Background: Thunbergia laurifolia is a Thai herb and has been used in Thai folklore medicine for centuries. Generally, Thais consume T. laurifolia as a herbal tea because of its beneficial properties as an antidote for chemical toxins, drug-, arsenic-, strychnine-, alcohol- and food-poisoning. However, its effectively against some insecticide compounds, e.g. methomyl, has not yet been determined.Objective: To examine the protective effect of aqueous extract from leaves of T. laurifolia on methomyl (MT) poisoning of murine macrophage cells (anti-MT effect) and to identify phenolic and flavonoid compounds in the extract. Methods: T. laurifolia was extracted with water and stored in freeze-dried form. The extract was investigated for its antioxidant activity and some phenolic and flavonoid compounds were identified using liquid chromatography–mass spectrometry (LC-MS). To study anti-MT effects in RAW264.7 murine macrophage cells, these were treated with leaf extract either before (pre-treatment), concomitantly (combined) or after (post-treatment) exposure to MT and cell viability determined in an MTT test (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide).Results: The extract exhibited strong antioxidant properties based on total extractable phenolic content (TPC), total extractable flavonoid content (TFC), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and Ferric ion reducing antioxidant power (FRAP) activity. The LC-MS analyses of phenolic compounds indicated the presence of caffeic acid, rosmarinic acid, catechin, rutin, isoquercetin, quercetin and apigenin as bioactive compounds. Viability of RAW 264.7 murine macrophage cells treated with MT was increased significantly by post-treatment with leaf extract but not by combined or pre-treatments. Conclusion: The aqueous extract of T. laurifolia leaves contained abundant antioxidant activity. Flavonoids present were catechin, rutin, isoquercetin, quercetin and apigenin. The aqueous leaf extract was able to help cells recover from the effects of exposure to MT.Keywords: Thunbergia laurifolia, phenolics, flavonoids, methomyl, RAW264.7 murine macrophages, insecticide

Background: Cinnamomum porrectum leaves, one kind of Cinnamomum family, has recently been used to produce a locally herbal tea. Although C. porrectum essential oil and aqueous extract have been reported to have some biological activities, including antioxidant, antimicrobial, and anti-inflammatory activities, there is no scientific data using the blanching process for the production of herbal tea. Therefore, this experiment aimed to study the effect of hot water blanching before drying process on microstructure, nutrition content of the tea powder, TPC, TFC, antioxidant activities of infusion, as well as the phenolic profile of the extract.Objective: To determine effect of hot water blanching process on nutritional value, microstructure, phenolic profile, and antioxidant activity of the C. porrectum herbal tea.Methods: The C. porrectum leaves were divided into 2 groups; control (un-treated) and blanched before dried for herbal tea processing. The fresh leaves and the powders of control and blanched leaves were checked for proximate composition and chlorophyll contents, in addition to color value. The powders were determined microstructure by SEM. The infusions were determined to have color value and total extractable phenolic and flavonoid contents, as well as antioxidant activities. The hydrolyzed extracts of freeze dried infusion were subjected to identify phenolic profile by HPLC. Results: The blanched tea powder yielded a percentage of fat and protein contents higher than untreated due to easier extraction because of the bigger pore size found in microstructure. Chlorophyll content of blanched was decreased compared with the control sample. However, it was found that blanching could greater maintain green color of both powder and infusion.Additionally, blanching helped increased TPC, TFC extractability, and antioxidant activities in all assays except metal chelating property. Based on retention time and peak profile determined by using HPLC, it was found that both control and treated extracts consisted of similar main phenolic and flavonoid compounds however, only kaempferol was found in un-treated. Moreover, hydrolyzed blanched extract showed a higher intensity of 2 unknown compounds than un-treated. Though un-treated provided a higher intensity of pyrogallol, gallic acid, and cinnamic acid, the blanched exhibited a higher intensity of caffeic acid, protocatechuic acid, p-coumaric acid, and rutin. Conclusion:Blanching before drying expanded pore size of dried leaves, increased yield extractability, maintained color value, chlorophylls and increased TPC and TFC which related to antioxidant activities. Blanched extract provided higher intensity of some phenolic compounds than un-treated.

Thunbergia laurifolia or Rang Jued has been used as an herbal tea and in folk medicine as a detoxifying agent. Cd contamination is globally widespread and a serious public health problem. The aim of this study was to determine the endogenous antioxidant enzyme activities and malondialdehyde (MDA) production of the crude dried extract (CDE) of T. laurifolia leaves, using human embryonic kidney (HEK293) and human liver (HepG2) cells as in vitro models. Moreover, the cytotoxicity including anti-cadmium (Cd) toxicity in both cells were measured. The experimental design had 3 treatment groups with combined, pre-, and post-treatments for investigating the anti-Cd toxicity, and cell viability was determined with MTT test (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). The CDE showed low cytotoxicity and increased catalase (CAT) and glutathione peroxidase (GPx) activities with decreased malondialdehyde (MDA) levels in both cell types. It was found that the CDE protected against Cd-induced toxicity in both cell types, and a synergistic combination therapy effect was seen when CaNa2EDTA, a chelating agent, was applied. Therefore, CDE can protect against Cd-induced oxidative stress in cells, possibly due to its antioxidant properties. Moreover, using the extract or drinking the herbal tea together with chelating agent should have an efficacy advantage over using the CDE or the chelating agent singly.

The effect of lipids on antioxidant activities of tested antioxidants and Tom-Kha paste extract was determined in the food system. 2,2'-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) scavenging activity, peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and p-anisidine value (AV) were methods for determining. The result showed that heating at 121˚C for 15 min caused decreasing on DPPH scavenging activity of lauric acid but didn't affect ABTS scavenging activity of both lauric acid and virgin coconut oil. DPPH scavenging activity of all mixtures was significantly decreased (p < 0.05) after thermal processing. ABTS scavenging activity of the mixtures lauric acid and antioxidants was decreased at ratios 2:1 and 5:1 while at ratios as 10:1 and 15:1 were not changed after heating. Additionally, ABTS scavenging activity in systems of virgin coconut oil mixed with gallic acid and Trolox was decreased after heating. Surprising ABTS scavenging activity of p-hydroxycinnamic acid and Tom-Kha paste extract in both lauric acid and virgin coconut oil systems increased after thermal processing. In food systems of lauric acid, PV of almost mixtures except lauric acid-Tom-Kha paste extract 2:1 and lauric acid-Trolox 15:1 was increased after heating. TBARS value of the mixtures was not significantly different (p  0.05) after thermal processing. AV of only lauric acid-gallic was enhanced after heating. PV of virgin coconut oil added with all tested antioxidant was not changed after heating. TBARS of virgin coconut oil added with antioxidant samples seemed to slightly increase after heating. AV of virgin coconut oil with added gallic acid and Tom-Kha paste extract were not changed by heat treatment while AV of virgin coconut oil with added p-hydroxycinnamic acid and Trolox seemed to decrease after heating.

Commercial instant Tom‐Yum mixes that are currently marketed compare unfavorably in taste and aroma with freshly prepared soup. By comparing an experimental garcinia Tom‐Yum with traditional ingredients and a commercial mix, this study evaluated the total phenolic content and antioxidant activity of herbs and spices used in preparation, and compared consumer preference. The galangal methanolic extract had the highest total phenolic content and antioxidant activity, while the garcinia methanolic extract was lowest in both. Antioxidant activity loss was significant during processing, using vacuum drying. However, adding dried kaffir lime leaf separately increased the total phenolic content and antioxidant activity. These affected the methanolic extracts of the experimental mix, which were higher than that of the commercial mix (P < 0.05). Consumers preferred the taste of the experimental garcinia Tom‐Yum soup than the commercial product. Results suggest that an instant garcinia Tom‐Yum mix can be produced with high nutritive value and consumer preference. PRACTICAL APPLICATIONS The garcinia Tom‐Yum mix could be used as a high acid seasoning to produce the Tom‐Yum soup, a popular hot and sour Thai soup. Its unique taste and spiciness, and being low in fat and calories, enhance its popularity worldwide.