Zingiber officinale, Phyllanthus emblica, Cinnamomum verum, and Curcuma longa to Prevent Type 2 Diabetes: An Integrative Review

Diabetes mellitus has become a global pandemic progressively rising and affecting almost every household in all world regions. Diet is a significant root cause of type II diabetes; thus, the significance of dietary interventions in preventing and managing the disease cannot be neglected. Lowering the glycemic impact of diet is an alternative way of managing type II diabetes while improving insulin sensitivity. Medicinal plants are rich in therapeutic phytochemicals which possess hypoglycemic properties. Therefore, it could be speculated that the glycemic impact of diet can be reduced by adding hypoglycemic plant ingredients without altering the sensory properties of food. The main aim of this review is to discuss dietary interventions to manage diabetes and summarize available information on the hypoglycemic properties of four prime herbs of Asian origin. This article collected, tabulated, and summarized groundbreaking reveals from promising studies. This integrative review provides information on the hypoglycemic properties of ginger, Indian gooseberry, cinnamon, and turmeric and discusses the possibility of those herbs reducing the glycemic impact of a diet once incorporated. Further research should be done regarding the incorporation of these herbs successfully into a regular diet.

Determination of macronutrient compositions in selected, frequently consumed cereals, cereal based foods, legumes and pulses prepared according to common culinary methods in Sri Lanka

Cereal grains, legumes and pulses comprise the largest proportion in a typical South-Asian diet plate. This research is mainly focusing on determining the macronutrient composition of major cereals, legumes and pulses commonly consumed in local Sri Lankan cuisine, in their cooked form. White samba, White Basmati, Red Kekulu and Nadu rice were selected as the main rice varieties and in addition maize, and wheat, finger millet flour-based foods too were analyzed. Red cowpea, green gram, chickpea and soya bean based foods were analyzed for macronutrient compositions as they are more frequently consumed by the local population, while the most preferred curry item; 'lentils', was analyzed along with soya curry; another preferred item by millions of locals. Wheat flour based items like bread were taken into analysis since, they have become the second most preferred food next to rice. Every item was cooked according to the common culinary practices in aim to determine the "realistic nutrient gain". Proximate analysis was carried out according to the AOAC standard guidelines for the determination of moisture, carbohydrate, fat, and protein whereas, insoluble dietary fiber and soluble dietary fiber were determined using enzymatic digestion in vitro models. Results revealed digestible carbohydrate level range from 64.6 ± 5.3 to 74.6 ± 7.2% among tested rice varieties, while protein content varies from 5.6 ± 2.2 to 8.9 ± 2.6. Insoluble dietary fiber was high in boiled raw rice (9.8 ± 0.2) and low in boiled White Basmati. Amongst tested leguminous beans, pressure cooked red cowpea elicited the highest protein level (24.5 ± 2.3%), while pressure cooked green gram had the lowest protein content (20.0 ± 0.6%). Pressure cooked chick pea was having higher insoluble dietary content (14.8 ± 1.3%) compared to other beans. Soybean curry elicited the highest protein (36.6%) and fat content (8.2%) among all the tested varieties. Pittu (puttu) and roti varieties made with wheat flour and finger millet flour resulted considerably higher levels of digestible fiber compared to roti made with whole wheat flour. It can be concluded that typical Sri Lankan diets are rich in fibre and protein, while they provide excellent macronutrient profiles due to the proper complementary mixing of food ingredients.

Determination of macronutrient compositions in selected, frequently consumed cereals, cereal based foods, legumes and pulses prepared according to common culinary methods in Sri Lanka

Cereal grains, legumes and pulses comprise the largest proportion in a typical South-Asian diet plate. This research is mainly focusing on determining the macronutrient composition of major cereals, legumes and pulses commonly consumed in local Sri Lankan cuisine, in their cooked form. White samba, White Basmati, Red Kekulu and Nadu rice were selected as the main rice varieties and in addition maize, and wheat, finger millet flour-based foods too were analyzed. Red cowpea, green gram, chickpea and soya bean based foods were analyzed for macronutrient compositions as they are more frequently consumed by the local population, while the most preferred curry item; 'lentils', was analyzed along with soya curry; another preferred item by millions of locals. Wheat flour based items like bread were taken into analysis since, they have become the second most preferred food next to rice. Every item was cooked according to the common culinary practices in aim to determine the "realistic nutrient gain". Proximate analysis was carried out according to the AOAC standard guidelines for the determination of moisture, carbohydrate, fat, and protein whereas, insoluble dietary fiber and soluble dietary fiber were determined using enzymatic digestion in vitro models. Results revealed digestible carbohydrate level range from 64.6 ± 5.3 to 74.6 ± 7.2% among tested rice varieties, while protein content varies from 5.6 ± 2.2 to 8.9 ± 2.6. Insoluble dietary fiber was high in boiled raw rice (9.8 ± 0.2) and low in boiled White Basmati. Amongst tested leguminous beans, pressure cooked red cowpea elicited the highest protein level (24.5 ± 2.3%), while pressure cooked green gram had the lowest protein content (20.0 ± 0.6%). Pressure cooked chick pea was having higher insoluble dietary content (14.8 ± 1.3%) compared to other beans. Soybean curry elicited the highest protein (36.6%) and fat content (8.2%) among all the tested varieties. Pittu (puttu) and roti varieties made with wheat flour and finger millet flour resulted considerably higher levels of digestible fiber compared to roti made with whole wheat flour. It can be concluded that typical Sri Lankan diets are rich in fibre and protein, while they provide excellent macronutrient profiles due to the proper complementary mixing of food ingredients.

Response surface optimization for recovery of polyphenols and carotenoids from leaves of Centella asiatica using an ethanol-based solvent system

Response surface methodology has been used to optimize the extraction conditions for total phenolics and carotenoids from leaves of Centella asiatica. Solvent concentration (30%-100%), extraction temperature (30-60°C), and extraction time (30-90 min) were used as the independent variables. A second-order polynomial model produced a satisfactory fitting of the experimental data with regard to total phenolics (R 2 = 84.75%, p < 0.004) and carotenoid (R 2 = 78.74, p < 0.019) contents. The optimum extraction conditions of ethanol concentration, extraction temperature, and extraction time for phenolics were 6.1%, 70.2°C, and 110.5 min and for carotenoids, the optimum parameters were 100%, 70.2°C, and 110.5 min, respectively. The optimal predicted contents for total phenolics (9.03 mg Gallic Acid Equivalent (GAE)/g DW) and carotenoid (8.74 mg/g DW) values in the extracts were agreed with the experimental values obtained with optimum extraction conditions for each response, and also they possess significantly higher total antioxidant capacity.

In Vitro Anti-Inflammatory Properties of Selected Green Leafy Vegetables

The study investigated the anti-inflammatory activity of the hydro methanolic extract of six leafy vegetables, namely Cassia auriculata, Passiflora edulis, Sesbania grandiflora, Olax zeylanica, Gymnema lactiferum, and Centella asiatica. The anti-inflammatory activity of methanolic extracts of leafy vegetables was evaluated using four in vitro-based assays: hemolysis inhibition, proteinase inhibition, protein denaturation inhibition, and lipoxygenase inhibition. Results showed that the percent inhibition of hemolysis from these leaf extracts (25–100 µg/mL dry weight basis (DW)) was within the range from 5.4% to 14.9%, and the leaves of P. edulis and O. zeylanica showed a significantly higher (p < 0.05) inhibition levels. Percent inhibition of protein denaturation of these leafy types was within the range of 36.0–61.0%, and the leaf extract of C. auriculata has exhibited a significantly higher (p < 0.05) inhibition level. Proteinase inhibitory activity of these leaf extracts was within the range of 20.2–25.9%. The lipoxygenase inhibition was within the range of 3.7–36.0%, and the leaf extract of G. lactiferum showed an improved ability to inhibit lipoxygenase activity. In conclusion, results revealed that all the studied leaves possess anti-inflammatory properties at different levels, and this could be due to the differences in the composition and concentration of bioactive compounds.

Antimicrobial activity and phytochemical screening of Alpinia malaccensis (Ran-kiriya) against food-borne bacteria

AIMS

Investigation of antimicrobial activity and phytochemicals of Alpinia malaccensis (Ran-kiriya) against foodborne bacteria Staphyloccocus aureus, Listeria monocytogenes, Escherichia coli and Salmonella Typhimurium.

METHODS AND RESULTS

Antibacterial activity was tested on the above four foodborne bacteria using agar disc diffusion and broth dilution assay. Alpinia malaccensis rhizome extract chemical composition was determined using gas chromatography-mass spectrometry (GCMS). Active compound was identified using thin-layer chromatography (TLC) and confirmed by nuclear magnetic resonance spectroscopy (NMR). The A. malaccensis rhizome hexane crude extract showed significantly (P < 0·05) higher diameter of inhibition (DIZ) 40 ± 0·52, 38 ± 0·96 and 36 ± 1·45 mm for S. aureusSA113, MSSASS25D and methicillin-resistant S. aureus compared with other tested bacteria. The minimum inhibition concentration and minimum bactericidal concentration were 0·625 and 5 mg ml^-1 for S. aureus 113. TLC showed DIZ 39 ± 0·12 mm only for one fraction. The crude extract showed 82·87% a major compound by GCMS which is the active fraction. This purified active fraction was confirmed as 1'acetoxychavicol acetate (1'ACA) by NMR. No significantly different inhibition was observed for crude extract and purified compound.

CONCLUSIONS

Bioactive 1'ACA of A. malaccensis showed strong antibacterial activity against S. aureus strains including MRSA strain.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first to identify 1'ACA from A. malaccensis. The crude or purified compound could potentially be developed as antimicrobials.

Change of phenolics, carotenoids, and antioxidant capacity following simulated gastrointestinal digestion and dialysis of selected edible green leaves

The bio-accessibility of phenolics, flavonoids, rutin, β-carotene and lutein and changes in antioxidant activities in six edible greens during simulating gastro-intestinal conditions has been investigated. It was found that the amount of dialysable phenolics, flavonoids and carotenoids which potentially available for further uptake is varying depending on the leafy type. Bioavailable phenolics after the gastric-phase, intestinal-phase and in dialysable fraction were in the ranges of 13.9-71.8%, 14.4-77.4% and 3.1-12.3% respectively when compared with their fresh leaves. Total antioxidant capacities in the dialysable fractions were significantly lower than their original. Bioactives of Centella asiatica showed comparatively higher bioavailability in all phases with respect to its original content. β-carotene seems more dialysable than lutein in all leaves studied. Higher rutin contents were found in both gastric and intestinal phases than in fresh leaves. These results highlighted that gastrointestinal digestion may substantially affect the absorption of polyphenols and carotenoids present in leafy greens.

Antidiabetic Compounds in Syzygium cumini Decoction and Ready to Serve Herbal Drink

Herbal beverages with desirable sensory attributes are an ideal way to offer consumers with phytochemicals having specific health promoting functionalities. Syzygium cumini bark decoction is used in treating diabetes mellitus in Ayurveda medicine. This work attempted to prove the presence of antidiabetic compounds in the S. cumini decoction and the ready to serve (RTS) herbal drink developed using the decoction. Activity guided fractionation of the decoction of the S. cumini was carried out by sequential extraction with organic solvents of different polarities. Thin Layer Chromatography (TLC) with authentic compounds and HPLC were performed for identification and confirmation of the compounds in the decoction and the RTS herbal drink. Presence of gallic and ellagic acids in the decoction and RTS herbal drink was proven and confirmed with HPLC. The LC UV-VIS spectra of the two compounds were identical with the corresponding spectra of the library. Further, gallic acid and umbelliferone were determined as the active compounds in the decoction by TLC and were confirmed by cochromatography with authentic compounds. The present investigation confirmed the presence of gallic acid, ellagic acid, and umbelliferone which are proven to have antidiabetic activities in the decoction and the RTS herbal drink prepared with the decoction.

Effect of heat-moisture treatment on digestibility of different cultivars of sweet potato (Ipomea batatas (L.) Lam) starch

Different heat-moisture levels were applied to native starches from different cultivars of sweet potatoes available in Sri Lanka (Wariyapola red, Wariyapola white, Pallepola variety, Malaysian variety and CARI 273) to study the digestibility level. Samples were treated with 20, 25, and 30% moisture at 85°C and 120°C for 6 h and in vitro starch digestibility was tested with porcine pancreatin enzyme. A range of 19.3-23.5% digestibility was shown by the native starches with no significant difference (P < 0.05). Significant changes were observed in the digestibility level of the hydrothermally modified starches and the moisture content showed a positive impact on the digestibility. Heat-moisture treatment at 85°C brought an overall increase in digestibility and temperature beyond 85°C had a negative impact. No significant difference (P < 0.05) in the digestibility was observed with 20% and 25% moisture at 85°C and increased level were seen at 85°C and 30% moisture.

Comparative analysis of nutritional quality of five different cultivars of sweet potatoes (Ipomea batatas (L) Lam) in Sri Lanka

Nutritional attributes of flours obtained from five different cultivars of sweet potato roots commonly available in Sri Lanka showed significant differences in the tested parameters. The starch level ranged between 33% and 64% on the dry basis and the extractability from fresh tubers was governed by the quantity of starch. The crude fiber level ranged between 2.1% and 13.6% on dry basis and the highest level was observed in swp7 (CARI 273) and resistant starch ranged from 14.2% to 17.2%. Higher percentage of resistant starch from total starch was found in Wariyapola red (swp1) cultivar resulting in lower digestion level while higher levels of digestion was evident in cultivars with lower levels of resistant starch with high level of total starch. Low levels of calcium and significant levels of iron were found in the five cultivars studied. Crude protein level was in the range of 1.2–3.3% on dry basis and trypsin inhibitor activity level (TIA) was significantly different (P > 0.05) in the cultivars studied while heating resulted in a significantly high reduction in the TIA level than in unheated condition. Polygonal or round shaped starch granules were in the range of 16.8–23.5 μm and low level of starch digestion was shown in cultivars containing larger granules. Total amylose content lies in the range 15.4–19.6% and cultivars having higher percentage of amylose showed higher level of in vitro pancreatic digestion (Pallepola [swp4] and swp7). The starch digestibility of sweet potato flour was in the range of 36–55% and the highest digestion was observed in swp7. Orange fleshed cultivars (swp4 and swp7) were comparatively rich in nutrients and digestibility than the other three studied cultivars.