Determination and comparison of phenolic compound content and antioxidant activity of selected local Zimbabwean herbal teas with exotic Aspalathus linearis

Lippia javanica (Burm.f.) Spreng.: Traditional and Commercial Uses and Phytochemical and Pharmacological Significance in the African and Indian Subcontinent

“…Lippia javanica is popular as herbal tea, particularly in Botswana, South Africa, and Zimbabwe [7–11]. Lippia javanica herbal tea is prepared by steeping fresh or dried leaves, stems, or twigs in boiling water and letting them stand for two to five minutes to release flavour, with or without milk and sugar added according to taste.…”

“…According to Shikanga et al [7], L. javanica tea is appreciated throughout its distributional range as a general health tonic and also because it is naturally caffeine-free and has a calming and relaxing effect. Research done by other workers, for example, Manenzhe et al [2], Shikanga et al [7], Parrant [8], Olivier et al [81], Motlhanka and Makhabu [9], and Bhebhe et al [10, 11], revealed that L. javanica is a popular recreational tea in southern Africa, consumed on a daily basis within a food context, while medicinal infusions or tisanes of L. javanica are taken for a specific medical purpose. During the past 20 years, the use of herbal teas has increased globally [107] because of their functional properties and consumer interest in the health promoting properties of such beverages [108].…”

“…Lippia javanica has higher radical scavenging activity than A. linearis (Table 3) which is probably due to higher total phenolic content in comparison to A. linearis which is a popular herbal tea consumed by 10% of the global herbal tea market [10]. In another study, Bhebhe et al [11] determined and compared the effect of several solvents, namely, hot water, 50% methanol, ethanol, 50% ethanol, acetone, 50% acetone, and ethyl acetate, on phenolic composition and free radical scavenging activity in common black tea, C. sinensis, and five other well-known herbal teas including L. javanica . In all the seven solvents used, L. javanica had higher total phenolic content than C. sinensis implying that L. javanica is competitive to the black tea in terms of phenolic content.…”

“…Scientific studies on L. javanica indicate that it has a wide range of pharmacological activities (Table 4), which include anticancer [140], antidiabetic [141], antimalarial [4, 49, 142], antimicrobial [2, 3, 7, 17, 73–75, 77, 83, 84, 126, 143], antioxidant [7, 10, 11, 75, 77, 125], antiplasmodial [2, 79, 80, 84, 144, 145], and pesticidal effects [1, 2, 59, 95, 120, 146–150] and cytotoxicity [2, 73, 79, 120] activities. Table 4 summarizes some of the pharmacological studies undertaken on L. javanica extracts aimed at evaluating some of the ethnomedicinal uses of the species documented throughout its distributional range (see Table 1).…”

“…Free radical scavenging activity of L. javanica is attributed to phenolic compounds since these compounds have an ideal structural chemistry for free radical scavenging activity [155]. Bhebhe et al [11] determined the effect of several solvents on the free radical scavenging activity of L. javanica using the DPPH assay. Free radical scavenging activity expressed as IC 50 ranged from 0.022 ± 0.001 g/mL to 0.066 ± 0.001 g/mL; see Table 4.…”