HPLC analysis and in vitro antioxidant mediated through cell migration effect of C.hystrix water extract on human keratinocytes and fibroblasts.

Citrus hystrix or kaffir lime is a native tropical plant containing a high level of phenolic and flavonoid compounds. Its fruits are used as a food ingredient to enhance the sour-sweet scent and flavor in many dishes. Due to its polyphenol-containing, it has also been used as traditional medicine for health benefits including oral and gum health, stress relief, hair care, and skincare. In this study, we demonstrated the antioxidant activity of C. hystrix water extract and its effect on human keratinocyte and fibroblast migration. The extract showed a high amount of phenolic and flavonoid contents. The HPLC analysis indicated the presence of gallic acid, catechin, caffeic acid, rutin, and quercetin. We showed that C. hystrix water extract exhibited free radical scavenging capacity, determined by DPPH assay, with IC50 of 14.91 mg/mL, and nitrite radical scavenging capacity, determined by NO assay, with IC50 of 4.46 mg/mL. The C. hystrix water extract displayed unnoticeable toxicity at all tested doses. We showed that the treatment of water extracts as low as 50 µg/mL decreased the reactive oxygen species (ROS) from H2O2-induced ROS formation in both cell lines. Besides, C. hystrix water extract promoted cell migration in a dose-dependent manner. Together, these results demonstrated the positive benefit of C. hystrix water extract as a wound-healing accelerator. Its health benefits may be due to the antioxidant capability of its phytochemical compounds contained in C. hystrix water extract that enhances the migration of two major cell types: fibroblast and keratinocytes, responsible for the proliferation and remodeling phase of wound healing.

Photo-Protective and Anti-Inflammatory Effects of Antidesma thwaitesianum Müll. Arg. Fruit Extract against UVB-Induced Keratinocyte Cell Damage.

The main cause of most skin cancers is damage from UVB from sunlight, which penetrate the skin surface and induce inflammation. For this reason, this study aims to identify natural products with photo-protection properties and their mode of action by using the UVB-irradiated HaCaT keratinocyte model. Antidesma thwaitesianum fruit extracts at 25, 50, and 100 µg/mL recovered cell viability following UVB exposure in a dose-dependent manner. Cell survival was associated with the reduction in intracellular ROS and NO. In addition, we showed that the pre-treatment with the fruit extract lowered the phosphorylation level of two MAPK-signaling pathways: p38 MAPKs and JNKs. The resulting lower MAPK activation decreased their downstream pro-inflammatory cascade through COX-2 expression and subsequently reduced the PGE2 proinflammatory mediator level. The photoprotective effects of the fruit extract were correlated with the presence of polyphenolic compounds, including cyanidin, ferulic acid, caffeic acid, vanillic acid, and protocatechuic acid, which have been previously described as antioxidant and anti-inflammation. Together, we demonstrated that the pre-treatment with the fruit extract had photo-protection by inhibiting oxidative stress and subsequently lowered stress-induced MAPK responses. Therefore, this fresh fruit is worthy of investigation to be utilized as a skincare ingredient for preventing UVB-induced skin damage.

Mechanisms of Trichomes and Terpene Compounds in Indigenous and Commercial Thai Rice Varieties against Brown Planthopper.

Plant trichomes generally act as a physical defense against herbivore attacks and are present in a variety of plants, including rice plants. This research examined the physical and chemical defenses of rice plants against the brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae). A total of 10 rice varieties were used in this study. An electron microscope was used to observe trichomes. Constitutive and induced volatile compound profiles were assessed using GC-MS analyses. The preference of BPH for volatiles from the 10 rice plants was tested using a two-choice arena olfactometer system. The density of prickle trichomes had a negative relationship with the BPH injury level. Without BPH infestation, the volatile of the most resistant rice variety (Rathu Heenati (RH)) was preferred by BPH than those of the other varieties, with the exception of Gled Plah Chawn. However, the relative BPH preference for volatiles from the RH variety decreased during BPH infestation. When rice plants were infested by BPH, the numbers of VOCs and these quantities decreased. In the RH variety, the emission of essentities found without BPH infestation ceased during infestation by BPH. During the BPH infestation, rice plants started to emit new VOCs that were not detected before the BPH infestation started. In conclusion, we discovered that rice plants defended against BPH by changing VOC components during BPH infestation and ß-Sesquiphellandrene was likely the most effective component.

The Leaf Extract of Coccinia grandis (L.) Voigt Accelerated In Vitro Wound Healing by Reducing Oxidative Stress Injury.

The impairment in the regulation of the physiological process in the inflammatory phase of wound healing results in oxidative stress damage, which increases the severity and extends the healing time. In this study, we aimed to evaluate the radical scavenging properties of Coccinia leaf extract and its ability to ameliorate a migration process in vitro. Coccinia is a medicinal plant that was used in ancient times for relieving insect bite itching and swelling. However, the role of Coccinia leaf extract as an antioxidant related to the process of wound healing has never been studied. In this study, we demonstrated that the leaf extract possessed antioxidant properties that acted as a proton donor to neutralize reactive oxygen species with the IC50 value of 4.85 mg/mL of the extract. It could chelate iron with the IC50 value of 21.39 mg/mL of the extract. The leaf extract protected the human fibroblasts and keratinocytes from hydrogen peroxide-induced oxidative stress by increasing cell survival rate by more than 20% in all test doses. The protective property was dose-dependently correlated with the decrease in reactive oxygen species formation. In addition, the leaf extract enhanced the cell migration rate of fibroblasts and keratinocytes up to 23% compared with vehicle control. The results suggested that Coccinia leaf extract may be a potential herb for increasing the wound healing process with its antioxidant capacity and can be used as an herbal ingredient for the utilization of skincare products.