Machine Learning and In Vitro Chemical Screening of Potential α-Amylase and α-Glucosidase Inhibitors from Thai Indigenous Plants.

Diabetes mellitus is a major predisposing factor for cardiovascular disease and mortality. α-Amylase and α-glucosidase enzymes are the rate-limiting steps for carbohydrate digestion. The inhibition of these two enzymes is clinically used for the treatment of diabetes mellitus. Here, in vitro study and machine learning models were employed for the chemical screening of inhibiting the activity of 31 plant samples on α-amylase and α-glucosidase enzymes. The results showed that the ethanolic twig extract of Pinus kesiya had the highest inhibitory activity against the α-amylase enzyme. The respective ethanolic extract of Croton oblongifolius stem, Parinari anamense twig, and Polyalthia evecta leaf showed high inhibitory activity against the α-glucosidase enzyme. The classification analysis revealed that the α-glucosidase inhibitory activity of Thai indigenous plants was more predictive based on phytochemical constituents, compared with the α-amylase inhibitory activity (1.00 versus 0.97 accuracy score). The correlation loading plot revealed that flavonoids and alkaloids contributed to the α-amylase inhibitory activity, while flavonoids, tannins, and reducing sugars contributed to the α-glucosidase inhibitory activity. In conclusion, the ethanolic extracts of P. kesiya, C. oblongifolius, P. anamense, and P. evecta have the potential for further chemical characterization and the development of anti-diabetic recipes.

Induction of apoptosis in human hepatocellular carcinoma cells by extracts of Lannea coromandelica (Houtt.) Merr. and Diospyros castanea (Craib) Fletcher.

BACKGROUND: Herbal plants are a preferred source of anticancer agents. This study aims to screen the anticancer activity of a crude extract of twigs of (a) Bombax anceps Pierre var. anceps (BA); (b) Catunaregam tomentosa (Blume ex DC.) Tirveng. (CT); (c) Erythrophleum succirubrum Gagnep. (ES); (d) Lannea coromandelica (Houtt.) Merr. (LC); and (e) leaves and (f) twigs of Diospyros castanea (Craib) Fletcher (DC). METHODS: The 50 % ethanol-water extracts were prepared from each plant sample. In vitro anticancer effects of six extracts on the human hepatocellular carcinoma cell line (HepG2) in terms of cytotoxicity were investigated by neutral red assay, apoptosis induction by 4',6-diamidino-2-phenylindole (DAPI) staining, and DNA fragmentation by agarose gel electrophoresis. Normal Vero cells were tested for comparison and to determine cancer selectivity. Gas chromatography-mass spectrometry analysis was performed to identify the compounds in the extracts. RESULTS: The six crude extracts had different cytotoxicities and were classified into three groups based on their IC50 value and selectivity index (SI). DC (twig) crude extract had both a high cytotoxicity and SI toward HepG2 cells comparable to melphalan (P = 0.023). The crude extracts of DC (leaves), LC (twig), and BA (twig) had moderate cytotoxicity and a lower SI. Although all crude plant extracts induced apoptosis in more than 50 % of the DAPI-positive apoptotic HepG2 cells, only DC (twig) and LC (twig) showed laddering in the DNA fragmentation assay. 2-Palmitoylglycerol was the major compound common to both. Pyrogallol and lupeol were the major compounds in DC (twig) crude extract. Hexadecanoic acid and octadecenoic acid were the major compounds in LC (twig) crude extract, which had high toxicity but low selectivity. CONCLUSION: Ethanolic extracts from DC and LC twigs induced apoptosis in the HepG2 cell line. Pyrogallol and lupeol in DC (twig) might be responsible for the cytotoxicity toward the HepG2 cancer cells.

Evaluation of the anticancer potential of six herbs against a hepatoma cell line.

BACKGROUND: Six herbs in the Plant Genetics Conservation Project that have been used as complementary medicines were chosen on the basis of their medicinal value, namely Terminalia mucronata, Diospyros winitii, Bridelia insulana, Artabotrys harmandii, Terminallia triptera, and Croton oblongifolius. This study aims to evaluate the potential anticancer activity of 50% ethanol-water extracts of these six herbs. METHODS: Fifty percent ethanol-water crude extracts of the six herbs were prepared. The cytotoxicity of the herbal extracts relative to that of melphalan was evaluated using a hepatoma cell line (HepG2), and examined by neutral red assays and apoptosis induction by gel electrophoresis and flow cytometry after 24 h. RESULTS: A significant difference was found between the cytotoxicity of the 50% ethanol-water crude extracts and melphalan (P = 0.000). The 50% ethanol-water crude extracts of all six herbs exhibited cytotoxicity against HepG2 cells, with IC50 values ranging from 100 to 500 µg/mL. The extract of T. triptera showed the highest cytotoxicity with an IC50 of 148.7 ± 12.3 µg/mL, while melphalan had an IC50 of 39.79 ± 7.62 µg/mL. The 50% ethanol-water crude extracts of D. winitii and T. triptera, but not A. harmandii, produced a DNA ladder. The 50% ethanol-water crude extracts of D. winitii, T. triptera, and A. harmandii induced apoptosis detected by flow cytometry. CONCLUSION: The 50% ethanol-water crude extracts of D. winitii, T. triptera, and A. harmandii showed anticancer activity in vitro.

Cytotoxic and apoptotic effects of six herbal plants against the human hepatocarcinoma (HepG2) cell line.

BACKGROUND: Six plants from Thailand were evaluated for their cytotoxicity and apoptosis induction in human hepatocarcinoma (HepG2) as compared to normal African green monkey kidney epithelial cell lines. METHODS: Ethanol-water crude extracts of the six plants were tested with neutral red assay for their cytotoxicity after 24 hours of exposure to the cells. Apoptotic induction was tested in the HepG2 cells with diamidino-2-phenylindole staining. DNA fragmentation, indicative of apoptosis, was analyzed with agarose gel electrophoresis. Alkylation, indicative of DNA damage, was also evaluated in vitro by 4-(4'-nitrobenzyl) pyridine assay. RESULTS: The extract of Pinus kesiya showed the highest selectivity (selectivity index = 9.6) and potent cytotoxicity in the HepG2 cell line, with an IC50 value of 52.0 ± 5.8 µg/ml (mean ± standard deviation). Extract of Catimbium speciosum exerted cytotoxicity with an IC50 value of 55.7 ± 8.1 µg/ml. Crude extracts from Glochidion daltonii, Cladogynos orientalis, Acorus tatarinowii and Amomum villosum exhibited cytotoxicity with IC50 values ranging 100-500 µg/ml. All crude extracts showed different alkylating abilities in vitro. Extracts of P. kesiya, C. speciosum and C. orientalis caused nuclei morphological changes and DNA laddering. CONCLUSION: The extracts of C. speciosum, C. orientalis and P. kesiya induced apoptosis. Among the three plants, P. kesiya possessed the most robust anticancer activity, with specific selectivity against HepG2 cells.