Evaluating the Antioxidative Defense Response of Selected Indoor Plants Against Benzene and Formaldehyde: Indoor Air Pollutants

Abstract Volatile organic compounds (VOCs) such as formaldehyde and benzene are among the key contributors to indoor air pollution. The current situation of environmental pollution is alarming, where especially the indoor air pollution is becoming challenge as affecting the plants and humans. VOCs are known to adversely affect indoor plants such as causing necrosis and chlorosis. In order to withstand these organic pollutants, plants are naturally equipped with antioxidative defense system. The current research study was aimed to evaluate the combined effect of formaldehyde and benzene on antioxidative response of selected indoor plants namely Chlorophytum, Dracaena and Ficus. After the combined application of different levels (2, 2; 2, 4; 4, 2 & 4, 4 ppm) of formaldehyde and benzene in an airtight glass chamber, the enzymatic and non-enzymatic antioxidants were analyzed. Analysis of various non enzymatic assays showed significant increase in the total phenolics to 10.72 mgGAE/g in Ficus; Chlorophytum (9.20 mgGAE/g) & Dracaena (8.74 mgGAE/g) as compared to their respective controls i-e, 3.76, 5.39 & 6.07 mgGAE/g. Total flavonoids in Ficus were also increased to1545.72 µg/g from 724 µg/g (in control) followed by 322.66 µg/g in Dracaena (control having only 167.11 µg/g) while total carotenoids content also increased in Dracaena (0.67 mg/g) followed by Chlorophytum (0.63 mg/g) while increasing the combined dose as compared to their control plants having only 0.62 and 0.24 mg/g content. The maximum increase in enzymatic antioxidants including total antioxidants (87.89%), catalase (59.21 U/mg) and guaiacol peroxidase (52.16 U/mg) was observed in Dracaena plant under combined dose of benzene (2 ppm) and formaldehyde (4 ppm). Although the experimental indoor plants have been reported to metabolize the indoor pollutants, but the current findings indicate that both benzene and formaldehydes are also affecting the physiology of indoor plants.