.01, 0.10, 1.0, 10 and 50 microg/mL respectively. Both extracts variably inhibited the activity of most of the isoforms in a concentration dependent manner. Andrographis paniculata extract was the better inhibitor of all the isoforms studied (IC(50) 1.70 microg/mL for UGT1A3, 2.57 microg/mL for UGT1A8, 2.82 microg/mL for UGT2B7, 5.00 micorg/mL for UGT1A1, 5.66 microg/mL for UGT1A6, 9.88 microg/mL for UGT1A7 and 15.66 microg/mL for UGT1A10). Both extracts showed less than 70% inhibition of UGT2B15, so the IC(50) values were >50 microg/mL. The inhibition of human UGTs by Andrographis paniculata and Orthosiphon stamineus extracts in vitro suggests a potential for drug-herbal extract interactions in the therapeutic setting.
The synthesis of derivatives of 4-Methylumbelliferone (4-MUs), which are structurally interesting antioxidants, was performed in this study. The modification of 4-Methylumbelliferone (4-MU) by different reaction steps was performed to yield the target compounds, the 4-MUs. The 4-MUs were characterized by different spectroscopic techniques (Fourier transform infrared; FT-IR and Nuclear magnetic resonance; NMR) and micro-elemental analysis (CHNS). The in vitro antioxidant activity of the 4-MUs was evaluated in terms of their free radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH), Nitric oxide radical scavenging activity assay, chelating activity and their (FRAP) ferric-reducing antioxidant power, which were compared with a standard antioxidant. Our results reveal that the 4-MUs exhibit excellent radical scavenging activities. The antioxidant mechanisms of the 4-MUs were also studied. Density Function Theory (DFT)-based quantum chemical studies were performed with the basis set at 3-21G. Molecular models of the synthesized compounds were studied to understand the antioxidant activity. The electron levels, namely HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), for these synthesized antioxidants were also studied.
Malaysia has a rich diversity of medicinal plants and some of them inhibit xanthine oxidase (XO), which can be introduced as new natural sources of gout medication and a substitute for synthetic xanthine oxidase inhibitors (XOI). The degree of XO inhibitory activity was determined by measuring the absorbance spectrophotometrically at 295 nm, which is associated with uric acid formation. Our preliminary screening study had employed the use of distilled water, 70% methanol and absolute ethanol to extract XOI from twenty parts of five plant species, namely, Averrhoa carambola, Carica papaya, Dimocarpus longan malesianus, Manilkara zapota and Salacca zalacca. These plants were selected based on their frequent medicinal usages by local folks. The results have shown that an aqueous extract of Carica papaya mature leaves has promising activity to inhibit XO up to 75.68 ± 0.1%. Statistical experimental design were employed to optimize the selected sample (dried Carica papaya leaves: distilled water) on extraction of XOI and the maximum XOI percentage of 86.93 ± 1.9% was obtained, which exhibited only 6.76% less than the activity exhibited by allopurinol (93.69 ± 0.2%), a commercial XOI. The comparison was made between allopurinol and optimized extract on the basis of IC50concentrations. Allopurinol showed IC50 value of 3.74 μg/ml that is considerably lower as compared to the optimized sample (4.33 μg/ml).